Is it feasible to make lens mounts/retaining rings at home?

[paul ewins]

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?

 

[Dan Fromm]

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.

 

[epatsellis]

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.


erie

 

[AZLF]

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.

 

[epatsellis]

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?


erie

 

[Poco]

I've used heavy copper wire wrapped around the threads to hold a lens in place. Not elegant, but works just fine.

 

[wfwhitaker]

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.

 

[Ole]

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.

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).

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

 

[ricksplace]

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!!)

 

[Jim Jones]

. . . 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?

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.

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.

 

[paul ewins]

Thanks everyone, it sounds like I should look at the smaller hobby lathes as I won't be making large retaining rings and I will stay away from combination machines.

There isn't a local (i.e. Australian) equivalent to SK Grimes so I might do some hunting around to see if there is a local machinist who can make up the odd ring when I find a lens that I want to use on a regular basis. I've seen the iris holders but was dubious as to how much weight they could hold. Some of the old brass lenses are huge.

 

[Ole]

The iris mounts easily hold all but the very heaviest lenses. The 500mm f:5.5 Schneider Aerotar sits well since it's relatively short, even if it weight about 2kg. The 620mm f:3.5 Petzval is just too much, but by supporting the front of it with a second tripod that works well too!

 

[Smudger]

Maybe not as elegant as a properly machined thread,but this method worked for me when I had to mount an EL-Nikkor 150 (wierd adapter size ) to a panel.
First,ensure you have a slightly oversize hole. Grease the thread section on the lens with petroleum jelly. Fit lens to panel. Pack epoxy putty around the threads. As soon as the epoxy begins to set,unscrew the lens. The jelly prevents the putty adhering to the lens and you are left with a perfect impression of the lens threading, so the lens can be removed/replaced at will.
If you require a permanent mounting , omit the jelly..

 

[Whiteymorange]

Hot glue is wonderful stuff - and reversible when you screw up.

 

[c.d.ewen]

Thanks everyone, it sounds like I should look at the smaller hobby lathes as I won't be making large retaining rings and I will stay away from combination machines.

Hi, Cousin

A hobby lathe will handle almost everything you need. Being in the USA, I use a Sherline for these small jobs. If you're near a larger town, look for an auction of a closed machine shop - they always seem to pop up here. The benefit of the hobby lathe, though, is that you can pick it up and store it somewhere. Even a small 6" lathe will weight quite a lot.

Don't be afraid of cutting threads. Even a hopeless hack like myself can produce workable lens rings. Make your first ones out of cheap plastic or nylon, e.g., Delrin.

Practice. Read books. Have fun.

Charley Ewen

 

[Jim Noel]

The thread cutter which is available for the Sherline is not difficult to master well enough to cut retaining rings.

 

[Nathan Smith]

Can the Sherline do the larger rings like, say, for a #5 shutter? Pardon my ignorance of this stuff, but what's the largest diameter work a small lathe like that can handle?
Thanks,
Nathan

 

[Donald Qualls]

The Sherline can, IIRC, swing 3.5 inch diameter over the bed (it's a pretty small lathe), though there are riser blocks for it that raise the headstock, tailstock, and carriage to let it swing 5.5 inches. The original chuck will only hold items up to something like 1.5 inches, but the spindle will take a lightweight 3-jaw or 4-jaw made for a Sieg mini-lathe (Shanghai-built 7x8, 12, 14, depending on model and vendor) with a suitable adapter plate. If you expect to need to work on a #5 shutter, I'd recommend getting a 7x lathe in the first place; these lathes are inexpensive, tooling is also quite reasonable, and they can handle 3.5 inch work diameter right out of the packing case (and they no longer require a complete rebuild before you do any work -- they've improved greatly in the 20 years since the first reviews were written; mine only needed the packing grease cleaned off, gibs adjusted, and a swipe with a file to take off the raised metal around the serial number stamping at the tail end of the ways).

However, the Seig lathes are bastards relative to measurement -- mine has a 16 tpi lead screw, making it a major pain to cut metric threads, but has 1 mm pitch on the cross slide and compound screws (pretty close to .040" per turn, but not quite -- but the collars are marked as if it were). There are metric lead screws, half nuts, and threading gages available for these lathes, and you can change from one to the other in half an hour -- sometime when I have money, I hope to get a set. There are also true inch feed screws for the cross and compound, but that's less critical.

Seig lathes, BTW, are sold under a wide variety of nameplates, including Harbor Freight, Homier, Busy Bee, Grizzly Tools, even Enco and MicroMark. Aside from the MicroMark 7x14 (different motor location, true inch screws throughout, and slightly stricter quality control), the only significant difference between any of them is the length of the bed and lead screw, and the color of the paint.

 

[Curt]

Donald which of the 7x lathes would you get if you had to choose. I have been pondering this for a while and would like to get one too. I recently got a hand knurler that has 6 different knurls with it. It's a hand knurler and is new. I am going to use it for knobs.

I would like to take the time to learn to make retainers and threaded components.

