El Beast - Initial design phase, comments and critique welcomed!

[Zeeflyboy]

The ones you made for me work well and are just tight enough but not too tight. You might have seen in the last video I put out that the steppers have no problem moving the axis so a big thank you for that.

Glad to hear it - haven't caught up on your work for a while actually... need to go see what's happened while i've been gone!

Missing a critical dimension is annoying. Sometimes I aim a few hundreds of a mm over size, check with the micrometer and use sand paper strips to get it to final size. Takes a while but quicker than starting again if you overshoot

Thanks - that's what I did this time and it worked well.

I assume you didn't fancy slots for the stepper to tension the belt? Also do you have bearings in the top plate for the end of the pulley and the end of the stepper shaft? If so I would make one of them floating in a separate small plate which bolts to the main plate. This will allow both bearings to sit where their respective shafts dictate - otherwise the pockets have to be machined very accurately. Something to think about. Have a good break and don't think about CNC too much.

Cheers for the thoughts. I was originally going to go with slots, but it makes it difficult to use a seperate bearing setup for the stepper motor which I wanted to do for the sake of my motor bearings, and the tensioner has the benefit of engaging more teeth on the small pulley.

I will think about floating the bearing above the ball screw - that's a good suggestion thanks.


So I re-made the shaft extension (it worked this time, I won't bore you with pictures as the process was much the same) and also made the knurled knob that allows me to manually move the Z-axis up/down. My thoughts are this is also an easy place to install a brake if the Z-axis proves heavy enough to slide down on it's own.

So started off by turning the alu stock down to size



Knurled and parting






Meanwhile, 3D printed a drill jig to make drilling the retaining grub screw hole easier.






Pressed into place




To save damaging the collar (plus it's a pretty small thing to clamp) I then mounted a 6mm rod in the lathe and used that to mount the knob to do the top side operations:




Final part:






This is the assembly: