[Emc-users] 4th axis ideas... any suggestions?
Hey guys, I'm going to add a 4th axis to my gettup here on my lagun emc refit, and wanted to ask for suggestions. My plan is (as of now) to find a rotary table on the cheap (ebay, craigslist etc) and mill up a motor mount to it with encoder feedback, and use the 4th channel on my 5i20. I've never even used a manual rot table, so if you guys would be so kind as to make me aware of what I'm totally overlooking here, that would be very much appreciated. I plan on finding a table that can sit perpendicular to the table, like in this video: http://www.dailymotion.com/video/x9a6s1_cnc-turning-on-4axis-mill-with-gala_tech i would also plan on running a lathe-like chuck too... any comments/suggestions/do'sdonts??? Thanks a ton! -Pat -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 4th axis ideas... any suggestions?
2009/12/10 Pat Lyons p27...@gmail.com: any comments/suggestions/do'sdonts??? I have converted one of these: http://www.axminster.co.uk/product.asp?pf_id=453684name=tableuser_search=1sfile=1jump=44 It took me too iterations. Initially I just made a motor mount and retained the existing bearing arrangements on the worm shaft. This turned out not to work very well at all as the plain bearings were inconsistent and not very smooth (partly due to not being very straight) with a rather poor end-thrust arrangment. . Iteration 2 involved making a complete new eccentric shaft with a pair of back-to-back angular contact bearings outside the main body and a needle roller inside the body adjacent to the worm. I modified the worm shaft to suit the needle roller and can't remember what I did at the other end. Outboard of the angular contact bearings there is a spider coupling, then a circular register for the stepper. Round the outside of this register there is a square plate, split, with a clamp screw. This has bolt holes for the NEMA23 stepper, and the split/clamp arrangement allows the motor to be rotated to suit the rotation of the eccentic mesh adjustment. I have a hand-drawn dimensioned drawing of the whole bearing and shaft arrangement I could digitise if you think it would be any help. -- atp -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 4th axis ideas... any suggestions?
On Thursday 10 December 2009, Pat Lyons wrote: If a brake is being used, what about a direct drive setup? -pat I hadn't given that any real thought. This one has a brass thumbscrew with IMO very limited holding power. Some sort of an eccentric to pull the table down and lock it against its base would do a much better job IMO. Or just replace it with a real table, heck, this one doesn't even have a #2 taper center socket. You really do get what you pay for. :) On Thu, Dec 10, 2009 at 7:08 AM, Gene Heskett gene.hesk...@gmail.comwrote: On Thursday 10 December 2009, Pat Lyons wrote: Hey guys, I'm going to add a 4th axis to my gettup here on my lagun emc refit, and wanted to ask for suggestions. My plan is (as of now) to find a rotary table on the cheap (ebay, craigslist etc) and mill up a motor mount to it with encoder feedback, and use the 4th channel on my 5i20. I've never even used a manual rot table, so if you guys would be so kind as to make me aware of what I'm totally overlooking here, that would be very much appreciated. I plan on finding a table that can sit perpendicular to the table, like in this video: http://www.dailymotion.com/video/x9a6s1_cnc-turning-on-4axis-mill-with-ga la _tech i would also plan on running a lathe-like chuck too... any comments/suggestions/do'sdonts??? Thanks a ton! -Pat 1. Most tables can be mounted that way, or face up so you get a twofer automatically. 2. For that video's sort of work, backlash won't be a huge problem. 3. face up making a sprocket, or lathe style carving gears, backlash will be a problem. So it may be wise to add a 2nd lock brake so that the table is locked pretty solidly when the motor is not moving it. I'm still figuring out how to do that with mine as it has a thumb screw with limited holding power. http://gene.homelinux.net:85/gene/emc/A-drv.jpg shows the motor mount I made for a cheap 4 Grizzly table. The coupling inside it is a heavy steel rig, two cups facing each other, with 1/4 slots cut across, with a steel disk trapped in the middle which has a 1/4 wide fin, laying 0-180 on one face, and 90-270 on the other so it presents a sliding u-joint with very little backlash that can absorb the axles being out of line a couple thou. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Fast ship? You mean you've never heard of the Millennium Falcon? -- Han Solo - - Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users --- --- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Ignorance is when you don't know anything and somebody finds it out. -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 4th axis ideas... any suggestions?
On Thu, Dec 10, 2009 at 07:08:21AM -0500, Gene Heskett wrote: 3. face up making a sprocket, or lathe style carving gears, backlash will be a problem. So it may be wise to add a 2nd lock brake so that the table is locked pretty solidly when the motor is not moving it. I'm still figuring out how to do that with mine as it has a thumb screw with limited holding power. It was with some shock and disappointment that I discovered that my brand new several-hundred-dollar rotary table has backlash, even with the variable-engagement worm adjusted for maximum engagement. It has two locking screw-clamps, each with a short captive tommy-bar, but if EMC is to control them, then powerful pneumatic brakes and solenoid valves would perhaps be easier to control. Perhaps I should disassemble the rotary table, to check how hard it is to improve worm and wheel engagement so that both flanks make contact. (I'm still aghast that a reputable manufacturer doesn't achieve that, out of the box.) http://gene.homelinux.net:85/gene/emc/A-drv.jpg shows the motor mount I made for a cheap 4 Grizzly table. The coupling inside it is a heavy steel rig, two cups facing each other, with 1/4 slots cut across, with a steel disk trapped in the middle which has a 1/4 wide fin, laying 0-180 on one face, and 90-270 on the other so it presents a sliding u-joint with very little backlash that can absorb the axles being out of line a couple thou. That sounds a lot like an Oldham coupling, Gene. For the OP, there are some pictures here:http://en.wikipedia.org/wiki/Oldham_coupler One idea I'm considering is driving via a toothed belt, from a motor clamped nearby, in the T-slots. Just looping the belt over a pulley added behind the rotary table handwheel allows it to still be used manually, when it isn't worth mucking with gcode. Erik -- Ninety-Ninety Rule of Project Schedules: The first ninety percent of the task takes ninety percent of the time, and the last ten percent takes the other ninety percent. -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 4th axis ideas... any suggestions?
