Comments sought on new build: A CNC Router for RC Gliders and Planes

[JAZZCNC]

Scratched my head a bit today trying to work out how to mount the Y axis stepper motor so I can adjust it to tension the belt. In the end I've decided to put the pulley on the rear of the stepper and mount the stepper on the front via a bracket...

I'm hoping that as the only tension on the stepper is from the belt that this arrangement will do?

Bad idea that dude.!! Bearings will suffer and could cause resonance which will affect motor. Just pocket the Mount deeper so pulley goes thru it.
Or have idler arm tensioner tension belt from side of gantry.

[Jonathan]

I agree with JazzCNC - loading the stepper motor bearings so much wont end well...

[njhussey]

I lay awake thinking about that last night and came to the conclusion that I was kidding myself it would be ok and should have known better....I'll pocket it deeper and tension the belt from the side....or weld up a bracket from steel that can slide to tension it. Cheers chaps.

[Clive S]

A bracket could be made to fit in between the top and bottom plates projecting back and lapping around the back face of the two plates ( like a tee piece) it would mean the motor is sticking out the back slightly.
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"TOOMAST ..Do you have special machining on ballscrew? I notice longer area for the pulley?" Just order the ball screw with the "F" measurement 30mm instead of standard 15mm. ..Clive

[njhussey]

Clive I'm going to pocket out the bracket that I've got and use that with a shorter belt I think....well that's the current plan anyway!

[njhussey]

Quick play on the milling machine...





A few bits for my PSU came today....just need some choc block connectors and some fuses and ill be away...

[njhussey]

Ok so pulled the gantry apart and machined the front and bottom plates (M8 counterbored hole in each)



Put it all back together and it's nice and solid...



Control cabinet and bits arrived just now so more stuff to play with



Going over to Wobblycogs tonight to have a catch up, talk CNC Routers and look at his control cabinet to get some inspiration...

[njhussey]

OK quick question. I'm now coming to the end of the mechanical build so my mind's turning to all things electrical

When connecting the CY cable to the stepper how do you folks do it? I was thinking of either via a chocolate block as near to the stepper as possible or probably I'll go with soldering the wires with heat shrink over them and then heatshrink over the whole lot?

[Jonathan]

I'd expect soldering+heatshrink to be the most reliable way to do it.

[JAZZCNC]

I'd expect soldering+heatshrink to be the most reliable way to do it.

Agreed it's the most hassle free way I find.!