31st January 6" f/10 H-a telescope all but finished.

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Friday 31st overcast 44-46F. The post brought the new, M5, stainless steel collimation screws and [A4 SS] T-nuts.

The laminated plywood counter cell proved to be far tighter on the main tube than I had imagined. I had the main tube standing on its flange on a heavy concrete slab. While I used a 2x4 as a pile driver to wallop the ring down the tube.

A plastic ring protected the plywood ring surface. It must have been at least 20 minutes before I reached the "business end." The flange finally sank into the recess and I could relax. Lunch time!

I made rapid progress this afternoon. I have the lens mounted on the tube. I used smaller M4 screws to hold the rings together. The heads have been flattened with a file to act as pressure pads for the collimation "push" screws. Nyloc nuts on the back of the rings will avoid loosening.

The tube rings are ready to be attached to the saddle on the mounting. With unused "machine feet" acting as thumbscrews with their shanks relieved to allow the rings to be clamped. The images show the details. The tube rings were rated for 160mm but the main tube was 162mm OD:

The tailpiece matches the one I made for the Celestron 6" f/8.

The alloy ring is a clamp for the 2" WO extender. Three screws clamp the extender while three screws hold the clamp to the tailpiece. Now fitted with much shorter screws counter-bored into the plywood tailpiece. I had threaded the holes in the ring so the nuts, in this earlier illustration form yesterday, were completely unnecessary.

With the addition of the PST etalon and filter stack the new telescope is almost ready for use. The only thing missing now is internal matt black painting and a baffle system. Oh, and the D-ERF and holder which I returned to Telescopes Express two weeks ago. That was because the filter would not fit into the holder! I haven't heard anything since they confirmed the returned items were received. Reminder email sent!

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