who builds telescopes?

[JReed]

I seem to remember someone here built Dobsonian telescopes. If so have some questions.

[GonnePhishin]

Calling Pitchy, was that you building them thar 'scopes?

[pdentrem]

I do. Ask away.
Pierre

[Pitchy]

Calling Pitchy, was that you building them thar 'scopes?

Not me, I have a 10 inch reflector though

[Rusty]

Pierre, what kind of telescopes do you build?

Got any pictures?

[pdentrem]

I have for myself and have helped others with ideas etc. I do not build commercially. You can get kits from dobstuff for example. I do have a drawing that one can use for a 12.5" mirror. It requires an autocad type program to open but it is viewable as a jpg. Danny, known as pinout on cloudynights, sent it to me. It is free to any user as long as he/she gives credit. Too big to post here. PM if interested.

Any questions that I can help on ask.

I have what started as a Coulter Odyessy. That is a 13.1 reflector. It has been heavily modified and now is going into it's third build. I have received my new mirror from Carl Zambuto and now making a new mirror cell and rocker box. I am on cloudynights.com which is the best site out there for anything dealing with Astro stuff. Go to the forum pages and in the ATM section there is more info than you can shake your stick at. I get some pictures up in a bit.

I do a little astro photography. I currently use a Sky Watcher 120ED. Some pictures are posted on my website. pierresplace.ca

Family issues are slowly things down a ton. Mom in hospital with Parkinson induced dementia and Dad goes next week for surgery on his bladder for an unknown type of tumour.
Pierre

[PriseDeFer]

Nice package. Sure beats dancing with that big red tube.

[pdentrem]

First thing I did with that BIG RED tube was cut about 5 inches off the top of that it would fit on the back seat of my car. Later I tried a split tube. Did not like it so I then tried a 8 tube truss design but was complicated to setup. In looking at ads in magazines I came across the 2 tube setup and this works the best for me. With the new mirror which is twice the weight of the Coulter, and the new mirror cell. The balance point will be much lower and therefore the rocker box will be much lower as well.
Pierre

[PriseDeFer]

I like the elegance of your two tube over the truss. What do you give up, if anything, for that simplicity?

[pdentrem]

No real issues as they are the same for any truss scope.

Need a shroud to block the stray light around the focuser. My shroud extends to the mirror box.
Naturally a support system for that shroud at the focus board.
Secondary support. I have a new curved support to try.
The tubes have to be stiff. STIFF otherwise you will get a collimation shift as you move up and down. The focus board may twist from the secondary mirror naturally not being in line with the tubes.
I used heavy wall conduit. 1.5" with .133" wall thickness.

Pros
Setup about 10 minutes or less. Need I say more!
Pierre

[PriseDeFer]

No, speed and ease are key in the late watches.

[JReed]

I do. Ask away.
Pierre

Wow Pierre those are nice.

Well one question I have is what would you recommend as a starter build? It would be a project for my teenage boys and I. Saw a good price for a 114mm coulter mirror set that would keep the wife happy but don't want to have something that would be out grown to soon.

I will have a look at cloudy sky's forum. Was looking at their classifieds earlier today but I think a pre made scope is a bit more then the budget would allow at this point.

Any advice in general is most appreciated.

[alnitak]

Well one question I have is what would you recommend as a starter build? It would be a project for my teenage boys and I. Saw a good price for a 114mm coulter mirror set that would keep the wife happy but don't want to have something that would be out grown to soon.

I will have a look at cloudy sky's forum. Was looking at their classifieds earlier today but I think a pre made scope is a bit more then the budget would allow at this point.

Any advice in general is most appreciated.

Check out Astromart as well...best astronomy classified (least it used to be).

Actually, I think a used Dobsonian, maybe from Orion, would be cheaper than making one. Good mirrors are costly, yet there is some inexpensive quality stuff made by the large manufacturers (Meade, Orion, Celestron). Basically, the difference is in the bells and whistles, and quality of the parts (like the tube and focuser). I would get at least an 8" one to have room to grow into.

[pdentrem]

It is really going to depend on your budget. You also look at a good set of binoculars in the $200 plus range. Something like Ultima 8X56 by Celestron. I would not go higher than 11X80 as the size and weight starts to be troublesome.