My 5 axis is made with two el cheapo rotaries one a vertex and the other a lesser name, both have backlash so I tend to lock up B when I can, else for both rotaries I hand code the gcode so drive is from one direction only wherever possible. If you put the worm into full engagement they jam, there is no provision for excentricity of the worm wheel, one day I will get around to making a better one I hope. when it was still 4 axis http://www.youtube.com/user/davethearchivist#p/a/u/2/adT8Dr5JZ4c Dave Caroline -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 4th axis ideas... any suggestions?
Gears have backlash period. And if they don;t have backlash out of the box... they increasingly will have it. There's a method of countering that, but it increases wear as it uses tension. I rely on my steel loaded timing belts instead. I use the type made for the car industry. Incredibly strong PU with little steel cables in them. Even exceeding the suggested load max by a factor ten to achieve a guitar string like tension has not resulted in any failures yet. I cannot measure any flex at 160lbs of tension and the speed they can achieve is incredible. Less than 3 bucks per foot is also cheap. Many belts run in Diesel engines as valve timing belts for more than 50,000 miles before they are changed just for good measure. That's a lot of rpm's... and heat... They last forever in our environment. R -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Portable EMC?
If the BeagleBoard port works out, we could then look at other, cheaper, ARM9 boards. The BeagleBoard has all kinds of stuff we don't need (e.g., video, including 2 or 3D acceleration), and leaves out ethernet, plus may be subsidized (and might have some availability issues). If we can get to a more generic ARM9 board, I think we'll have a really excellent solution going forward for EMC, with even more of the benefits Jon lists below. (There are even some fairly cheap--$100/qty 10--boards with ARM9 and a small FPGA, along with ethernet, memory card, etc.) However, the BeagleBoard is popular, has lots of on-board resources, and so may be just the right environment in which to get the ARM9 project going. I look forward to hearing more progress on this front. It's not going to be the only solution for everyone, but for a lot of us, it will be very useful and very powerful, and will get us past the parallel port issue definitively. (As a Mac user, I'm looking forward to running Axis on my main laptop for real, not just simulation.) --Dale At 8:27 PM -0600 12/9/09, Jon Elson wrote: Stephen Wille Padnos wrote: Considering that a D945GCLF2 motherboard is $80, 2GB memory is $40, a hard drive is $50, and a DC-DC power supply is $50 (you could of course get a full ATX case with power supply for less), I'm not sure where the beagleboard really helps. It's definitely smaller. It's somewhat less expensive (though I'm not sure how far below $220 you're going to get, once you add a power supply, I/O conditioning, etc), it takes somewhat less power (3W vs. 26W). For the small differences in cost, size, and power, you end up with a full PC with gigabit network, 1.6GHz dual-core CPU, reasonable 3D graphics, excellent latency numbers (maybe 8000 or so IIRC), and a PCI slot. Of course there's always a bit of pride to be taken in doing more with less, I'm not sure there's really a great payoff here. Does this have a parallel port that does EPP? The Beagle is actually quit cute. You can run it quite well off an 8 GB SD card, no hard drive at all, and a USB-Ethernet dongle. So, that is about $208. I just found out how to use one of the $9.95 Chinese USB-net dongles, so that drops the price down to $175 plus some shipping. It runs off a single 5 V supply, a wall-wart is fine at these power levels. It would also run quite well from 12 V with a little regulator chip. You'd need some surge protection from the spiky car electrical system, though. I have a board that converts the Beagle's expansion port to 5 V levels and EPP parallel port pinout. (That will runs any standard parallel port function as well.) This whole new direction was started as insurance against loss of the old parallel port and possibly destruction of real time latency with newer incarnations of the Intel core 9000 hyper-megaplex CPUs in the pipeline. It would also allow people who INSIST on using old laptops to get their way. They could run the GUI on the laptop, and link to the beagle via Ethernet. The Beagle would be inside the CNC control box. Jon -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 4th axis ideas... any suggestions?
On Thu, 2009-12-10 at 09:23 -0500, Rainer Schmidt wrote: Gears have backlash period. And if they don;t have backlash out of the box... they increasingly will have it. There's a method of countering that, but it increases wear as it uses tension. I rely on my steel loaded timing belts instead. I use the type made for the car industry. Incredibly strong PU with little steel cables in them. Even exceeding the suggested load max by a factor ten to achieve a guitar string like tension has not resulted in any failures yet. I cannot measure any flex at 160lbs of tension and the speed they can achieve is incredible. Less than 3 bucks per foot is also cheap. Many belts run in Diesel engines as valve timing belts for more than 50,000 miles before they are changed just for good measure. That's a lot of rpm's... and heat... They last forever in our environment. R I like the idea of using an automotive timing belt. I use an inch wide on the Y and W axes of my little mill. I would also consider direct coupling a 2500 ppr encoder to the main shaft. With quadrature you get about 2 minutes of resolution; probably better than most tables. ;-) Maybe use a disk brake to hold for really tough cutting. Some year I may get around to implementing something like this. Good luck. HTH Dave -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Mini mill conversion
Good Afternoon listers, I have posted a picture of my mini mill. The reason I wanted to do a conversion over to EMC was because the Centroid OS is very antiquated and when I saw what EMC would do, I knew it would make the mini mill more flexible. The Centroid OS has a very limited memory to about 250 lines on NC code and no buffer. And since I have a CAD CAM system updating the OS looked very doable. Thanks, Martin -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mini mill conversion
2009/12/10 Martin Pinkston martinpinks...@gmail.com: Good Afternoon listers, I have posted a picture of my mini mill. www.212steam.blogspot.com I get the feeling that was all very expensive back in 1988. I wonder what it all does? The pinout that you published a while ago seemed to show pulse and direction inputs to a 26 way header. Where was that in the system? -- atp -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 4th axis ideas... any suggestions?
