New Build Near Detroit, MI

New Home Forum Mostly Printed CNC – MPCNC Your Builds – MPCNC New Build Near Detroit, MI

This topic contains 33 replies, has 8 voices, and was last updated by  Garrett 1 week, 1 day ago.

Viewing 30 posts - 1 through 30 (of 34 total)
  • Author
    Posts
  • #100316

    Garrett
    Participant

    Howdy,

    Here is my MPCNC that I have been slowly making progress on. I was going for an Iron Man color scheme. If you couldn’t tell.

    The working dimensions are 19 x 19 x 3 inches. This allowed it to just fit on the cabinet I was able to snag from work.

    I’m currently finishing up the wiring and belts and hopefully should be able to run some initial tests soon.

    I plan on using this primarily for wood but I want to try my hand at aluminum and steel eventually.

    I am going to build an enclosure for this where I can lift the sides to be able to run longer pieces on it.

    I am quite surprised at how sturdy this is given its cost and materials. Props to a nifty design.

    How level should the rails be with the table top? All my rails are currently +/- 0.2 degrees. I figured that should be fine but wanted to double check if I should try to improve them.

    mpcnc

    Attachments:
    1 user thanked author for this post.
    #100375

    Ryan
    Keymaster

    Looks good, good size, don’t worry about the angle for now just get it dirty!!!

    and Welcome!

    1 user thanked author for this post.
    #100825

    John Pollman
    Participant

    Looks good!

    I’m making progress .on mine too. It’s gonna be 36×24. I’m in Rochester Hills.

    1 user thanked author for this post.
    #100936

    Garrett
    Participant

    Looks good!

    I’m making progress .on mine too. It’s gonna be 36×24. I’m in Rochester Hills.

    Thank you.

    Yours is looking good as well. Is that your working dimensions or outside dimensions?

    I used to live in Rochester Hills but moved down to Sterling Heights last year.

    #100984

    Garrett
    Participant

    I finally got some time to finish the wiring and start on some drawings to test it’s performance.

    20190519_151826

    Here is a picture of the crown drawing. I ran it a second time over the first one just to confirm its repeatability. I am happy with it.

    20190519_151844

    I then wanted to test the accuracy so I created a simple design that I could check how square it was and its dimensional accuracy. everything looked and measured close enough. I’ll probably run another calibration test like this after I attach the router and can measure parts better.

    20190519_155156

    Lastly, I have seen some people draw Mayan calendars to see how it performs with lots of details. I figured I’d run something similar and more fitting to my color scheme. And why not throw a Star Wars one in there just for the fun of it.

    20190519_190129
    20190519_170119

    Overall, I am very happy with how it is performing so far. Next time that I have some free time I will be attaching the router and finally getting it dirty.

    3 users thanked author for this post.
    #101055

    Ryan
    Keymaster

    and finally getting it dirty.

    Finally……

     

    Drawings look great to me.

    1 user thanked author for this post.
    #101181

    John Pollman
    Participant

    Hi Garrett,

    36×24 are my working dimensions. My table is 48×36.

    #101246

    Garrett
    Participant

    I had some time yesterday and was going to try some cutting but little one went down early and I didn’t want to wake the baby so I ended up adding a spoil board and cleaned up all my cables. I really like the tape measure trick, it was simple and cheap and looks pretty nice. I decided to add an upper bar to mount the y axis cables to so that it would leave the side open so that I can run long boards through without the cables being in the way. It also gave be a surface to mount the electronics onto until I enclose it.

    20190521_215730
    20190521_215738
    20190521_215745

    #101269

    Ryan
    Keymaster

    +1 for the tape measure trick! I really like the way you have your spoil board set up. I might have to give that a shot on mine. The easy swap spoil board.

    1 user thanked author for this post.
    #101271

    Garrett
    Participant

    +1 for the tape measure trick! I really like the way you have your spoil board set up. I might have to give that a shot on mine. The easy swap spoil board.

