Worm/motor support metalwork. Box tubular sleeve?

*

The 70mm square x 4mm wall thickness square tube ought to be tried next. Just to see if it would work both mechanically and aesthetically as a motor housing. The square tubing nicely matches that of the mounting itself. Carrying through the sharply outlined, "rectangular" theme without any jarring, visual discontinuities. Perhaps more importantly, the worm is lifted to the correct height for engaging the wormwheel.

The image shows the neat, outside, fully boxed-in view with the new 10mm motor plate. I think this could look quite smart if the square tubing was cleaned up and smoothed for an unblemished cosmetic appearance.

There is 2mm of freedom between the motor and the inside of the square tubing measured both ways. Which could be easily packed out with some thin aluminium sheet to stop any movement. This would help to ensure adequate conduction for motor cooling. An alternative [or addition] would be to suitably perforate the square tubing at the rear to allow air to circulate more freely around the motor.

Here is the inside view which faces towards the wormwheel. The box section, tubular aluminium needed to be slotted to allow the stepper motor to reach right forwards to the motor plate. The motor being much shorter than the worm bearing housing sitting above it. A beveled edge to the closed end of the slot avoids cable chaffing and aids plug fitting and removal.

I have just noticed that the sleeve could easily be reversed to place the large slot directly over the motor for cooling. I'll have to look into this option before I do anything else to the sleeve.

The worm housing has yet to be bolted down on top of the sleeve. An easily removable motor cover has obvious advantages for dismantling.

I have given the scrap tubular material a quick 'going over' with the angle grinder fitted with a flap wheel.  I had no idea until then that the aluminium tube had some form of coating. The ugly rust stains and scale needed removal anyway. The motor plate will need to be relieved on this side to allow contact between the worm and the large 11" RA wormwheel.

The box section, filled with its solid stepper motor, is more than stiff enough to be bolted directly down onto the base plate with short adjustment slots for worm adjustment.

Another cycle ride and I have the two hole saws I needed. A 31mm for minimal hub clearance in the motor plates for the large pulleys. Plus a 51mm for close clearance on the shafts for making axis locks. I thought something along the lines of a well anchored, split block. With a long tension screw clamping the split closed when needed. I am not keen on screws pressing directly [radially] on the axis shafts. Any burring will mean the shafts won't slide through the close-fitting bearings.

Click on any picture for an enlargement.

*