584,871 active members*
5,221 visitors online*
Register for free
Login
Results 1 to 16 of 16
  1. #1
    Join Date
    Jun 2006
    Posts
    259

    New CNC machine build (big pics)

    All,

    I've been reading these forums for some time and I was going to buy a CNC ready Taig even though it did not really have as much travel as I would have liked. After seeing one 'in the flesh', I was even more disappointed by the size.

    However, while scrounging for parts at a local industrial surplus place, I came across the perfect X-Y axis for a CNC build (sorry for the crappy pics, I only had my phone with me).



    It's a Micro-Pax automated packing machine. Unlike a lot of packers, however, it has a cast iron base and arm, so it's very, very stiff.



    It's got THK rails and ball screws, all tied to servos. The X axis in 32" with around 28" of travel, while the Y is around 26", with 20" of travel. There is around 10" under the arm, but I could put the whole machine on blocks to raise the Z a bit. The whole assembly probabaly weighs in the region of 200-250 lbs, it took 3 of us to move it easily (two can lift, 'tho).



    As you can see from the above image, the connection to the arm is a very, very stout cast iron piece, ribbed on the backside. All the mounting surfaces on the cast iron bits are machined flat, and the arm is also cast.



    The machine has 2 servos moving the X & Y axis. They appear to be Minertia RM Series servos, but I don't know the exact power. Everything moves very smoothly, by gravity if tilted. The whole machine has sheet metal covering all the ways, which is nice. Most of it was removed for the pictures.

    For the Z-axis, I found an Intelligent Acutator linear actuator. It has two THX linear bearings and a ball screw coupled to a Japan Servo 30v 60w servo.



    I'm not sure this motor will be enough to move the head + motor I plan to eventually use (a Sherline Industrial piece + a Surplus Center DC motor), so I might have to change it for a larger servo.

    I'm planning on using Uli's servo controller, with fully assembled boards from Manjeet .

    The real open question at the momment is what kind of base do I mount all this on? I've been looking at granite surface plates, but they are very, very heavy in the size I need. I could get one for around $200, but the typically have equipment holes in the them (usually right in the middle), which I guess is where coolant would eventually drain. It might not be much of an issue as I plan on having some sort of T-slot holding plate as well. I also priced out MIC6/cast tool plate. It was $350-$450 for 1/2 or 3/4 in the size I need and I'm not sure that's even actually thick enough. At that price, it would almost double my current dollar outlay.

    I could really use some guidance here, particularly since I only have access to rudimentary tools (well, and a CNC plasma ) and I don't have ready access to a pickup.

    Thoughts, comments, etc. are appreciated. I hope to machine aluminum with this, as well as some plastics. Nothing ultra-precise, mostly car bits, but perhaps I am naive as I've never done anything like this before.

    I still need to figure out how to power these servos. I've seen some schematics for power supplies, but I'm guessing that an unregulated DC power supply of the appropriate voltage/amperage would work.

    Thx.

    Chris.

    [PS: I hope I posted this in the right place, please move it if not. Thx.]

  2. #2
    Join Date
    Feb 2006
    Posts
    60
    Looks very cool

    FYI, those ballscrews on the arm are probably going to be too fast a CNC mill application (they look to be about 1tpi), so plan on upgrading or scrounging for some more desirable 5tpi screws.

    Where are you located? I'd love to find a surplus place like that around me. What kind of prices are they getting for stuff like that if you don't mind me asking?

  3. #3
    Join Date
    Jun 2006
    Posts
    259
    Thanks for the comments.

    Yeah, I was wondering about the ball screws. I can get others, but they would have to be machined down to size and this thing is already assembled. Since I'm using servos, I hope to have better speed control and compensate that way. As I said, I've never done this before, so it's all really and experiment. I want to get everything running before trying to improve it.

    I'm in the San Francisco Bay Area. We have tons of industrial surplus places (here a good list: http://www.bluefeathertech.com/techn...swapindex.html). So far I've spent around $700 or so. I'm guessing that I'll have the machine running with a Rotozip head for less than $1000, a couple hundred $$$ more for the Sherline.

    The major question really is what am I going to mount this on? It bascally has two bases on either end of the long axis (you can see one base on the second photo) and the arm is cantilevered off that. I don't really know what is the best solution here, but I'm thinking stiff and heavy.

    Chris.

  4. #4
    Join Date
    Mar 2005
    Posts
    103
    is there a convenient way to mount timing pulleys and belts to compensate for the high lead ballscrews? It would be pretty nice to use those slides as complete units. in what configuration are you going to mount those slides? is the casting one piece or can you separate those two slides?

  5. #5
    Join Date
    Jun 2006
    Posts
    259
    Thanks for the comments.

    I guess I don't understand the question. There are two castings, a long axis with mounting pads and a shorter one. They both have dual THK linear bearings and ball screws, with servo's mounted on the end via some sort of coupling. The shorter axis has an aluminum carriage (which will be used to hold the Z-axis) that moves along the two rails seen in the second picture. Here's a picture of the base of the cast iron carriage on the long axis.



