Azimuth Motion and My New Dob...

Oh my goodness! I finished my 12.5" F6 dob and it is absolutely wonderful except for one small problem. Motions on both Axis are virtually identical however I have noticed that when moving the scope in Az. the initial movement is a little jerky to get it going. Once moving, its as smooth as silk though and has the same "feel" as the Alt axis.

Let me emphasize that this "jerky" start is ever so slight. I had the scope up to 275X and could still track comfortably however as every ATM knows, close is never good enough in a scope. I am just wondering if there is anything I can do to minimize the jerky start in Az.

I have cleaned the teflon with mild solvent and then waxed and armoraled the ebony star already. This made the movements smooth but still jerky in Az.

I'd really appreciate some comments on now to minimize this. I don't want to make the teflon pads smaller as the motions are already great. Its just that initial start.

Thanks in Advance - Rob

Yes they are, and right over the feet too. Like I say, its just that bit of stiction to get going. I am going to try and take off the amorall and see what happens. Being that it is lighter,(only 12.5" F6) that indeed, may be the problem. If it doesn't work, I may try adding some spacers to the pivot bolt but I am hoping not to do that.

For alt motion, I used the spring and wire method travelling over a bearing as per S&T a few years back. It works remarkably well. I wanted to build the scope as light as possible so getting that perfect balance was tricky without using some counterweights. That, combined with an F6 lever made for a tricky balancing act. I must say however that alt motions are not only smooth but the springs allow me to let go of the tube at any height with any eyepiece (35 Pan to 7 Nag) and the tube stays put. Just a pleasure to use.

Now if I can only get that little bit of stickiness in Az sorted out......

Thanks for your input - Rob