Re: [Emc-users] home-mad CNC machine project.
Kirk, Thank you for the detail thoughts. I agree that there needs to be a special chemistry for open source hardware projects to take off and that people contribute. Its curerntly my job to figure this out or at least give it a hard long try. As soon as I have the project up I will share my thoughts on a portal for the project development. My initial strategy is to create a place where, you can a. explore a project and its content. b. view/edit/download all relevant engineering data (parts drawings, schematics) c. view/edit/download assembly instructions (think instructable and EMC) d. view/edit/download sourcing information My hope is to seed the site with the current project, I have a bunch of picturer in this facebook group http://www.facebook.com/group.php?gid=11911880588 I will be looking into a conversion, project some of the points brought up make perfect sense to me As for bringing down the cost, China will play a roll, as will cutting away at the middle man. Doesn't EMC with some IO boards cut aways at some appropriately controllers. I've spoken with two CNC manufactures and distributors and they both pointed out how are going to get the motors and controllers those guys make all the money in this business On the business side - well there is no business plan besides reaching out to the machine shops of the world with our brand. There will be opportunities for others to consult, be integrators or sell kits. What I do see is the opportunity to put some funding and administrative support behind open source hardware - perhaps we should do routers too. I've been a big fan of Niel Gershenfeld and his work with fab labs at MIT and around the world. He has a phrase that sums up what we are trying to accomplish. the world has had a software revolution - free software tools are here, but that hardware to make use of the software has not had a revolution, the means of producing it are still in the hands of a few Is this making any sense? Jorge Barrera Director of MFG Labs MFG.com - Original Message From: Kirk Wallace [EMAIL PROTECTED] To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Sent: Wednesday, March 19, 2008 2:12:39 AM Subject: Re: [Emc-users] home-mad CNC machine project. On Tue, 2008-03-18 at 18:52 -0700, Jorge Barrera wrote: Jim, At some point I would like to do a retrofit, I know it would be the most ecomical way to go if frames are available. However the purpose of my project is a bit more complicated. I learned allot on my first conversion. Don't underestimate the value of traveling the beaten path to get the lay of the land. Plus, you will have a machine to make parts for the real project. I am trying to see if through innovative sourcing and design the price of VMC of HMC could be brought down. Way down. The current innovative sourcing, and increasingly the design, is called China, or the next poor country lucky enough to get a chance to gain what many take for granted. Trying to get people to do more work for less money has a long history. The over all objective is to try and create open source hardware designs. I am not doing this on my own I am being sponsored by my company MFG.com to try and get this off the ground. I've never build a CNC machine before, however I like the challenge of reducing the price of proprietary hardware. I wonder if the advantage of an open or collaborative project is not in reducing cost of production, but the cost of distribution or similar costs by cutting out the middle man (and maybe the tax man). This has a history too. Now you may be thinking Open Source Hardware? What am I smoking, Well projects like EMC have created expectation that perhaps this would be possible. If software can be open source why not hardware? Well I've been giving this lots of thought. And although there are projects out there like OSCAR (open source car) and a number of machine designs (mostly pictures), I am out to create a full set of detail drawings and a detail BOM, together with a site for collaborative engineering that works. I am also looking to get off the bench top into something in 2-4 ton range. I like some of the project on Instrutable but I want to go bigger. I agree that an open source project is worth trying, but I tried twice to start a small collaborative project and got no response. The latest was a project to make a batch of router type machines with each person contributing their specialty, be it design, drafting, cheer leading, sales of extra machines, manual writing, machining, welding, etc or just plain spending cash. I have no idea why it didn't go anywhere. So I am thinking that many of the problems you will face will not be technical at all. Collaborative work is a piece of the puzzle and the tools for collaborative software development have been here for a long time (with low cost to entree). For hardware we have not been so lucky but with the right tools
Re: [Emc-users] home-mad CNC machine project.
This list is probably as good a place to carry forward a bit of thinking about open hardware and virtual CNC machine companies as any because this is THE place to find the control software for a wide range of these kinds of devices. I'll snip both Kirk and Jorge quite a bit and I suggest you do the same if you reply to this. --- [EMAIL PROTECTED] wrote: I am trying to see if through innovative sourcing and design the price of VMC of HMC could be brought down. Way down. The current innovative sourcing, and increasingly the design, is called China, or the next poor country lucky enough to get a chance to gain what many take for granted. Trying to get people to do more work for less money has a long history. Um yes in a way but the low-cost labor advantage works best for mass produced products which CNC has never been. Consider even the largest room full of CNCs and it's a small handful compared to toasters or automobiles. And yes many Chinese machine tool companies, all of the ones I've visited, have engineering staffs that are hungry to design and develop these kinds of projects. They also have managers and bean counters that compel cost effective work and distribution agreements within the constraints of international trade. IMO the issue of low cost labor out there doesn't prevent the development of a low-cost CNC machine elsewhere -- ie this list. Certainly it will lower the bar that we have to slide under and in the long run our cost effective designs will become their next round of released products. The over all objective is to try and create open source hardware designs. I am not doing this on my own I am being sponsored by my company MFG.com to try and get this off the ground. It is easy to imagine a place in an open machine project for a broker like MFG. But a business like that assumes a demand for a specific number of widgets on the customer side. Any open design is going to take a while to place the first few. I think this was one of the issues with Kirks first suggested project. It doesn't just happen out of a couple of posts. Several years ago, a fellow named Hassan designed and built a nice, low-cost benchtop mill as part of his graduate degree and brought it to NAMES and Fest (EMC-Monday). I believe that he is still receiving this list. That mill created a LOT of interest at the show and quite a few folk were ready to sign up to purchase a kit that included all of the aluminum and leadscrew parts. Just guessing but I'd say he could have sold 25 kits on the spot. The point is that it is possible to stir interest that would lead to a first round of ordering. But it does require a real prototype that does some real work. This list is not the place to stir up that interest. We tend to be much to independent but then that is a very different lecture that I refer to as Explorers vs Settlers. I've never build a CNC machine before, however I like the challenge of reducing the price of proprietary hardware. I wonder if the advantage of an open or collaborative project is not in reducing cost of production, but the cost of distribution or similar costs by cutting out the middle man (and maybe the tax man). This has a history too. The cost of production might go up a bit over a Haas or similar machine because of quantity discounts and aftermarket sales and service. It's a bit like the cost of a PC being lower if it includes that other OS because of all the advertising and steering of next expenditure provided by that company's install. But you are right that there are savings to be had at nearly all levels. Put on top of that the customer supplying the assembly, tuning, and testing and we have some real advantage. Rayh - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] home-mad CNC machine project.
