Ben's 3' x 6' Rebuild with pics

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This topic contains 129 replies, has 14 voices, and was last updated by  Smith Hayward 2 months, 4 weeks ago.

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  • #73595

    Benjammann
    Participant

    Two years ago I did a 2’x2′ build that only cut one test part. Since then I’ve been messing around with a Taig Minimill cutting all kinds of metal, wood, and plastic parts, but have been frustrated by the small table size. So I’ve finally realized that all along I could have had a huge table (compared to the Taigs 5″ x 14″ table) if I completed the mission of resizing the MPCNC.

    Due to being tight on time and budget, I’m going for a dead simple table. I built it this past Saturday, and somehow ended up making the legs a bit too long so I had to chop them just below the lower supports, but actually, I think I like the height since I’m 6’4″; and the low supports now create a huge area under the table to be used for storage. So it worked out. On Sunday I disassembled the old build and discarded the printed parts because many of them had cracked, probably from being a bit too tight, and being in a cold garage for two years. I’m hoping this doesn’t happen again so I’m going to go a little easier on the tightening.

    I’m printing the latest burly parts and going with 25.4mm stainless tube. Reusing the hardware and Ramps 4.1 board.

    I need to order the remaining upgrade parts today. Does anyone see anything missing from this list?

    1. Longer belts
    2. New zip ties
    3. Some more limit switches for the auto squaring deal
    4. Upgrade to auto squaring firmware on ramps board?
    5. T8 Lead Screw
    6. Longer wiring. I see there is now a series and individual kit. Would the individual kit work with my 3′ x 6′ tube length? The kit says 60″ but my 6′ tube is 72″
    7. New rails (acquired)
    8. Wire sleeve

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    #73617

    Barry
    Participant

    Hey Ben, just throwing this out there, add some diagonal braces to the legs.  My mpcnc can wobble my table and it’s built on top of kitchen cabinets!  I also had to add some to my beefy lowrider table.

    #73624

    Benjammann
    Participant

    add some diagonal braces to the legs.

    Hey Barry! It did cross my mind. Was going to wait and see. Do you think I need it on both X & Y ?

    #73635

    Ryan
    Keymaster

    At 6′ you will probably need to extend them. Can’t wait to see what you think of the new stuff.

    #73645

    Benjammann
    Participant

    At 6′ you will probably need to extend them. Can’t wait to see what you think of the new stuff.

    Thanks Ryan!  Really looking forward to it, especially now that I have some CNC experience under my belt from the Taig. What would you recommend for the wiring on this 3′ x 6′ with the auto squaring? I do have the old wiring, but I’m wondering if I should start fresh with one of the other options you offer. And also, what would you extend that selection with?

    Thanks so much.

    #73651

    Ryan
    Keymaster

    I would say, use it as you had it for now. Then add the auto square later since it is pretty easy. At that size you might easily be able to square it by hand. The smaller it is the more auto square helps.

    #73656

    Benjammann
    Participant

    use it as you had it for now.

    As much as I want the auto squaring, I see the validity of this. Won’t have to reflash the board, will only need a couple wire extensions.

    On the other hand, there is the argument that I should do it now while I have everything torn apart and am upgrading everything. I was looking into the measuring tape guide and the whole thing looks like something I’m not going to look forward to ripping apart.

    If I can get away without using it by squaring everything up really well that makes the most sense I guess. I was just excited at the prospect of super accurate cut geometry.

    #73658

    Ryan
    Keymaster

    Either way really. You can wire it individually and plug in the series harness near the board (that is how I test firmware) then switch at any time.

    #73662

    Barry
    Participant

    add some diagonal braces to the legs.

    Hey Barry! It did cross my mind. Was going to wait and see. Do you think I need it on both X & Y ?

    It wouldn’t hurt, but definitely on X(assuming it’s the long side).  They don’t have to be giant X’s or anything, just cut a 2X4 with 45’s on the ends, maybe a foot, foot and a half long.  Stick them up in the top corners and call it good.  You could also use a piece of plywood along the back, also doesn’t have to go the full height, same foot, to a foot and a half.  Basically just to keep the legs from racking.

    #73665

    Benjammann
    Participant

    Either way really. You can wire it individually and plug in the series harness near the board (that is how I test firmware) then switch at any time.

    Took me a minute, but I just figured out what you are saying. Just ordered some more drv8825 from Amazon, and an individual wiring kit along with a few endmills from you. I was reading something on here about the benefits of a lower top speed but more power. Do I get this with the individual wired setup?

    Also, It amazes me that you are still on here relentlessly answering questions and excitedly making comments. You’ve got some drive and dedication man.

    #73686

    Benjammann
    Participant

    All the parts!

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    Attachments:
    #73689

    Barry
    Participant

    I see you’ve also accidentally glued a part to something with the residual glue stick glue!

    #73742

    Ryan
    Keymaster

    excitedly making comments.

    Bold statement…..Not always exactly excited…. 😉

     

    Do I get this with the individual wired setup?

    Doesn’t apply, individual is a win win.

    #73843

    Benjammann
    Participant

    new stuff.

    Started building last night following the instructions again. Got as far as the nut lock and noticed that it’s not included in the new files or the list of files. Wondering what I am not seeing here..?  I’m using a leadscrew, but the instructions say to just add the nut lock without hardware in that case.

