Carl
I have posted here:
http://www.iceinspace.com.au/forum/s...ad.php?t=76314 and I cannot get good results with an 80mm OTA with the HoTech Flattener yet - still trying to work out a solution but the bad weather in WA is holding me back so far!
In theory you will insert the FF into your 2" focuser drawtube in the rear end and on the T2 Thread end is where you attach a camera/imaging CCD - there is a fixed distance requirement from that T2 ring to your image sensor and I believe it should be 55mm backfocus
If you can make it work please post the spacer distance that you use so I can try it out too!
The instruction sheet can be found here :
http://www.hotechusa.com/v/vspfiles/...0sca%20ffl.pdf
HTH
Cheers
Bill