On Wednesday 19 March 2008, Jorge Barrera wrote: Kirk, Thank you for the detail thoughts. I agree that there needs to be a special chemistry for open source hardware projects to take off and that people contribute. Its curerntly my job to figure this out or at least give it a hard long try. As soon as I have the project up I will share my thoughts on a portal for the project development. My initial strategy is to create a place where, you can a. explore a project and its content. b. view/edit/download all relevant engineering data (parts drawings, schematics) c. view/edit/download assembly instructions (think instructable and EMC) d. view/edit/download sourcing information My hope is to seed the site with the current project, I have a bunch of picturer in this facebook group http://www.facebook.com/group.php?gid=11911880588 is a password protected site. [...] Jorge Barrera Director of MFG Labs MFG.com Is this the same business that sold me a grid dip meter a year ago? It went to tv station WDTV at the time. It works great, but the delivery was a bit slow. [...] -- 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) You don't have to explain something you never said. -- Calvin Coolidge - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] home-mad CNC machine project.
On Wed, 2008-03-19 at 08:44 -0700, [EMAIL PROTECTED] wrote: ... snip ... It doesn't just happen out of a couple of posts. ...But it does require a real prototype that does some real work. My vision of a real collaborative project has the collaboration start at the very beginning with the concept development. The old model has one person risking buckets of money to pay other people to go along. What drives the project is money and not so much its merits. This list is not the place to stir up that interest. EMC may be a major part of the whole and could be impacted by the results. We tend to be much to independent ... The frustrating part is that one person can only do so much. So we are relegated to pastime or hobby activities (not that that is bad). -- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC lathe, Bridgeport mill conversion, doing XY now, Zubal lathe conversion pending) - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] home-mad CNC machine project.
Comments and feed back it what I am seeking the most, a really appreciate the participation This list is not the place to stir up that interest. We tend to be much to independent but then that is a very different lecture that I refer to as Explorers vs Settlers. I see this list as the most forward thinking groups out there, with both Explorers and Settles. However I would love to hear a short version of your lecture. I also would like to point out a few things. I don't pretend to be independent but our discourse is more about vision rather than a pitch. We envisions a day when a machinist apprentice instead of making practice parts he or she makes parts that can be assembled into a machine for them selves. I personally see a huge potential to democratize access to manufacturing tools around the world. Growing up in a third world country i now about the needs and the high cost (200-300%) of what it cost in the US. If it wasn't for the US, Japan and Western Europe's investment in China they wouldn't be able to produce anything cheaply even with low cost labor. It is easy to imagine a place in an open machine project for a broker like MFG. But a business like that assumes a demand for a specific number of widgets on the customer side. A project like this has little impact on the bottom line of MFG we are really exploring here...that is why we created MFG Labs to play in a sand box. I've been at Bell Labs and HP and I never liked the secrecy thing. I am experimenting here having an open discussion with a user community. The cost of production might go up a bit over a Haas or similar machine because of quantity discounts and after market sales and service. indeed, however a 50% cost reduction DIY is what we are looking at. I personally would like something a bit more precision than a Hass, plus this wouldn't be for everyone, some user will stick with what they have and know. I've never build a CNC machine before, however I like the challenge of reducing the price of proprietary hardware. I wonder if the advantage of an open or collaborative project is not in reducing cost of production, but the cost of distribution or similar costs by cutting out the middle man (and maybe the tax man). This has a history too. What about empowerment? having control over what the hardware can do? One of the reasons I don't like new cars We tend to be much to independent ... The frustrating part is that one person can only do so much. So we are relegated to pastime or hobby activities (not that that is bad). That is way I want to go big, and ask the question what do people need? - Original Message From: [EMAIL PROTECTED] [EMAIL PROTECTED] To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Sent: Wednesday, March 19, 2008 11:44:42 AM Subject: Re: [Emc-users] home-mad CNC machine project. This list is probably as good a place to carry forward a bit of thinking about open hardware and virtual CNC machine companies as any because this is THE place to find the control software for a wide range of these kinds of devices. I'll snip both Kirk and Jorge quite a bit and I suggest you do the same if you reply to this. --- [EMAIL PROTECTED] wrote: I am trying to see if through innovative sourcing and design the price of VMC of HMC could be brought down. Way down. The current innovative sourcing, and increasingly the design, is called China, or the next poor country lucky enough to get a chance to gain what many take for granted. Trying to get people to do more work for less money has a long history. Um yes in a way but the low-cost labor advantage works best for mass produced products which CNC has never been. Consider even the largest room full of CNCs and it's a small handful compared to toasters or automobiles. And yes many Chinese machine tool companies, all of the ones I've visited, have engineering staffs that are hungry to design and develop these kinds of projects. They also have managers and bean counters that compel cost effective work and distribution agreements within the constraints of international trade. IMO the issue of low cost labor out there doesn't prevent the development of a low-cost CNC machine elsewhere -- ie this list. Certainly it will lower the bar that we have to slide under and in the long run our cost effective designs will become their next round of released products. The over all objective is to try and create open source hardware designs. I am not doing this on my own I am being sponsored by my company MFG.com to try and get this off the ground. It is easy to imagine a place in an open machine project for a broker like MFG. But a business like that assumes a demand for a specific number of widgets on the customer side. Any open design is going to take a while to place the first few. I think this was one of the issues with Kirks first suggested project. It doesn't just happen out of a couple
Re: [Emc-users] home-mad CNC machine project.
