Smooth Movement on Dob Bases

[ballaratdragons (Ken)]

Your confused Steve? Imagine how the newbies feel!

[Orion]

I used Formica (Stardust) and 3mm thick Teflon pads cut to the right size by calculating the weight of the telescope and I have never had any problems. With a little car polish and a bit of armorall it makes the telescope move beautifully!

[Starkler (Geoff)]

I found after working on improving the azimuth motions that the alt needed some work.
The gso dob moves much nicer if you can balance the tube up and go without the springs on the alt hub. I used rectangular lead divers weights, nice and cheap

[slice of heaven]

Originally Posted by Starkler

I found after working on improving the azimuth motions that the alt needed some work.
The gso dob moves much nicer if you can balance the tube up and go without the springs on the alt hub. I used rectangular lead divers weights, nice and cheap

I never fitted the springs as I did the same as you and tuned the balance of the OT instead from day 1.
Then I added foam strips to the alt bearing supports to match the movement to the az motion.

[RAJAH235]

I still reckon that 'clean & dry' is the way to go, especially if you have 'Ebony Star' installed. Anything you put on a surface will attract dust & grit.
I also changed the position of the alt bearing teflon, (up in the D), to give a little more stiction, as it was too easy to move. (Cheap Meade plastic bearings/pads too far down?).
One saving grace that Meade did, was to include 50 mm? x 1 mm? Teflon disks for the centre pivot bolt. I believe you all use 'milk bottle washers' for this?
All I can say is, try it. You can always, well mostly always, rectify it if things go wrong.
We can but post, what works for us.
HTH. L.

[davidpretorius]

anyone tried wd40 on the teflon on the az??

i did a couple of nights ago and very happy. not sure of long term effects.

If people think it is ok, then i will bring a box of samples of wd40 that have been sittingon our roof at work for years and hand out at star camp if anyone is interested!

[ballaratdragons (Ken)]

Dave, the problem with WD40 and like products is that they trap dust and eventually turn to Gluck! Dry lubricants are better.

[davidpretorius]

good point, anybody want the wd40 cans for anything else????

could be a flame thrower to light up the area whilst viewing!!!

hmmmmm reminds me of a thread????

[ballaratdragons (Ken)]

Those cans of WD40 are excellent for anyone that owns a car. In other words almost everyone needs one

[Starkler (Geoff)]

Originally Posted by RAJAH235

I still reckon that 'clean & dry' is the way to go, especially if you have 'Ebony Star' installed. Anything you put on a surface will attract dust & grit.

Why am I resurrecting this thread?

I have done a bit of work to my dob to see if i could improve the motions.
I ditched the rather tall magic sliders I was using and have applied a pimply laminate to the underside of the rocker box, and going back to the stock pads as supplied.

I was playing with milk bottle washers and couldnt get it right, one extra would make the scope wobble but without it still not enough weight taken on the centre to reduce friction to an acceptable level..... until I tried waxing the laminate and altitude hubs with turtle wax.

Wow what a difference

The scope is moving beautifully now I just hope that lasts.
The wax is a dry substance so its not going to attract any grit.

[cjmarsh81]

I tried the milk washer mod myself and found the same problems as you. Too many and it rocks and not enough then there is no benefit. I could not get a perfect balance.

Between the two boards there is three pads for the dob to move on. I simply added three more so there is now six evenly spaced around the base. I did this not long after I got my scope and it has worked really well so far. Just cut some old smooth plastic and double-sided tape it down.

[RAJAH235]

FWIW, if you need 'just that little less thickness', you can always use 'shim brass or coke can' between the MB washers......... L.
ps. You're only 'just' supporting the centre..

[astro_nutt]

Hi everyone,
I discovered with both my dobs (8 and 10 inch) I had to give the laminate surfaces a good clean with metho..then applied carwax and polish off..as for the teflon pads..I gave them a very slight buff with steelwool around the edges..in case of burrs on the teflon pads...the blank portion of central bolt has been smoothed down by placing in a drill and using 400 then 1200 grade wet-and-dry to remove any imperfections..finish off with carwax. A ring of medium-density foam sandwiched between two plastic rings have helped to support the centre...I dust in between the boards using a piece of felt wrapped around a ruler every few observation sessions. So far it works well.
Dark skies everyone.