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peterbat
28-01-2008, 09:37 PM
I've completed the new bearings for my Lightbridge 16, and at present I'm pretty happy with them. I've increased the size of the altitude bearings, and pretty much halved the height and weight of the rocker box.

The altitude bearings are slightly offset, so that more weight is behind the axis when the tube is pointing towards the horizon. This means that with an Ethos eyepiece I don't need any weights on the bottom of the tube. My 1.25" plossl is just in balance, but my lighter plossls make the top of the tube bottom heavy...

I've put some photos and a description at http://www.batchelors.net/personal/telescope/16-inch-meade-lightbridge-telescope.html. The update with the new mount is at the bottom of the page.

Cheers, Peter

astro_nutt
29-01-2008, 10:17 AM
Hi Peter!
That's a very impresive mount you've made there..I've built a few around my 10" dob and the tricky part is getting the altitude balance to agree with a variety of eyepieces, etc..I've built a cradle to hold the optical tube which sits on ball bearings..as this provides a very smooth motion it also has a friction dampening wheel which has adjustable tension via a threaded bar and locknut which pulls a spring that is attached to the flatbar holding the friction wheel.
The friction wheel is just a large rubber washer which has a metal sleeve and has a metal washer on each side..this is mounted on a hex headed bolt...a compression spring sits next to the metal washer and another washer on the other side of the spring...all that's required is tighted the nuts against the spring to the required speed control when the wheel is placed against the altitude hub..(only slight resistance is needed to hold the scope)
Mount this on a piece of flatbar and adjust the amount of tension against the hub as described earlier..this set-up will give a wide range of adjustments..but you should be able to find a setting which cover a wide variety of eyepieces.
Cheers!

Phil
31-01-2008, 08:46 AM
Nice work Peter. One day could be on the cards for my 16".
Look very nice to.
Phil