On Sat, 15 Mar 2008, [EMAIL PROTECTED] wrote: The second thought is EMC2 related. The linear scales, while very accurate in themselves have not proven to be very good for use with EMC2 control. The problem has to do with backlash in the drive components. Our backlash compensation counts encoder pulses to find the other edge of the lash whenever the direction reverses. Since the linear scale is connected on the work piece side of the lash EMC will not see pulses until the lash has been taken up. Even small amounts of lash will cause a well controlled servo system to hunt and overshoot. We've talked about using a motor driven encoder connected to one PID loop in our software to handle this lash problem and another PID connected to the linear scale to handle final positioning. I don't know that any real tests of such a system have been reported. Done and done. See http://jmkasunich.com/cgi-bin/blosxom/shoptask/wichita-trip-02-20-08.html - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] home-mad CNC machine project.
Fantastic. Thanks for that link. --- [EMAIL PROTECTED] wrote: ... F We've talked about using a motor driven encoder connected to one PID loop in our software to handle this lash problem and another PID connected to the linear scale to handle final positioning. I don't know that any real tests of such a system have been reported. Done and done. See http://jmkasunich.com/cgi-bin/blosxom/shoptask/wichita-trip-02-20-08.html - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] home-mad CNC machine project.
Couple of thoughts Jorge. First is how to manage building the machine base. I'm sure that you know that the parts of the machine that hold it together and allow it to move are what absorb the cutting forces and harmonics and allow it to cut accurately. The KT company built quite a business with large machines using welded bases rather than cast. You might look at some of their designs. The concrete floor provided quite a bit of the rigidity of the assembled machine. You might also consider concrete castings for some of the base. Portable concrete step manufacturing companies do some great work with small aggregates and fiber mixes.The second thought is EMC2 related. The linear scales, while very accurate in themselves have not proven to be very good for use with EMC2 control. The problem has to do with backlash in the drive components. Our backlash compensation counts encoder pulses to find the other edge of the lash whenever the direction reverses. Since the linear scale is connected on the work piece side of the lash EMC will not see pulses until the lash has been taken up. Even small amounts of lash will cause a well controlled servo system to hunt and overshoot. We've talked about using a motor driven encoder connected to one PID loop in our software to handle this lash problem and another PID connected to the linear scale to handle final positioning. I don't know that any real tests of such a system have been reported.HTH Rayh--- [EMAIL PROTECTED] wrote:From: Jorge Barrera [EMAIL PROTECTED]To: "Enhanced Machine Controller (EMC)" emc-users@lists.sourceforge.netSubject: Re: [Emc-users] home-mad CNC machine project.Date: Fri, 14 Mar 2008 20:09:24 -0700 (PDT)I am curious about bigger machines, anybody tried making something with a 40 taper spindle. I am halfway done with my own design, using servos, linear scales, linear bearings and ballscrews. I am trying to keep the BOM under 20k and of course I am using EMC. Its work envelope is 800mmx500mmx500mm vertial machine and I am trying to build it with simple tools and machines that are smaller and less sophisticated than itself.I would love to connect with anybody that has relevant experienceJorge- Original Message From: Doug Metzler [EMAIL PROTECTED]To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net; [EMAIL PROTECTED]Sent: Friday, March 14, 2008 1:35:27 AMSubject: Re: [Emc-users] home-mad CNC machine project. I’m on my third rev of my home-built CNC project. My best advice is to make it much more rigid than you think you need to. I started out with small slider shafts and now I’m up to 7/8” (which you can get surprisingly cheap at speedymetals). But in my case every rev got considerably bigger. The first rev was a little 8*11 PCB cutter and it had ¼” sliders, the second rev grew to 11*17 with 3/8’s and the latest rev will be a whopping 20*34”, thus the need for the huge sliders. But definitely err on the side of over-engineering for rigidity. The other part that I couldn’t afford that I wish I could have was good linear bearings. I tried many times to come up with my own linear bearing surface but in the end most of the available torque was spent trying to overcome the sliders. I still can’t afford good linear bearings but my latest home-brew setup uses small standard bearings (some of which are spring-loaded). These are a bear to manufacture but will dramatically increase the quality of the machine. I am using threaded rod but it makes for a very slow machine. If anyone here has a line on good inexpensive ballscrews please let me know. As for electronics I am doing it all myself because I want smart nodes. But I think the consensus here is probably right – spend the money to save the time. Drop me a note if you have specific questions. DougM From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of seth wiley Sent: Sunday, March 02, 2008 1:10 PM To: [EMAIL PROTECTED]; Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] home-mad CNC machine project. sean, i'm slowly (in my very spare sparetime) working up a small (12"x12"x3") low tolerance cnc machine for light wood and plastics. it is also serving as a general teach-myself-cnc project. i chose to go with a pre-config'd electronics / servos package from keling inc. (http://www.kelinginc.net/ThreeXCNCPackage2.html). after reading lots of cnczone entries and doing lots of chipset / board / wiring research, i figured it's 329$ well spent by saving me time, and it's a pretty complete set of items for a good price. also, this site has some helpful info on wiring (http://www.robertguyser.com/). i am next building up the machine using basic 8020 or minitec extrusions and linear accessories. lovejoy couplings will round out the basic bom. i'll use whatever i have as a c
Re: [Emc-users] home-mad CNC machine project.