Regards,
Curt

 

[Donald Qualls]

I bought (three-four years ago) a Homier Speedway 7x12 and haven't regretted it. I chose this particular 7x because it was the lowest priced, though it didn't include quite as much tooling as the other 7x12 offerings -- there was and is no other reason to choose, unless you can afford the slightly nicer MicroMark 7x14. I bought a 21T change gear kit to allow cutting "almost metric" threads (though at some point I'd like to get a pair of 50-127 gears in finer pitch that fit the banjo, it'd work better to get a true-metric threading screw and mating parts), 5" 4-jaw chuck, bored the center hole in the 3-jaw chuck to match the 13/16" spindle bore, and have bought some tool bits, boring bars, etc. -- I probably have $550 to $600 invested, total.

Given the level of quality control these lathes have gotten in recent years, I wouldn't recommend a Sherline or Taig unless you need something as portable as a sewing machine (my 7x12 weighs close to 90 pounds with the chuck, carriage, and tailstock mounted). If you *do* need extreme portability, a Sherline with riser blocks is the lightest tool you can buy for the size work it can handle, but it's only capable of very light cuts on work more than a couple inches in diameter.

If you have the money, a MicroMark is the way to go -- it's got true inch screws on cross slide and compound, and on the milling attachment, you can easily buy a metric long feed screw (plus matching split nut and threading indicator) to allow cutting correct metric threads, and also get true metric (i.e. marked in .01 mm instead of 1/40 mm) screws for the slides if needed. The extra two inches of bed will never come amiss, and the motor location is significantly better.

Either way, you'll then want to bookmark littlemachineshop.com, *the* online source for tooling and parts for these lathes and their cousins, the mini-mills. If you had more money and time than sense, you could literally buy the parts from Little Machine Shop to build a complete mini-lathe from the ground up, including the motor, speed control circuit board, all fasteners, even the rubber feet. BTW, they also have metric lead screws available to fit all three sizes of 7x lathe, and the other parts that go with them -- you'll certainly want one of those if you're interested in making retaining rings, since you'll need to be able to cut 1.0, 0.75, and most likely other metric thread pitches (but also US/British pitches, not to mention modern, Whitworth, and BSA threads). I'll leave it up to you to become proficient doing so inside a tube end -- I still stick to outside threads, but I don't use my lathe as much as I wish I had time and material/tooling money to do.

 

[Lachlan Young]

I'm surprised no one has mentioned Dave Gingery's backyard foundry lathe - the one made from bits of scrap aluminium melted down and built up into something surprisngly accurate!

Anyway for those in the UK WARCO have a good range of far eastern machines which are built to their quality controls and which have gained a reputation in the UK as sturdy well made machine tools at good prices.

Hope this helps,

Lachlan

 

[Donald Qualls]

Even Gingery enthusiasts will tell you that if you just want a lathe, buy a Chinese made 7x or start looking for a used South Bend etc. If you want the experience of making a lathe, you want a Gingery, because those books teach you everything from how to make a furnace to cast scrap metal into useful items, to how to make accurate machine tools with nothing more sophisticated than a file and some basic homeowner power tools (electric drill, mostly).

I started a Gingery style lathe, because I didn't have the money for a 7x, but when I came into some money, I bought the 7x12 and sold off the completed Gingery type bed. At no point was I ever interested primarily in building a lathe -- I wanted a lathe, but had money only in small increments. I figure I would have gone a couple years working on that bolt-together variant design -- and still not had thread cutting capability. I cut my first thread on the Seig-built mini-lathe a couple days after UPS dropped the machine off (had to clean it up and get a suitable tool bit).

 

[c.d.ewen]

Can the Sherline do the larger rings like, say, for a #5 shutter? Pardon my ignorance of this stuff, but what's the largest diameter work a small lathe like that can handle?
Thanks,
Nathan

Nathan:

Just to answer your specific question, yes, you could do it on a Sherline, but not as easily as on a larger machine. I once cut a retaining ring for an 18" Verito (about 4.75") on a Sherline, as that was all I had at home. I had to make a special jig for it, though.

I can't add anything to Don's excellent advise, except to mention to newbies that buying a lathe can be compared to buying a camera body - it's a start, but you still need lots more equipment before you can make what you want.

In the US, a good way to learn about machining is to take a course at a community college or technical high school.

Be warned, though, that GAS is not photography-specific!

Charley

 

[Curt]

Thanks Donald, I checked the sites out. The Micro-Lux looks like a good one, I hadn't hear of it before but it has all the accessories that are needed. the LittleMachineShop has a ton of accessories for all of the machines. It's a lot to digest. I'll have to add it up and see what I am going to get.

Regards,
Curt

 

[Donald Qualls]

Be warned, though, that GAS is not photography-specific!

True, but home shop machining GAS is a lot cheaper than camera GAS -- you can buy more machines than will fit in your house for less than the price of one upper echelon film camera body (if you have a means to haul them, you can often get BIG machines cheaper than small ones, because they cost too much to ship). Where machining gets you is in consumables (like photography, to some extent), but also in electricity -- doesn't take much before you start needing 3-phase power for your machines, which costs quite a few dollars a month just to have the wires connected (and a bundle to get installed), and some aspects you can see the electric bill ratcheting up when you turn on certain equipment (like, say, an electric foundry). And then there's the cost of storing the consumables -- a $50 used freezer will store a lifetime supply of film, but you'll be out a couple grand for a shed to protect your machining metal stock...