10" LX200 Problems

I am hoping i can get one or several problems fixed through here.

I have the 10"LX200 3 years old.

First problem.

I seem to have a dead spot in my focus.
The focus knob is smooth, but i get to a point where i hit a slight bind for about 1 full turn. Usualy that spot is at the same point where i need the focus for say Jupiter, or a Star. I can not retain a precise image on a star.

Second problem.
I can not get a pin point star? I mean even after the scope is cooled down, i have never been able to get pin point stars. I threaded a Kendricks 2" laser to the rear cell and the beam does not even come back to the laser, it sits on the other side of the return baffel.

I tried to colminate my C-8 once and never again. It was a long process, and i always ended back up where i started never any better.

Third problem.
Even though i have the scope saver table, it's a pain to screw in the threaed rod to hold the forks. Last night it took me 40 mins to attach the scope to the table. In the process i started to strip the threads on the base of the forks.


Can anyone help me out here? I am so frustrated and have less hair from pulling it out.

I will take a pic with the laser hooked up to show what i mean, but i cant for the life of me imagine the mirrors being off that much as the Moon and Jupiter to come in very clear.

Thanks
Roger

Ok here is a pic, best i could do sorry about it not being clear.

I did notice that the laser does go inside the baffle tube now? not sure how that happened as i never touched the screws on the secondary.

Also should the laser bounce off the secondary and right back to the laser as in one beam? Or will vary on scope to scope as the mirrors are not all the same?

Thanks
Roger

Attached Image:

Here is what I can come up with...

1. Maybe from the focus being in one spot for a long time the grease has shifted or even made a slight rough spot on the bearings? There are focuser replacments available and I've read nothing but good about them. EZ-Focus and them are on the Amart homepage.

2. Depending on your seeing... you'll never get pinpoint stars with an 8" scope unless you are at a very low power or the atmosphere is perfect that night. With the supplied 26mm SP you should get them though under decent conditions.

Also, you may have some optical problems not collimation problems. That would allow you to come to focus on the moon and things, but not get perfect stars under higher power.

3. The LX200's are a pain to get on there ... no way around it from what I've found. I don't use a SS table, but what I do is just set it down very gently on the tripod with 1 hand UNDER the base and my finger on the hole. That way I can feel where the screw is and guide it into the base easily. Then I just make sure that is screws on smoothly. If you notice a lot of resistance, it is cross threaded.

Hope that helps! Maybe some optical experts can help you out... I'm not one at all

Roger,
For your focus problem, try turning the knob all the way CCW, until it stops, then back CW, until it stops, several times. This will move the mirror from one end to the other on the baffle and will help redistribute the grease. If this doesn't work, then you may need to remove the focus knob assembly and re-grease it. I give instructions for installing the bearing modification on my web page, www.starcrwzr.com/focuser.htm which should help you get it apart and re-greased. I highly recommend this modification.

Your second problem sounds like collimation to me. First thing you should do is throw away the laser, they are useless, in my humble opinion, on SCT's. Next, collimate the scope in the daytime, using an artificial star, it's MUCH easier. Search the Mapug archive for information on doing this. www.mapug.com

As far as mounting the scope, the best think I can recommend is a little bearing grease on the threads of the bolt and inside on the threads of the base. You'll be surprised how much easier it is to mount.

Hope this helps.

--
Scott Baker
Vice President, New Member Mentor
San Diego Astronomy Association
http://www.sdaa.org
International Dark-Sky Association
http://www.darksky.org
Personal web page: www.starcrwzr.com