[Emc-users] Joint 1 following error using plasma-thc-sim configuration
Hello, I have EMC 2.4.4 installed by using installation script on system where EMC 2.3.5 was installed (Ubuntu 8.04). EMC is running inside virtual machine. The problem I have is following: 1. I use original plasma-thc-sim configuration 2. Start EMC and home axis 3. Jog joints 1 and 2 4. Switch view to world mode Problem: Joint 1 following error I checked axis.1.joint-pos-cmd and axis.1.joint-pos-fb which are the same, but following error still occurs. EMC Status shows actual position for Y axis = 0, which is what I don't understand. -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Joint 1 following error using plasma-thc-sim configuration
On 27 September 2010 09:09, Sasa Vilic sasavi...@gmail.com wrote: 1. I use original plasma-thc-sim configuration 2. Start EMC and home axis 3. Jog joints 1 and 2 4. Switch view to world mode Problem: Joint 1 following error That config is a gantry kinematics setup. (ie one with two motors moving each side of an axis) Axis 1 uses joints 1 and 3. When you switch to world mode emc checks that the gantry position matches the joint 1 and 3 motor (joint) positions. As you have jogged joint 1 but not joint 3 this can not be resolved to an unambiguous axis position and a following error is the result. (I practice this would correspond to a badly racked gantry, so an error is appropriate) If you home the axes (homing Y will home joints 1 and 3 simultaneously) then it will switch to world mode correctly. It will also switch correctly if you jog joints 1 and 3 to be very close in position. My feeling is that for systems with semi-trivial kinematics (where the equations of motion do not vary with joint position) there should perhaps be an ini-file option to start up in world mode (but home in joint mode), to disable joint-mode jogging and to auto-switch to world mode when homed. Clearly not all combinations of these options make sense, and some can be achieved through HAL functions. -- atp -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] OT: a fun toy, the Best Buy Insignia Infocast
Gentle persons: Kirk's question about PDAs is forcing me to tip my hand about a fun toy I picked up last week at Best Buy. The Best Buy Insignia Infocast is an internet appliance that looks like a digital picture frame but acts as a window into internet-based information and multimedia. Cost: US$170 (Caveat: Best Buy has no idea how to sell this thing. I went through two sales people and a manager before we could find it in the store). But, under the covers, it is a hacker-friendly 800MHz ARM-based computer with 2GB RAM, an 8 inch 800x600 LCD touchscreen display, 802.11b/g WiFi, 2 USB2.0 ports, 7-in-1 media reader, and embedded Linux (2.6.28 at the moment). All the user applications are Flash-widgets but one can easily hack to bare Linux. It runs off a 120vac wall-wart rated at 5v/2500ma but rigging up a rechargeable battery pack would be child's play. The moment I saw mention of it on HackaDay I was in love with it. Like it's older but lesser cousin, the Chumby, the Infocast has a growing user community at forum.chumby.com, wiki.chumby.com, and elsewhere. I bought it with thoughts of my robot project with my grandkids, but my first attempt at hacking has been to compile and run Nano-X with a VNC client to see how it would function as a wireless remote EMC2 display. It was a challenge finding enough information but through brute force and ignorance applied over the weekend I got it running. On my first attempt, screen updates are slow and color mapping is corrupt but I'm sure I'll sort things out. Another user got Qt and a web browser running on it, so I have an alternative to Nano-X available if need be. Figuring out useful touchscreen interactions will keep me occupied for a while. Just thought I'd mention it. Regards, Kent PS - it's fun as an Internet appliance too. Right now mine is alternating among webcams at Marienplatz Munich Germany (where my sister lives), the Sydney Harbor bridge (where my heart is), Southwest Harbor, Maine (where I'm about to spend a late vacation), and several information sites (NYTimes headlines, Engadget, and Hacker News). -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: PDA's and machine control
