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View Full Version here: : Loose screws on my scope causing "falling" back


alexk13
11-06-2008, 03:09 PM
Hi Guys

I've noticed that my dob falls slightly backwards when release pressure when lining up n any object, and I tracked the problem to these screws:
http://i76.photobucket.com/albums/j8/unimaetrix/dob_loose_screws.jpg
it is the same on both sides - seems they just loosened up a bit on the weekend, they were fine when I first setup my scope (not even 2 weeks old yet):(

:help: My question here is this: is there a special way I should tighten these as the corresponding nuts (inside the tube) are a long way from the open end of the scope, but I do not really feel like taking the mirror off - I have thin arms, and can just reach the first nut, but not the second - and yes I am being extremely careful with the spanner I'm holding inside the tube above the mirror, I have it strapped to my wrist - lucky i have thin arms, but do i need them to be 6 inches longer.

Would like to solve this myself as taking the scope to the shop on my motorbike is not an option, and I don't have access to the car for a few days

Any tips on this issue appreciated

astronut
11-06-2008, 05:01 PM
Alex,
Yes, make sure that the screws are tightened up.
Then to keep everything tight, I suggest that you use BLUE LOCTITE.
This is the semi permanent version. It will still hold everything securely without slippage, but it will still allow you to pull it apart if necessary.
Don't use the RED LOCTITE this is the permanent version.:thumbsup:

JimmyH155
11-06-2008, 05:14 PM
AND DONT GET THAT LOCKTITE ANYWHERE OTHER THAN THE SCREW THREADS:eyepop:I got some on the plastic case of my Argo Navis and it ate into the plastic AAAGGGHHHHHH:mad2:

astronut
11-06-2008, 05:25 PM
Great advice!! I agree:thumbsup:

rmcpb
11-06-2008, 06:10 PM
Just drop the primary mirror cell out of the tube, 6 screws around the base. Reach in and tighten the screws, not over tight, and fix with Locktite. Put the mirror cell back in and collimate. Easy!!

Screwdriverone
11-06-2008, 08:16 PM
Hi Alex,

I am glad to hear that you have found out the reason for the dob not staying put. I must admit that it was starting to annoy me in the small time I was using your excellent scope on the weekend. It almost, "almost" made me want to rush out and buy a dob. Ahh yes, then I remembered my tracking EQ mount and viewing Centaurus A as well as M104 - Sombrero galaxy through my scope and I fell in love with it again.

Doesnt mean I wont ever buy a dob, but for now, I will make do by stealing some time on yours whenever we catch up, which by the quality of the WSAAG night is anything to go by, will probably be every meeting :lol:

PS. I like the signature, very cool.

Cheers

Chris

alexk13
12-06-2008, 09:31 PM
Thanks Guys, I was able to tighten the screws, but i do not have any loctite yet - will try to get to Bunnings on Saturday.

It has made a world of difference to my viewing, and I'll be posting an image or 2 really soon that I have taken tonight :D

Chris: That image in my avatar is one of the moon i took while it was trying to pose as Mars or Jupiter ;) It's pretty cool I think