Astro Images

    

Working with the NexStar 130 SLT Telescope

I have been using my NexStar 130 SLT for a year now.  I have had the problems that you would expect of a new scope user.  My first problem was alignment using the GOTO hand controller.  That is not a big issue now.  From the first day I could see that vibration was a major problem.  I have followed the suggestions that several groups have made.  All have made a difference.  The things that I will show you on my scope have made a big difference. 


One of my first problems was using the hand controller to align the scope to the stars.  One problem was not using actuate time, date and time zone information.  The next problem was low voltage on the internal batteries.  A set would be good for one or two sessions. Then alignment problems would start again.  I tried NiCad rechargeable, but they were worse.  They start with low voltage(1.2V vs. 1.5V).  The lead acid battery was the answer.  This is called a power tank or power station by some. 


The battery hangs close to the ground.

The image in the eye piece would bounce and vibrate each time that I touched the focuser or moved the direction of the scope.  The best suggestions were to tighten the nuts and bolts on the tripod.  I tightened them to the point that I could still move the legs, but they would not move with just gravity.  This helped noticeably.  The next suggestion was to stress the legs by attaching a weight to ropes and hang it from the support arms.  I was short on usable weights, so I used my battery and bungee cords.
The tripod is a great source of vibration.  Tighten all to the nuts and bolts so that they move with effort.  The bolt at the top of the legs need an Allen wrench for the socket head.  The others need a Phillips screwdriver.  If you need to fold the legs, they may need to be looser.  The tray that attaches to the spreaders needs to be in place for the additional support. 
Tightening a loose clutch assembly may reduce vibration.  These illustrations show how to tighten the nut and clutch assembly.  The tube assembly has a clutch which will allow you to move the tube to an up or down parked position by hand.  The clutch slips and does not over stress the plastic gears in the drive.  Too much force and a gear will break.  You might need adjustment if the tube moves up or down with very little hand pressure.  It seems to take a little force to start moving, then continues with little effort.  Do not over tighten this nut!
1).  The top photo shows the arm with the cover removed (2 screws).  The 10mm wrench in the start position.
2).  The bottom photo shows about a 1/8 turn, which may be to much.  Remove the wrench and test the pressure needed to make it move.  Turn on the power and run the tube up and down a little.  Listen to the sound to make sure that the motor is not working harder.  Loosen if needed.