TheSkySearchers

Hi All,

I have obtained a new scope. One of the interesting things about the DIY dob is that comes with a prototype for the Kineoptics HC-2, a helical focuser.

Kineoptics website is here: http://www.kineoptics.com/HC-2.html

To be honest, I have never used one before, but do have a Crayford Moonlite to compare it to. What I have found is that the helical focuser is growing on me.

1. The nice things this focuser has is its very light weight, and an extremely low profile. The beauty of a low profile is that the design allows for a very small secondary. Also, the design is very minimalist - with little intrusion of the focuser tube into light path of the business end of the scope. As its a Crayford, its smooth. Also this is a very inexpensive focuser @ $107 USD or so. Its so light that my scope has an extra balance weight up top to provide overall balance.

2. What may not be too good about the design:
The ID of the draw tube provides the bearing surface for the crayford mechanism, and it can accumulate dirt, which can lead to a grainy feel when focusing in and out. There is no fine focus per se.

How does it compare to my Moonlite Crayford?

Honestly, I found that in my dob, I could achieve as fine a focus as I can with the Moonlite in the XT10, and then lock that down with the lock screw.

Overall, the helical focuser design emphasizes low profile and low weight, and my first inclination was to replace it. After a couple of sessions, I have decided NOT to replace it.
They are a nice piece of kit.

Thanks for reading to the bottom,
Ian

Thanks for the insights Ian. I see that this is not your typical helical focuser which usually have short travel. Nice that there are some options for DOB focuser replacement out there.