On 27 September 2010 12:24, Kent A. Reed knbr...@erols.com wrote: On 9/27/2010 4:09 AM, Kirk Wallace wrote: I want to read encoders with a PDA, In terms of fulfilling your requirements, are you thinking PDA because it is a convenient packaging of display and input devices or because...? If it is just the packaging, I wonder if one of these could be re-purposed? http://www.seeedstudio.com/depot/dso-nano-v2-beta-test-p-681.html?cPath=104_108 It says that the software is open... -- atp -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] EMC2 for work group
On 9/27/2010 4:09 AM, Aram wrote: Hi I can see that big demand in CNC controllers for multi spindle machines. There are many shops where most machines are CNC multi spindle 3-5 axis lathe. There are something like 2 and up to 6 CNC lathe machine ? including up to 5 axis spindle- lathe in one machine. Something similar to http://www.index-werke.de/ic/englisch/524_ENU_HTML.htm In order to use EMC2 to retrofit them need to use 6 independent EMC2 3-5 axis machine but all those 6 independent EMC2 machines must be synchronize by main computer. In other word need to build system where EMC2 is a building block of much larger machine. Industry start produce more complex parts and to make good production it is impossible to use single machining unit like 3-5 axis machine. When EMC2 for work group or EMC2.2 or EMC3 will be done then there will not be competition with other low cost CNC systems. Right now EMC2 as a single system compete with MACH 3, Anilam, CENTROID and few other systems. In system for work group ( EMC2.2 or EMC3) main computer will synchronize about 10 independent EMC2 machines, and provide additional control of machining system in whole like part loader and unloader, count of total parts, etc. I think it will make EMC2 very unique and more powerful. Tnaks Aram . Aram: The NBS/NIST program that brought us the original EMC was all about factory automation. Jim Albus, the visionary Division Chief who led the program developed the hierarchical control system architecture of which the Automated Manufacturing Research Facility (AMRF) was a reference implementation. Machining centers, possibly running EMC, could be controlled in the way you describe. (disclaimer, I was in an entirely different part of NBS/NIST but was involved with AMRF and its follow-ons in a peripheral way because I was working on the product data standards that were used to define the parts to be made. If I get details about the program wrong, blame it on my bad memory.). There are lots of reports online. Look for combinations of keywords like NBS/NIST, hierarchical control system (HCS), real-time control system (RCS), Albus, AMRF, etc. Check out the current research (http://www.nist.gov/MEL). This is a major undertaking that requires major resources. Communicating among the machines (that's what NML is about) is the easy part. Controlling the complex of machines is the hard part. First off, one needs to settle on a language to define the production process analogous to (but one hopes better than) the way g-code defines certain machine-tool processes. Then one needs an interpreter that converts the production definition into coordinated machine-tool processes. And that's just for starters. It's an interesting goal but a bit of a stretch for a loose confederation of open-source developers. Regards, Kent -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Rigid tapping on a CNC mill
I have a possible job to do to drill and tap 200 holes. The more I think, the more it seems that I would be served well if I get rigid tapping to work. My question is, how does rigid tapping handle spindle reversal? How does EMC know so well how speeds acts when the spindle is stopped, then reversed? i -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: PDA's and machine control
On Mon, 2010-09-27 at 07:24 -0400, Kent A. Reed wrote: ... snip In terms of fulfilling your requirements, are you thinking PDA because it is a convenient packaging of display and input devices or because...? Regards, Kent At the risk of becoming too off topic, I'll describe my project. I did some research on 1x or infinity finders for telescopes. Here is an example: http://www.backyard-astro.com/equipment/accessories/telrad/telrad.html One nice thing about these is your eye can move, but the aiming image (cross hairs) and your target and telescope stay aligned. This is just like a Head Up Display: http://en.wikipedia.org/wiki/Head-up_display Then I got to thinking I could use a small LCD display as the aiming image and display the telescope aiming data from Alt-Az encoders along with the cross hairs. While I'm at it, I could install KStars and overlay a sky map of the area that I am pointing at. Then search the Internet for any appropriate music: http://en.wikipedia.org/wiki/The_Planets and dynamically collimate... (feature creep?) So, I'm considering something with Linux, a small display (monochrome okay, will change backlight to red) and TTL I/O, (and sub $50, used on eBay). -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Rigid tapping on a CNC mill
