22.12.2020 RA drive mods underway.

 *

 

Tuesday 22nd mild, 46F, misty and overcast with early drizzle.

I have started work on reinforcing the RA drive assembly. The M6 screw holes need countersinking inside the motor box to allow the heads to clear the motor. This process is very time consuming and there are lots of them. 

The images show the progress so far. All firmly bolted together. The assembly was posed in the correct orientation. It hangs below the large, 10mm motor support plate from the two, projecting screws at the top.

I still have to make a new, front motor plate. This plate helps to lock the motor to the rest of the assembly. At present the motor is just inserted into the box section. There are flour threaded holes in the motor end plate and a further four in the worm housing. Providing a solid connection between the two when the plate is in place.

I have a whole selection of small grub screws now. So I can reduce the diameter of the larger [32T] timing sprocket hub in the lathe. It wants to be smaller than 28mm. So that the motor plate can act as a bearing stop for the outer race. The old motor plate had a very large hole, to clear the generous hub. Which did nothing to restrain the bearing.

The angle profile stiffener I had made for the tail end of the motor no longer fits the new layout. So it will have to be remade from scratch.

The bearings shown are the old ones and just pushed into place for these photos.

Grr! The drive belt is now so tight that it stalls the drive motor! I was tempted to order a longer belt from Rip-off Spares.dk but they want 85DKK or £10.38 for delivery of an item weighing just a few grams. I'll keep looking for a Danish stockist of T5 x 10mm belts in 265-270 length 52 or 53T.

I have now ordered several different, slightly longer belts, a smaller timing pulley and a microswitch from a German dealer pretending to be Danish. Rather than a UK dealer only pretending to be Danish. The prices were much lower. As was the postage. Delivery in the new year.

I spent some time on the lathe reducing the hub of the 32T sprocket to 27mm. Then fitted shorter grub screws. Any idea of moving the worm across via slots for the fixing screws would have made a motor plate impossible.

Later I re-checked the dome base ring with the laser level as I turned the dome. The problem seems to be the dome base ring is not flat. Since there are gaps between the tops of some of the rollers and the base ring only some of the time.

*