    Thanks. I needed a spoil board and because I was going to use a thin piece of MDF I wanted an easy way to swap them out. The spoil board is a standard 2ft x 2ft piece of MDF so I just need to buy another $4 board when I need to replace it. Nice and easy swap.

    I also plan on adding threaded inserts in the bottom plastic board and then have through holes in the MDF. That way when I replace the MDF, I can just rerun the through hole gcode from a close enough staring spot and I wont need to replace the inserts.

    #101319

    Dui, ni shuo de dui
    Participant

    Very nice build so far, kudos!

    1 user thanked author for this post.
    #101401

    George Coyne
    Participant

    What is the “tape measure trick”?

    #101402

    kd2018
    Participant

    What is the “tape measure trick”?

    https://hackaday.com/2017/12/17/diy-cable-chain-looks-great-stays-cheap/

    3 users thanked author for this post.
    #101403

    Garrett
    Participant

    What is the “tape measure trick”?

    It is where you use a tape measure in the cable sleeve instead of using a cable chain. you can see the yellow of the tape measure through the cable sleeve in my pictures above.

    It is discussed more here if you are interested.

    #101404

    Garrett
    Participant
    #101405

    George Coyne
    Participant

    Hmm. That is clever.

    #101854

    Garrett
    Participant

    This weekend I was able to finish my spoil board and add the threaded inserts and do some initial engravings.

    20190526_154927

    I cut some squares to check the accuracy and the 50mm square was coming in around 49.3mm. The others were smaller than designed as well. I’m guessing there is a way to correct this in estlcam but I could use some help finding where that is at.

    20190526_154931
    Other than the dimensions being off, everything else cut fine. Everything moved smoothly and looked clean. Now to play with estlcam some more so that I can try some more complex shaping.

    #101864

    Ryan
    Keymaster

    I cut some squares to check the accuracy and the 50mm square was coming in around 49.3mm. The others were smaller than designed as well. I’m guessing there is a way to correct this in estlcam but I could use some help finding where that is at.

    Cut some 100mm squares and see if that number doubles or not.

    #102708

    Garrett
    Participant

    I got around to cutting out a 100mm square and a 50mm square to check their accuracy. I got better results than the first 50mm cut because I found one of my belts was loose but I’d still like to improve if possible.

    20190605_214606
    The 100mm square measured 99.42 x 99.71 and the 50mm square measured 49.62 x 49.70.

    20190605_215300
    Any suggestions on what I could try to get theses a little more accurate? Especially in the Y direction.

    Just for reference, I was using estlcam and using the standard starting settings. I ran these with a finishing pass to hopefully keep the sides as smooth as possible for measuring.

    #102752

    Ryan
    Keymaster

    Try drawing with a pen, if the dimensions are correct we can narrow down the source of the error.

     

    Also try a few more of those cuts your errors are not making sense. One is staying the same and one is double, it should be one or the other never both.

    #102783

    Garrett
    Participant

    I thought it was odd that only one side changed as well. I wasn’t sure if anyone else had seen this before. I’ll run it a couple more times at different locations and see if there are any changes.

    #104224

    Garrett
    Participant

    I finally got around to cutting some more 100mm squares with 50mm squares inside them to work on the dimensional accuracy. I adjusted the belts some, two were a tad loose, and then I cut two out of pine and one out of oak. I also changed the cut speed and cut depth and neither the material or cutting setting affected the results.

    Are there any problems with over tightening the belts? Or is it only bad if they are not tight enough?

    The first one didn’t get to cutting out the 50mm inside square because I found out that you need to be careful where you position the clamps to hold down the piece because it can get in the way which messes everything up. I didn’t account for how far the Z rails stuck out and they ended up hitting one of the clamps.

    this is the results I got (all squares came out at pretty much the same dimensions no matter the location on the cutting surface, the material, or cutting speed and depth)

    100mm squares:

    • x – axis: 99.45mm
    • y – axis: 99.30mm

    50mm squares:

    • x – axis: 49.55mm
    • y – axis: 49.40mm

    Below is a picture of the original squares (left) compared to the two pine squares I cut (center and right).