On 9/27/2010 7:32 AM, Igor Chudov wrote: I have a possible job to do to drill and tap 200 holes. The more I think, the more it seems that I would be served well if I get rigid tapping to work. Thought just occurred to me, EMC will thread mill, right? Given the number of holes, you might consider popping for a Thriller made by Emuge. Properly programmed, it will drill, thread, and chamfer the hole. Emuge has details of how to program the thread milling, use that data in a subroutine. I'm not familiar with subroutine calls with repeats, but done properly, I think you could get away with a sub call for one row, a sub call repeating that row call in the other axis, and the subroutine itself. A potential job several years ago would have involved huge amounts of drilling and tapping 1/4-20 blind holes. Had the job come through I would have quickly gotten into a machining center. I contacted Emuge for some details on cycle time. Given a 10K spindle and proper coolant, an engineer told me to expect a cycle time of a few seconds per hole. You don't have that RPM or high volume coolant, but it should give you an idea. Of course, being mostly hobby, gotta weigh time vs money... Jon -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Rigid tapping on a CNC mill
On Mon, Sep 27, 2010 at 11:56 AM, Jon Anderson janders1...@comcast.net wrote: On 9/27/2010 7:32 AM, Igor Chudov wrote: I have a possible job to do to drill and tap 200 holes. The more I think, the more it seems that I would be served well if I get rigid tapping to work. Thought just occurred to me, EMC will thread mill, right? Given the number of holes, you might consider popping for a Thriller made by Emuge. Properly programmed, it will drill, thread, and chamfer the hole. Emuge has details of how to program the thread milling, use that data in a subroutine. I'm not familiar with subroutine calls with repeats, but done properly, I think you could get away with a sub call for one row, a sub call repeating that row call in the other axis, and the subroutine itself. A potential job several years ago would have involved huge amounts of drilling and tapping 1/4-20 blind holes. Had the job come through I would have quickly gotten into a machining center. I contacted Emuge for some details on cycle time. Given a 10K spindle and proper coolant, an engineer told me to expect a cycle time of a few seconds per hole. You don't have that RPM or high volume coolant, but it should give you an idea. Of course, being mostly hobby, gotta weigh time vs money... I have high enough volume coolant for this application. My top RPM for a long job is 2,600 RPM. -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: a fun toy, the Best Buy Insignia Infocast
Kent A. Reed wrote: The Best Buy Insignia Infocast is an internet appliance that looks like a digital picture frame but acts as a window into internet-based information and multimedia. Cost: US$170 (Caveat: Best Buy has no idea how to sell this thing. I went through two sales people and a manager before we could find it in the store). But, under the covers, it is a hacker-friendly 800MHz ARM-based computer with 2GB RAM, an 8 inch 800x600 LCD touchscreen display, 802.11b/g WiFi, 2 USB2.0 ports, 7-in-1 media reader, and embedded Linux (2.6.28 at the moment). All the user applications are Flash-widgets but one can easily hack to bare Linux. It runs off a 120vac wall-wart rated at 5v/2500ma but rigging up a rechargeable battery pack would be child's play. The moment I saw mention of it on HackaDay I was in love with it. Oh, wow! Not only the processor, but the touch screen too, for $170! I've been working with the Beagle board, which is a quite impressive CPU, with USB and SD card for hard drive, plus XDVI video. Runs Linux of your choice great. The ARM maintainer for RTAI is currently working on an RTAI port, but it isn't done yet. It uses the OMAP3530 CPU. What CPU is in the Infocast? Jon -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Rigid tapping on a CNC mill
