Old mount strong enough?

[badgerchap]

I have this old mount,

from about 1950. The axes are about 4 inches in diameter and the whole thing is constructed of a pretty heavy metal, probably some kind of steel from the fine rust on some external surfaces. It is of very solid construction (Broadhurst & Clarkson) and is currently holding a period refractor, long tube, weighing about 7-8kg. What I am wondering is whether the mount would be sturdy enough to support a 14 kg dob without putting too much stress on the tracking system? The worm gears are thick and heavy, with the drive wheel being about half an inch thick and around three inches in diameter. All in all, it's pretty sound, but I'd like to know if anyone has any thoughts on the matter, or any experience regarding these old B&C mounts.

Thanks guys,

Badgerchap

[andrew s]

Hi - I think the Dob will be too heavy for the mount/tripod. Also before you try check the Dod has a conventional mirror cell. Dods can have a sling support that will not hold the main mirror in an equatorial mount and the mirror may fall out! Andrew

[NGC 1502]

It doesn't sound promising, being as you are thinking of doubling the

scope weight, plus you will need to fit heavier counterweights as well.

Sorry not be more encouraging !

Regards, Ed.

[badgerchap]

'salright, will just have to carry on with the refractor. Just worried about chromatic aberration. Luckily it's quite a lengthy tube. Anyone reckon I'll have a problem with imaging?

[philj]

Looks like a Fullerscopes Mk11/Mk111 eq mount a mate of mine had the 8.25" Fullerscopes Newt on one fitted with a pier and this was solid enough but I suspect it will struggle with a 10"

As for imaging with the refractor, what is it? You mention long tube, is that f15, what quality are the optics and do you have adrive for the ra axes and finally what do yoi want to image and with whatcamera. Sorry to ask so many questions but there are so many variables

Philj

[HD-AP]

Hi

This is a fullerscope mk 3 now the quote from my fuller catalogue states it's intended to carry refractors up to 4 1/2 inches

newtonians up to 8 1/2 inches and cassegrains up to 10 inches.

But it also says the maximum loading capacity for this mount is

6 inch refractors 10 inch short focus newtonians and 11 3/4 inch cassegrains which i think is a tad optamistic and pushing it too far on this mount.

hope this helps

clive

[badgerchap]

@philj

Optics are in good nick but I don't really have anything modern to compare them to.

Yes it is f/15

yes, I have an RA drive (which electrocuted me this evening - remember badgerchap disconnect the mains before meddling)

the camera is tricky - at the moment it is a fujifilm finepix s5600 which is a fixed lens compact. However, after trying it with its lens attached, I intend to remove the lens and expose the CCD. I will also look into overriding the exposure limitation as currently, the best I can obtain is a 30 second exposure. It can do raw images, is 5.1 megapixel. Will also be trying a ccd webcam but I dont hold much hope for this as the ccd is tiny!

@HD-AP (Clive) Yeah, that does sound optimistic, but I reckon I could replace the tube of the dob with a lighter material. Also some of the weight in the dob is taken up by the rocker bearings and 2 dovetail-type bars, 1 of which I can lose. So I estimate I can probably end up with a 10kg scope.