After deforking my CPC800 I was intending to dispose of the CPC mount. However there was very little buyer interest and no-one was inclined to offer very much, so it sat around getting in the way for a year or so.
I was using the deforked C8 on the NEQ6 and also as a quick set-up on a modified AZ4 with an improved clamping arrangement. The NEQ6 was slow to set up and and the lack of tracking and rigidity made the AZ4 difficult to use at high magnification for planetary work. The aquisition of a C9.25 then started me thinking it would be nice to have a tracking Alt AZmount again, one that could be used with a variety of
OTA's and was relatively easy to set up.
After looking at the available options it apeared that the best course might be to modify the old CPC mount. My observations during the deforking strip down were that the drive side arm and bearings were extremely rigid and the opposite arm was almost purely decoration, having only a simple plain bearing with about 0.2mm of radial clearance. Some measurements with a dial indicator and load cell which gave a deflection of less than 0.25mm with 100N of horizontal force on the end of the drive side arm reassured me that a single arm setup was feasible.
I have a well equipped machine shop so the work did not pose any problems. The original drive side mounting plate and axle were utilised with fairly extensive modifications to get rid of the mounting arrangements for the C8 OTA. For mounting of the OTA on the new setup a second hand NEQ6 puck was obtained and machined to suit and also fitted with brass guide bars to improve mount rigidity.
A handle was made with a recess to contain the GPS.
I havn't yet had time to try the mount - as usual the weather turned bad just when I completed it. Some quick terrestrial observations with the 9.25 indicate that rigidity is very good and damping rapid.
To be continued...