Hi
nice design.
In order to keep welded steel "in shape" you should try to find an industrial oven and relax it before using your epoxy.
I simply doubt you wil achive 0,01 accuracy for two reasons:
Your linear rails are- sorry to say so- crap, preventing any accuracy in your desired region. Why not change them over to Hiwin (just example) square ones?
Square ones can be bought in different preload-categories ... and for precision a v1 or even v2 category is recomendet ... these do not slide on their rails "by them self" anymore ... just to mention a difference (more friction - less play - higher precision)
Your cheap rolled chinese spindles usually build to about 0.03 mm accuracy each 300mm only, meaning twice the much on say 600mm. Without a even a test protocol (cheaply bought) you can asume it to be even worse. On top the traveled distance per rev (tpi) will vary (sorry do not know the english term for it) because the spindle is only rolled on manufacturing not precision grind...
Last but not least steppers and backlash will ad some more inacuracy...
I have seen numerous professional cnc-centers up close and know what kind of effort companies put in parts that need an over all accuracy of 0,01.

Do not despair a good cnc is doable for us hobbyists and 0,05-0,1 accuracy is more than good for anybodies standardts.
Your design looks sound and that is most important.
Upgrades later are an option always...

go for it

flo

 

Florian, he's looking for 0.01 inch repeatability. I'd think that would be very doable based on the equipment he is using.

 

Uuups, my bad.

flo

 

Thanks guys. Yes, .01" is the goal. Actually, I will be taking an indicator and "sweeping" the rails on my surface plate to get a rough idea of how far off the rails are. Placing a precision straight edge on them, I see slight gaps, roughly a thou or so. But it will change once bolted down. We'll see!

Also, I do have a buddy with a powder coating oven. I might give the stress relief thing a shot! Do you have any experience with this?

 

I know this has been covered, but I'm looking for a spindle right now. I have 220V already, but would like preferably a non Chinese vfd, the spindle itself can be Chinese. Does anyone have experience with any other VFD that can be controlled through mach3, a Leadshine 3660, and a smooth stepper kit? Maybe even one with support?

 

Maybe this one?

BuildYourCNC - spindle-inverter-2!2kw-spindle-vfd

 

Does anyone know where this black stepper motor wire goes?