On Mon, Sep 27, 2010 at 11:21 AM, Igor Chudov ichu...@gmail.com wrote: On Mon, Sep 27, 2010 at 11:56 AM, Jon Anderson janders1...@comcast.net wrote: On 9/27/2010 7:32 AM, Igor Chudov wrote: I have a possible job to do to drill and tap 200 holes. The more I think, the more it seems that I would be served well if I get rigid tapping to work. Thought just occurred to me, EMC will thread mill, right? Given the number of holes, you might consider popping for a Thriller made by Emuge. Properly programmed, it will drill, thread, and chamfer the hole. Emuge has details of how to program the thread milling, use that data in a subroutine. I'm not familiar with subroutine calls with repeats, but done properly, I think you could get away with a sub call for one row, a sub call repeating that row call in the other axis, and the subroutine itself. A potential job several years ago would have involved huge amounts of drilling and tapping 1/4-20 blind holes. Had the job come through I would have quickly gotten into a machining center. I contacted Emuge for some details on cycle time. Given a 10K spindle and proper coolant, an engineer told me to expect a cycle time of a few seconds per hole. You don't have that RPM or high volume coolant, but it should give you an idea. Of course, being mostly hobby, gotta weigh time vs money... I have high enough volume coolant for this application. My top RPM for a long job is 2,600 RPM. -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users the thread milling was interesting here's a link to thier programming tips (interesting too they're old school enuf to use tabbed programming forms ;) http://www.emuge.com/carbide_thread/bgfprog.pdf tom3p -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: a fun toy, the Best Buy Insignia Infocast
According to this link, 800mhz http://www.tested.com/news/hack-an-affordable-diy-touch-computer-with-the-170-insignia-infocast/951/ -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Rigid tapping on a CNC mill
all you need is a quadature encoder + index installed on your spindle. (and some way to get it into emc.) I don't know if you have the same mill as jonE - but he used an existing gear in his mill as an encoder. http://pico-systems.com/bridge_spindle.html sam emc w On 9/27/2010 11:21 AM, Igor Chudov wrote: On Mon, Sep 27, 2010 at 11:56 AM, Jon Andersonjanders1...@comcast.net wrote: On 9/27/2010 7:32 AM, Igor Chudov wrote: I have a possible job to do to drill and tap 200 holes. The more I think, the more it seems that I would be served well if I get rigid tapping to work. Thought just occurred to me, EMC will thread mill, right? Given the number of holes, you might consider popping for a Thriller made by Emuge. Properly programmed, it will drill, thread, and chamfer the hole. Emuge has details of how to program the thread milling, use that data in a subroutine. I'm not familiar with subroutine calls with repeats, but done properly, I think you could get away with a sub call for one row, a sub call repeating that row call in the other axis, and the subroutine itself. A potential job several years ago would have involved huge amounts of drilling and tapping 1/4-20 blind holes. Had the job come through I would have quickly gotten into a machining center. I contacted Emuge for some details on cycle time. Given a 10K spindle and proper coolant, an engineer told me to expect a cycle time of a few seconds per hole. You don't have that RPM or high volume coolant, but it should give you an idea. Of course, being mostly hobby, gotta weigh time vs money... I have high enough volume coolant for this application. My top RPM for a long job is 2,600 RPM. -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Rigid tapping on a CNC mill