On Thursday 10 December 2009, Erik Christiansen wrote: On Thu, Dec 10, 2009 at 07:08:21AM -0500, Gene Heskett wrote: 3. face up making a sprocket, or lathe style carving gears, backlash will be a problem. So it may be wise to add a 2nd lock brake so that the table is locked pretty solidly when the motor is not moving it. I'm still figuring out how to do that with mine as it has a thumb screw with limited holding power. It was with some shock and disappointment that I discovered that my brand new several-hundred-dollar rotary table has backlash, even with the variable-engagement worm adjusted for maximum engagement. It has two locking screw-clamps, each with a short captive tommy-bar, but if EMC is to control them, then powerful pneumatic brakes and solenoid valves would perhaps be easier to control. Given the Tommy bar clamps on the one you showed in the link, a pair of small double acting air cylinders and an electric solenoid would be ideal. Unforch mine doesn't have those. Bear in mind then need for clearance when mounting it aligned with the X axis. Perhaps I should disassemble the rotary table, to check how hard it is to improve worm and wheel engagement so that both flanks make contact. (I'm still aghast that a reputable manufacturer doesn't achieve that, out of the box.) I doubt you will be impressed with what you see. I sure as heck wasn't. I was at Grizzly about thanksgiving picking up a dust collector for my planer and table saw and checked several of the more expensive tables on the display table, and they all turned much easier than mine cuz they had better bearings, and they all had some feel-able backlash. Most had provisions to adjust the worm engagement, and in my case I pushed it in till it drug over part of the turn, then ran it back and forth a few thousand times with emc to wear it in, but I don't think its possible to make it perfect. Much less than a degree, but its still there. Had the $200 one been tight, I would have dropped the card on the spot, but it was far worse than my 100 dollar one is now. The $200 version was also about 40 pounds heavier, a consideration on my micromill. http://gene.homelinux.net:85/gene/emc/A-drv.jpg shows the motor mount I made for a cheap 4 Grizzly table. The coupling inside it is a heavy steel rig, two cups facing each other, with 1/4 slots cut across, with a steel disk trapped in the middle which has a 1/4 wide fin, laying 0-180 on one face, and 90-270 on the other so it presents a sliding u-joint with very little backlash that can absorb the axles being out of line a couple thou. That sounds a lot like an Oldham coupling, Gene. For the OP, there are some pictures here:http://en.wikipedia.org/wiki/Oldham_coupler Heck, I knew I wasn't inventing anything that wasn't just common sense, but my way leaves room in the middle for the nuts that attach it to the screws in the mill, and my center disk has the fins rather than slots. All carved from some very hard steel mine shafting from the scrap yard. I didn't count on its hardness though, they were hell on carbide to carve out. OTOH, I both didn't look at wikipedia, but wouldn't have known what to look for either. Such is life. :) One idea I'm considering is driving via a toothed belt, from a motor clamped nearby, in the T-slots. Just looping the belt over a pulley added behind the rotary table handwheel allows it to still be used manually, when it isn't worth mucking with gcode. Belt tightness I found is very important as I'm belt driving my Z and found I had to wedge a good sized bar in there when tightening the motor mounts slider to get the backlash down. With visible belt slop as it reverses, the backlash went from 3 thou to 50 thou! OTOH, my Z, formerly locked up tight with a 5 pound push on a drill bit, can now come down on the bathroom scales to 155 pounds before that 425 motor cogs back the first time. Drilling holes is no longer a problem. :) As you can see, there is a knob on the back of the tables motor that can be used when the motor is unplugged, (don't forget to shut off the psu when doing the plugging!) but seeing the vernier scales is a bit difficult. I didn't consider that because plugging in the motor and running it with emc is 10x more accurate anyway. Erik -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp hardware stress fractures -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mini mill conversion
On Thu, 2009-12-10 at 11:22 -0500, Martin Pinkston wrote: Good Afternoon listers, I have posted a picture of my mini mill. The reason I wanted to do a conversion over to EMC was because the Centroid OS is very antiquated and when I saw what EMC would do, I knew it would make the mini mill more flexible. The Centroid OS has a very limited memory to about 250 lines on NC code and no buffer. And since I have a CAD CAM system updating the OS looked very doable. Thanks, Martin I took some time to look at your blog site. The mill looks like it's fairly well built. I'm not a big fan of round column mill's but I have never used one and it may have some advantages. I see the Z axis is driven by the quill rack and pinion, which tend to have a lot backlash. You might consider, cruising eBay for a short ball screw (double nut or adjustable preloaded only) and mill up the bits to drive the quill directly with the screw. http://www.microkinetics.com/images/quillkit.jpg http://pico-systems.com/zaxis.html Considering the results of your other projects this should be a piece of cake. :) When you checked the axes for squareness, did you use an indicator and square clamped to the table or use the table surfaces? It looks to me that this machine should be pretty square. If the gibbs are worn the table might rock. A little Prussian blue might indicate something needing attention. The top two board pictures look like a dual power supply with PWM voltage or current control(?). The SG3526's are listed as REGULATING PULSE WIDTH MODULATOR. These seem to control the nearby power FET's which push-pull the large inductors just above the FET's, creating a higher voltage AC. The AC is then converted to DC by the diode array, just above the inductors. At the top, are capacitors that smooth out any ripple that the diodes pass on. My guess is that the red and black wires at the bottom go to a power transformer? The upper red and black wires go to the motor drivers? The next board down looks like the CPU/logic board which won't be needed. The next board labeled INPUTG on the upper right corner, I'm guessing is for digital input from limit and home switches? There are four power switches that may control relays or solenoids. The last board looks like the, or an, axis motor driver. How many of these do you have? I bet those red and black wires come from the first board. The screw terminals on the middle left edge go to the motor or motors? It looks like there is a microprocessor on this board, so there may be a proprietary motion command input from the CPU/logic board which the microprocessor turns into step pulses that goes to the power side of the board on the left, but then how does your .pdf file fit in? It would take more employing the little gray cells to figure this out. I may concede to Jon and recommend using the Gecko's. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 4th axis ideas... any suggestions?
