39 replies to this topic

[jragsdale]

Machining is unavoidable in your case, unfortunately.

The AP Star 12 is from 1991.
In 2011 I was able to upgrade it to the current AP 2-speed focuser easily by simply threading on. It’s a good system for easily changing focusers, a system still in place. Although in 2011 the focuser was half the price of current ones.

Yeah, that's a gorgeous scope! Since I'm moving to M117 threads, it will be fairly upgradable in the future since it'll be a standardized thread size that are used by a lot of different focusers. I consider an Astro-Physics scope to be a "modern" scope, so upgrading parts that adds to extra utility and performance shouldn't detract from its value and desirability (in my opinion).

[CHASLX200]

I got two AP focusers from 1998 but would have to be rigged to work on a 6" tube since the back plates are missing.  These were worth money back in the day but not sure now.  All machined.

[Senex Bibax]

As my dear old dad used to say, “If it don’t work, use a bigger hammer!”

 

DonW

"If it jams, force it. If it breaks, it needed replacing anyway"

[starman876]

Yeah, that's a gorgeous scope! Since I'm moving to M117 threads, it will be fairly upgradable in the future since it'll be a standardized thread size that are used by a lot of different focusers. I consider an Astro-Physics scope to be a "modern" scope, so upgrading parts that adds to extra utility and performance shouldn't detract from its value and desirability (in my opinion).

feather touch used to make a backing plate for the AP 6" F8.  I went down this path with them.  They still had it listed, but could not find the drawings to make one.  I think they removed it from their catalog since then. 

[jragsdale]

I took the focuser flange and tube into the machine shop today. Had them reface the flange to remove the casting texture to allow a cleaner install of the new focuser. Going to powder coat or anodize the flange when it's done.

 

Had them cut an inch off the tube, it was already square before but a little damaged and out of round on the lip, plus extra holes I didn't plan on using. I will redrill the mounting holes but go with 6 tapped screws into the flange instead of 3 tiny set screws to hold on the focuser flange. 

 

I have the new focuser already, just need to have an adapter machined to fit the flange. Then drop off the tube and parts to be stripped and powder coated. Woohoo!

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[starman876]

I took the focuser flange and tube into the machine shop today. Had them reface the flange to remove the casting texture to allow a cleaner install of the new focuser. Going to powder coat or anodize the flange when it's done.

 

Had them cut an inch off the tube, it was already square before but a little damaged and out of round on the lip, plus extra holes I didn't plan on using. I will redrill the mounting holes but go with 6 tapped screws into the flange instead of 3 tiny set screws to hold on the focuser flange. 

 

I have the new focuser already, just need to have an adapter machined to fit the flange. Then drop off the tube and parts to be stripped and powder coated. Woohoo!

The love you are putting into that scopes.   The scope deserves it 

[jragsdale]

The love you are putting into that scopes.   The scope deserves it 

Absolutely, it's rare to find a scope as worthy of an extensive makeover as this one. This is also the silver lining of getting a great deal, there's more flexibility in the budget to perform a GREAT restoration on it, to elevate it to iconic status that will easily last for many more decades to come.

[jragsdale]

Flange drilled and tapped with 6x #8-32 stainless screws now, big improvement over the 3x 6-32 tiny set screws!

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[starman876]

I always thought those little set screws was an interesting way to build a scope

[jragsdale]

I always thought those little set screws was an interesting way to build a scope

It was interesting, that's for sure. Especially with such thin wall tube. It certainly kept the focuser square as there was no way to adjust the flange with the set screws present. I'm sure they were "good enough", but good enough is not the approach Rolando takes with his lenses, so the scope should match the lens in this case IMO.

[rwiederrich]

It was interesting, that's for sure. Especially with such thin wall tube. It certainly kept the focuser square as there was no way to adjust the flange with the set screws present. I'm sure they were "good enough", but good enough is not the approach Rolando takes with his lenses, so the scope should match the lens in this case IMO.

Your focuser will fall off before that back plate......  fun work indeed.

 

Rob

[bremms]

Please allow me to suggest an older used modern AP focuser , one with the same threads as the current ones. Single speed and often in the classifieds as owners upgrade to the current version. Has “Astro Physics “ engraved. That’s the best part.

Examples below.

https://www.astromar...-focuser-605929

https://www.astromar...-focuser-582264

https://www.astromar...ser-and-adapter

I’ve bought a few of these on the Classifieds. 

[CHASLX200]

I’ve bought a few of these on the Classifieds. 

I got two like it for some kind of trade years ago and forgot i had em until i was throwing junk in the trunk out. They cost a lot back in 1998.

[jragsdale]

Here's the finished focuser, tilt plate/adapter and flange. My "lathe master" friend rocked out this perfect part that fits the flange with 4 sets of push/pull screws to help during collimation and converts it to a nice male M117 thread that fits this awesome TS Optics 2.5" R&P focuser. I'm going to send these parts off to be anodized and I'll be good to go!

 

Unrelated to the focuser, but the tube and dew shield are off being painted at body shop in classic Astro-Physics Cadet Blue! 

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[starman876]

Absolutely beautiful