Parts for Vixen SP mount

[NickRose2006]

I'm going to test out the mount again but I don't think I have fixed it yet. I'm having some problems with the declination of my Super Polaris mount. I suspect it is the worm gear that is causing the problem. When I start to move the mount in Dec. at 1x/2x or even 8x it takes a longer time then normally to move. It seems like it doesn't grab on right away.

Has anyone had this type of problem with this mount or any other mount?

I e-mailed Vixen to see if they have any spare parts that would fit the SP mount.

[Peter Drew]

Sounds like backlash to me due to the worm not mating tightly enough to the wormwheel. The bracket carrying the worm is adjustable, undo 1/2 turn of the two outer screws of the three in the bracket and then tighten the central screw, this will reduce the backlash. Do this carefully and it should fix the problem.

[NickRose2006]

I have tried that but when I use the slow motion knob it is stiff to move.

[Peter Drew]

It is a fine dividing line between backlash and stiffness, try backing off again a fraction.

[Peter Drew]

Forgot to mention, the worm is also adjustable for end float, check that there is none, if there is, then the worm will advance backwards and forwards by that amount which also causes the effect of backlash.

[NickRose2006]

Last night I tested the mount and found there was still the backlash. So today I did both adjustments with the worm. I checked it by pointing the scope to the near by hill/mountain and used the 10mm Ep. and it seems like it might have helped a little. The real test will be the next clear and non busy night.

I guess if I still have some backlash it wont really be a huge deal, as long as I know what direction Dec. drift is and how PHD is making the corrections. Right???