Azmuth and Elevation bearings for a dob

[Dennis G]

In reply to a request for information regarding the bearings used on my Dob scope.
The 4 pictures attached may make this easier to understand.
Previous article, balancing the Dob, I mentioned using roller bearings. They were just that, simple plain rollers. These work well on the elevation, but suffered badly with sticksion on the azmath, so I replaced the 3 rollers with 3 sealed ball races. The angle supports are made from 1.6 mm aluminium angle and the shafts are stainless steel.
The base board and the curved elevation supports are routed to accomadate the bearing assemblies which should be accuratly made and with side clearances to run free.
Note. I used a centre ball race to take the 10mm pivot bolt which reduces further friction. The difference between Teflon pads and bearing rollers - my scope is a heavy brute - is just terrific!
If further info is needed please ask.
Dennis G.

[ving (David)]

hey, that looks cool dennis
thanks for the pics and info

[rmcpb (Rob)]

That is sleaker than what I was going to do to my 8" scope so I can attach stepper motors on both axis with a joystick. I think I will steal your ideas

[Tannehill]

That is beautiful, Dennis, thank you for sharing.

How do you secure the roller bearing on the shaft? Loctite? Press-fit? How does the shaft stay secure in the mount?

Scott

[davidpretorius]

hmmm, i must increase the size of my alt bearing for the dob driver II soonish.

i love your work!

[astro_nutt]

That is so cool Dennis!!!..and pracitical to boot!!..good one!

[erick (Eric)]

I think I've just realised one further advantage of having a small lightweight 8" dob - fixes don't have to be too complicated - the new laminate and slightly better teflon is working just fine on the bearings. Anything much heavier and I can see why one has to get into these more complex approaches.

Upside - it's only 8"!!

Downside - it's only 8"??

[ving (David)]

upside = its only 8"... and you can mount it on a heq5