[richardda1st (Richard)]

Yes Barry I agree, replacing the chipboard with ply will greatly improve stability, and if I was going to make a new dob that is the way to go.

The axle bearing on my LB 10" is the same as your detail but without the recess for the thrust bearing (ie thrust bearing presses directily on upper face of base).

I still think that the larger the diameter of the lazy susan bearing the better, ideal would be to have the bearing as large as possible right up to the full diameter of the base. I have found some lazy susan bearings that come in large sizes, but at this stage I want to use the same design as the original.
The original bearing uses very thin needle rollers and two steel plates which results in a combined thickness of 3 to 4mm. I want to keep this thickness as it suits my new azimuth calibrations with added vernier setup.

You seem to think that the bearing on your dob is 18", that would be ideal for my simple modification. Can you give me the total thickness of the lazy susan bearing on your scope. Barry is your scope a Lightbridge and what size is it?

Hi Bevan, what size Lightbridge do you have? So you think that the LB 10" 12" & 16" all use the same 320mm diameter bearing, and using the three teflon pads for stability.

I should add that I had to remove the teflon pads as they interferred with my azimuth calibrations setup. Note that I compared the stability with the pads on and off and found no discernible difference.

I must mention that the stability I'm trying to minimise is only an issue at high magnifications of 300x plus.

Hi charles, thanks for that but at this stage I just want to use the same design as explained above.

Thanks all
Richard