2009/12/10 Gene Heskett gene.hesk...@gmail.com: Given the Tommy bar clamps on the one you showed in the link, a pair of small double acting air cylinders and an electric solenoid would be ideal. Neater still would be an air bearing arrangement. Tighten the table down hard with belville washers. When you want to rotate it, apply compressed air to the holes drilled in the mating face that I forgot to mention earlier so it rotates on a minimal thickness air-bearing. To clamp, turn off the air. In case you doubt that this will work, it was how we clamped the tool height adjusters on the testing machines I used to design. They were for knocking balls off of ICs, and pulling out the tiny gold wires from carrier to die. You were working under moderate magnification and still could barely see the tool move as the air went on and off, the clamping force was enough to scrape entire dies off of substrates, but the sliding force when released was enough to not even mark the substrate. (the process was release, land, clamp, back off a few microns) -- atp -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 4th axis ideas... any suggestions?
On Thu, 2009-12-10 at 13:10 -0500, Gene Heskett wrote: ... snip didn't consider that because plugging in the motor and running it with emc is 10x more accurate anyway. Erik -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp hardware stress fractures ... snip I Googled hardware stress fractures and got: http://www.plig.net/bofh/bofh14.html Ah... the good ol days -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 4th axis ideas... any suggestions?
On Thursday 10 December 2009, Andy Pugh wrote: 2009/12/10 Gene Heskett gene.hesk...@gmail.com: Given the Tommy bar clamps on the one you showed in the link, a pair of small double acting air cylinders and an electric solenoid would be ideal. Neater still would be an air bearing arrangement. Tighten the table down hard with belville washers. When you want to rotate it, apply compressed air to the holes drilled in the mating face that I forgot to mention earlier so it rotates on a minimal thickness air-bearing. To clamp, turn off the air. Now there is original thinking, and IF I can find the right sized washer, certainly doable with my toy table. Drill an 1/8 air hole in the side, and intersect that with another hole that feeds a groove milled in the casting under the table. The right sized washer will be about 3/16 wide, and something over 1 ID. I'm madly digging thru the junk hardware here. :) Just one Q though, wouldn't this also need an oil injector to keep it from rusting since the air is going to have water in it? In case you doubt that this will work, it was how we clamped the tool height adjusters on the testing machines I used to design. They were for knocking balls off of ICs, and pulling out the tiny gold wires from carrier to die. You were working under moderate magnification and still could barely see the tool move as the air went on and off, the clamping force was enough to scrape entire dies off of substrates, but the sliding force when released was enough to not even mark the substrate. (the process was release, land, clamp, back off a few microns) -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp There are two ways of disliking art. One is to dislike it. The other is to like it rationally. -- Oscar Wilde -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 4th axis ideas... any suggestions?
