Longmill seems to be a no-brainer. Or am I wrong?

Not trying to be a thorn, but that resolution doesn’t matter if the precision and accuracy aren’t there.

Just noticed your hobbies, I build amps, great hobby

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I just realized you were asking me about the top size. I bought a 49x97 MDF sheet. I cut 48x48 for the table. I then cut strips in the 49x49 of (1) 5.5" and (5) 6" for the spoilboard slats. I used the entire leftover piece to overlap the controller side of the table to get me a little more room. My final top dimension is 49 x 52 7/8 . Obviously, this width includes the T rail widths.

Jim

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a little more breathing room than I ended up with.

Where do you place your computer? I wish I had included a platform for mine. I may add that later.
I also may look at improving the lighting on the work surface.

Jim

I repurposed an old rolling tool box to hold my computer and extras into. My table ended up with just enough room to house machine

slide out door beneath the top

Do you have a picture?

BTW, I added an outlet with split circuits. One is unswitched and one is switched by Solid State Relay driven by control board for spindle power.

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There used to be a table category, can’t seem to find it now.

Here is what my table looks like vertical



I also have a small hd monitor you can see on the top right corner, so I can run it with the laptop drawer closed, wireless mouse makes running files easy.

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Very nice. I can see you put lots of work and thought into your table.

Good job,

Jim

I was thinking of building a table like yours do you have any plans for it. Thanks in advance

Hi Lifter, welcome to the forum. Sorry, I didn’t document the build.

Not a problem thanks anyway

Pros of the Longmills:

  • Lead screw driven. This improves rigidity by a lot compared to a belt driven system. While it probably can’t move as fast due to there being more friction, you can hold tighter tolerances and make more precise movements.

  • Simple design! If you wanted to order more feet, longer lead screws, and some aluminum extrusions you could easily expand this machine as large as long as you want. Just beware X axis deflection.

  • Easy-ish assembly.

  • Longboard controller is actually alright for basic control outputs for spindle motors.

  • Rigidity. You can stand on the X axis and it will be fine, though I don’t recommend it.

Biggest Cons:

  • Fake E Stop. Stops power to motors, doesn’t process and alarm. This means the spindle will continue spinning and can potentially be dangerous if someone accidently falls into your machine for some stupid reason or if something goes terribly wrong. Also since there is no alarm the program keeps going! This means if you undo the E-Stop button which you would think would throw an alarm and halt the program it will continue off on whatever line is being sent and not where it even left off. This combined with no spindle shutoff = bad news.

  • No effective way to square the spindle up with the other axis. I’m enjoying the challenges of trying to get my spindle squared up right now and without further modification it seems to be unlikely to happen. If you want to just do 2D cuts this is not a problem with smaller end mills. It shows when you go to surface anything. A way around this is to find how deep the stair-step effect is (lowest point of your tool from the center of the tool’s diameter) and only cut that deep to keep it consistent. Will work for surfacing the spoilboard but will make everything else a pain.

  • V wheels can kind of more easily than expected bind up on the rails and skew the X axis even at the rated speeds. I don’t even like to run mine over 3500 rapid on the Y axis because of this…

  • Anti-backlash nut design is frustrating at best. The screws will get in the way of the full travel distance by a few millimeters and can be very annoying. Obviously you don’t want to be ramming screws into their threads a bunch, so you can use shorter screws and some shims inside those slots for them like I did, as well as reverse their orientation on the machine to be the opposite of instructions. As you can see in the picture below this is the Z axis. The screw will push into the nut for the lead screw and bend outwards, as well as restrict some of your height. It’s a pain in the butt to adjust it from below but you get your few extra millimeters back.

  • Weaker than needed Z axis motor. Struggles to lift a heavier spindle (2.2kw) and I am worried of how it will perform with upcut bits since it has force pulling the spindle down into the workpiece.

I included a laptop space on my one side and put shelving for wood scraps on the other end. Here is my mostly cleaned table 20220101_104228|690x310

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