    The blue thing in the pictures above is a linear motion device I'm hoping to use as a Z-axis. So I guess the answer is that the configuration I plan to use is a wierd device that is not a mill or a router, where the head is moves on the X-Y axis of the large red device with blue Z axis hanging in mid-air. If you look at the first picture, you'll see a block of aluminum with some cap screws on it at the base of the short axis (you can also see the same block on two pictures in this post, one bellow shows the lead screw attached to it). That is a mounting point for the Z-axis, and that carriage travels left to right in the picture. Orientation wise, the whole thing will be bolted to some sort of mounting plate using the two 'feet' at the bottom of the long axis, oriented as shown in the first picture. This is also the way it would have been mounted in it's original application. I'm still trying to figure what to mount it on. The working area of the machine would be that orange/wood shelf it's currently laying on.

    Here's a picture of the long axis servo mounting point, followed by a picture of that servo.





    To be honest, I have looked at replacing anything yet since I would like to get the whole X-Y-Z assembly working, then I'll worry about getting it to perform just right. The place I acquired this from has hundreds of ball screw assemblies in stock, so this should not be a problem.

    What I am hoping is that the ball screws can be used as is by just controlling the speed in software. Don't know wether that's possible or what the resolution of the servo's actually is. HOWEVER, the servos are pretty small.

    Also, I'm guessing that the TPI problem is closely related to the head's milling capabilities? Or does it have an impact on resolution as well? Guess I'm going to have to do some reading about that as I hadn't realized that this would be an issue....

    Chris

  6. #6
    Join Date
    Jan 2006
    Posts
    481
    hi

    Nice work ckm , anymore updates and pics

    keep up the good work

    cheers

  7. #7
    Join Date
    Feb 2006
    Posts
    1187
    Nice find, hey can ya show us a pic standing back looking at the whole thing? I,m tryin to figure out what that was at one time.

  8. #8
    Join Date
    Jun 2006
    Posts
    259

    Machine updates

    More pics tomorrow, probably. It took me a long time to figure what to do about all the electronics, operator console and how to build an enclosure. I think I finally have it all ready. For those who had some concerns about the TPI on the ball screws, I decided to leave those alone until everything was running. If I can't adjust feed speeds low enough in software/driver hardware, then I will change them.

    @ZipSnipe: I'll take my camera to the shop and get some better pictures tomorrow, but the sheetmetal says that it was a 'pick and place' robot. Must have been some pretty heavy stuff as the whole thing is cast iron....

    Some more details for those who are interested:

    Operator Console and Electronics

    For electronics, I'm using the UHU Servo board and the CandCNC Super I/O with the MPG-02 pendant. Believe it or not, this combo is much cheaper than if I had assembled everything myself. $300-$400 cheaper, actually, when you start adding up all the bits and pieces like dual breakout boards, all the buttons, cabling, connectors, MPG hardware, etc., and a lot easier to deal with as well. I've also bought a touchscreen from Computer Geeks, which, at $165, is very, very cheap. Eventually, all this hardware will wind up in an operator console similar to this. I like the way the pendant parks in the console. BTW, that is from Bob Warfield's great collection of control panels.

    Control Software

    Software wise, this will all be controlled with Mach3, with CAM provided by MeshCAM. I had a spare 1Ghz Dell box and I bought an extra parallel card for it. As much as I hate using Windows for this, it should be fine as that's the only thing running on that machine and it's not connected to the internet. Also, I noticed that Tarus uses Windows on their huge mills (check out the video [warning - it's huge], one of the coolest things I have seen), so I think I'm in good company.

    Machine Stand and Enclosure

    For mounting the machine, I bought a heavy duty workbench from Lowes, some MIC6 plate from Metal Connections (very cheap at $3.90/lb, 1/2 the price it would cost locally) and some extrusions from 8020 (big ones 6x3x45 or so - every DIY CNC machine has to have some 8020).

    PVC Sheet

    The enclosure and coolant catchment will be made from PVC sheet. Not only is it cheap, but it's very easy to work with and light. This guy built a darkroom sink out of the stuff. There are two version of it, one is 'foamed', basically an expanded PVC foam with integral skins on both sides. The other is solid sheet. The foam kind is very good for sides, but has no compression resistance, but the solid stuff is designed for high compression applications (eg. it will not dent under weight). The other good thing about it is that it's heat deformable. By heating it up with a heat gun, you can easily create bends or bowels.

    Spindle

    I also bought a Hitachi M12VC router. I can't say enough good things about this machine. It will easily route aluminum with a 1/2" endmill (that is, if I could actually hold it by hand...). The only real problem is a lack of collet sizes. I solved this by buying a 3/4 shank extender than I will have machined to fit the router. Supposedly, hand-held tools like this one can be run on DC as they are 'universal' electric motors. I bought a Minarik DC motor driver/control (model PCMXP05) and we'll see if that actually work as a controller. I tried hacking apart the speed control in the Hitachi, and, although I figured out how it works, I also destroyed it in the process...

