Missing lens flange???

[tmcsweeney]

I was just wondering what does everybody do when they purchase a lens that is missing the lens mounting flange? Machine a new one? Hunt for one online? The issue I am having is that the lens set I purchased "Queen and Co. E. Francais" casket set did not come with the mounting flange. It is also not easy to hunt for one that fits due to is being a bayonet style mount and not threaded. I am considering bringing it to my local machine shop to have a flange made, but before that I just wanted to see what everyone else would do. Thanks

[Jac@stafford.net]

I was just wondering what does everybody do when they purchase a lens that is missing the lens mounting flange? Machine a new one? Hunt for one online?

Speaking from my own experiences of confusion, ignorance and poor luck I would look for a talented old-school machinist. Why? Because many who advertise lens flanges cannot properly measure the necessary thread specs, and neither can we!

About thirty years ago I sent an orphan lens to the late Steve Grimes who not only made the correct thread flange but reproduced the external taper appropriate to the lens era. That kind of knowledge is quickly evaporating.

Choose function and fit first and thank gosh if your machinist knows old lenses - which is highly unlikely. Most so-called machinists today are just CAD/CAM machine operators without a clue or concern.

I had a moment of disappointment and enlightenment when I tried to work with a chap who worked in the machine shop for a famous USA nuclear research facility where much of their work was unique and his only response was, "Send the CAD file and I will knock it off." He exposed his ineptitude. Nuff said. The craft is fading away.

[Steven Tribe]

Sometimes the missing flange in a casket set is hidden in a concealed compartment in the lid! This was certainly the case in Darlot Universal Casket I once had.

Very few lenses have bayonet type mounting in a flange. Gasc et Charconnet had an early Petzval called "the simplified" which has a unique system - but not used on other models.
I can see the Francais casket flange system is more traditional with 2/3 "knobs" that fit into channels in the flange.
I think that it would not be a problem to make a new flange with these channels. It is certainly easier to make than finding a suitable piece of brass/aluminium and cutting the right thread!

Universal iris type mounts work well for smaller lenses (under 1 kilo) whilst the better italian model can manage 2 kilos (in my opinion, anyway!). Slightly larger flanges can be used with suitable gasket tape.

[tmcsweeney]

It is definitely the 2 "knob" style mount. I said bayonet because I have an antique car that uses the bayonet style light bulbs that the lens reminds me of. My machinist is capable of doing it and he actually seemed excited to try and make it. I will update with photos when I get a chance of what he made for me.

[Jac@stafford.net]

I said bayonet because I have an antique car that uses the bayonet style light bulbs

When I read a reference to an antique car I shiver. I gave up my pristine 1958 VW Sedan only last year.

[Duolab123]

I was just wondering what does everybody do when they purchase a lens that is missing the lens mounting flange? Machine a new one? Hunt for one online? The issue I am having is that the lens set I purchased "Queen and Co. E. Francais" casket set did not come with the mounting flange. It is also not easy to hunt for one that fits due to is being a bayonet style mount and not threaded. I am considering bringing it to my local machine shop to have a flange made, but before that I just wanted to see what everyone else would do. Thanks

SKGrimes.com they can make any lens flange and also have some surplus vintage flanges. The best there is.

[Steven Tribe]

I thought the enclosed photos of my Gasc et Charconnet might serve as a starting point for you and your metal worker! I have other bayonet fittings on french caskets (Puyo anachromatic) but the slots are hidden inside the barrel.
Note this is a double system, where the bayonet fits into a barrel - which is again fitted into a simple flange (home-made replacement) with another smart locking system. The mounting done like this - in two parts - to allowed landscape meniscus use of the front achromat.

[Rick A]

When I read a reference to an antique car I shiver. I gave up my pristine 1958 VW Sedan only last year.

My first car was a 57 VW. I still miss it, what a stupid thing I did by selling it. Such memories.

[tmcsweeney]

I thought the enclosed photos of my Gasc et Charconnet might serve as a starting point for you and your metal worker! I have other bayonet fittings on french caskets (Puyo anachromatic) but the slots are hidden inside the barrel.
Note this is a double system, where the bayonet fits into a barrel - which is again fitted into a simple flange (home-made replacement) with another smart locking system. The mounting done like this - in two parts - to allowed landscape meniscus use of the front achromat.

Here is a pic of the knob on one side of the lens. The issue is that just in front of the knob the lens flares a bit so I can’t cut slots into a brass tube because it would hit prior to be able to rotate the lens and lock it in

[tmcsweeney]

I decided to try my hand at designing the flange in 3D CAD software then have someone print it out in ABS plastic for me. I figured that it was worth the $20 to give it a try. Anybody else use 3D printed parts? Maybe even for mold making to cast a part you need?