Is it feasible to make lens mounts/retaining rings at home?
I'm getting more interested in older LF cameras and some of the weird and wonderful barrel lenses out there. The trouble is that many of the lenses no longer have their lens mounts. If I could make my own it would make life a lot easier.
The specifics that I am confused about are whether the normal thread cutting function is suitable for putting a thread on the inside surface of a ring and whether there are size limits to this. I'm think of a mount for things like Aero lenses and old brass lenses that may have a 3-4" inside diameter and need a 5" outside diameter.
The lathes I have (very briefly) looked at have specs based on "centre height", "swing over bed", "swing over carriage" and "distance between centres". Which of these will be the crucial ones?
I've also seen a few combined lathe and mill set ups. Is this a good idea or should I stick to two separate tools?
If you are lucky, you'll be able to find a suitable iris type lens holder on eBay. If, that is, Ole Tjugen, who collects them, doesn't outbid you for it.
if you check skgrimes website, he has the dimensions and thread pitches. However if you've never cut threads on a lathe before, it's a long road to hoe. I have a machinist that I will make a bunch of 4x4 lensboards, with 1" holes, give him a list and tell him centering isn't aerospace critical, just whenever he can get to them. Usually takes him about a week or so, charges me straight time, at $35 an hour. comes out to around $5 or $6 a lens board, and 99% of the time they fit right out of the gate, occaisionally I leave a barrel with hime, then it always fits,( and usually cost more too)
So, short answer is yes,but why bother? even if you had a metric and an english lathe, unless you absolutely enjoy machining ( I do, even) it's not worth it.
Certainly it is feasible but in my opinion threading is one of the most exacting tasks to be performed on the lathe. Especially the small type thread to be found on barrel lenses. I have owned a lathe for 10 years and have completed quite a few projects but my self taught skill level is not up to that fine a job. I'm sure there are others here who have the skills and perhaps they can give us both some tips on this type of work. I have done some single point threading on both OD and ID but this was in a much larger thread size.
When I was shopping for a mill and lathe my machinist buddies all warned me off the "combo" type units. They said that such units do neither job as well and usually limit the size of the piece that can be worked. Especially in the "mill" format. I have found their warnings to be true
I ended up with a 12x36" gap bed, gear head lathe and a "mill/drill" unit with 22" of cross travel.With the gap section of the lathe removed I have 17" of swing over bed. These have served me well for every project I have attempted to date. The only camera project to date was a fixed focus 4x5" body I made using the mill for routing the wood body to accept the Omega E model ground glass/film holder.
So far I have taken the advice of others on this thread and shopped around for filter adaptors and other finely threaded items rather than attempting to make them myself.
Speaking of which, we need to find somebody to run some inserts for copal/compur/betax type shutters to accept threaded filters. Think easy ultra simple s/f using diopter lenses.... if they were 39mm and 42mm ( I think) then an awful lot of great ( and cheap!) enlarging lenses instantly get shutters, my mind hurts at the idea of not using a packard shutter with a 135mm or 150 componon. I've got to persue this, at some point. Am I the only one who sees some real benefits to this?
Sponsored Ad. (Subscribers to APUG have the option to remove this ad.)
I've used heavy copper wire wrapped around the threads to hold a lens in place. Not elegant, but works just fine.
For simplicity's sake I second Dan's suggestion. Find one of the adjustable iris holders and mount it on a board for your camera. Mount a Packard behind it and you have a setup which is good to go for a lot of lenses.
My Verito page
Anyone can appreciate a fine print. But it takes a real photographer to appreciate a fine negative.
I don't collect them exactly, I use them. But now I have one for each camera, so I can stop buying them (until I get another camera).
Originally Posted by Dan Fromm
The funny thing is that an iris holder alone tends to go for a lot more than a camera with iris holder! That's what started me off - I bought a camera for the holder, then decided to keep the camera. With the holder. So I needed another one. The one I got then was too big for the lens board of the 30x40cm camera, but was a great fit for the 24x30cm camera. Which is a better camera anyway...
As I said I have enough now. There's even a chance I may put one up for sale soon, but I'll have to check the size of the lens board for the 8x10" Gandolfi first
-- Ole Tjugen, Luddite Elitist
I do quite a bit of machining, and I have to agree, threading on a lathe is difficult and takes LOTS of practice.
Stay away from the combo machines. They do all sorts of operations poorly.
I really enjoy machining, but I rarely machine threads to mount a lens. If the lens does not have a retaining ring, I usually cut a 4X4 lensboard from 1/8" board, and bore the hole on the lathe. I bore the hole tight enough that the lens will screw into the board and "cut" its own threads as it is screwed in. No need to cut internal threads with a single point tool (difficult and time consuming).
FWIW, my lathe is a 1945 Moody (made in Canada) 11" swing, 4' bed, 1" through the roller bearing headstock. With the milling attachment, I can make just about anything. The only limit is my skill level. (which is very limiting!!)
"I'm still developing"
Swing over bed is the critical consideration. 6" (swing over bed) lathes are common, and suffice for making mounting flanges and retaining rings for all but really big lenses. A larger than 6" lathe will let you thread the lensboard itself. My ancient Craftsman 6" lathe will barely handle a 4" lens board.
Originally Posted by paul ewins
Until you have access to a lathe, this works for cameras that take wood or thick metal boards. Make a lensboard of Masonite or plywood. Make the hole slightly smaller than the outside diameter of the lens threads. Thread the lens into the board, making sure the lens is kept parallel to the board. It's more work than Poco's copper wire.