Kentmd Is there an adapter on the market to be able to use the EAF?
Funny that you asked, since I posted this just last night:
https://bbs.astronomy-imaging-camera.com/d/16207-alternate-eaf-mounting
The long EAF plate is bolted onto one of the M4 threaded holes on a Borg 7517 tube. You may need to drill and tap your own holes if you are using some other tube (and remember to use short screws to avoid the light cone, and paint it matte black.
The focuser shown is the Borg 7761. If you are using the Borg 7757/7758 series, be mindful that their resolution is half of the 7761.
Otherwise, all the brackets are from the standard EAF kit. I do use my own EAF mounting plates for my other OTA.
The follow-focus rubber ring gear (MXL teeth) is from here:
https://tilta.com/shop/seamless-focus-gear-ring
They are double wide with a seam down the middle to let you slice it in half, and that is what I did.
I haven't yet checked to see if they have a ring gear to fit the Borg helical focusers for their 80mm tubes, like the Borg 7835 and 7875 (I have a couple of those too).
The drill bit needed for a M4 tap is 3.3 mm, but you can often buy a tap set that comes with the correct drill bit. But you can just use a 1/8" drill bit -- it will work :-).
Remember that the focuser ring of a Borg helical focuser moves. So you will need a pulley at the EAF (5mm bore) that is wider than the ring gear itself (which you can see in my earlier post).
The only backlash I notice is from the EAF itself. But I have yet to test it when it is freezing.
Chen