    On a side note, I also found a quick-change adaptor that I might be able to use from High Tech Systems and Derek (owner of HT) has said he could make it with a 1/2" shank. This may become the basis for a tool changer.... I also got a hold of a cheap 4th axis rotary table with a servo attached, but I'm holding off on using this for a bit.

    Outsanding Issues

    My current stumbling block is mounts for the Z-axis. I don't have ready access to machine tools, so this is an issue. I made some preliminary drawings (attached) for thems (NOTE: they are NOT accurate or complete), but I need to have them made.

    Finally, I have been debating how to built the material mounting. Traditionally, this on the X-Y table, but I have no X-Y table. I would like to use a vacuum table (similar to the NEMI table), but I'm not sure that it would be strong enough, esp for smaller parts. I think I might eventually go with High Tech Systems clamping kit which is actually smaller than my cutting area, but would work until I figure something else out.

    Thanks for asking. I'm pretty lazy about posting all this stuff as it's hard to tell if anyone is actually interested.

    Chris.
    Attached Thumbnails Attached Thumbnails z-axis motor mount.jpg   z-y assembly.jpg  

  9. #9
    Join Date
    Feb 2006
    Posts
    1187
    I always love to see what people come up with so don,t be lazy about posting stuff. It looks like you got some workable stuff there to use. Just lay it all out nice and neat and conjure up what you can do with all.

  10. #10
    Join Date
    Jun 2006
    Posts
    259

    Update wiith pics

    Well, I spent a good amount of time today cutting aluminum and generally finishing the mechanicals and mountings. I had bought a bunch of 8020 on ebay and all of it came in handy. The machine is just clamped together right how, but it's pretty much the way it's going to look. I have to figure out how to deal with coolant management.

    Here an overview pic of the machine on it's stand:


    The stand is a standard heavy duty Lowes workbench with some, er, adjustments. The machine is sitting on a 3/4" plate (about 5" x 44") of MIC6 that is supported by both the bench and dual 3" x 1.5" 8020 extrusions. These in turn are supported by 3" x 1" extrusions running across the bench to yet another 3" x 1.5" extrusion. I'm hoping this will be stiff enough. Kinda hard to tell right now as the whole structure is on a pallet jack so I can move it around easily.



    This image shows the Y-axis. You can kinda see the limit switch in the lower left. This machine came with limit switches on all axis and home switches on all axis. The large aluminum plate is the Z-axis mounting. Still have to figure out a way to tie that all together.



    This shows how the Z-axis will be mounted (or something like that). I've got it clamped for now.

    I got the motor controller today, looks like it's perfect. 115 VAC to 130 VDC with a 0-10v control signal and continuous torque adjustment. It a compact little thing. I also got a bunch of DIN rail and terminal blocks to easy the wiring pains that are coming....




    That's it for now. More updates after Labor Day, probably.

    Chris.

  11. #11
    Join Date
    Aug 2004
    Posts
    98
    that thing looks rock solid, I see that is a minarik speed control, I have one similar for the cnc lathe I am buidling. Keep up the great work, and all the guys love the pictures, keep em rolling! :banana:

  12. #12
    Join Date
    Jun 2006
    Posts
    259

    More crappy phone pictures...

    So I finally made a Z-axis mount. If you are following this thread, you will remember that I need to mount the Z-axis somehow, in this sort of positon:

    (click to enlarge)


    The mounting faces look like this:

    Z-axis backside

    (click to enlarge)


    Y-axis mount

    (click to enlarge)




    I was going to just bolt some 8020 between the two and be done with it, but after checking out the 8020 bit I had, I found a better solution:



    I basically shaved off some of the 8020, leaving some of the internal structure to act as a keyway for the backside of the Z-axis.

    If you look carefully at two 8020 pieces side-by-side, you'll see what I did:



    Anyway, all this was done on a table saw and finish on a band sander we have for metal work. I think the surfaces came out pretty good, although I don't know how flat they actually are.



    That's all for now. I went ahead and ordered the CandCNC.com Super I/O + pendant. It should be here next week or so and I'll post pictures when I get it.

    Chris.

  13. #13
    Join Date
    Apr 2009
    Posts
    3
    I have Japan Servo 60w 30v Intelligent Actuato TYPE: DSE55B60-001
    Encoder 5 wire: red, black, white, green, yellow
    Q: I dont't know how to cornect encoder to driver
    Please help me!

  14. #14
    Join Date
    Sep 2005
    Posts
    1195
    ckm,
    I did not see your picture?

  15. #15
    Join Date
    Apr 2009
    Posts
    3

  16. #16
    Join Date
    Apr 2009
    Posts
    5516
    Holy thread resurrection, Batman!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •