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

[Zeeflyboy]

I now just need to machine a slightly longer collar for the FK12 so that the pulley doesn't bind on the housing.

With that done, I moved on to the motor shaft extension.

First up, centred the smaller pulley (had to remove the top cap) and bored to 6mm.



For the shaft I centre drilled first as this is going to be quite long/thin so needs support at the far end from the live centre.




Turned down to 6mm





Flipped, re-centred and then did the work on the other end. It's critical that this is a really precise fit on the motor shaft and that it's concentric to the outside as any error will either cause the motor to bind or damage the bearings. To that end I used a 7.8mm drill followed by 8mm h7 reamer and then turned down the external diameter.






I did all this work and then ended up turning down the external dimension a hair too far, so now it's a loose fit in the bearing. Frustrating doesn't quite cover it! Will have to put this on the re-do list once I get back from holiday.

While all this was going on, the 3d printer was at work on the seals.



Who says 3d printers can't be accurate - this was spot on! (I did adjust by 0.8% for thermal expansion before printing)




The big bottom seal next (6hr print!)






Very nice fit - smooth and doesn't stick at all along the rails, but close enough that it should keep the nasty stuff out.

That's all for now. Hope to re-do the shaft extension and get the idler done when I'm back next week.