Igor Chudov wrote: I have a possible job to do to drill and tap 200 holes. The more I think, the more it seems that I would be served well if I get rigid tapping to work. Having done exactly that - a fixture plate with 288 holes - I am sure you are right. Either a tapping head or rigid tapping. Otherwise, very sore arms and back. My question is, how does rigid tapping handle spindle reversal? When the depth specified in the command is reached, the spindle speed is reversed. If your spindle direction is by relays only, then it is a pretty abrupt reversal. if you have spindle speed set by analog output to the VFD, then it can be run through the HAL component lowpass (how I did it because I understood the component) or limit (recommended by others). You set the filtering rate-of-change so that your Z axis servo can follow the reversal without excessive following error. How does EMC know so well how speeds acts when the spindle is stopped, then reversed? It is constantly watching the spindle position. Speed, in fact, isn't really monitored, it is position. The spindle's encoder counter is zeroed at the index mark when entering spindle-sync'ed motion, and then the encoder is a count of rotation. 1.00 equals the first full turn, 2.00 is the second full turn, etc. The Z axis is slaved to the rotation times the thread pitch. As the spindle stops and reverses, the Z just stays in sync with the encoder, all the way in, and all the way back out. There are a couple things that have to be right for this to work. One is that the trajectory planner must be run at the same period as the servo thread. Otherwise, the position interpolation of the T.P. introduces a delay which causes Z to lag one way going in and the opposite way coming back out, dragging the tap. So, you would have something like this in the .ini file : # Servo task period, in nanoseconds - will be rounded to an integer multiple # of BASE_PERIOD SERVO_PERIOD = 100 # Trajectory Planner task period, in nanoseconds - will be rounded to an # integer multiple of SERVO_PERIOD TRAJ_PERIOD = 100 Your spindle encoder needs to have minimal backlash in however you attach it to the spindle. You have to check with air cuts and Halscope to make sure the Z following error is within a reasonable tolerance during the spindle reversal, at the thread pitch and spindle RPMs in question. Once you have this figured out, you can probably come up with a table that threads finer than X TPI can be cut at 2000 RPM, threads down to Y TPI can be done at 1000 RPM, and the threads coarser than Z TPI must be done at 500 RPM or below. If your following error limits are set tight, then exceeding that rule would cause a following error on Z, requiring you to back the tap out manually - not a lot of fun! The tradeoff on the VFD acceleration is that the tap will go deeper than the commanded depth. The slower the acceleration of the spindle, the more the tap will coast in before the reversal happens. When tapping thick material or blind holes, the amount of this overrun can be a concern. Jon -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Rigid tapping on a CNC mill
Jon Anderson wrote: Thought just occurred to me, EMC will thread mill, right? This has been there since the VERY beginning of EMC, helical inerpolation. The problem with thread mills is that they are very expensive, never EVER seen one even close to $50, most run over $100 EACH. Wouldn't be that bad, but these only do one thread pitch over a modest range of diameters. There are also single-row thread mills that can do a wide range of thread pitches. The downside is you have to do the entire thread one turn at a time, thereby taking several times longer that a specific-pitch thread mill. But, these cost about $50. For a few holes, the single-row thread mill is great for that oddball pitch or diameter. But, for hundreds of holes, the $10 tap is faster and more affordable. Jon -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: a fun toy, the Best Buy Insignia Infocast
Well according to the schematics posted here: http://files.chumby.com/bunnie/silvermoon_oem/silvermoon_OEM_ref_v3.pdf ... the processor is a Marvell 88AP166-A0-BJD2C008 http://www.marvell.com/products/processors/applications/armada_100/ http://www.marvell.com/products/processors/applications/armada_100/armada_16 8/pxa_168_pb.pdf -Original Message- From: Jon Elson [mailto:el...@pico-systems.com] Sent: Monday, September 27, 2010 11:27 AM To: Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] OT: a fun toy, the Best Buy Insignia Infocast Oh, wow! Not only the processor, but the touch screen too, for $170! I've been working with the Beagle board, which is a quite impressive CPU, with USB and SD card for hard drive, plus XDVI video. Runs Linux of your choice great. The ARM maintainer for RTAI is currently working on an RTAI port, but it isn't done yet. It uses the OMAP3530 CPU. What CPU is in the Infocast? Jon -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Rigid tapping on a CNC mill
