AWR Intelligent Drive System Pt.9. Worm support metalwork 3.

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30 years after I bought the cheapest Chinese pillar drill available at the time, I have replaced it with a bigger and better one. The smaller pillar drill had clapped out head bearings from new which needed replacing. It worked after a fashion, after that, but was always noisy, grossly under-powered and ran far too fast even at the lowest of its 5 speeds. Now I have 12 speeds down to 180rpm and a much more useful throat depth. 

The major cost was in having to handle a huge lump of machinery weighing nearly 70kg. Then find a space for it in my cluttered workshop. I had to adapt and beef up the original shelving with 3/4" plywood and support it with independent 'legs'  to avoid overloading the [heavy duty but still amateur] shelving units. The workshop required a once in a lifetime tidy which it is unlikely to forget.

The next job was to photograph the ridiculously tiny pulley selection chart inside the drill's hinged lid. Then blow it up to a useful size to just fit on A4 paper. I then printed a clear black and white image, with pulley numbers added, and pinned it to the wall behind the drill.

I still have to attend to the table locking lever which is a grossly undersized, hinged, waste of space. The present device does not offer remotely enough leverage without lots of unnecessary hand strength at full arm's reach. Easily fixed without altering the drill.

The new drill proved easily able to drill steel in 16mm diameter from a suitably large pilot hole. The old drill couldn't manage 10mm safely.

The next problem was finding some 6mm [1/4"] aluminium angle for the motor fixing brackets. I had various sizes up to 50 x 50 x 5mm but nothing at all in 6mm. A 20 mile cycle ride produced nothing from my engineering sources. So I resorted to the Internet and placed an order with a German company willing to deal with private customers.

With a little help from Google translate I ordered a couple of 30cm lengths of 70 x 70 x 6mm angle. These will be cut to shorter lengths and one angle "wrapped around" each stepper motor. Vertical, countersunk screws will fix down the worm housings to lie right on top of the motors. An 'inverted' angle will then be "nested," one inside the other, to bolt down the worms to the 10mm base plates. The front motor plates will continue to join the motors to the worm housings.

Serious Danish metal stockists are strictly wholesale. They might as well be situated on the Moon as far as I am concerned. Neither Amazon nor eBay[UK] had anything to offer and the prices and postage were higher on eBay for the same profiles.

Once the worm/wheel mesh is perfectly adjusted I shall probably add narrower sections of 6mm angle, or solid metal strip, at the fronts of the motors, to further reinforce them against twisting away from the wormwheels under load. Slots with through bolts will allow the vital but small degree of movement.

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