Anyone ever built a scope?

[Rob_Black]

I'm thinking of something along the lines of a Lyman, Unertl or Fecker. Basic tube with external adjustments. I see books on telescopes and such; it seems to me there must be an article or something buried somewhere back in history.
I mean, all you need is basically just a spyglass with a reticle in it. Should be doable, but I don't want to tear down my Lyman for reverse engineering just yet.
Anyone got any ideas?

Thanks
Rob

[Skeeter5000]

Hi Rob,

Not a gunsmith. But I like guns.

I think that most scopes are filled with something like nitrogen. I would think this might be to keep them from fogging up.

Some one makes them, so it is doably. Might take some trial and error.

[jpfalt]

I've built telescopes, but not a riflescope. There's a couple of extra layers of difficulty. An astronomical scope has one long focal length lens and a short one. The magnification is the ratio of the focal lengths. Problem is the image is upside down. To get past it you need to add another lens to flip the image right side up and set the focuses of each set so that you end up with magnification and eye relief at the same time.

The crosshairs are located at one of the planes of focus between the lenses. It also gets hard to find cross hairs thin enough that they don't cover up the impact point. The original scopes used spiderweb threads and were easy to destroy.

The nitrogen fill is just what you suspect. That is to exclude moisture and fogging inside. the challenge will be to get crosshair adjustment without introducing an air leak. If you pull it off, you will be able to be really proud of it.

[jmscott]

I looked into reproducing a simple staight tube 4x military scope. Problem is finding lens of proper focal lengths without buying 10,000 of them. Crosshair wire is available.

[mendoje1]

The other thing you can't ignore is recoil forces. Food for thought: I remember talking to an air rifle dealer (high end stuff, target and hunting), optics for spring piston air rifles are designed for recoil in the opposite direction that were are accustomed to. Even though the recoil forces are extremely light, most scopes aren't designed for that direction, so they slowly fall apart, at least that's what he claimed. Most high end air rifle stuff is CO2 and Scuba now, so the recoil is in the "correct" direction. Jeff

[Rob_Black]

Thanks for the input guys, crunch time at work again and haven't been home much. Familiar with recoil problems; have seen difficulties with air guns when I was in the gun business. Also seen problems with every scope out there too. Application in this case would be rimfire or small (.22 hornet size) rounds.
Just something I've wondered about for awhile; it seems some of the early scopes must have been produced in relatively simple shops, just surprised I've never seen anything much on them. I've heard of surplus places having various lenses cheap, just don't know what I need. Maybe I'll order one of those telescope books from Lindsay and go from there. Not a burning need, just keeps nagging at me for some reason though.

Rob

[Skeeter5000]

Hi Rob,

Try this site.

http://www.turbofast.com.au/astrotel/index.html

Good luck,

Skeeter

[MikeB]

I've heard of people building scopes with glass they bought through Edmond Scientific.