On Thursday 10 December 2009, Rainer Schmidt wrote: You can start out with the cheapest table you can find because you can take the motor and probably the mount to another level later when you mill the el cheapo into the ground. Backlash is not a problem as long as you have control over your toolpath. I build a 4th out of 2 inch thick al using a 1.5 ready made rod form McMasters and timkin bearings. I used a belt to drive it. I chose the rod because it had the right thread for the chuck I used. The chuck at the front and the pulley on the back together with a tiny stamped out shim stock disk provide the pressure to keep the assembly in the timkin bearings. Rock solid, no backlash, and good to swing an ox over the BBQ pit if need be 8))). Here's a picture. I bolted the drive right onto the 4th as the amount of AL is perfect for a heat sink haha. All self contained now. The tail stock has a MT3... just for size info. It's HUGE. http://www.machsupport.com/forum/index.php/topic,11044.0.html Sweet! The alu blocks remind me of my Z drive, but I'm turning the nuts on a piece of 1/2 acme bolted solidly into the head's sled casting. Not rollers either, but ball cartridges designed for half a ton of axially aligned thrust. Semi sealed, the grease fittings are aligned with the small hole in the outer dust cover. But I figure I'll fall over before they need grease again. :-) Fudged turn table, fudged indexer, self build, all will work. Just do not expect to get great turn ratios with the machine shop based turn tables. My Self build one with the belt and stepper can run at least 400 rpm. Nice for many very shallow passes. I stabilized burl and am 'turning' that with the spindle and high 4th rpm's rather quickly. No way to do that by hand. best of luck! Rainer --- --- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp No matter who you are, some scholar can show you the great idea you had was had by someone before you. -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mini mill conversion
Centroid OS has a very limited memory to about 250 lines on NC code and no buffer. Wow, how old is this Centroid control?? 250 lines seems miniscule. Dave Martin Pinkston wrote: Good Afternoon listers, I have posted a picture of my mini mill. The reason I wanted to do a conversion over to EMC was because the Centroid OS is very antiquated and when I saw what EMC would do, I knew it would make the mini mill more flexible. The Centroid OS has a very limited memory to about 250 lines on NC code and no buffer. And since I have a CAD CAM system updating the OS looked very doable. Thanks, Martin -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Mini mill conversion
Some of the operations that are within the Centroid controller are things like a circle drilling program, circle milling program, pocket milling program, face milling program, letter/number engraving. All called up on a single one line of code. It will also do some simple macros as well. And yes, the quill is fed off the rack, but the only backlash issue I have ever had has been error on the side of not deep enough. However the natural tendency for the end mill to want to pull deeper into the part seems to balance things out very well. The only real challenge is running a 3-D program with a ball end mill. It must be sharp and if not, you will know it right away. It just bounces off the piece. Squareness has never been an issue. I was amazed to find the head swept in less than .0005. And even if the head is ever out, it's just a matter of four very large bolt which hold the column to the base. Just shim to adjust. Simple. When I checked the X and Y for squareness, I cut a square block and then check the squareness of the product with a solid square. Ultra precision is not needed in steam locomotive manufacturing. Average tolerances is +/-.003 I like the round column because it allows me to swing out and machine on things outside the surface of the table. As for the electronics, the large diameter red and black wires carry 40V to power the steppers. The small red and black wires carry 12V for the front panel buttons and switches. There are three axis drive cards. The backs of the drive cards just has 8 power transistors mounted to the heat sink which also serves as a way to mount the cards in the main box. Andy, the 26 pin header pin out sheet is wrong. the Centroid guy saw a picture I took and told me I had a different board than what he initially thought should have been in this unit. Let me see if I can take a picture of the pin out schematic and post it on my blog. www.212steam.blogspot.com Kirk, (snip) *The top two board pictures look like a dual power supply with PWM voltage or current control(?). The SG3526's are listed as REGULATING PULSE WIDTH MODULATOR. These seem to control the nearby power FET's which push-pull the large inductors just above the FET's, creating a higher voltage AC. The AC is then converted to DC by the diode array, just above the inductors. At the top, are capacitors that smooth out any ripple that the diodes pass on. My guess is that the red and black wires at the bottom go to a power transformer? The upper red and black wires go to the motor drivers?* *The next board down looks like the CPU/logic board which won't be needed.* *The next board labeled INPUTG on the upper right corner, I'm guessing is for digital input from limit and home switches? There are four power switches that may control relays or solenoids.* *The last board looks like the, or an, axis motor driver. How many of these do you have? I bet those red and black wires come from the first board. The screw terminals on the middle left edge go to the motor or motors? It looks like there is a microprocessor on this board, so there may be a proprietary motion command input from the CPU/logic board which the microprocessor turns into step pulses that goes to the power side of the board on the left, but then how does your .pdf file fit in? It would take more employing the little gray cells to figure this out. I may concede to Jon and recommend using the Gecko's* ** Uhhhyeaif you say so??? (8-|) -blankdeer in the headlights look That would be my typical answer when we talk about something over my head...and as much as I really do appreciate your imputthat was over my head. Sorry... I was able to get a couple pics of the pin out header so they will be on my blog in just a couple of minutes. thanks again guys, I really do admire your knowledge with this stuff. ( more than willing to trade some steam engine and machining know how on *neruon card* for some knowledge on this stuff on *neuron card.* Martin -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mini mill conversion
On Thu, 2009-12-10 at 14:53 -0500, Martin Pinkston wrote: ... snip Squareness has never been an issue. I was amazed to find the head swept in less than .0005. And even if the head is ever out, it's just a matter of four very large bolt which hold the column to the base. Just shim to adjust. Simple. When I checked the X and Y for squareness, I cut a square block and then check the squareness of the product with a solid square. Ultra precision is not needed in steam locomotive manufacturing. Average tolerances is +/-.003 ... snip Oops, my mistake, I'm getting my e-mail threads confused, sorry. The Z getting pulled into your work is a sign of significant backlash. In my opinion, getting rid of it is well worth the effort, especially with machines using servos. I wouldn't worry too much about understanding the electronics details. I was hoping someone could confirm or correct my thinking so that you could an idea of how much of these parts you might want to reuse with EMC2. My guess at this point is, that you can reuse the first board, the motor supply, and the last board/s, motor driver, and the I/O board by matching the EMC2 step/dir and I/O signals on your parallel port buffer card to your Centroid boards. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mini mill conversion
