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  1. The jam up may have moved the worm-wheel mesh and it might now be too tight causing the bad tracking & guiding effects you're now seeing. You need the smallest amount of backlash (free play )in the mesh. This explains the worm wheel adjustment procedure - https://www.astro-baby.com/EQ6 rebuild guide/EQ6 worm alignment.htm
  2. Hi, I would record a number of guiding runs in PHD2 of say 10 minutes each but with the actual guiding corrections turned off. The guide log will record the native tracking errors of the mount. Then load the guide log in to PecPrep to analyse and display where the guide errors originate.. Pecprep takes out 99% of the guess work on where best to do your fettling.
  3. Ali, The small clearance between the bore and bearing will allow the bearing outer race to turn. However when you fit the shaft and taper bearing at the other end and add a little bit of preload with the round nut, it will almost certainly hold the outer race in place with out slipping. Or a tiny bit of shim as mentioned by Skipper. I wouldn't use Loctite in this case as it will make disassembly much more difficult in the future.
  4. The belts & pulleys replace factory fitted gears. Therefore the number of teeth of the pulleys has to match the original gearing to maintain the correct drive ratio of 9:47 So the design constraint is pretty much fixed at those number of teeth or the tracking rates would be wrong. The belts are polyurethane and reinforced with steel tension members so wear is not an issue if the belts are tensioned correctly ie not over tensioned.
  5. Could be the worm wheel gearing is tight from taking a bump while in storage. Does the mount sound nice and smooth when slewing a various rates with the hand set ? If not, check and adjust the mesh so it has a fraction clearance so the motor does not bind. Also check the clutches are tight and don't easily allow the axis to slip.
  6. I'd guess it is backlash in the Dec axis worm wheel. When you image away from the zenith you probably have a small imbalance that keeps the contact on one side of the gearing. At the zenith the mount is more likely to 'wander between the gap in the gears causing the trailing because the scope is vertical. First thing to check / adjust is the Dec backlash. A search for' backlash adjustment' should show a lot of links on how to do it. ATB Dave.
  7. Rowan have never recommended that belt converted mounts should be perfectly balanced. Not sure where this has arisen from. Set a minimal RA East heavy imbalance to ensure the worm & worm gear clearance is working on the same side at all times. The wobble in RA is a common issue (backlash in the worm gearing) but it may not be the reason for the guiding problems. Thanks, Dave.
  8. Another way to 'fix' a damaged thread is to use a thread file. https://www.ebay.co.uk/itm/Sykes-Pickavant-Metric-Thread-Restorer-File-01560200/174655192797?epid=1310959088&hash=item28aa42bedd:g:ipwAAOSwYcJgOUTz I've used these on various jobs to good effect when a die isn't available.
  9. If you take the cover off the side of the mount you'll be able to to see the motor 9 tooth pinion gear. The end of the motor shaft can be seen and measured for the extractor size.
  10. Hi, It looks like the noise is in sync with each complete revolution of the belt. This could point to the belt tension being too tight. Loosen the tension a fraction and see if that help.
  11. I'd buff it with a Scotchbrite pad and wipe over with an oiled cloth. Most stainless steel weights are made from 303 stainless steel which isn't 100% corrosion resistant. 316 has increased molybdenum which gives it the additional corrosion resistance. Weights from 316 are possible but 316 costs more and takes longer to machine and would probably cost twice that of the same weight in 303.
  12. Hi, First thing to do is check that the worm-wheel gear mesh is set correctly. It might have moved a fraction during your strip down or it was just a bit to too tight any way. If it's too tight it will bind the and cause the stepper motor to stall which is what the sound is in the video. Read the instruction on on the adjustment an setting on Astro Baby's website http://www.astro-baby.com/EQ6 rebuild guide/EQ6 worm alignment.htm
  13. The clutch couples the axis housing to the worm-wheel gear.
  14. You can get the collimation close with a camera but I always do the final adjustments at the eyepiece on an in focus mag. 1 to 2 star. Use a high magnification say x500. You should be able to see the Airy disc and a faint diffraction ring around it. Adjust the collimation so the ring and central star are concentric. You need a steady night as a lot of the time the seeing won't allow you to do this final step. In the eyepiece you should see some thing like this -
  15. Does the 'humm' noise change when you change the slewing speeds on the hand controller ? If the noise is that quiet it's likely it's not to be a problem. How tight are the belts? Too tight is bad! You should have 1-2 mm deflection of the belt with light finger pressure. @SiriusB comment is spot on. To evaluate tracking performance you need to record a guide log with the actual guide corrections turned off. i.e the camera is then recording the change in position of the guide star caused by the tracking errors of the mount - the PE. Then load that file in to EQ mod's PecPrec or PHD2 viewer. The graphs will tell you exactly what the errors are and where they're coming from.
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