I will double check but be careful of the thickness. I think 4.25" is the absolute max if not a little less.
Yeah the ends of the table are just wheel extensions, and I did it so I could clamp or screw the material.
I guess now is a good time to point out screwing down the material is almost the only option, clamps will always get in the way, wedge clamps would be the better option. Luckily just a few screws should be enough around the edges, a full sheet doesn’t like to move much.
OK, I’m going to build the first one 60"x36", and then make some wheel extensions that are removable. I’ll also stick another piece of frame at a 45degree angle in the first chunk to be able to clamp smaller material in place there. I hope I can get some time this weekend to do that, but work is going to be a bit crazy the next 2 weeks, so we’ll see.
Unfortunately my $2 harbor freight hearing protectors don’t do a great job at blocking the needle cutter noise. They block my shop vac and router well…but the needle cutter is still obnoxious 
Space for me is hyper limited. I grew up with basements, but here in AZ they’re exceedingly rare. The first house I lived in here had a finished basement but that’s the only one I’ve seen in this town. A garage was the one requirement I had when we bought our house…but then we fell in love with the house we bought which didn’t have one. I do have 2 sheds - but they’re only really usable for storage. And until a few years ago my current shop (a 12’x12’ building) was my office and I worked from home. So all projects had to be done outside. Thankfully we have an outside kitchen with large counters and shade, a big 40’x20’ RV shade, and a big carport that stretches around two sides of the house. But it’s still not the same as a garage or actual shop.
I drew up a wheel in openscad…wasn’t sure what the thickness should be but designed it around an 8mm thick spacer and a 608 bearing on either side:
https://drive.google.com/open?id=0B5JVPXZ3vDfBbGVVNC05c1ZSaXM
But then it hit me. This probably isn’t printable. The curves are doable. But the unsupported center is an issue. Supports don’t work with TPU unless you have a dual head printer and can do them in a different material - and I don’t have a dual head printer.
Could maybe cut it in half and print the two halves then glue them together…hmm…
I should probably focus on work instead 
Geez, I haven’t posted in a month… Not good.
I have been working on it. I’m ready to assemble the first chunk of table. It’s 32x60, and I plan on pretty quickly making some wings to make the cutting surface 48x32 by default.
I cut out most of the CNC parts today, from 1/2" ply. I have the two y cover parts left. Just from looking at the size of there parts, I can tell this thing is a beast.
I added some photos to the album. I built the first part of the table. The “studs” are 3" wide, and there are five, so they are about 15" apart. I added glue, and two screws to each stud end.
I added the 1/8" hardboard. It was oversized, o added glue, and then used a cheap stapler to put 18 Gage, 1" Staples to secure the top. The Staples were a mess. The first side, I had the pressure too high, but even the second side would miss Staples, double fire, or the end would go wild and wacky. Everywhere, there was some problem with the surface. I cleaned them up by pulling some out, hammering some back down, and cutting the ones that shot through to the outside with a Dremel cutoff tool. Then I sanded the top down so it would last flat.
I then used a router and a flush trim bit to cut off the excess.
Once I had both sides installed, I’m pretty happy with it. It’s pretty light, and big, and pretty rigid.
That’s sweet! Next time use something like half inch staples. They’re only needed to hold the top until the glue dries anyway. That much staple into the wood was probably pushing the gun up causing your double taps. I’m already looking into making a new top. The steel stud idea works okay, but not the best. I can make do with it for now though.
I started the actual build, finally.
I cleaned up the cut parts, they are looking pretty good. I didn’t want to change bits, and I wanted to cut the plywood with a 1/8" downward spiral bit, so I couldn’t cut the 1/8" through holes, so I just went to a depth of 2mm, and I finished the drilling with the drill press. I think it probably saved time overall anyway.
I got as far as I could today. I am going to take the controller and motors from my MPCNC, and it’s spot in the garage. It’s days are numbered .
I also didn’t account for the extra thickness of my cut material. I’m using 1/2" plywood, so the #6/32 and 5/16" screws that go through those parts need to be longer. I have a bunch of 1" #6/32 screws, but I need to go buy some longer of the 4" and 5" screws. I just realized that since I didn’t install the motors in the side assembly, I have to take them apart anyway.
I also am not quite done with printing. My printer has needed some TLC for a few weeks, and I only got to it today. I have 1 more of the “tensioner” parts to print, and the larger lock knobs to print.