2009/12/10 Martin Pinkston martinpinks...@gmail.com: Andy, the 26 pin header pin out sheet is wrong. the Centroid guy saw a picture I took and told me I had a different board than what he initially thought should have been in this unit. Let me see if I can take a picture of the pin out schematic and post it on my blog. www.212steam.blogspot.com Aha! EMC can quite possibly drive that, but it is a little wasteful on Parallel port pins. It needs to be unipolar for EMC to drive it, ie each motor phase wire can only ever go +5 or 0v. Is it possible to check the inputs to those terminals with a multimeter (with the motors stationary in a number of positions as far as the software is concerned? Probably best checked on the mating connector between the GND pin and each of the phase pins. If you see them alternating between 0v and 5v in a difficult-to-fathom sequence then you ought to be able to use one of the other stepgen types built in to EMC to drive the board. Have a look at http://linuxcnc.org/docs/2.1/html/man/man9/stepgen.9.html, especially stepgen types 9 and 10. (and feel free to come back with any questions, of course). I am at a bit of a loss to know how to decide if your drive is bipolar or unipolar. The motor lead count probably gives a bit of a clue. 4 wires = bipolar, 5 or 6 = unipolar, more than that = anybody's guess. (And I am quite prepared to have someone more knowledgeable to shoot me down in flames on any or all of the above) -- atp -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mini mill conversion
Martin Pinkston wrote: ...snip Andy, the 26 pin header pin out sheet is wrong. the Centroid guy saw a picture I took and told me I had a different board than what he initially thought should have been in this unit. Let me see if I can take a picture of the pin out schematic and post it on my blog. www.212steam.blogspot.com ...smip Martin are you sure you only have 4 wires going to each motor. The new pin out on your blog suggests that you should have 6 or 8 wires with possibly 2 or 4 of them going to ground and the four you mentioned being driven by transistors. These being the four phases for each motor. This pin out also implies that the step and direction are handled by the cpu and it is separately developing the phase signals in appropriate order to turn the proper direction. I guess it is possible for each winding to have one end tied to ground or power supply at the motor. Can you check the resistance of a winding to ground? Otherwise I don't understand 4 phases for each motor with only 4 wires unless they are really two phases with their complements. Does anybody else have an explanation for 4 phases with only 4 wires? The drawing also implies that all of the driver cards receive the identical signals and possibly some jumpers or switches are used to select which ones are used for the particular card. If you do have another connection to the windings you have not located yet it would explain the performance you are getting as the resistance would be halved. The fact that you are only raising lowering the quill by steppers also explains why you can get by with the same size for Z. Martin I just looked at some driver schematics using transistors. It showed the power supply feeding through the motor to the transistor. Do you have separate wires running from the power supply to each motor as well as the 4 wires that connect to the driver card. If so what is the resistance from the power cable to each of the phase wires? Hubert I was able to get a couple pics of the pin out header so they will be on my blog in just a couple of minutes. thanks again guys, I really do admire your knowledge with this stuff. ( more than willing to trade some steam engine and machining know how on *neruon card* for some knowledge on this stuff on *neuron card.* Martin -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mini mill conversion
On Thu, 2009-12-10 at 21:31 +, Andy Pugh wrote: 2009/12/10 Martin Pinkston martinpinks...@gmail.com: Andy, the 26 pin header pin out sheet is wrong. the Centroid guy saw a picture I took and told me I had a different board than what he initially thought should have been in this unit. Let me see if I can take a picture of the pin out schematic and post it on my blog. www.212steam.blogspot.com Aha! EMC can quite possibly drive that, but it is a little wasteful on Parallel port pins. It needs to be unipolar for EMC to drive it, ie each motor phase wire can only ever go +5 or 0v. Is it possible to check the inputs to those terminals with a multimeter (with the motors stationary in a number of positions as far as the software is concerned? Probably best checked on the mating connector between the GND pin and each of the phase pins. If you see them alternating between 0v and 5v in a difficult-to-fathom sequence then you ought to be able to use one of the other stepgen types built in to EMC to drive the board. Have a look at http://linuxcnc.org/docs/2.1/html/man/man9/stepgen.9.html, especially stepgen types 9 and 10. (and feel free to come back with any questions, of course). I am at a bit of a loss to know how to decide if your drive is bipolar or unipolar. The motor lead count probably gives a bit of a clue. 4 wires = bipolar, 5 or 6 = unipolar, more than that = anybody's guess. (And I am quite prepared to have someone more knowledgeable to shoot me down in flames on any or all of the above) I hope you don't mind more of my mental swarf, there's snow outside so I'm not too interested in doing any real work. Do we know if the driver board drives only one motor, therefore there are three of them. If that's the case, that supports the four phase input as opposed to my earlier guess at step/dir. If the orange resistor arrays are in series with the opto-isolators, an LED could be temporarily soldered on the two input pins of the 4N25's: http://www.fairchildsemi.com/ds/4N%2F4N25-M.pdf putting an LED in parallel to the opto-isolator LED. The LED's would then indicate the step sequence. Everything after that is already handled by the driver board, so unipolar bipolar might not matter. (For fun, it would be nice to get the numbers on the eight power transistors.) I wonder what the microprocessor is doing. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mini mill conversion
2009/12/10 Hubert Bahr h...@hbahr.org: Does anybody else have an explanation for 4 phases with only 4 wires? It might be 2 phase bipolar, but labelled oddly. ie imagine that P1-P4 drive a motor wire each, at +40V if the pin is high and 0V if the pin is low. Here's plan: after checking that the drive to that connector is +5 V logic level, wire it into the P-port of the EMC machine and plot the pattern on Halscope. using EMC as a simple oscilloscope. -- atp -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Mini Mill conversion update