Hey Doug. Thanks for the report. Good thoughts all.You might look at www.McMaster.com and search for ball screws. Or attempt to put the link below back together. Their 5/8 screws are about $1.25 an inch and the nuts run $25. I used a single nut to test lash and got between 0.001 and 0.003. I know folk who used two nuts on a single shaft and a Belleville Disc Spring or two between. I don't use the bearing end blocks rather I make up my own using trailer wheel bearings.HTHRayhhttp://www.mcmaster.com/ctlg/DisplCtlgPage.aspx?ReqTyp=CATALOGCtlgPgNbr=1083RelatedCtlgPgs=1083,1084term=Ball%2bScrewssesnextrep=453086149965954ScreenWidth=1024McMMainWidth=817--- [EMAIL PROTECTED] wrote:...I am using threaded rod but it makes for a very slow machine. If anyone here has a line on good inexpensive ballscrews please let me know. - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] home-mad CNC machine project.
Hi Doug, I've had passable luck on ebay for ball screws. Sometime you look and there is nothing and other times several good ones. Just depends. Good hunting. Dave On Mar 14, 2008, at 5:24 AM, [EMAIL PROTECTED] wrote: Hey Doug. Thanks for the report. Good thoughts all. You might look at www.McMaster.com and search for ball screws. Or attempt to put the link below back together. Their 5/8 screws are about $1.25 an inch and the nuts run $25. I used a single nut to test lash and got between 0.001 and 0.003. I know folk who used two nuts on a single shaft and a Belleville Disc Spring or two between. I don't use the bearing end blocks rather I make up my own using trailer wheel bearings. HTH Rayh http://www.mcmaster.com/ctlg/DisplCtlgPage.aspx? ReqTyp=CATALOGCtlgPgNbr=1083RelatedCtlgPgs=1083,1084term=Ball% 2bScrewssesnextrep=453086149965954ScreenWidth=1024McMMainWidth=817 --- [EMAIL PROTECTED] wrote: ... I am using threaded rod but it makes for a very slow machine. If anyone here has a line on good inexpensive ballscrews please let me know. -- --- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] home-mad CNC machine project.
Hi Rayh, Can you tell me or point me to a website that describes the process for measuring backlash? Thanks. Andy [EMAIL PROTECTED] wrote: Hey Doug. Thanks for the report. Good thoughts all. You might look at www.McMaster.com and search for ball screws. Or attempt to put the link below back together. Their 5/8 screws are about $1.25 an inch and the nuts run $25. I used a single nut to test lash and got between 0.001 and 0.003. I know folk who used two nuts on a single shaft and a Belleville Disc Spring or two between. I don't use the bearing end blocks rather I make up my own using trailer wheel bearings. HTH Rayh http://www.mcmaster.com/ctlg/DisplCtlgPage.aspx?ReqTyp=CATALOGCtlgPgNbr=1083RelatedCtlgPgs=1083,1084term=Ball%2bScrewssesnextrep=453086149965954ScreenWidth=1024McMMainWidth=817 --- [EMAIL PROTECTED] wrote: ... I am using threaded rod but it makes for a very slow machine. If anyone here has a line on good inexpensive ballscrews please let me know. - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Andy PGP Key ID: 0x67090A54 - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] home-mad CNC machine project.
Andrew Ayre wrote: Hi Rayh, Can you tell me or point me to a website that describes the process for measuring backlash? Thanks. Assuming the screws are mounted on a machine, you put a dial indicator (preferably one that reads out in .0001 units -- they call that a tenths reading indicator) across the slide and step the control back and forth, seeing how many units you need to move the CNC control before the axis actually moves. If you want to know the backlash on a ballscrew and nut set sitting alone on a table, you'd have to build some sort of test rig to evaluate it. You'd need to hold the screw rigid and prevent the nut from turning, and then apply force to the nut and read linear free play with the dial indicator. Jon - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] home-mad CNC machine project.
Hi Andrew, Jon Sorry I didn't get the post from Andrew. Gonna have to look at why. Jon's right. I set up a machine in order to test several things. It was an old Grizzly Sieg. The goal was to retrofit for low cost and reasonably good benchtop quality. I measured the lash on all three of the axes because they all used the same screws and nuts. There was a little bit of difference between but not a lot. I also know that the lash was not caused or made worse by the quality of the thrust bearings because I made the ends myself and setup the preload correctly. Nor was it caused by loose linkage between the nut and the slideways. I spent a couple days with a bpt getting all that right. For the electrical system on it I used several different drives connected to a PMDX-120 breakout and very light duty MAE motors with a three to one belt reduction. These motors were about 100 inch ounce. Another fellow demonstrated the machine at a NAMES show with his own control. Someone was shaking their head and muttering that those little motors would never run the machine in a cut. The operator asked the skeptic to push against the x axis while he jogged it. He was able to push the machine across the display table but not stop the motion. HTH Rayh --- [EMAIL PROTECTED] wrote: From: Jon Elson [EMAIL PROTECTED] To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Subject: Re: [Emc-users] home-mad CNC machine project. Date: Fri, 14 Mar 2008 11:20:23 -0600 Andrew Ayre wrote: Hi Rayh, Can you tell me or point me to a website that describes the process for measuring backlash? Thanks. Assuming the screws are mounted on a machine, you put a dial indicator (preferably one that reads out in .0001 units -- they call that a tenths reading indicator) across the slide and step the control back and forth, seeing how many units you need to move the CNC control before the axis actually moves. If you want to know the backlash on a ballscrew and nut set sitting alone on a table, you'd have to build some sort of test rig to evaluate it. You'd need to hold the screw rigid and prevent the nut from turning, and then apply force to the nut and read linear free play with the dial indicator. Jon - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] home-mad CNC machine project.
