Making a Equatorial Mount

[jdg600]

I'm thinking of building an equatorial mount for my 6" Dobsonian. I've seen a couple of designs on the internet that seem fairly straightforward. These involve constructing the mount from Steam pipe connected with malleable iron BSP fittings.

Whilst the necessary fittings seem easy enough to track down on Ebay, I'm having difficulty sourcing the pipe. If anyone can point me in the direction of a supplier for steam pipe in various sizes from 2" BSP to 3/4"BSP I'd be grateful. Ideally I'd like to be able to get short lengths cut and threaded to order as I don't have the necessary pipe dies.

Many thanks,

John

[DannyL]

You can get the lot from industrial pipework suppliers, every decent town will have one, and its not specifically steam pipe you need, just plain ordinary mild steel pipe in the required sizes.

As to cuting and screwing, you can hire the kit from tool hire shops if the suppliers wont do it, and it's not difficult to use, the hire shop will show you how it all works.

I did one of these for a 10inch reflector back in the late 1970's, bit crude, but as smooth and steady as any Dob I've used since.

The key to a pipe mount is that the threads on the pipe and fittings will be BSP which is a tapered thread, gets tighter over a short distance. this allows the take up of slack or backlash in the system, but the threads are rough and need grinding together. I used car valve grinding paste from Halfords. Grind each mating connection together till they run smooth, then remove all traces of grinding paste and reassemble with a thin smear of grease.

Remember, the mounts only turn half a revolution at most, so if you get it feeling firm but smooth it should not need attention for years.

[jdg600]

Thanks for the info Danny. I'll see if I can track down a industrial pipework supplier near to me.

John

[Bizibilder]

If I were you I would check the prices of suitable commercial mounts before you go for a homebuild. I was amazed at the LOW prices at which these are now available. I built my original 6" Newtonian, including the mirrors and an iron pipe mount back in the 1970's so I realise the satisfaction of a "home build", however you may find it more expensive than a DIY version if you add up all the costs.

[orionhunter]

ive just priced up the costs of pipe & fittings at an engineers suppliers.

i was staggered at the cost of pipe & elbows etc...

think it was 48 quid total. ( H Tipton-Jones Co Ltd. Salford).

so i went to a scrap yard and got most of what i needed for less than 5 quid.

Paris scrap yard in Salford.

ps.

that new price did not include any pipe!

and the pipe only came in 2.4m lenths. far too long for my needs.

[raduen]

I'm thinking of building an equatorial mount for my 6" Dobsonian. I've seen a couple of designs on the internet that seem fairly straightforward. These involve constructing the mount from Steam pipe connected with malleable iron BSP fittings.

Whilst the necessary fittings seem easy enough to track down on Ebay, I'm having difficulty sourcing the pipe. If anyone can point me in the direction of a supplier for steam pipe in various sizes from 2" BSP to 3/4"BSP I'd be grateful. Ideally I'd like to be able to get short lengths cut and threaded to order as I don't have the necessary pipe dies.

Many thanks,

John

Hallo John,

Did you succeed in makeing the mount? if so can you provide me with the internet link you used as an example?

Rado