Craig, and list, You are correct. It is a Cardinal Engineering unit. I had forgotten about the name on the spindle belt cover. As you can see in the picture the belt cover is not present because when the head as close to the table as it is for most of the work I do, the belt cover does not move out of the way enough for me to get to the pulleys to change the spindle speed. So right after I got the unit I pulled the hinge pins and took the cover off. The name Cardinal rang a bell so I went to take a look at the cover and sure enough it has a big name plate on it with* Cardinal Engineering CAD CAM* on it. And this one had dates on the chips of 1987 and 1989. So either way it's 20+ years old. Martin -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mini mill conversion
On Thu, 2009-12-10 at 22:27 +, Andy Pugh wrote: 2009/12/10 Hubert Bahr h...@hbahr.org: Does anybody else have an explanation for 4 phases with only 4 wires? It might be 2 phase bipolar, but labelled oddly. ie imagine that P1-P4 drive a motor wire each, at +40V if the pin is high and 0V if the pin is low. Here's plan: after checking that the drive to that connector is +5 V logic level, wire it into the P-port of the EMC machine and plot the pattern on Halscope. using EMC as a simple oscilloscope. The four inputs might control each half of the two h-bridges (four halves). This may help prevent shoot through. That's what I did here: http://wallacecompany.com/E45/Rotor%20Cam/rotor_driver-2b.png http://wallacecompany.com/E45/rotor_cam.html -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mini mill conversion
Those controls are 20+ years old and the control design is likely even older than that. My guess is that you have unipolar motors. I have some motors - Slo Syn's here that have 5 terminals. The one terminal is ground and the other 4 are the 4 phases. If you disconnect the motors - I bet you find that you have 5 wires leading to each motor. If you can find a common wire between all of the leads you have a unipolar motor. I'd scrap the motors, the boards, and the power supply and start with a new PS, step drivers, and motors and use a LPT port and EMC2 to drive everything. The new Gecko 203V and the 540's 250/251 drives can be driven directly from a LPT port - even a 3.3 volt port. A cheap $10 BOB will work fine. Use an Estop setup to kill the drives if things get out of hand. Even a low cost bipolar setup should run circles around an old unipolar setup. If those were servos, I'd try to save them but those stepper motors can be replaced with decent Nema 34 bipolars for about $70 each or less. You are already going to put a bunch of time into this conversion, why make it more difficult than it needs to be? Dave Kirk Wallace wrote: On Thu, 2009-12-10 at 22:27 +, Andy Pugh wrote: 2009/12/10 Hubert Bahr h...@hbahr.org: Does anybody else have an explanation for 4 phases with only 4 wires? It might be 2 phase bipolar, but labelled oddly. ie imagine that P1-P4 drive a motor wire each, at +40V if the pin is high and 0V if the pin is low. Here's plan: after checking that the drive to that connector is +5 V logic level, wire it into the P-port of the EMC machine and plot the pattern on Halscope. using EMC as a simple oscilloscope. The four inputs might control each half of the two h-bridges (four halves). This may help prevent shoot through. That's what I did here: http://wallacecompany.com/E45/Rotor%20Cam/rotor_driver-2b.png http://wallacecompany.com/E45/rotor_cam.html -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mini mill conversion
On Thu, 2009-12-10 at 18:25 -0500, Dave wrote: ... snip Even a low cost bipolar setup should run circles around an old unipolar setup. If those were servos, I'd try to save them but those stepper motors can be replaced with decent Nema 34 bipolars for about $70 each or less. You are already going to put a bunch of time into this conversion, why make it more difficult than it needs to be? Dave Kirk Wallace wrote: On Thu, 2009-12-10 at 22:27 +, Andy Pugh wrote: 2009/12/10 Hubert Bahr h...@hbahr.org: Does anybody else have an explanation for 4 phases with only 4 wires? It might be 2 phase bipolar, but labelled oddly. ie imagine that P1-P4 drive a motor wire each, at +40V if the pin is high and 0V if the pin is low. ... snip I think it depends on what value Martin places on his time, money and patience. If he reuses his power supply, drivers, motors and I/O card, and having a parallel port buffer card in hand, he can have EMC2 running in a short time and with very little more money, if any. Martin will need to get into the guts of EMC2 and HAL more than most, which may be a deal breaker. Making motor mounts, screw couplers, re-wiring, learning about the new parts, and the $500 or more, is a significant issue. It just depends. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mini mill conversion
On Thu, Dec 10, 2009 at 06:25:24PM -0500, Dave wrote: I'd scrap the motors, the boards, and the power supply and start with a new PS, step drivers, and motors and use a LPT port and EMC2 to drive everything. Judging by the four TIPxxx transistors and MTR1_PH[1-4] on that first pinout, I bet these are full step or half step unipolar drives and motors. In this case I agree with Dave 100%. Chris -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mini mill conversion
2009/12/10 Kirk Wallace kwall...@wallacecompany.com: Martin will need to get into the guts of EMC2 and HAL more than most, which may be a deal breaker. He is already further down that road than many, having started off reading the HAL manual. not realising that stepconf was there. I suspect that altering the existing stepconf config to a type-10 stepgen isn't a huge job. -- atp -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mini mill conversion
2009/12/10 Chris Radek ch...@timeguy.com: Judging by the four TIPxxx transistors and MTR1_PH[1-4] on that first pinout, I bet these are full step or half step unipolar drives and motors. I think we have only got evidence of 4 motor wires. -- atp -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mini mill conversion
On Thu, 2009-12-10 at 17:47 -0600, Chris Radek wrote: ... snip Judging by the four TIPxxx transistors and MTR1_PH[1-4] on that first pinout, I bet these are full step or half step unipolar drives and motors. In this case I agree with Dave 100%. Chris Et tu, Brute. What happened to your wild side? :) (Apparently, some of us didn't have to make-do when they had rationing during The Great Conflict. I'm speaking of the Oil Embargo of '73, of course) -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mini mill conversion
I think we have only got evidence of 4 motor wires. Yep, sorry. I missed that in the previous message. Since the driver board is named Chop... something I bet it is a true chopper drive board. Still I'd at least dump the drive boards, keep the power supply and go with something like this.. times 3. http://geckodrive.com/product.aspx?c=3i=14471 The Gecko G540 would be a good fit also and require even less wiring. Isn't there a G540 configuration in the latest EMC2 setup? That would be pretty easy to setup. If those are round stepper motors and 1980's vintage they have probably lost a lot of magnetism. New Bipolar stepper motors would be best. Of course if money is tight.. then ?? Geckodrive had a big sale a few months ago. Didn't they have their big sale just prior to Xmas last year? I thought they might put on another pre-Xmas sale.. I mean.what am I going to put in the stockings ;-) Dave Andy Pugh wrote: 2009/12/10 Chris Radek ch...@timeguy.com: Judging by the four TIPxxx transistors and MTR1_PH[1-4] on that first pinout, I bet these are full step or half step unipolar drives and motors. I think we have only got evidence of 4 motor wires. -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 4th axis ideas... any suggestions?
