home made scope question..

[lostinspace]

hi all, does anyone have any experiance or knowlege of building a telescope? i see pics of obviously home made scopes but am wondering how on earth can someone make a mirror to the extremely high specs it needs to be of any real benifit? i`ve seen pics of 18" scopes home made, i cant afford one so hence my interest..

(my ob build is proving very chalenging, i`m taking photos as i go tho)

thanks for any comments,

john

[orionhunter]

i think most builders buy in the mirrors (new or used) and make the rest.

advanced builders will make the mirrors too, but as you get to bigger sizes the prices shoot up. even new glass blanks are expensive.

ive read of builders taking years to build a scope. a year for making just the mirrors is not rare.

be aware:

with all the chinese imports, the cost factor/advantage is very different compared to 20/40 years ago.

a brand name used scope will be cheaper than making a new one.

[brianb]

The mirror is actually the easy bit - testing is just trial & error. The really hard bit is keeping grit out, one speck & you can be back to the beginning of the polishing process.

Making a decent equatorial mount, that's what's beyond most of us.

[lostinspace]

Making a decent equatorial mount, that's what's beyond most of us.

thanks for your speedy replies, so its cheaper to buy than to make one? who`d of thunk it?, talkin of mounts, im having real trouble finding a pier for my new ob. i`d like it to be able to accomodate a few different mounts as i progress to better equipment ( when i`ve paid the bills and fed the tribe and put what pennys are left in the hopes and dreams jar) are they available to buy? i`ve only seen realy big two and three tier ones where all i need is a smallish affordable one? i appreciate your help guys,

john

[callump]

Depends on what you want at the end of the day. If you want a bog-standard SCT, then it's not a very practical self build option at all.

Mirror making is not difficult, just needs patience, persistence and perspicacity.

But it would probably not be a good idea to star a mirror making project bigger than 10".

If you want an obsession-style dob, then they are not particularly difficult to build and you'll save a lot over the real thing.

Sadly the days of the amateur astronomer being an experimenter too, seem to have passed by. But there are lots of avenues for innovation and experimentation and I would encourage people to have a go, rather than just splash the cash...

/callump

[callump]

And... re. making an EQ mount. If you are making a permament installation, not really hard at all - yoke, english, fork, and split ring mounts are actually all better than german eq mounts in many ways. Making these portable is more of a challenge, but do-able.

/callump

[orionhunter]

all depends on what you mean by decent?

the above is simple enough to make and cheap if you use scrap materials. i use scrap parts where ever possible.

i made an alt/az mount in a few hours for next to nothing. based on the above.

[TopHouse]

All from an old copper boiler and some parts from a typewriter, he had watched several episodes of the A team though.

[lostinspace]

thanks for your ideas guys, i think i`ll buy a pier but am still having trouble finding a simple one, any ideas or links would be very helpfull if anyone knows of any, thanks again guys,

john

[Merlin66]

Over the years I've designed and built telescopes up to 29" apertures.

I 've ground and polished mirrors from 6" to 12" and a couple of Cassegrainian secondaries.... easy to do; you just need time and patience.

Ken

[Bizibilder]

Why not get a pier made by your local steel fabricators? You can get exactly what you want at a fraction of the cost of a commercial one and if you use a "double top plate" you can just make a new top whenever you want to put a new scope on it. I've bunged in a couple of shots of my own to give an idea of what you can do. Mine is 1m high and cost about £75 (I think!)

[orionhunter]

All from an old copper boiler and some parts from a typewriter, he had watched several episodes of the A team though.

aye.

some of us cannot afford a 500/600/700 quid heq5 or whatever theyre called!

plus im from an age when 500 quid could buy you a terraced house.

it just seems so wrong (to me) spend that amount on a scope mounting.

[Astro_Baby]

Aye and I go back far enough to think £500 for a house is a rip off - you were obviously softies.

We lived in a hole in middle of the road