CG5 Mount Axis Locking Problems

[YorkieGraham]

I wonder if anyone can help me with my CG5 mount. The locks to both axis clamp up tightly but the declination axis still retains some play in it and this is become worse over time. When fully locked I can still move North and South before it comes against a stop. I dont want to start stripping it down before knowing what I am looking for. I posted this problem a while back but the advice about taking the lock handle off and adjusting the pin has not made any difference. Has anyone else had this problem and if so - how did they fix it - It is making life very difficult when changing EPs as I can easily knock the image out of the FOV. Then I am back to low power again to find the target. Imaging is becoming a nightmare!

[spaceboy]

You need to adjust the worm gears and end bearings.

[billhinge]

Coincidently I've just completely stripped down and put my CG5 back together again. The black plastic clutches are just a pressure friction pad against the outer surface respective aluminium worm wheels. When locked the worm wheel is held stationary and the axis rotates inside the worm wheel caused by the screw effect of the worm turning on the wheel

When you say there is movement do you mean rotational movement, i.e. you can hand rotate each axis when the locks are down, i.e. its slipping

Or do you mean that there is some side to side or up and down movement?

By the way have you ever opened the mount up before?

[YorkieGraham]

Thanks,

If the locks are down the axis wont move very far - it only moves a very small amount and then stops in both directions but its enough at high magnification to cause a nuisance - and its enough to see visually looking at the mounted scope. Also when I am using the motors it takes time for the commands to start moving the axis - I dont know if this is related. I have never opened the mount before and was reluctant to do so unless I had to, plus I didnt want my mount to be out of use too long. Especially with Mars so good at the moment. I guess if it is adjustments to the worm gears and end bearings I had better take the plunge.

[spaceboy]

This may help Astronomy Boy: CG-5 Mount Improvements. Don't think you have to do a complete strip ETC as it is only slack in the worms/end bearings. There are plenty of other guides how to adjust the worms on the net if you do a quick search. Time and patience is the key as too tight the worms will bind and you already know the too loose

[billhinge]

One thing to be aware of and it really isn't documented well on the astronomy boy site is try to record where things came from - preferably take pictures. Be careful especially with the RA axis as the plastic CG5 motor housing is a very tight fit for the internal circuit boards (I read somewhere to avoid touching certain metal parts of the circuit board - will be covered in clear plastic). I recommend making a note of the orientation of the circuit boards etc before you pull the housing fully apart because it can be very fiddly to put back together. Celestron shot themselves in the foot with a bad design to save a few cubic inches and came up with an ingenious solution to solve a problem of their own making. Notice the two teflon sliders under the RA motor. When the floating circuit board goes back you need to tuck one edge of the board in a little recess on the plastic housing, as you push the two halves together the bottom of the circuit board will slide at an angle on these teflon pads.

As an aid to get the tension right I normally test the naked parts in situ with the motors running to judge if its too tight.

Sounds complicated but once you've done it once you will be able to strip every screw and ball bearing down and put it back together again.

Before you do that though I take it you can't get it fixed under guarantee ?

edit - the dec axis is easy, just the RA that is fiddly to put back together

good luck!

[YorkieGraham]

Thank you everyone for your advice. Now I know what needs doing, I am about just start stripping the mount to get to the wormgears. Wish me luck!! I will post how I get on.

[spaceboy]

? You don't actually need to strip the mount to adjust the worms. You may have to remove motors & boards but that's about it.

[YorkieGraham]

:hello2:Didn't even need to strip the motor and board for the declination axis. Have tightened the worms and the bearings and its a solid as a rock now, so THANKS for all the help and encouragement. Now I might be able to experiment with my guiding kit which I purchased a while back. Shoestring conversion for the handset, skywatcher startravel 80 and QHY5. No doubt Ill be back on hear soon for tips getting that going!!! Smiling now though

[billhinge]

How did you do that if I can ask? The worms and bearings covered on my CG5 with no visible moving parts

[spaceboy]

How did you do that if I can ask? The worms and bearings covered on my CG5 with no visible moving parts

CG5 with dual axis motors not a CG5-GT

[billhinge]

Ah - I see, my mistake