Thanks Jon for the explanation. Andy Jon Elson wrote: Andrew Ayre wrote: Hi Rayh, Can you tell me or point me to a website that describes the process for measuring backlash? Thanks. Assuming the screws are mounted on a machine, you put a dial indicator (preferably one that reads out in .0001 units -- they call that a tenths reading indicator) across the slide and step the control back and forth, seeing how many units you need to move the CNC control before the axis actually moves. If you want to know the backlash on a ballscrew and nut set sitting alone on a table, you'd have to build some sort of test rig to evaluate it. You'd need to hold the screw rigid and prevent the nut from turning, and then apply force to the nut and read linear free play with the dial indicator. Jon -- Andy PGP Key ID: 0x67090A54 - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] home-mad CNC machine project.
I am curious about bigger machines, anybody tried making something with a 40
taper spindle. I am halfway done with my own design, using servos, linear
scales, linear bearings and ballscrews. I am trying to keep the BOM under 20k
and of course I am using EMC. Its work envelope is 800mmx500mmx500mm vertial
machine and I am trying to build it with simple tools and machines that are
smaller and less sophisticated than itself.
I would love to connect with anybody that has relevant experience
Jorge
- Original Message
From: Doug Metzler [EMAIL PROTECTED]
To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net; [EMAIL
PROTECTED]
Sent: Friday, March 14, 2008 1:35:27 AM
Subject: Re: [Emc-users] home-mad CNC machine project.
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I’m on my third rev of my home-built
CNC project. My best advice is to make it much more rigid than you think you
need to. I started out with small slider shafts and now I’m up to 7/8”
(which you can get surprisingly cheap at speedymetals). But in my case every
rev got considerably bigger. The first rev was a little 8*11 PCB cutter and it
had ¼” sliders, the second rev grew to 11*17 with 3/8’s and the
latest rev will be a whopping 20*34”, thus the need for the huge
sliders. But definitely err on the side of over-engineering for rigidity.
The other part that I couldn’t
afford that I wish I could have was good linear bearings. I tried many times
to come up with my own linear bearing surface but in the end most of the
available
torque was spent trying to overcome the sliders. I still can’t afford
good linear bearings but my latest home-brew setup uses small standard bearings
(some of which are spring-loaded). These are a bear to manufacture but will
dramatically
increase the quality of the machine.
I am using threaded rod but it makes for a
very slow machine. If anyone here has a line on good inexpensive ballscrews
please let me know.
As for electronics I am doing it all
myself because I want smart nodes. But I think the consensus here is probably
right – spend the money to save the time.
Drop me a note if you have specific questions.
DougM
From: [EMAIL PROTECTED]:[EMAIL PROTECTED] On Behalf Of seth wiley
Sent: Sunday, March 02, 2008 1:10PM
To: [EMAIL PROTECTED]; Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] home-madCNC machine project.
sean,
i'm slowly (in my very spare sparetime) working up a small(12x12x3) low
tolerance cnc machine for light wood andplastics. it is also serving as a
general teach-myself-cnc project. i chose togo with a pre-config'd electronics
/ servos package from keling inc.
(http://www.kelinginc.net/ThreeXCNCPackage2.html).after reading lots of cnczone
entries and doing lots of chipset / board /wiring research, i figured it's 329$
well spent by saving me time, and it's apretty complete set of items for a good
price. also, this site has some helpfulinfo on wiring
(http://www.robertguyser.com/).i am next building up the machine using basic
8020 or minitec extrusions andlinear accessories. lovejoy couplings will round
out the basic bom. i'll usewhatever i have as a cutter head - dremel, trim
router, etc. it should turn outto be a fairly cheap machine without eating up
too much time reinventing thewheel. cam environment: emc2 packaged with ubuntu.
it was a smooth install
andthe forums are great. so, i cannot say that this route is flawless and
workedout yet since i'm still in the process, but i can say that i've spent a
bunchof time running cnc machines, spent lots of time reading everything i
couldfind on the internet and printed about various diy cnc options. i think
thisroute seems like a pretty efficient and solid starting point. i'll let you
knowhow it comes out - if i ever get the time to complete it!
have fun regardless of which direction you choose. good luck.
-seth
On Fri, Feb 29, 2008 at 10:59 PM, [EMAIL PROTECTED] wrote:
I was wondering if anyonehas ever tried a do-it-yourself CNC project like
this.
http://www.instructables.com/id/Easy-to-build-CNC-Mill-Stepper-Motor-and-Driver-ci/and
this
http://www.instructables.com/id/Easy-to-Build-Desk-Top-3-Axis-CNC-Milling-Machine/.
If so, any pointers or words of knowledge before I dive in?
Also, I'm still looking for some stepper motors to use if anyone has a
goodsource.. I'm a college student, so I'm obviously broke andstarving. So,
inexpensive would be good. Thanks guys.
Sean
Re: [Emc-users] home-mad CNC machine project.