    20190622_184259-2

    I would think the 50mm square would have half the error as the 100mm squares but that doesn’t appear to be the case. At least the errors are both changing now and in the same direction by the same amount.

    I also double checked my bit diameter and estlcam settings and they all match up with what you state in the directions.

    It moves and cuts great and as long as I don’t care if it’s super accurate then everything is wonderful and repeatable.

    Any recommendations on what can be done to improve the accuracy or what test I can run to further diagnose it? Can the program be adjusted or maybe something needs to be tightened down? I’d just like to improve it if possible. I’d just like to get in the +/- 0.2 mm if possible.

     

    #104246

    Ryan
    Keymaster

    Are there any problems with over tightening the belts?

    Yes, you will stall the steppers, or skip steps.

    Are you using a finishing pass?

    Try cutting an outside 100mm square as you are doing and a 50mm hole in side of it to check what the error does, to outside squares only tells you you have a systematic error (good info) but not what kind.

    1 user thanked author for this post.
    #104250

    Garrett
    Participant

    Yes, you will stall the steppers, or skip steps.

    Are you using a finishing pass?

    Try cutting an outside 100mm square as you are doing and a 50mm hole in side of it to check what the error does, to outside squares only tells you you have a systematic error (good info) but not what kind.

    Ok, my belts aren’t too tight then.

    No, I didn’t use a finishing pass this time. Would that affect the dimensions?

    I’ll try doing the 50mm square as a hole next time and see what it does.

    Thanks.

    #104251

    Ryan
    Keymaster

    You have to use a finishing pass if you care about dimensions at all.

    #104262

    Garrett
    Participant

    You have to use a finishing pass if you care about dimensions at all.

    That would be great if it was just loose belts and needing a finishing pass. I didn’t think a finishing pass would affect it but guess I was wrong.

    Should I reduce the speed and depth setting for the finishing pass?

    #104264

    Ryan
    Keymaster

    Have a look at my milling basics page.

    You are “roughing” out the part. This means your tool is under as high a load as you are comfortable with meaning the entire machine is moving and flexing. A Finishing or Spring pass take the last few percent off of the part with extremely minimal load, meaning nothing should be moving or flexing.

    #104452

    Garrett
    Participant

    I re-ran this again with a finishing pass and then with the 50mm square as a hole.

    Below is an image showing the cuts without a fishing pass (left) and then with a finishing pass (center) and then with the center as a hole (right)

    20190625_200536-2

    The accuracy increased when adding a finishing pass but the Y dimension on the 50mm square changed from 49.45 when cutting out the outside to 50.20 when cutting it as a hole.

    The X dimension is doing pretty good but it appears the Y needs more attention.

    Any suggestions on something to adjust or any additional cuts to try? I really just want to improve the Y cuts when cutting out the outside of the cubes.

    Do you think the error would continue to grow if I make even larger cuts?

    #104465

    Ryan
    Keymaster

    Larger is to be expected do to runout and such. What is the outer 100mm error vs the inner 50mm error? Did it double  or stay the same?

    I really so suggest just having some fun for a while and tune it up later, do you really need it within a 1/4 mm right now? Carve some stuff break it in, just doing calibrations is no fun, who knows maybe you are just using the CAM wrong…

    #104576

    Garrett
    Participant

    I really so suggest just having some fun for a while and tune it up later, do you really need it within a 1/4 mm right now? Carve some stuff break it in, just doing calibrations is no fun, who knows maybe you are just using the CAM wrong…

    Oh, that’s defiantly the plan. I’ve just been running these as I am trying to learn inkscape and estlcam to be able to make some fun parts.

Viewing 30 posts - 1 through 30 (of 34 total)

You must be logged in to reply to this topic.