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    Attachments:
    #73861

    Ryan
    Keymaster

    I have updated everything but that page of instructions, Working on them today.

    You will notice a piece that looks extremely similar, the spacer. You will have two of them the previous parts had one or two and/or a nutlock. If that doesn’t make sense check back this evening hopefully I will have finished taking the pictures.

    1 user thanked author for this post.
    #73883

    Benjammann
    Participant

    Getting my Z & leg tubes dialed in.

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    #73888

    Ryan
    Keymaster

    Holy cow!

    #74466

    Benjammann
    Participant

    Making good progress. Realized I should have ordered two of the wiring kits. I had to rig up some bootleg extensions that seem to be mostly working so far. I am having a few issues though.

    I’m on Ramps 4.1 with each motor wired to its own driver to utilize the auto squaring firmware. When I connect to the board with Repitier, most of the time I can manually jog the Z right away, but the X & Y takes sometimes 30 seconds of clicking the button for them to move. Also, my X2 motor seems to be lagging or underpowered. I move and the X1 motor goes fine, but the X2 acts like its sluggish or slow or getting caught up on something. I tried swapping out the drivers but it still does it. I triple checked the wiring. When the motors are off everything moves freely. Any thoughts on what could be causing this?

     

    IMG_1757

    Attachments:
    #74489

    Ryan
    Keymaster

    Make sure they are all moving the correct direction and the drivers are set properly.

    1 user thanked author for this post.
    #74507

    Benjammann
    Participant

    Make sure they are all moving the correct direction and the drivers are set properly.

    Hi Ryan,

    All motors are going the correct way. I just adjusted all the drivers to .630 V.

    Still the exact same behavior. Y2 motor lagging. Also The X axis works well, but then after a few clicks of manual movement, both motors become totally unresponsive. Could this be some sort of communication issue?

    #74510

    Ryan
    Keymaster

    I have no idea what could cause that lagging. It should be getting the exact same steps sent to it. Triple check the extensions you put on, and make sure they are turning the same amount, like use some tape flags and make sure they both have the same step rate and such.

     

    My gut says the ramps is the issue but there are too many possibilities to jump straight to that.

    #74511

    Ryan
    Keymaster

    Swap the plugs and see if the issue follows the stepper or port.

    #74512

    Benjammann
    Participant

    Swap the plugs and see if the issue follows the stepper or port.

    I just switched motors and no change. Still lagging on Y2. Still intermittently stops responding on X or Y axis after repeated manual moves. I did test the Ramps board as good before this build, but that was with the parallel wiring with three drivers.

    Swapped the motor plugs and the Y1 now has the Y2 behavior, but the Y2 is barely moving as well. So hard to diagnose when nothing is repeatable. I try to move the X by 50 and it just stops after 10

    #74519

    Benjammann
    Participant

    Just to verify, I’m running the 32 step dual endstop firmware. Is this the correct version?

    #74527

    Ryan
    Keymaster

    Try it this way.

    Power down and unplug. Directly plug in one stepper to the x driver, power up and move 50 mm.

    Repeat trying each driver individually with the same stepper.

    #74579

    Lénaïc
    Participant

    Did you try with shorter and / or thicker wires ?

    if they’re too thin some losses happen, that could explain this lag and random behavior.

    #74600

    Benjammann
    Participant

    Power down and unplug. Directly plug in one stepper to the x driver, power up and move 50 mm. Repeat trying each driver individually with the same stepper.

    I missed this comment while I was still out there messing with it. Although I ran a similar test like you described earlier. My brother in law came over with a fresh mind and we ran through some things. First, many of the strange randomnesses were coming from the setting for the ” build area” in Repitier not being correct. So I would manually be jogging and it hit either the lower or higher extent and I didn’t notice that was the cause of the stop.

    So in eliminating those issues, we were able to isolate the X2 motor as the remaining problem. Putting a brand new tuned driver on that slot did not help. Swapping motors or positions did not help. At this point, I am fairly certain the issue is coming from the signals sent from the board to that driver. I turned the default speed down and all other motors run smooth and quiet. That one acts like it’s got the speed turned up like crazy. If you try to bump it a mm at a time it will quickly jerk and make the move, but if you try to go 10mm it acts like its trying to do it all at once and you get the sound as if it ran up against something and is still trying to move.

    Starting to think you were right when you said to stick with the way I had it wired, not using the auto squaring. I’m guessing I could go back to that wiring and everything would work, saving me from having to buy a new board right now, as well as cutting down a lot on the amount of wiring.

    Sound like a board issue?

    #74613

    Raied Hasan
    Participant

    Try to reduce the length of wire and see if that helps. If that does work, then you need to switch the wires to a thicker gauge.

    #74621

    Benjammann
    Participant

    Did you try with shorter and / or thicker wires ?
    if they’re too thin some losses happen, that could explain this lag and random behavior.

    Try to reduce the length of wire and see if that helps. If that does work, then you need to switch the wires to a thicker gauge.

    I’m not sure this is an issue since my X1 motor has the same wiring at a much longer run than the Y2 and it’s totally fine. I’ll give it a shot tonight though. Thanks!

    #74679

    Raied Hasan
    Participant

    Ah then that will probably not work. Have you tried switching the motors with the drivers and see if you get the same issue with the same motor or the swapped motor?

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