Big-ish router concept review

[mbele]

Hi Boyan, thanks for the reply!

I'm still at the concept phase...

For the long axis, I figured that 3232 screw pre-stretched between 2 BK mounts with 20:48 reduction could maybe work, screw would turn 330 rpm to get to 10m/min (i think that's below critical speed), and 2048ppr encoder would then allow 0.001628mm/pulse.
It's just that I'm trying to get by with the low rpm/high torque motors I already have (I would also have to reduce moving weight). Rotating nut would be better but more complicated and probably more expensive solution. And I'll probably end up doing it "your" way after all, but I want to check all the options before investing.

I saw bolts and epoxy putty(eg. jb weld) leveling method in "principles of rapid machine design", so I assumed it worked fine.

1.8kW is what I already have, and I haven't ran into problems not having enough torque (it gets to max at 12kRPM).

I read your build threads, and I was amazed :) Thank you for sharing all the info, it's invaluable resource. Without the epoxy leveling solution you've adapted for your machine I wouldn't even think about making something this big.

Since the space is not a problem, and machine will not move, I'm thinking about pouring concrete foundation(frame) and ditch the steel frame completely, so there will be no overhangs and unsupported parts at the base.

I'm also considering aluminium gantry to reduce weight, same outer dimensions but with thicker walls and ribs, made of 250x10 plate screwed and glued together.

I will draw the complete machine with all the features, and when/if I'm sure and happy about all the details, I'll buy what's needed.

Thanks again for looking at it!

[Boyan Silyavski]

I think you are mistaken about the spindle. Ideal speeds with most of the most popular bits are 16k-24k.

[mbele]

I think you are mistaken about the spindle. Ideal speeds with most of the most popular bits are 16k-24k.

Again, I should have been more clear in what I'm writing... sorry. Spindle reaches max torque at 12kRPM, but it can spin up to 24kRPM:
https://www.damencnc.com/en/milling-...rospindle/1226
It works well with both alu and wood. With constant TEA paths and smaller TiAlN coated endmills it has enough torque for light work in steel (min. 6kRPM), but I don't do that often since the machine is not rigid enough.