is making the cnc 32x32 inch a bad idea? also, what kind of design for a table that the center could drop down for larger objects should I use? I cant really find any, im thinking some kind of slide in and out shelf design for it
I have a 28" x 28" work area. One issue is if you have mid span supports, you lose the ability to slip larger material in. If you are talking about perimeter of feet, that’s about what I have. Any larger and you are going beyond normal dimensions for 48" wide plywood for your corners. How about a Lowrider?
Alright, I think ill stick to 24x24 (that dosnt need supports, right?) What about the table with the drop down spoilboard? do you know of any designs i could use?
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is really well-documented and a great example.
I looked at that table, but I don’t see how you could drop down the spoil board for larger objects?
And i looked at his cnc machine and they looked way taller than 4 inces, i though 4 inches was the max before the whole thing got wobbly?
D7006DAA-720A-4CE7-BE0A-B9D5B4E36092.jpeg in that thread, posed Jan 2, 2019 shows the spoilboard lifted out (not dropped down). Later images show ice carving that are suspended in the hole in the table.
Do you have mid span supports? and is the cutting detail quality of a 28" work space lesser than say 24"?
I have mid span supports. I have had no issues with accuracy over the distance I don’t pick up a sag in the middle. I’m happy with it.
I think ill do 28" also. 32 seems to big and 24 seems to small, does the mpcnc page have any links for instructions for mid supports i can use?. Also, I see other people’s mpcnc and their legs look a lot more than the recommended 4" and some actually saying 6" and above, I though 4" was the max before the thing began to wobble and loose accuracy?
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Depends on what and how they’re cutting. Generally that’s a true statement, but there are workarounds. It’s best to stay with the recommended until you know how the machine works.
oh ok, how much accuracy do you loose going from 2 to 4 inches?
It’s not the legs that cause the issue as much as the router being further from the XYZ block in the middle. If the router goes below the lower bearing, it acts as a lever on the whole system and wood grain will drag the bit out of alignment while cutting. I had 6" legs and they’re too long for accurate cuts. I have 4" legs now with 1/2" spoilboard between and that gives me just over 3" from the collet nut to the spoilboard, or about 2" milling depth, give or take.
There is a ton of complicated math involved but >2x the rigidity is lost so assume 2x slower or 2x less accurate minimum, and 10x better CAM is needed.
Build a small machine learn it and if you need/want to go larger later you easily can like all the pages and posts say. You can even use all the same parts for a large build just make is small to learn on.
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I’ll do that, I was planning on building a 32x32 for cutting pieces out of plywood, but for now ill do 24x24 I think. I’m still going to do 4-inch legs. I will be building a drop-down table so I can lower the spoilboard at some point. Also, what does CAM mean? The z-axis screw looks like it can move the router further down that the bottom of the legs, does that mean having a spoilboard that can drown down a few inches could increase how far the router can go down?
btw I just ordered my parts today 
CAM is the software between cad and gcode. A slicer in 3D printing. Estlcam is CAM software. When Ryan says 10x CAM, he’s saying that you have to be right on with your settings, whereas with the shorter Z, you can be farther off, and still get the job done.
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