Im on my third rev of my home-built CNC project. My best advice is to make it much more rigid than you think you need to. I started out with small slider shafts and now Im up to 7/8 (which you can get surprisingly cheap at speedymetals). But in my case every rev got considerably bigger. The first rev was a little 8*11 PCB cutter and it had ¼ sliders, the second rev grew to 11*17 with 3/8s and the latest rev will be a whopping 20*34, thus the need for the huge sliders. But definitely err on the side of over-engineering for rigidity. The other part that I couldnt afford that I wish I could have was good linear bearings. I tried many times to come up with my own linear bearing surface but in the end most of the available torque was spent trying to overcome the sliders. I still cant afford good linear bearings but my latest home-brew setup uses small standard bearings (some of which are spring-loaded). These are a bear to manufacture but will dramatically increase the quality of the machine. I am using threaded rod but it makes for a very slow machine. If anyone here has a line on good inexpensive ballscrews please let me know. As for electronics I am doing it all myself because I want smart nodes. But I think the consensus here is probably right spend the money to save the time. Drop me a note if you have specific questions. DougM _ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of seth wiley Sent: Sunday, March 02, 2008 1:10 PM To: [EMAIL PROTECTED]; Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] home-mad CNC machine project. sean, i'm slowly (in my very spare sparetime) working up a small (12x12x3) low tolerance cnc machine for light wood and plastics. it is also serving as a general teach-myself-cnc project. i chose to go with a pre-config'd electronics / servos package from keling inc. (http://www.kelinginc.net/ThreeXCNCPackage2.html). after reading lots of cnczone entries and doing lots of chipset / board / wiring research, i figured it's 329$ well spent by saving me time, and it's a pretty complete set of items for a good price. also, this site has some helpful info on wiring (http://www.robertguyser.com/). i am next building up the machine using basic 8020 or minitec extrusions and linear accessories. lovejoy couplings will round out the basic bom. i'll use whatever i have as a cutter head - dremel, trim router, etc. it should turn out to be a fairly cheap machine without eating up too much time reinventing the wheel. cam environment: emc2 packaged with ubuntu. it was a smooth install and the forums are great. so, i cannot say that this route is flawless and worked out yet since i'm still in the process, but i can say that i've spent a bunch of time running cnc machines, spent lots of time reading everything i could find on the internet and printed about various diy cnc options. i think this route seems like a pretty efficient and solid starting point. i'll let you know how it comes out - if i ever get the time to complete it! have fun regardless of which direction you choose. good luck. -seth On Fri, Feb 29, 2008 at 10:59 PM, [EMAIL PROTECTED] wrote: I was wondering if anyone has ever tried a do-it-yourself CNC project like this. http://www.instructables.com/id/Easy-to-build-CNC-Mill-Stepper-Motor-and-Dri ver-ci/ and this http://www.instructables.com/id/Easy-to-Build-Desk-Top-3-Axis-CNC-Milling-Ma chine/ . If so, any pointers or words of knowledge before I dive in? Also, I'm still looking for some stepper motors to use if anyone has a good source.. I'm a college student, so I'm obviously broke and starving. So, inexpensive would be good. Thanks guys. Sean - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- s e t h w i l e y 827 south saint bernard street philadelphia, pa, 19143 - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] home-mad CNC machine project.
sean, i'm slowly (in my very spare sparetime) working up a small (12x12x3) low tolerance cnc machine for light wood and plastics. it is also serving as a general teach-myself-cnc project. i chose to go with a pre-config'd electronics / servos package from keling inc. ( http://www.kelinginc.net/ThreeXCNCPackage2.html). after reading lots of cnczone entries and doing lots of chipset / board / wiring research, i figured it's 329$ well spent by saving me time, and it's a pretty complete set of items for a good price. also, this site has some helpful info on wiring (http://www.robertguyser.com/). i am next building up the machine using basic 8020 or minitec extrusions and linear accessories. lovejoy couplings will round out the basic bom. i'll use whatever i have as a cutter head - dremel, trim router, etc. it should turn out to be a fairly cheap machine without eating up too much time reinventing the wheel. cam environment: emc2 packaged with ubuntu. it was a smooth install and the forums are great. so, i cannot say that this route is flawless and worked out yet since i'm still in the process, but i can say that i've spent a bunch of time running cnc machines, spent lots of time reading everything i could find on the internet and printed about various diy cnc options. i think this route seems like a pretty efficient and solid starting point. i'll let you know how it comes out - if i ever get the time to complete it! have fun regardless of which direction you choose. good luck. -seth On Fri, Feb 29, 2008 at 10:59 PM, [EMAIL PROTECTED] wrote: I was wondering if anyone has ever tried a do-it-yourself CNC project like this. http://www.instructables.com/id/Easy-to-build-CNC-Mill-Stepper-Motor-and-Driver-ci/and this http://www.instructables.com/id/Easy-to-Build-Desk-Top-3-Axis-CNC-Milling-Machine/. If so, any pointers or words of knowledge before I dive in? Also, I'm still looking for some stepper motors to use if anyone has a good source.. I'm a college student, so I'm obviously broke and starving. So, inexpensive would be good. Thanks guys. Sean - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- s e t h w i l e y 827 south saint bernard street philadelphia, pa, 19143 - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] home-mad CNC machine project.
Sean, An easy way to go for a first project is to us drawer slides for the guide ways.. Look at http://tinyurl.com/3b6gkf and you may get some ideas. You can usually pick up suitable drawer slides fairly cheaply and all you need to do then is to mount them parallel to each other - you can use hot melt glue for initial positioning before screwing them down.. You do need to be aware that a machine like this will only be capable of cutting foam or wax as it won't have the rigidity for anything harder. If you want to make a more serious machine, you could consider one of the X-Y table vices from Machine Mart or whatever it is called in your part of the world, or you could do as I did and look out for the cross slide/topslide assembly off an old lathe in a scrap yard. This gives the basis for a very rigid and useful machine. If you can build your own driver boards I would suggest using a basic L297/L298 chip design which will give you a rugged and reliable half step drive. I have found Futurelec hard to beat on price for components although they can be a bit sluggish at dispatching them. -- Best wishes, Ian Ian W. Wright Sheffield UK The difference between theory and practice is much smaller in theory than in practice... - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] home-mad CNC machine project.