On Thursday 10 December 2009, Andy Pugh wrote: 2009/12/10 Gene Heskett gene.hesk...@gmail.com: Just one Q though, wouldn't this also need an oil injector to keep it from rusting since the air is going to have water in it? Clean and dry should be enough, but our mating parts were aluminium and stainless, so I don't know how much of an issue it would be. This table is some sort of cast iron, base and table ANAICT. Inside, its straight from the same quality of sand molds that I poured in my 20's at a small foundry in Perry Iowa that had contracts with both John Deer for corn planter seed disks, and Maytag for washing machine transmission castings. Actually I think we were doing better work back then. ;-) -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp Never leave anything to chance; make sure all your crimes are premeditated. -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Mini mill conversion
Wow...that was a lot of stuff First of all I have to say that I am really impressed with what some of you guys have put on the web as projects. Kirk, I went to your web site and you tear into a machine like I tear into a locomotive. Your lathe project was impressive. Have you finished it yet ? Anyway; Each stepper motor has it's own board. And each board has it's own 40V supplied to drive the steppers. There are actually only 4 wires + a shielded ground wire. HOWEVER the motors still work just fine if the ground wire is not screwed to the back of the case. So I have to count that as just 4 wires. At this point I have to re-think the conversion. Because, I have a couple of other priorities that need handled before I invest serious cash into re-fitting this mill. And at the top of the priority list is building a small machine/work shop in my back yard. Initially when I considered doing this conversion, I thought it might have been a little more doable than it seems to be turning out. I don't have any problem with putting in the time (during the winter). I do want to learn more about EMC and I would like to attend the conference this year. Here's a thought I had. I'm wondering why I can't replace the computer SW OS with EMC? In other use Centroids control box, but instead of using Centroids software to communicate with the control box through the serial port, use EMC. I know it would be like stepping back 20years for Linux, but I wonder if it would be possible to decompile Centroid's SW in order to get EMC what it needed to get talking to the big black box? I mean, the SW is 20+ years old, could it be that difficult ? Now, in light of that last question, I first have to say, YES, I'm guessing that it would be very for me. I don't know about the rest of you ;-} Just a thought. Martin -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mini mill conversion
Martin Nice work. My kids would be hanging out in your yard all year One option could be the HobbyCNC Driver and motor kit. Its a low cost way to get upgraded and learn how the various components work at the same time. These kits run $280 for a three axis board with three 305oz-in steppers which should be adequate to run your mill. For another $25-30 you can get a 24V 10A transformer to power it. This would allow you to run your Centroid control until the switch - then swap everything over. THis would not affect your centroid controller if you decide to go back to it (or sell it intact on ebay). The board must be assembled by you, but only takes an evening at best. I have this board, use it for home projects and am quite happy with it. http://www.hobbycnc.com/products/hobbycnc-pro-driver-board-packages/ Just an alternate thought. Brian -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 4th axis ideas... any suggestions?
On Thu, Dec 10, 2009 at 06:34:01PM +, Andy Pugh wrote: Neater still would be an air bearing arrangement. Tighten the table down hard with belville washers. That sounds inspired! OK, hard implies the washers wouldn't be series stacked, but parallel, I guess [1]. (I'm imagining one or more of them under a locknut on the tables's axle.) When you want to rotate it, apply compressed air to the holes drilled in the mating face that I forgot to mention earlier so it rotates on a minimal thickness air-bearing. To clamp, turn off the air. Lacking fancy grinding facilities, I'd be tempted to try lapping the surfaces, to allow it to move with a minimal thickness air-bearing, and lock with minimal jiggle. The simulation running in my mind locks tighter with a coned air bearing around the table perimeter, but if the cone is too acute, excessive air pressure is needed to free it. I wonder if 45° is anywhere near optimum? Now we just need one of those recirculating ball wormwheel contraptions to drive it with minimal backlash. In case you doubt that this will work, it was how we clamped the tool height adjusters on the testing machines I used to design. They were for knocking balls off of ICs, and pulling out the tiny gold wires from carrier to die. You were working under moderate magnification and still could barely see the tool move as the air went on and off, the clamping force was enough to scrape entire dies off of substrates, but the sliding force when released was enough to not even mark the substrate. (the process was release, land, clamp, back off a few microns) Err, I'm not sure that I understand land, clamp. I'd inferred that the great attraction of this approach is that landing is clamping? Erik [1] http://en.wikipedia.org/wiki/Belleville_washer -- If you understand what you're doing, you're not learning anything. - A. L. -- Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
