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View Full Version here: : HEQ 5 pro backlash problem


jimmyh1555
22-11-2017, 07:12 PM
I went out this afternoon to set up the scope for trialling my Synguider 2, and was trying to align the main scope (BT200 Neut) with the Celestron 60mm finder. I got all lined up on the TV aerial on a house about 100 m away. I couldnt seem to get both eyepieces to centre the target (one EP was illuminated crosshair recticle) then I noticed that when I nudged the scope in the declination direction, with the clutch tight, the view moved considerably. I took off the covers poked sbout with the gears, but all seemed tight. There must be something deep in the bowels of the mount that is loose :shrug: It would seem a big job to strip everything down.....Any suggestions? The backlash seems to be enough to completely stuff up any imaging because if the scope moves and changes the balance, then the whole view will change quite a few arc sec onds.
The R.A. axis seems pretty tight:mad2:

doppler
22-11-2017, 09:37 PM
It's pretty easy to tighten things up if you have a guide to work to. Section 5 has info about adjusting the worms.
http://www.astro-baby.com/heq5-rebuild/heq5-m1.htm

jimmyh1555
23-11-2017, 09:39 PM
HEY! thanks for that Doppler. Those instructions seem really professionally done! That's what I will be doing this weekend. It's down to the servo for some lithium grease :D

pjphilli
24-11-2017, 01:11 PM
Another thing to look out for with HEQ5 is the way the azimuth knobs work loose and can spoil hard won polar alignment and give puzzling results. I recently fitted locking nuts to both azimuth screws so that I can lock them in place after polar alignment.

jimmyh1555
25-11-2017, 09:57 PM
Good idea, Peter, I will do that. One other problem I have with the HEQ5 is those T bolts, when polar aligning. They are so hard to turn, I almost bust my fingers when lining up the star as instructed by the Synscan. And when they did turn, the star whizzed across the eyepiece! Can I loosen the elevation somehow to make it easier to turn the T bolts, or is it always hard because of the weight of the scope? (I always balance it quite well!)

pjphilli
26-11-2017, 10:39 AM
I also find the T bolts a bit hard to turn and you can often overshoot the desired mark. Last time I polar aligned I took the bolts out and put a bit of lubricant on them which helped. By the way, do you use the PHD software for guiding? I find that this is a great program and it makes polar alignment much easier using your control PC screen - are you familiar with the technique?

raymo
29-11-2017, 11:31 PM
I have never had trouble moving the azimuth bolts; are you slackening off the
central bolt beneath the mount a little, and retightening it after azimuth
adjustments are complete? If not, you will eventually strip the threads
either in the mount or on the bolts, or both.
raymo