home made 4 1/2in dob

[Wbarkingmad]

I just wondered if anyone fancied a look at my back-to-basics 4 1/2in reflector on a home made dob mount. The OTA is branded Topic (Japan) and dates from the mid 70s. It was given to me with an appalling tripod. In an effort to make it usable I decided to make a new mount and attempted to follow the original principles of a basic dobsonian. The ground board is a piece of worktop and the rest of the wood is half inch ply offcuts. The azimuth guides are two halves of an old aluminium record player platter. All the bearings are PTFE blocks or bushes. The odd thing sticking out of the top of the OTA mounting is a counterweight. With no additional friction the tube holds precisely whatever position you put it in. There is an adjustable friction dapmer too. The finder scope came off my 8 inch SW dob (swapped for a 90° finder - much better). The only issue is the 0.965in eyepieces but an adaptor is being considered to allow 1.25in EPs to be tried. It is now off to help introduce a newcomer to astronomy.

[NGC 1502]

Hi, my first scope was a 4 1/2" newtonian on a wobbly EQ mount,

but this mount looks much more stable

In spite of the dodgy mount, I did find Halley's Comet (eventually!)

These very portable scopes get a lot of use as they are no hassle

to set up & use.

Good luck to the new user, Ed.

[Moonshane]

this is great - I love dobs!

what a superb way to put a virtually unusuable scope back on the tracks and in the hands of someone who'll love it I bet. looks really stable. I love the use of materials to hand - fabulous mate!

[Bizibilder]

Nice one! That has got to be 1000% better than the mount it was on and makes it a really useful scope at last.

That newcomer will be of to a really good start

[Wbarkingmad]

Thank you for the positive comments, much appreciated. I'm wondering if anyone has spotted the deliberate mistake yet? Altitude, not azimuth... sorry!

[Moonshane]

Thank you for the positive comments, much appreciated. I'm wondering if anyone has spotted the deliberate mistake yet? Altitude, not azimuth... sorry!

ha ha just goes to show how we skim things when reading!

[StuW]

I have this exact same scope badged as a Tasco, but the mirrors need resilvering. You've given me something to ponder now

[Joe gray]

Looks great, you a chippy?

[Wbarkingmad]

To Joe Gray, thanks for the comment, much appreciated. I'm actually an electronics engineer whose other hobby is model engineering... in metal. I normally don't get on at all well with wood, you can't weld it, you have to use stuff called glue...