Jon, thanks, very good. This is the long term plan. Now, if I wanted to do it with a floating tap holder, I could just measure accurately the speed of the spindle with a handheld tachometer, match the downfeed rate as carefully as possible, and just do it with G code. Note that right now I set RPM manually by operating an air motor to change speed. I just wrote a sub to do it. It is untested. Otap_with_floating_holder sub #depth = #1 (Hole Depth) #tpi = #2 (Threads per Inch) #rpm = #3 (RPM of the spindle, EXACTLY MEASURED) #safez = #4 (Safe Height) #frate = [#rpm / #tpi] M3 (Forward) G1 Z#depth F#frate M4 (Reverse) G1 Z#safez F#frate M3 (Forward again) Otap_with_floating_holder endsub M2 As the quill reverses, the tap will lag the movement and offset itself in the floating holder a little bit, but that is what floating holders are for. On Mon, Sep 27, 2010 at 12:04 PM, Jon Elson el...@pico-systems.com wrote: Igor Chudov wrote: I have a possible job to do to drill and tap 200 holes. The more I think, the more it seems that I would be served well if I get rigid tapping to work. Having done exactly that - a fixture plate with 288 holes - I am sure you are right. Either a tapping head or rigid tapping. Otherwise, very sore arms and back. My question is, how does rigid tapping handle spindle reversal? When the depth specified in the command is reached, the spindle speed is reversed. If your spindle direction is by relays only, then it is a pretty abrupt reversal. if you have spindle speed set by analog output to the VFD, then it can be run through the HAL component lowpass (how I did it because I understood the component) or limit (recommended by others). You set the filtering rate-of-change so that your Z axis servo can follow the reversal without excessive following error. How does EMC know so well how speeds acts when the spindle is stopped, then reversed? It is constantly watching the spindle position. Speed, in fact, isn't really monitored, it is position. The spindle's encoder counter is zeroed at the index mark when entering spindle-sync'ed motion, and then the encoder is a count of rotation. 1.00 equals the first full turn, 2.00 is the second full turn, etc. The Z axis is slaved to the rotation times the thread pitch. As the spindle stops and reverses, the Z just stays in sync with the encoder, all the way in, and all the way back out. There are a couple things that have to be right for this to work. One is that the trajectory planner must be run at the same period as the servo thread. Otherwise, the position interpolation of the T.P. introduces a delay which causes Z to lag one way going in and the opposite way coming back out, dragging the tap. So, you would have something like this in the .ini file : # Servo task period, in nanoseconds - will be rounded to an integer multiple # of BASE_PERIOD SERVO_PERIOD = 100 # Trajectory Planner task period, in nanoseconds - will be rounded to an # integer multiple of SERVO_PERIOD TRAJ_PERIOD = 100 Your spindle encoder needs to have minimal backlash in however you attach it to the spindle. You have to check with air cuts and Halscope to make sure the Z following error is within a reasonable tolerance during the spindle reversal, at the thread pitch and spindle RPMs in question. Once you have this figured out, you can probably come up with a table that threads finer than X TPI can be cut at 2000 RPM, threads down to Y TPI can be done at 1000 RPM, and the threads coarser than Z TPI must be done at 500 RPM or below. If your following error limits are set tight, then exceeding that rule would cause a following error on Z, requiring you to back the tap out manually - not a lot of fun! The tradeoff on the VFD acceleration is that the tap will go deeper than the commanded depth. The slower the acceleration of the spindle, the more the tap will coast in before the reversal happens. When tapping thick material or blind holes, the amount of this overrun can be a concern. Jon -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net
Re: [Emc-users] OT: PDA's and machine control