I started down the path of building the Instructible you mentioned. I even have the metal framework built. However unless you scavenge everything, the costs will add up. For example, look up the cost of each of the stepper driver chips mentioned in the instructible. Times that by three (one for each motor). I bought a HobbyCNC controller board and motors for $170. A 10A power supply that I built myself cost another $80. I guess I could have gone cheaper, but if you scavenge motors from things then you don't know the torque and you have to work out the wiring yourself (there doesn't appear to be a standard). I happen to think the HobbyCNC package was a good deal. Even getting threaded rod from a place like Ace Hardware is a pain. I bought a nut and it doesn't go down the rod smoothly. The solution I suppose is to re-tap the rod, which means buying a tapping kit. My suggestion is to look at www.fireballcnc.com. The machines are hand made in the USA, are made with quality parts and are cheap for the price. Still need to add motors and electronics. These machines have been used to create PCBs. Currently the maker is offering a nice discount for the beta-testers of his new machine. There are also plans you can get from people, for example look on cnczone.com. Check for recommendations/good reviews. Andy Rob Jansen wrote: Sean, The stepper driver looks OK at a first glance but I did not have a detailed look at the schematics. It looks to be a full-step driver which is nice since full step drivers tend to have a higher torque than microstep ones. But I would stay away from the easy to build desktop thingy from instructables.com, it's just too weird a design and these funny piping and aluminium profile parts do cost money, there are other design on instructables that I think make more sense: http://www.instructables.com/id/How-to-Make-a-Three-Axis-CNC-Machine-Cheaply-and-/ http://www.instructables.com/id/Build-a-CNC-Router-from-Scratch-Part-1%3a-Complete/ make more sense, I prefer the top one since it contains a more detailed description on how to build it (instead of videos showing how to handle a saw) and some links to stores selling parts. Rockcliff Machine sells the plans and parts for a home-made CNC router but if you have a look at the photos in the gallery you'll get a fairly good idea of its construction. Using aluminium L strips to do the linear guidance looks nice and cheaper than the round steel axes. Before building/buying anything I would advice to make some detailed drawings of what the linear support should look like and then make a price calculation. When I started drawing and building my machine I made a rough guestimate of around $4,000 but on the go I updated the plans and got to a total of $10,000 and now I want to buld a second (small) one much like the Rockcliff design but from aluminium instead of MDF board. Since the first machine left a nice hole in my savings account this second machine needs to be low-cost, but I still want to be able to use it to do some real work in plastics/foam/wood and maybe later even aluminium. You'll find rockcliff at http://www.rockcliffmachine.com/cnchome.htm Some words of advice for going cheap: Use MDF board, it is easy to work with, and select standard threaded rods from the DIY store that will fit in roller-skating bearings so you can fix the bearing using standard nuts instead of having to make special mounts. Use thick-walled (not to thick, not to rigid) plastic hose with hose clamps as motor couplings this is by far the easiest and cheapest coupling I could think of. If investing any real money, invest it in a milling spindle that does not make too much noise. When I started I used a Dremel tool but it makes just too much noise to let it run for more than 10 minutes - I defenitely did not want to be in the same room as a constantly running Dremel... This may build you a working CNC milling machine but it will only do some light milling and I would be surprised if it gives you an accuracy as good as 0.02 inch Just my two cents worth - and don't spend it all at once ;-) Rob I was wondering if anyone has ever tried a do-it-yourself CNC project like this. http://www.instructables.com/id/Easy-to-build-CNC-Mill-Stepper-Motor-and-Driver-ci/ and this http://www.instructables.com/id/Easy-to-Build-Desk-Top-3-Axis-CNC-Milling-Machine/ . If so, any pointers or words of knowledge before I dive in? Also, I'm still looking for some stepper motors to use if anyone has a good source.. I'm a college student, so I'm obviously broke and starving. So, inexpensive would be good. Thanks guys. Sean - This SF.net email is sponsored by: Microsoft Defy all challenges.
Re: [Emc-users] home-mad CNC machine project.
Sean, If your on a budget then go with one of the Allegro chipset based controllers (Hobbycnc etc..) Try to get motors that are rated at 2.5-3 amps (about the max that an Allegro chip can drive) and are rated around 3-5 volts. Also, make sure you run the highest voltage the controller can handle (usually around 36-42volts with an Allegro base controller). These means hunting down a good 30VAC 10 amp transformer. Don't waste your time or money with anything that is not a constant current, pwm type controller. There are schematics for Allegro based controllers to be found on the web if you want to roll your own. If you don't mind spending a bit more then go with the Geckos. You won't regret it. From: [EMAIL PROTECTED] To: emc-users@lists.sourceforge.net Sent: Friday, February 29, 2008 10:59 PM Subject: [Emc-users] home-mad CNC machine project. I was wondering if anyone has ever tried a do-it-yourself CNC project like this. http://www.instructables.com/id/Easy-to-build-CNC-Mill-Stepper-Motor-and-Driver-ci/ and this http://www.instructables.com/id/Easy-to-Build-Desk-Top-3-Axis-CNC-Milling-Machine/ . If so, any pointers or words of knowledge before I dive in? Also, I'm still looking for some stepper motors to use if anyone has a good source.. I'm a college student, so I'm obviously broke and starving. So, inexpensive would be good. Thanks guys. Sean - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] home-mad CNC machine project.
