Moonlite Focuser for a 30cm Orion Optics

[John]

Thanks all

I'm not going to hurry this. I have the old focuser back on the tube for now so the scope is useable. The scope tube does already have a couple of holes from a previous owners guide scope (currently neatly stoppered) and one or two other marks from use - it's a 2006 OTA but the primary and secondary were Hiluxed in 2010.

[Moonshane]

Fair points above but the good fit of the base will stop any flop although as we know oouk tubes always move a little with weighty eps. I agree with tiny pilot hole then increase size carefully. The thin wall drills easily once you have a pilot hole.

[Moonshane]

I have some sheet Ali. Could send a piece to reinforce tube wall if it's of interest.

[John]

I have some sheet Ali. Could send a piece to reinforce tube wall if it's of interest.

Thanks Shane

I think I've actually got something like that here (amazingly !) - need to have a rummage in the garage though. I'll need to brace myself for that as it's a bit of a mess

[John]

Found myself with a few hours to spare today so I carefully made a paper pattern of the Moonlite base and selected fastening holes that were away from ones that the current focuser uses. I positioned the pattern over the tube, taped it in place and drilled 4 small pilot holes after carefully making sure the interior of the tube was completely shielded from metal fragments.  I then enlarged the holes to accept the M4 fastening screws. One hole needed a little extra enlargement to get the base plate snugly fitted and square with the circular aperture for the focuser. The baseplate fitted on quite easily then with the 4 hex headed screws and small washers going from the inside of the tube into the appropriate threaded holes in the curved baseplate bottom. The radius of the base plate almost exactly matches that of the tube so no filler / fillets are going to be needed. It all looks very neat and tidy and, importantly, firm. The old focuser fastening holes are completely covered by the Moonlite base plate. I'll probably touch up the matt black paint on the Moonlite fastening screws and washers instide the tube once I'm happy with the installation.

Next steps are to install the spacers, the focuser, then collimation and testing

Thanks for all the suggestions and helpful comments - much appreciated

[John]

Got the focuser fitted this evening - I needed both the .5 and the 1 inch spacers to get the right range of travel for my eyepieces. I've been observing with the scope a little this evening and it works really well. Collimation hardly needed adjusting.

The old focuser was a light weight job so I'm going to have to play with the counterweights at the back end of my dob a bit to cater for the heavier Moonlite unit.

A great upgrade and a pleasure to use