Questions on repairing a broken C8
Posted 08 September 2013 - 04:05 PM
I have since found a great deal on an orange-tube, vintage C8. My plan is to use the corrector from the older scope to repair the damaged C8. My thinking is that C8 correctors were mass-produced so it shouldn't matter if the corrector came from an older scope.
- Will the replacement corrector work with the newer mirrors?
- Is the size of the corrector opening the same for a Fastar-compatible secondary holder as a standard holder?
- Am I better off parting out the remains of the broken C8 and just using the orange-tube instead?
Any advise is greatly appreciated - thanks in advance!
Posted 08 September 2013 - 08:20 PM
Posted 08 September 2013 - 08:26 PM
... by touch up of the secondary mirror, and marking the optical orientation each component that provides the best view in the system.
Based on what I have seen stated here, the correctors are matched to the primaries at the factory by the opticians ...
Posted 09 September 2013 - 10:57 AM
Anyone else have more info or has anyone swapped a corrector from another C8?
Posted 09 September 2013 - 03:16 PM
Posted 11 September 2013 - 01:14 PM
Posted 11 September 2013 - 02:58 PM
Posted 11 September 2013 - 03:59 PM
Posted 12 September 2013 - 09:21 AM
Posted 12 September 2013 - 12:35 PM
Posted 17 September 2013 - 08:51 AM
BTW, I don't think any Super C8 was ever shipped with the Fastar secondary. Fastar first appeared on the second generation Ultima 8 in 1990. Long after Super C8 production ended.
Posted 17 September 2013 - 09:38 AM
It's that outer ring that starts to rotate (and then renders the notched registration pointless) which annoys folks with the faster compatible secondaries.
Posted 17 September 2013 - 01:20 PM
Posted 18 September 2013 - 12:24 PM
A lot of people said it couldn't be done but it worked out fine, using the Primary AND secondary with another corrector.
They were BOTH Black Starbright tubes tho.
We may have simply gotten lucky having both tubes made on the same corrector making machine??? or the mass produced
systems come out very close,
I tend to go with the Luck/same corrector grinding machine.
I would NEVER guarantee those excellent results again,
especially between an Orange and black tube.
If you are buying it anyway it would only be a matter of a waste of time if it didn't work.
remember to mark the corrector and cell.
Try placing the S/N on the corrector at the 3:00 position in the broken Black tube to start. I simply rotated the corrector 1/4" at a time until I achieved the best results.
I then fine tuned the components by first marking the secondary and turning it as well 1/4" at a time, then back to the corrector..you get it.
It was very time consuming, but it came out great!
The Doubles I split, and Planetary details were diffraction limited (at least) using known separation angles of the Stars.
I used up to a 4mm Ortho to visually test.
How did that system end up with a fastar Secondary on an old SC8+? I wasn't aware they were interchangeable?
Then again I never tried or asked if it could be retrofitted.
Good Luck.. and SHAME on the Shipper!