After a couple of months of disuse because of the bad night weather I fired up my HEQ5Pro last night. I roughly rechecked the polar alignment and then set it running on PHD guiding. I noticed that over several minutes the DEC guiding was drifting by up to about 5 pixels even though the correct pulses were being sent by PHD (I monitor these on leds). After about 5 pixels North I could hear the mount give a clunk and the DEC guiding would jump to about 2 pixels South and the above process would repeat itself. I think that after a couple of months of disuse my mount may need a service (couple of years old and not touched since new).
Could anyone point me to directions for simple service/lubrication procedures for the DEC drive (maybe the RA at the same time). I would prefer not to do a complete strip down - just as much as necessary.
Thanks Alfi and Doug
This is just what I was looking for and I will first try the worm gear adjustment to decide whether I need the complete stripdown.
Cheers Peter
Be very careful when you do this. I did it myself and introduced the most horrendous backlash into my system that took me forever to work it out.
If there is one peice of advice I'd give you it's that when you make the adjustment make sure you only turn the grub screws a quarter turn at most, and when you first try the new setting make sure that you only have your mount slewing at a slow speed. If you do it on 9 and you have the setting is wrong you could get slipage or binding and beleive me, there is nothing more terrifying than listening to your gears binding . The feeling is similar to being in a car when you notice you are about to go over a cliff.
If you do a full strip down as I did, make sure you have a full day to do it, you dont want to be out in the garden doing this when it gets dark. It takes a long long time to strip it down and put it back together. Actually that part is quite quick. Getting rid of any backlash you have introduced is what takes the time.
Thanks Good Luke - I mean White Rabbit - at first I thought I may have been receiving divine guidance!
Your comments are well received and since I am in the mould of "if it ain't broke don't fix it", I certainly will be cautious. I intend to do all the work on my workshop bench during the coming bright Moon period.
I am determined to be ready for the great summer feast of the Pleiades and all the goodies in the Orion constellation.
Cheers Peter
Good greif, I really need to check my posts before I hit the reply button.
I corrected my typo with another typo hahahaha.
Greasing the gears down is no problem you dont need to take anything apart only if you want to adjust the worm, and as BA from the A Team would say " I pitty the fool".
Hi White Rabbit
I have just spent the afternoon taking the DEC apart, cleaning and regreasing it. It was surprisingly clean and pretty well greased but a lot of the allen key grub screws were rather loose. However, I did not find any obvious problem. Well it is together now and as you said getting the worm adjusted took a bit of time. The problem is when you have the grub adjusting screws right, the tightening of the silver holding bolts effects the adjustments. I gradually worked up to it and just barely loosened the bolts so that tightening them had less effect. Took the DEC for a spin around 360 degrees and both possible free play and binding look OK. However, the acid test will be how it tracks/guides on a star.
Cheers Peter
Hi White Rabbit
I have just spent the afternoon taking the DEC apart, cleaning and regreasing it. It was surprisingly clean and pretty well greased but a lot of the allen key grub screws were rather loose. However, I did not find any obvious problem. Well it is together now and as you said getting the worm adjusted took a bit of time. The problem is when you have the grub adjusting screws right, the tightening of the silver holding bolts effects the adjustments. I gradually worked up to it and just barely loosened the bolts so that tightening them had less effect. Took the DEC for a spin around 360 degrees and both possible free play and binding look OK. However, the acid test will be how it tracks/guides on a star.
Cheers Peter
I'd love to continue to hear updates on this Peter. Your posts on slewing/cable/hand-controllers were a huge help for me early on with my HEQ5Pro, and Guidemaster is always nagging me about a largish backlash so this is on my list of things to do.
I'm pretty average with a screwdriver, so keen to hear if you think you improve the situation.
When I first got mine (new) I could not balance the scope in the dec axis as the thing had seized. I never bothered trying to use it and stripped it down completely and cleaned it out. I found several stripped threads and corrosion between the dec worm wheel and dovetail mount cap. This prevented the dec axis moving freely when the clutch was released making it impossible to balance the scope. I carefully removed the corrosion using fine emery and oil, re-tapped the threads to the next size and basically blueprinted everything as I put it back together. I had no trouble setting any of the clearences (worms, gears etc), just used rolly papers to get the distances right. I used some red grease I got with the peterson kit for my LX200 to grease everything up as I had plenty to spare. The mount has run like a champ ever since and I have not had to touch it again (3 years). Tracking is very good when polar aligned correctly and it will hold an object in the centre of a 14mm EP on a F7 refractor all night. It also finds all the targets with little fuss. They are a nice little mount when setup correctly just QA/QC from the factory leaves a little to be desired. It is not a difficult task if you have some mechanical dexterity but I would not attempt it if you have three thumbs on each hand.
Thanks Mark and others for your contributions. As with most posts I find that I can pick up a lot of tips that often strike a chord with my own dificulties/experiences.
Rob, I will probably not get the opportunity of testing my HEQ5Pro until about mid November but I will post the results at that time.
By the way, I stripped the DEC down completely according the the excellent directions. It also advised to try just adjusting the worm/wheel and driving gears before doing this. I stripped it because of others experience with remnant manufacturing stuff like turnings and not well greased bearings. In the event, I found that the inside of the mount was spotlessly clean and the bearings and worm well greased. Hence, if I have trouble with the RA I will try worm adjustments initially before stripping.
After thinking about my original problem with DEC sticking, I think it will almost certainly turn out to be the worm binding on the wheel at a certain part of the wheel cycle. However, tests will confirm whether my adjustments have succeeded and curing the problem.
I have this problem every now and then when i don't have my balance set quite right. As there is alot of weight sometimes the dec axis will hold under its own weight (even though the axis spin freely) after a quick change of weight distribution my guiding comes back good. another thing i have noticed with EQ6's is when nearing zenith tracking they make a strange clicking clunk sound. but ive heard it with all of my friends mounts.
I think once i finish uni im going to strip down my eq6 and look at replacing it with better bearings and reagrease everything!
Hi Brendan
Thanks for this tip. I will keep DEC balance in mind when I get restarted.
Tracking/guiding does strange things when passing through zenith and I like to avoid this situation (eg look for another object until the desired one gets off zenith). I am not familiar with the EQ6 but I can say that the bearings in the EQ5 are very robust and they looked perfect to me. I like the way that
there is a tapered bearing at one end of the DEC shaft so you can load up the bearings to eliminate possibility of end play whilst still maintaining smooth operation.
Cheers Peter
. The feeling is similar to being in a car when you notice you are about to go over a cliff. 
