Helical non-rotating focuser

[Merlin66]

It's not everyday that something ordered from China/eBay turns out to exceed expectations.
Well I have to say that the helical focuser which recently arrived, did that and more! https://www.ebay.com.au/itm/164439365507


I use these focusers on all my spectrographs and up until now the Borg #7315 set the bar. Made in Japan, not cheap but excellent workmanship and rigidity.


This one, has the same well finished quality feel, well marked fine graduations (0.5mm), a very smooth movement over the 10mm travel and has a male T thread fitting for the telescope ( I think they also offer a variety of connections)
The 28mm clear opening is the same as the Borg.
All in all a great focuser for the price $36 delivered. (the Borg is us$109 +post)

So far, I'd highly recommend it.

[multiweb]

Been looking for a small travel 2" model. Most I've seen are 1 1/4". Have you heard of larger models? Would that hold ~900g without sag?

[Merlin66]

Marc,
Borg have a 2” model, but I think the connection options may be an issue.
I haven’t tried hanging 900gms from the helical, the cooled ASI 1600 or the ATiK 314L were about the heaviest I used.

[multiweb]

Cool - thanks. Will look it up. :thumbsup:

[Merlin66]

Marc,
Just had a look at the Borg/Hutech larger helical focusers....unfortunately they are NOT non-rotating......

[multiweb]

Bummer. I have a small QHY OAG that has one. I'll pull it apart and have a look. I might make one myself.