Sabir,

I have created a page on my site regarding the Azimuth Bearing problem:
Jims Orion XT10 site - Azimuth Bearing friction/stiction and mods

I too have added a lazy susan and have detailed the part number and my intention is to create a page detailing the mod. Sorry its not done yet (its on my todo list!).

With regards potential damage to the sensor, the brass bush is designed to ensure the correct critical gap is maintained between magnetic disc and sensor surface for the IntelliScope to operate properly. Problems only occur if poor assembly results in the two base parts becoming skewed off axis, i.e. perhaps the central nut is not done up tight enough which allows too much wobble of the two base sections to each other. If anything a lazy susan makes this less likely to happen since it provides a wider diameter for support of the top base onto the bottom.

Other notes are in agreement with other posters, i.e. the scope now rotates incredibly freely, and I need to implement a braking mechanism (such as carpet!), otherwise even the wind will blow it round, and/or my movement near the scope has to be careful.

The bearings do have a notching effect sometimes, i.e. you move the scope but the bearings want to roll it back or fore slightly before it rests. This might be due to me making a silly mistake when installing the lazy susan. I drilled mounting screw pilot holes, with the bearing in place, and blew the resulting sawdust away, but some got into the ball bearings! Ooops.

So something to be careful of for would-be modders.

This could account for the idea of "flat spots" mentioned by you, meaning they are NOT flat spots, but more likely to be dirt or particles which have got into the bearings. I think the low cost of the lazy susan might warrant a 2-yearly renewal?

I do sometimes feel that the Teflon pads and stiction approach, if maintained well, offers better control for wide viewing. Its just the high magnification that requires the smoothness of a ball bearing.

I'm sure Dobsonian designers have considered ball bearings but felt that Teflon was a better approach. I don't think Teflon is particularly a cheaper method, unless high quality lazy susan were used.

Generally I much prefer the smoothness of the lazy susan, but it can sometimes be annoying having to move so gingerly around the scope if I have aligned it on something, and want to change the eyepiece for example (must sort out that brake).

The LS I used raises the top baseplate above the teflon pads by about 1.5mm so the pads are no longer in contact. This also means the mod is non-destructive - I can remove the LS and have it working in the normal Teflon way quite easily.

Some additional notes and pics on this page might be of use also:-
Orion XT10 - Azimuth Bearing Assembly

Jim