I’ve pulled it inside, and added a few photos of it in my dingy basement. I am really liking this torsion box, it is not incredibly light, but it seems very rigid for its weight. I should probably weight it to give you a better idea.
I realized last night that I’m missing the GT belt. I looked at my order history, and I just didn’t buy it. oh well, I’m not planning on going full size immediately, so I’ll just “borrow” the belt from the MPCNC for now. I think that’s probably why I didn’t buy it in the first place, I wasn’t sure how much I would want in different configs.
I cut the tubing with a quickly made miter box. Just put some glue on some 3/4" pine blocks, with a 3" wide base. No screws or anything. Clamped the walls down with a piece of tubing in while the glue dried. I then started a cut on the table saw, so it would be relatively straight/square. Then I used my hack saw to cut the tubes. Left some burr, but not hard to remove. Took less than a minute per cut.
I’m down to a few steps before it starts moving:
I also need to make the front “ears” part, but I can get it moving before I finish that.
I’ll try to remember to pause and take some more pics next time I’m working on it.
Tubes installed.
Can’t see the pic!
I couldn’t figure out how to fill the tubes with cement, so I just installed some wires instead 
. I have the wiring done. The belts arrived today (amazon lost the first set, when you have packages go missing is when you know you order too much from amazon). I mounted my raspberry pi and grbl board to the side of it. I am going to move this beast to the garage. I should have a few hours tomorrow morning when the wife takes the kid, so… I hope to be cutting tomorrow.
I have to “install” a spoil board, attach the belts, and change the steps/mm for the z axis. Oh, and install the router, but that should be a cinch.
@Ryan, I know the aluminum angle mounts are “alpha”, so no need to mention it again, but they make the al angle sit so low that the carriage hits the zip ties I use to hold the hose down. Any updates on those parts? I will just remove the zip ties for the time being.
I drilled holes in the angle and zip tied to that.
Ah, on the side that won’t rub on the carriage. That’s an easy fix.
Success! 1300, 870, 60 to 0,0,0:
I added a spoil board, with is actually the old spoil board. I left it cantilevered off the edge, and it actually works OK. I’ll have to see if there is much sagging in z when cutting there when the wheels go over the edge there. This wasn’t how I was planning on getting the full 32" cutting area, but it just might work. The torsion box is 32x60 and the spoil board is 48x60.
I had some alignment issues with the z axis acme screws. I was worried they were binding too much, but after I greased them, it does it’s little sink at the end (I dropped the DC adaptor at the end, that’s that clack noise):
There are some creaking noises, but I think that’s mostly the spoil board creaking against the torsion box.
Drilling holes for the zip ties worked great.
I think I will have to attach my power controller to the side of the Low Rider. I really like turning the router on and off with the gcode.
I have to say, I was a little worried when I was putting all this together. It seemed heavy, and soft of like a house of cards. But now I think it’s rather elegant. The wheels roll really smoothly. The cords are managed much better than my MPCNC.
I’m using the controller from my MPCNC (I think it’s most likely retired, at this point, R.I.P.). I swapped the X and Z drivers (I have X as the 60" direction) since the Z was set to only one motor current. I’m still running in parallel. If I put a little pressure on the Z axis while it’s rising, I can get it to skip. I will need to check to make sure that limit is set right, and I may have to go to serial wiring. The gantry isn’t light, so that’s definitely making those motors work a bit harder to lift.
The 60" axis (my x, your y) is less smooth than the other axis. I’m not sure but I think since I didn’t cut the holes oversized that they might be pinching the pipe even though the top 5/16" screws are not tight.
Enough sharing, if I hurry, I can cut something before I’m needed again.
AWesome, Another one comes to life!
Very cool!
It cut great! I was using very conservative speeds 15mm/s, 1mm depth. I have to pay closer attention to the squareness of the belts. The torsion box is square, but the spoil board isn’t. The sides of the spoil board (and the belts) are straight and parallel. I’m going to spring clamp something to the torsion box then powering on the motors if I care about square.
I never had dust collection with the mpcnc. It’s collecting most of the chips. I think adding some bristles around the outside would be cool. I also want to make the 611 plate out of clear plastic something so I can see it cut easier.
Nice!
Ah, infinite edit! I fixed the name of this thread. It’s like removing a splinter.
I have a paranoid thought. The couplers on the z axis allow the thread to move a bit more or less, while pulling the spring. Since it sinks to it’s resting spot, the two sides can settle with different amount of spring. Maybe those should be rigid couplers? I should check the Z height at different places to put myself at ease.
