wobbly mount?

[algol]

So I was out with my 200 mm dob last night and noticed something that hadn't been there previously, the scope had a wobble no matter what surface it was on.

I've not had a look at the mount yet but I'm thinking it may be the screw underneath the mount, but I am not sure, any advice guys?

[Scott]

sounds to me like one of the feet have fallen off

[Steve Ward]

Might be an idea to have a look then , will save a lot of attempted telepathy on behalf of the rest of us ... 

Could be a foot missing I guess , but it would still have three points of contact albeit one wide one ... ?

[algol]

I thought it only had three to begin with?

Better have a check tomorrow, felt a bit rough today so haven't summoned the energy to do so yet. It's only a slight wobble but noticeable when trying to track objects

[Steve Ward]

Only got three feet , but if one's dropped off it will rest on the remaining two and the curved edge of the base which could cause a wobble if you're set up on a hard surface ... 

[Carina Lass]

Sounds like a rock under the base.

It must be almost unusable .Buy a goto on a big tripod....

[algol]

Quick update guys, I've checked the feet and they're all there. There seems to be a wobble between the two base plates as if the centre screw is loose, I've tightened it but no joy the wobble persists.

It is noticeable, each time I attempt to alter the focus or slightly adjust the image the view vibrates violently for several seconds, definitely wasn't like this before and I can't think what the cause may be

[Chris]

Sounds like you might need to undo the azimuth bearing screw and take the base off to have a look. Something might have got in there or a burr might have formed on one of the teflon bearings maybe?

[michael.h.f.wilkinson]

Sounds like a rock under the base.

It must be almost unusable .Buy a goto on a big tripod....

I think you will find repairing a Dob base (or even replacing it) is rather cheaper than the solution you suggest

[Carina Lass]

Cheaper?

I thought the idea was to find excuses to upgrade....

Further to my earlier thoughts, it DOES sound like something between the two rotating parts.

Also check the area round the bolt hole which may have swollen.

[Scott]

Im upgrading my 200p/eq5 by building a dob base

[Carina Lass]

You DO know the meaning of upgrade????

[michael.h.f.wilkinson]

You DO know the meaning of upgrade????

You do know the advantage of a Dobsonian over an EQ mount for visual? If not ask your chiropractor

[Scott]

You DO know the meaning of upgrade????

Yes I do. It's moving to the next level of an existing product, not changing to a completely different one. like a kenworth truck is NOT an upgrade from a vespa....both modes of transport but completely different animals.

[Ant]

Carina lass,

The only person that has mentioned upgrading is YOU.

Algol wants help in fixing the scope he has, not buying another. If you can help him with that then great if not ....

Ant

[swamp thing]

Hi

The centre bolt on a Dob base is merely to keep things in the correct location. It has no need to be tight. If there is wobble between the two plates, tightening this bolt will not be the solution. It sounds like either, one of the boards is warped or perhaps one of the Teflon pads has worked its way out.

[Scott]

As mr Thing has suggested, it could be that a teflon pad has come lose. Pull it apart, Dont be scared, there really isn't mucch that can go wrong (famous last words). Thats the beauty of the dob

[algol]

I'll tackle it on the morrow guys thanks for the help

[Carina Lass]

Replace bottom plate with stub axle and front wheel bearing from a truck and place top plate on wheel with tyre removed. A small lever to operate the drum brake (or disc) will allow some amazing cont4rol and it is unlikely to be lumpy wobbly or rough unless truck was a write off before you got the axle.....lol

Best of luck Mr Phelps... this post will self destruct in a millenium or so....

[swamp thing]

Replace bottom plate with stub axle and front wheel bearing from a truck and place top plate on wheel with tyre removed. A small lever to operate the drum brake (or disc) will allow some amazing cont4rol and it is unlikely to be lumpy wobbly or rough unless truck was a write off before you got the axle.....lol

Best of luck Mr Phelps... this post will self destruct in a millenium or so....

Are you serious? Have you any idea how heavy a truck axle is........... :D you'd never even move it let alone lift it up. The steel wheels alone off a big rig weigh over 30Kg's each. 

[Carina Lass]

Lets go for a sub compact then...

[michael.h.f.wilkinson]

Not very helpful really. Car axles are not the most refined types. If you do want to upgrade from the usual Teflon bearings, go for a lazy Suzan bearing.