Not technically a PDA, but this would be easy to install in a pendant and should do everything you need: http://andahammer.com/mini3/?PHPSESSID=c47b0c96938c86847ccf80119dab7d42 On Sun, Sep 26, 2010 at 10:04 AM, Kirk Wallace kwall...@wallacecompany.comwrote: I want to read encoders with a PDA, such as for a DRO, but I would prefer to use something like a PC parallel port. I suspect no PDA has a parallel port, so does anyone know of a good PDA that has GPIO or other hackable ports for digital I/O? It seems the Sharp Zaurus has good Linux support, has anyone hacked one of these for machine control? Thanks. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: PDA's and machine control
On Mon, 2010-09-27 at 10:42 -0700, Mike Payson wrote: Not technically a PDA, but this would be easy to install in a pendant and should do everything you need: http://andahammer.com/mini3/?PHPSESSID=c47b0c96938c86847ccf80119dab7d42 From my brief look at it, it looks ideal (34 GPIO pins, yea). I would be mounting it, or the display at least, at the focal point of a lens of the same size as the display area. This will project the image up to a clear glass panel, tilted 45 degrees to the telescope view. The user looks straight through the glass to see stars and also the reflection of the screen. (eye)\ (glass) (view of screen and star) \ == (lens) [--] (screen) * | (telescope)| (star) | | /|\ / | \ / | \ -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: PDA's and machine control
On 09/27/2010 11:52 AM, Kirk Wallace wrote: On Mon, 2010-09-27 at 07:24 -0400, Kent A. Reed wrote: ... snip In terms of fulfilling your requirements, are you thinking PDA because it is a convenient packaging of display and input devices or because...? Regards, Kent At the risk of becoming too off topic, I'll describe my project. I did some research on 1x or infinity finders for telescopes. Here is an example: http://www.backyard-astro.com/equipment/accessories/telrad/telrad.html One nice thing about these is your eye can move, but the aiming image (cross hairs) and your target and telescope stay aligned. This is just like a Head Up Display: http://en.wikipedia.org/wiki/Head-up_display Then I got to thinking I could use a small LCD display as the aiming image and display the telescope aiming data from Alt-Az encoders along with the cross hairs. While I'm at it, I could install KStars and overlay a sky map of the area that I am pointing at. Then search the Internet for any appropriate music: http://en.wikipedia.org/wiki/The_Planets and dynamically collimate... (feature creep?) So, I'm considering something with Linux, a small display (monochrome okay, will change backlight to red) and TTL I/O, (and sub $50, used on eBay). You have to consider the needed computing power if you want to load something extra on, like Kstars. Aptitude says Kstars needs 197MB of space to install, and having a cpu 200MHz will improve how responsive it is, I'm sure. I'd recommend looking at old(ish) thin clients on ebay - in particular, there are ones made by Neoware, some with NatSemi Geode GX1 cpus, and some with Via C3 or C7, you can easily remove the NTe or XPe installed on the DOM (disk-on-module), and install a lightweight linux. I'm currently playing with a few of these, building custom OpenWRT images. I have one running at the house right now as a cellular modem router :) Look around, you can find something with parallel port, serial, ps/2, usb1.1, video, ethernet and audio, ram that can be upgraded, a usable-sized DOM (which can be upgraded by a compact flash - ide adapter), for $30 including shipping. -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Old Iron in Redmond
I live in Bellevue - I'll check in and let you know :-) DougM On Sun, Sep 26, 2010 at 8:34 PM, Przemek Klosowski przemek.klosow...@gmail.com wrote: I wonder how this will go down. A senior Microsoft engineer with a metalworking hobby opens a machine shop near Redmond: http://seattletimes.nwsource.com/html/sundaybuzz/2012981363_sundaybuzz26.html Can someone from the Northwest help him retrofit with EMC ? :) -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Old Iron in Redmond
http://toltmachineworks.com/default.aspx should get you close. It has a Carnation address. On Mon, 2010-09-27 at 22:01 -0700, doug metzler wrote: I live in Bellevue - I'll check in and let you know :-) DougM On Sun, Sep 26, 2010 at 8:34 PM, Przemek Klosowski przemek.klosow...@gmail.com wrote: I wonder how this will go down. A senior Microsoft engineer with a metalworking hobby opens a machine shop near Redmond: http://seattletimes.nwsource.com/html/sundaybuzz/2012981363_sundaybuzz26.html Can someone from the Northwest help him retrofit with EMC ? :) -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