If you're going for the cheap, and dont need to really cut anything more than wax or foam, i would think some of these motors could do nicely for less than $10 each. http://www.allelectronics.com/cgi-bin/category/400600/Stepper_Motors.html I think we could provide some better direction if we know exactly what you're going for. you tryin to get your toes wet with cnc stuff, or are you wanting to produce parts? what tools / supplies / resources do you have available? if you happen to have access to say a school or employer's machines, that could be very handy in building your machine. im assuming you have at least bsic electronics skills if you're wanting to build those stepper drives. I've seen that instructables, and thought about trying something like that but decided I'd come up with my own design using mostly MDF. On Sat, Mar 1, 2008 at 8:28 PM, Dean Hedin [EMAIL PROTECTED] wrote: Sean, If your on a budget then go with one of the Allegro chipset based controllers (Hobbycnc etc..) Try to get motors that are rated at 2.5-3 amps (about the max that an Allegro chip can drive) and are rated around 3-5 volts. Also, make sure you run the highest voltage the controller can handle (usually around 36-42volts with an Allegro base controller). These means hunting down a good 30VAC 10 amp transformer. Don't waste your time or money with anything that is not a constant current, pwm type controller. There are schematics for Allegro based controllers to be found on the web if you want to roll your own. If you don't mind spending a bit more then go with the Geckos. You won't regret it. *From:* [EMAIL PROTECTED] *To:* emc-users@lists.sourceforge.net *Sent:* Friday, February 29, 2008 10:59 PM *Subject:* [Emc-users] home-mad CNC machine project. I was wondering if anyone has ever tried a do-it-yourself CNC project like this. http://www.instructables.com/id/Easy-to-build-CNC-Mill-Stepper-Motor-and-Driver-ci/and this http://www.instructables.com/id/Easy-to-Build-Desk-Top-3-Axis-CNC-Milling-Machine/. If so, any pointers or words of knowledge before I dive in? Also, I'm still looking for some stepper motors to use if anyone has a good source.. I'm a college student, so I'm obviously broke and starving. So, inexpensive would be good. Thanks guys. Sean - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] home-mad CNC machine project.
I was wondering if anyone has ever tried a do-it-yourself CNC project like this. [LINK: http://www.instructables.com/id/Easy-to-build-CNC-Mill-Stepper-Motor-and-Driver-ci/] http://www.instructables.com/id/Easy-to-build-CNC-Mill-Stepper-Motor-and-Driver-ci/ and this [LINK: http://www.instructables.com/id/Easy-to-Build-Desk-Top-3-Axis-CNC-Milling-Machine/] http://www.instructables.com/id/Easy-to-Build-Desk-Top-3-Axis-CNC-Milling-Machine/ . If so, any pointers or words of knowledge before I dive in? Also, I'm still looking for some stepper motors to use if anyone has a good source.. I'm a college student, so I'm obviously broke and starving. So, inexpensive would be good. Thanks guys. Sean - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] home-mad CNC machine project.
Sean, The stepper driver looks OK at a first glance but I did not have a detailed look at the schematics. It looks to be a full-step driver which is nice since full step drivers tend to have a higher torque than microstep ones. But I would stay away from the easy to build desktop thingy from instructables.com, it's just too weird a design and these funny piping and aluminium profile parts do cost money, there are other design on instructables that I think make more sense: http://www.instructables.com/id/How-to-Make-a-Three-Axis-CNC-Machine-Cheaply-and-/ http://www.instructables.com/id/Build-a-CNC-Router-from-Scratch-Part-1%3a-Complete/ make more sense, I prefer the top one since it contains a more detailed description on how to build it (instead of videos showing how to handle a saw) and some links to stores selling parts. Rockcliff Machine sells the plans and parts for a home-made CNC router but if you have a look at the photos in the gallery you'll get a fairly good idea of its construction. Using aluminium L strips to do the linear guidance looks nice and cheaper than the round steel axes. Before building/buying anything I would advice to make some detailed drawings of what the linear support should look like and then make a price calculation. When I started drawing and building my machine I made a rough guestimate of around $4,000 but on the go I updated the plans and got to a total of $10,000 and now I want to buld a second (small) one much like the Rockcliff design but from aluminium instead of MDF board. Since the first machine left a nice hole in my savings account this second machine needs to be low-cost, but I still want to be able to use it to do some real work in plastics/foam/wood and maybe later even aluminium. You'll find rockcliff at http://www.rockcliffmachine.com/cnchome.htm Some words of advice for going cheap: Use MDF board, it is easy to work with, and select standard threaded rods from the DIY store that will fit in roller-skating bearings so you can fix the bearing using standard nuts instead of having to make special mounts. Use thick-walled (not to thick, not to rigid) plastic hose with hose clamps as motor couplings this is by far the easiest and cheapest coupling I could think of. If investing any real money, invest it in a milling spindle that does not make too much noise. When I started I used a Dremel tool but it makes just too much noise to let it run for more than 10 minutes - I defenitely did not want to be in the same room as a constantly running Dremel... This may build you a working CNC milling machine but it will only do some light milling and I would be surprised if it gives you an accuracy as good as 0.02 inch Just my two cents worth - and don't spend it all at once ;-) Rob I was wondering if anyone has ever tried a do-it-yourself CNC project like this. http://www.instructables.com/id/Easy-to-build-CNC-Mill-Stepper-Motor-and-Driver-ci/ and this http://www.instructables.com/id/Easy-to-Build-Desk-Top-3-Axis-CNC-Milling-Machine/ . If so, any pointers or words of knowledge before I dive in? Also, I'm still looking for some stepper motors to use if anyone has a good source.. I'm a college student, so I'm obviously broke and starving. So, inexpensive would be good. Thanks guys. Sean - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