The 4.5"/115mm mirror is the common setup used in the old Tasco telescope you saw at Sears, and Walmart etc.
Alot of sellers have that scope. I do not know about the Coulter mirror in that size. My Coulter 13" is 1990 vintage and even back then it was cheap. It served my purposes as it got my a large scope for it day and lots of enjoyment.

I would start off at 6" F8 or so scope. If you have more funds then the 8" scope is a good jump up in light gathering as Alnitak suggested. Unfortunately there is more than just the scope. Eyepieces, barlows, charts, etc.

Orion has their 6 and 8" on sale with free shipping. It is a good value. It comes with 2 eyepieces and on the 8" a 2" focuser which in most experienced users offers an advantage. Wide field views will be better with the 2" unit. There is a $200 step though.

The 6"
http://www.telescope.com/Telescopes/Dob ... 102012.uts

The 8"
http://www.telescope.com/Telescopes/Dob ... 102012.uts

I know you were thinking a kit to interest the boys and I think that it is a very good idea. Mostly jigsaw, table saw and hand tools. Fairly ease to make with success.
As for kits - Stargazer Steve sells good quality kits. http://stargazer.isys.ca/

You can also get a plan from scopemaking.net/dobson it is a pdf and very complete. Richard Berry published a good book a few years ago called "Build Your Own Telescope" I have a copy of it. Maybe look at a used book store or website for one?
This is a start, I hope I have not discouraged you.
Pierre

[JReed]

Nope not discouraged lol.

I have been looking at the plans on Stelefane (sp?) and a few others. Right now just gathering info and getting ideas. Wont be getting serious until I get home from this deployment and find out how serious the boys are.

The more I read up the more I am swinging to the 8" seems to be the most bang for the buck. Does the 2" eye piece make that big of a difference over the 1.25"? It gets mentioned alot and all the high end tubes seem to come with it but no one explaines the advantages. I did see that Orion sells a mostly striped down Dob at a decent price that you then have to add a spotter and the other odds and ends. But it comes with the mount, optics, and focuser installed. I have also been looking at the classifieds seems most folks dont want to ship (dont blame them).

Thanks guys for the info

[pdentrem]

The advantage to the 2" focuser, is the use of wide field eyepieces. The field stop in 1.25" eyepieces is 27 mm while 2" is closer to 43 mm. It all depends on the f ratio of the primary mirror. Complex math but many discussions about it on line.
Pierre

Update I found this. Televue and Al Nagler are well respected in the industry.
http://televue.com/engine/TV3b_page.asp?id=154
http://www.televue.com/engine/TV3b_page.asp?id=79

Set of plans for different scopes
http://sketchup.google.com/3dwarehouse/ ... 19237e39a0

http://www.clearskyobserver.com/images/ ... _Plans.pdf

[alnitak]

I have also been looking at the classifieds seems most folks dont want to ship (dont blame them).

Keep looking, you'll eventually find one within a couple of hours drive. I drove from VA to NJ to pick up mine.

Also, look for a set of used Plossels to get you started. They offer 90% of the view at 20% of the price. If you get a 2" focuser, initially, I would still go with 1.25" eyepieces until you see how much you use it. Nice 2" eyepieces can cost almost as much as the scope...each!

[Newtmaker]

You may have been referring to me. My handle is Newtmaker because I used to make a lot of Newtonian scopes. Not so much anymore. Have mostly been observing when the weather cooperates and building a goto mount. Finally got it finished and she's a jewel! It is discussed on the Astromart Forum under Reviews, "New Life for an Old Mount."

A lot of good advice already given. Finding good mirrors takes some time but in all honesty you will spend more making one than buying one. Check out these folks http://www.opticsmart.com
I have bought from them and they ship free. Good product for the money. If your kids are older teens I would recommend a 10", otherwise an 8. Don't buy the extras they tout, just learn to use it and get extra's after to learn that you need or want it.

Walt

Where will you hang your hat when returning from deployment?

[JReed]

Walt I am stationed out of North Carolina so will be heading back there.

Thanks all for the links and advice. looks like i have some shopping to do

[PriseDeFer]

1.25 eyepeices for the best bang for the buck, those bigger ones are dear, can be better to have more of them. Dobsonians are the way to get the biggest mirror for any given price and the AltAzimuth Mount makes the observer learn the sky and travel in it. If you go "cheap but good enough" for design and parts you could consider a 10 inch mirror. Better for for the deep sky dim and whispies, globulars and galaxies and the other denizens of the dark reaches of intergalactic space. Good luck and keep your blast tubes clear.