Fitting a Moonlite focuser to a TMB 105 CNC

[dannybgoode]

Well this is potentially quite exciting for me. Whilst the huge CNC focus wheels of my original TMB 105 are things of engineering beauty and do a fantastic job for visual, making ultra fine adjustments for AP is very difficult (though not impossible-just takes time) and any form of autofocus is out of the question without modifying the scope which I really don’t want to do. 

So the alternatives are something like the Primaluce Asseto or somehow fitting another focuser in the chain. I have a Moonlite unit which has an SCT mount for my Meade 10” and then I remembered the noise piece for my Antares 2” extension unscrews. Hmmm, will the nose piece have the same threading as a Meade SCT meaning I could screw it into the focuser and then plop the Moonlite focuser into the 2” EP holder in the main focuser?

And would you believe - it does! The only question is whether the optical chain is too long. I don’t think it is because before without the Moonlite there was the extra bit of the extension tube and the main focuser needed to be an inch or so out but will only know for sure when I have chance to try it out. 

If it does reach focus though then autofocus becomes a reality . If it doesn’t at least I have proof of concept that an Asseto or a shallower second focus unit will work. 

[Merlin66]

I use the same idea, the nose piece from a 2" adaptor which gives a male SCT thread. This allows the SCT accessories to be fitted to my ED80 scopes.

Re focus motor The original Genesis I have doesn't lend itself to modification to fit a new motorised focuser. Thought about the problem for almost ten years...........

Finally figured out a solution - just add a belt driven SW focus motor to the edge of the existing focuser knob. Works very well.

 

[dannybgoode]

Darn it. Can’t reach focus with the Moonlite. Hmmm, a little frustrating but at least I know it can be done. Just need to decide which route to go as an autofocus unit would be a significant help.