@gmack Yes, that’s the conclusion I seem to be coming to. Not what I was expecting - from following the forums, I had figured steel belts + linear guides was the magic combination. I do see deflection in the V-wheels, but it’s an order of magnitude less than the belt stretch… enough that I’ll want to fix it eventually, but it’s nowhere near the top of my list, now. And the extrusions + frame plates seem pretty solid.
Here are the belts I’m using:
(Same ones @luc.onthego mentions below)
(Plus 8mm 20-tooth GT2 pulley to mate with my new stepper, links mentioned in an earlier post… stock stepper would want a 6.35mm. Edit: to clarify, the 8mm/6.35mm refers to stepper shaft diameter. Pulley width is 10mm for 10mm belts.)
Re: spindle - I have a Jianken JGD-80/1.5R40 on order. 80mm diameter, “1.5kW”, ER16, 40k RPM. Unlike some of the other high-RPM spindles, power is flat between 30k and 40k RPM, which I think is nice - it gives me the flexibility of using either .25" or .375" end mills with good MRR without exceeding the “happy” SFM of 3000 for aluminum (or is that a myth and I can just go as fast as I want???). I don’t need peak power at peak RPM when using smaller end mills (like 1/8"), just the extra RPMs.
Thanks for the link to the Mechatron… I was looking at their spindles, but somehow missed that one (and the HFP-8022-50-ER20). The power/torque curves on those look great compared to other spindles on the market. Maybe for next time!