[MajaMorris]

Hi!

I have some t-slot extrusions that I wonder if I could start a CNC-router build with.
A couple meters of 88x88mm and 44x88mm, 2mm thick (thin).
Also have some alu. u-channel 80x40x5mm.

Want a router mainly for wood, but also occasional aluminium work.
2,2kw china spindle.

Planning to make a good gantry beam at first. Then decide if I go for moving bed och moving gantry style. Maybe try out different configurations.

1m long beam wich will give me at least 600mm work distance in Y.

What do you think? Something to move on with or scrap it and rethink from the beginning?
I have played some in fusion 360, but i´m not able to do a FEA. Running out of memory and all things of problems, i´m just to bad at it.

One idea as in the picture. Three 88x88 bonded (epoxy?) and bolted togheter in L-config with an additional U-channel and solid aluminium where rails mount.
Rigid enough or what do you think? Other (better) ways to uttilize the profiles Ive got?


Thanks

[NIC 77]

As long as everything is bolted together in several places along the length, I don't see a problem with the concept.

Have you taken a straight edge to the pieces you have to see what shape they're in? T-slot and solid aluminum extrusions usually come pretty flat, but you should check it.

Alternatively, you could make it three tall instead of an L shape.

It looks like the holes on your fixed and free end bearing supports might magically line up with the T-slot spacing? Do they? I don't think your "C" channel on it's own will give you adequate thread engagement for your end supports, but if you can use the T-slots that's in behind to fasten them, that's different.

It's worth it to draw out the whole machine before starting to build or order parts.

[MajaMorris]

Thanks!

Well, I will proceed with the idea then.
T-slots are matching BK/FK12 bearings. I have a 1605 screw. But unsure if I should by a 2010 instead.

[NIC 77]

I just wanted to clarify....when I said bolted through in several places along the length, I was talking about drilling holes through the extrusions to bolt them into the T-Nuts of the extrusion below or to the side. I'm not sure that I said that very well.

It depends on what motor you use and what acceleration and speed you want as to how it will perform with a 5mm lead. In general, 10mm is a better choice IMO, even 20mm, but since you already have it, you could look for a stepper with low mH that gives decent performance at higher RPM's.

As said before, I'd complete the design before building anything.