5 replies to this topic

[Stswensson]

Hello fellow stargazers. I purchased a second hand Celestron C6-R and AVX mount and I'm very excited to try out my "yard cannon" but it needs a little bit of TLC first. Unfortunately the prior owner kept the telescope and mount outside here in humid Florida. It was kept in a screened in porch but still exposed to the high humidity. There is a small amount of surface rust on the tripod and exposed screws which I have already removed. I also disassembled the AVX mount and cleaned out the "grease" and replaced it with Super Lube. I have also replaced the stock focuser with the stock focuser from my XLT 120mm which I have already fine tuned.
The last thing I want to do is replace the 3 Phillips head collimation screws. The 3 screws have some surface rust but due to their small size I would rather replace them but I have no idea what size they are and I cannot find any information after hours of searching online.

Does anyone the size of the 3 Phillips head collimation screws on the Celestron C6-R??
Thank you and clear skies!

[Sean13]

I would check mine but its collimation is perfect and I don't want to screw it up. Why not just remove one and go match it up at a hardware store? Even if they don't have the exact replacement, you could at least figure out its thread and length by matching it to other hardware or the sizing chart at most hardware stores.

[terrellfriedrich]

Order a set of Bob's Knobs and replace them all 1 at a time. Makes collimation much easier which you will certainly need to do if you replace the collimation screws. Make sure you familiarize yourself with the collimation procedure. You may find the process a bit daunting, to the point the rust on the screws may be tolerable compared to re-collimating. Unless of course the scope needs to be collimated in the first place.

[Stswensson]

I would check mine but its collimation is perfect and I don't want to screw it up. Why not just remove one and go match it up at a hardware store? Even if they don't have the exact replacement, you could at least figure out its thread and length by matching it to other hardware or the sizing chart at most hardware stores.

I wouldn't want you to remove any screws especially if you have perfect collimation. I think I will just take one out and take it to the hardware store.

[Stswensson]

Order a set of Bob's Knobs and replace them all 1 at a time. Makes collimation much easier which you will certainly need to do if you replace the collimation screws. Make sure you familiarize yourself with the collimation procedure. You may find the process a bit daunting, to the point the rust on the screws may be tolerable compared to re-collimating. Unless of course the scope needs to be collimated in the first place.

I was surprised to see that the C6-R was in pretty good collimation but I still want to replace the screws. I am familiar with the procedure. I tried Bob's knobs on my Evo 8 and I found it hard to make very small adjustments. I replaced the Evo 8 collimation screws with Allen head screws and have a T handle allen wrench which allows for extremely small adjustments that I was unable to do with Bob's knobs. Unlike my sct my refractors don't require collimation as often. Thank you.

[terrellfriedrich]

Agree, and in a perfect world Bob's Knobs would have an Allen wrench socket incorporated in the head to make those final tweaks easier.