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Thread Seizing (Binding) Woes

Started by brucesdad13, 02/04/2015 08:26AM
Posted 02/04/2015 08:26AM | Edited 02/04/2015 08:28AM Opening Post
I'm having some issues with threads getting stuck. It may be due to temperature changes. The first time my Celestron f/6.3 reducer got stuck to my C8 SCT. I had been viewing outside in 0 degree weather and came inside. I thought perhaps it was due to the metals expanding differently. Then the other night I was viewing again and my Celestron 2" diagonal got stuck to the Celestron reducer (on the 2" side this time).

It took some large clamps and wrenches to loose them. The first time the teeth from one wrench left marks in the reducer. cwy I had tried to protect it with some fabric but perhaps some leather or rubber would have been better. Last night I tried leaving the reducer and diagonal outside in the low temperature air all day in hopes that at lower temp I could separate but no luck so it was back to the tools.

How can I prevent the threads from seizing up on my equipment? :S It's very frustrating and I don't want to damage anything. ~ Charlie

Edit: Does this look like it would do the trick

~ Charlie Stevenson

8" f/5.7 String Telescope - 1st Scope Build; 2nd Place Stellafane 2016 Optical Award for Newtonians 12.5" and Smaller
10" f/4.5 Newtonian (June 2015) mirror refigured by Optic Wave Labs P-V WaveFront 1/14.24, Strehl Ratio 0.993 (Aug '15)
Criterion RV-6 seems to be circa 1973 (June 2015) [For Sale]
Celestron C8-A XLT (January 2015) [For Sale]
Celestron PowerSeeker 70AZ (Christmas 2014)
Aldrich Astronomical Society member since 2015
Posted 02/04/2015 09:46AM #1

A friend had the same problem several years ago with his C9.25. If I remember correctly, we wrapped a couple layers of Teflon tape (in the plumbing aisle at Home Depot) on the male threads and that helped.

The other thing is to remember that these parts don't need to be screwed together with gorilla force. Finger tight should do it.
Posted 02/04/2015 10:35AM #2
Hi Charles, my two cents also. Certainly been there on my SCT and scared I would demolish it when I was replacing the existing back with the "Eye Opener" which has a bigger clear thru-hole. Catch-22 is some stuff we add onto the business end are SO heavy and cantilevered that if you don't go quite tight the whole thing can decide to spin when least expected. Like 2-inch diag with huge WF eyepiece, OAGs, cameras etc. I haven't ruined anything yet. At work, the techs would use "differential heat" in extreme cases. You heat the outer part FAST with a shop heat gun and twist off before the inner part gets as hot. Risk is of course ruining the thing with heat. At home I STARE at it a long time and then (if possible) take it out to the shop where I can brace everything in a controlled environment. Often anodized Al parts they fail to take into account the added thickness introduced by the surface hardening treatment. And if you break thru the surface the Al underneath is soft as butter and galls like glue so a bad situation gets far worse. In the most touchy situations I have added clocking constraints that don't rely on ultra-tight thread friction holding it. That's easy to do and fool proof, provided you don't mind customizing your stuff. I don't think I've helped...just venting same complaint as yours. Tom Dey

29-inch Dob in a dome
36-inch upgrade soon
LUNT 80/80 solar scope
FLI 6803 cam
APM 100mm APO Binos
JMI RB-16 Night Vision Binos
Zeiss 20x60 IS binos
Posted 02/04/2015 01:41PM #3
Charles, I don't know if this is helpful, but I have a friend(Ken Dauzat) who once made telescope parts, and anytime he buys something with two aluminum screw together components, he greases the two threaded parts.

[COLOR="Blue"]Darian Rachal[/COLOR]