OTA slips in the rings

[Marko of Oz (Mark)]

When pointing up at say 50° or more my 10" trys to slip out of the rings. If it wasn't for the dob mounts still on the ota it'd slip right out I feel I've tightened them sufficently. I don't want to crush/distort the tube.

Is there a secret here? Something tacky to put on the ota maybe

The tube rings have some sort of felt lining or similar.

What do you do?

cheers

[iceman (Mike)]

The altitude hub on the tube is a saviour! I have mine resting against the bottom ring as well, to stop it slipping out.

I wouldn't put anything tacky on the OTA.. I guess it needs to be sufficiently tight without crushing it, while not allowing it to slip.

[Marko of Oz (Mark)]

Hi Mike,
that's a good idea to let the hub rest on the bottom ring but what does that do for your ota balance, do you have the dovetail/ring assembly further forward in the dovetail mount rather than centered?

thanks

[iceman (Mike)]

Yep, that's what I do Mark.

My dovetail bar is a custom one and much longer than normal, allowing me to move it forward in the mount to ensure proper balance.

[rmcpb (Rob)]

If you cannot tighten your rings any more to give a FIRM but not crushingly tight grip then consider getting some more felt (Spotlight has felt sheets with adhesive on one side) and putting an extra layer in your rings to get the desired grip.

If you want to be able to rotate the tube in the rings then you should make a collar ring that locks in place that stops your OTA slipping back in your ring setup.

Cheers

[ving (David)]

thats what i was thinking rob. they both proabably need to pack thier rings out a bit more...

[ballaratdragons (Ken)]

Replace the felt with rubber. Clark rubber can help you with all sorts of widths and thicknesses.

I have a rubber type lining in my 12" rings and they grip like glue!

[33South (Chris)]

What I found worked really well on my ex 10" Starfinder was to use some strips of the foam stuff you wack under a rug to stop it from slipping on polished floors.

[ving (David)]

yup chris, i can say that wht you did worked wonders

[Astroman (Andrew Wall)]

or try this http://www.andysshotglass.com/wilcox...ing_rings.html

[ballaratdragons (Ken)]

Here's my method of the object Andrew is talking about.

I designed it to get the mirror cell in and out easier, but it also works great as a lock ring to stop OTA's sliding in their tube rings.

http://www.iceinspace.com.au/forum/s...=locking+paint

[rmcpb (Rob)]

I have a version of Ken's locking rings and it works a treat. I was gong to use it when I was working on my split ring mount as the eyepiece would end up in some interesting positions but witht he equatorial platform I don't need to use them.

A great and easy solution to the major problem with GEMs and visual observing.