Upgrading, need advices

excessnet · June 4, 2019, 7:17am

Hello,

I got a pretty large (I think?) MPCNC (Tubing is 48" x 36"). The working surface is about 35" x 24" x 3". I’m using a 500W Spindle.

It was “okay” for Wood (plywood, MDF), but now I wish to do some plate in aluminium (3mm) to repair/upgrade my actual 3D Printer.

I tried, but it dosent seems to work very well… eighter I see the bit moving all around (1/8 single flute), or it dosent do any “good chips”… I tried many setup, but I think my MPCNC is too sluggish (not sure if it’s the right word, I’m French ! :))… maybe cause it’s too big. Tried to raise the plate I’m milling closer to the tool, that helped a lot, but still not working very well.

I started with the 525 versions.

I upgraded to the leadscrew.

I will upgrade to the “new” feet (since mine have cracked where the screw meet, but they are very tight) when my printer will be working again (but I need the plate from the CNC :p)

But now, my questions :

Should I upgrade from EMT 3/4" (23.4mm here in Canada) to Stainless Steel tubing (I think they will be 24.5mm)? Will it help the ridigity ?
Is my 500W Spindle okay? Should I get something else? It's supposed to run 12000rpm unloaded. Not sure if it's true.
Should I upgrade to the new "burly center", will it help rigidity ?
Adding "middle support" will help with my size ? The only downside to this, is that I won't be able to place wood that are "larger" than the CNC itself.
Will I ever be able to mill aluminium on that "big" MPCNC ? Cause, I still want to do some big wood part... so I don't really want to reduce the size... I could build another one, but I would need to buy motor and stuff...

If you have anything else to suggest, go ahead !

vicious1 · June 4, 2019, 7:29am

All those things will help but not nearly as much as just making a smaller build.

Aluminum is possible and has been done at a larger size but at that size but your settings need to be exactly perfect, with very little window for error and it will be much much slower than a smaller build. The least expensive option is to build a small one and share the expensive Control card between them.

excessnet · June 4, 2019, 7:34am

okay, I had hope, but I guess I will try to reduce de size or make another one. Thanks a lot Ryan !

That 500W Spindle is okay for Aluminium ? Should I upgrade to the Dewalt DW660 I see in every videos doing aluminium ?

dorkblaster · June 4, 2019, 9:24am

Depends on feeds and speeds, quality of the spindle bearings and collet (etc). There are a few vids of folks cutting aluminum with Dremels (3000 and 4000 series) which are in the 200/300 W range. Their DOCs are much smaller of course, one chap was using 0.1mm.