Don’t know if anyone else has done this, but I built my Burly table top to fit snugly onto my Husky work table. It’s very stable and the whole thing comes apart quite easy and stands on edge.
Also added interchangeable waste boards. There is a clamp next to each leg.
I am quite happy with the machine. It absolutes tears through 3/4" plywood in a single rough pass followed by a single finish cut.
(Hmmm, system won’t let me post the mp4 of it cutting the plywood.)
Videos are hard. It would be better to post it to youtube or imgur and post a link.
Thanks Jeff, I’ll try that.
Here’s the video:
And the final 100mm circle is only 0.5mm out of round. That’s good enough for now.
The machine standing on its legs. Don’t laugh at all my different colors. I got rid of a lot of partial rolls of filament building this.
Those are very impressive cutting speeds. I think the limiting setting is probably the acceleration in xy in the firmware with that high speed trochoidal milling.
I was amazed too at how fast it could cut through 3/4 plywood in a single pass. But after I saw Ryan’s video where he was cutting 1/2 inch at 17 mm/sec, I just tried rounding up to 20mm/sec (1200mm/min) and it worked. Also tried 1800mm/min but the steppers started missing steps. I am quite happy at 1200.
I never knew about trochoidal until I “discovered” it here in the forums and Ryan’s video. I have a small Sherline CNC mill that I have been using for ten years, but never ran across trochoidal before. I was frustrated after burning up a couple of 1/4 inch router bits with my Sherline and my Burly and started to search the forums for solutions. The 100mm circle was my trochoidal test case. I’m pretty much sold on trochoidal. So now it’s back to my (my wife’s) original project.
It’s pretty great for aluminum, too. I cut off a 1cm piece in 3,5mm steps with a 3mm bit, could have done it in one or two I think.
I’m also considering a “table on table” like this for my build. I think it will be a single sheet of 18mm plywood, with another layer of 18mm for spillboard (and that on top of a sturdy workbench). Is that sturdy enough to hold the mpcnc, or is it better to create a torsion box and bolt the whole thing on to that.
That should be strong enough. The key will be the glue or screws that join the two sheets.
I used a torsion box like design because I was thinking it would do two things. One, it would provide stiffness and help to prevent the plywood from warping over time. Second, it provides a nice firm grip to hold onto the work table so that I don’t need any other clamps or latches to hold the MPCNC to the work table. So far it has worked as planned.
My MPCNC table is 3/4 inch plywood (23/32 actual, approx 18mm) and my torsion box is made with 1x3s. The interchangeable waste board in my photo is 1/2 inch MDF which I happened to have on hand but is working out fine. The working area of the MPCNC is 24.5 x 24.5 inches and the table is 37 x 44 inches. The whole thing is fairly heavy and I can just manage to lift it on and off the work table by myself (I’m 70 Y.O.). So depending on the size of your MPCNC, you might want to consider total weight as well.
Good luck with your project, and post some photos when you’re done.
