Information needed for construction of flanges

[akfreak]

Well I grow tired of searching for flanges. I plan to buy a small lathe and start making my own flanges. I know there are thread pitch gauges but how does one know what size lip on the mounting side of the flange need to be. All of the flanges I have are not flat on the bottom, the have a indexing lip that centers in the hole of a lens board. Does it matter how thick that indexing lip is?

To those who do this already what are the tools I need to buy in order to build these flanges. I assume a nice parting tool, a set of inside and out side jaws, various tips for thread cutting. A indexing table to drill the holes in the flange lip itself.

It seems flanges are scarce for certain lenses. Also The prices for these rare flanges are ridiculousness IMO.

I am also planning to be converting some DSLR lens mounts so the investment in a lathe was already in the cards so to speak. If you guys have any ideas that I may need to consider, as well as flanges that always seem to be in short supply, please let me know so I can add them to the development list.

I know SK grimes already does this type of work, I also know they are awesome at all they do. I am just a glutton for punishment and like to do one off stuff to help further drive myself insane

[Leigh]

Cutting threads in the size and pitch of mounting flanges is a non-trivial task, requiring a good lathe and mastery of its use.

I would strongly recommend leaving this to someone who has the tools and skills to do it right.

- Leigh

[goamules]

And to counter the above, go for it! Everyone starts somewhere when learning a skill (such as LF photography). They were making screw flanges in 1840 with primitive lathes. I don't recall reading about a long, multi-year apprenticeship for becoming a "LatheSmith".

[Leigh]

They were making screw flanges in 1840 with primitive lathes. I don't recall reading about a long, multi-year apprenticeship for becoming a "LatheSmith".

There's nothing "primitive" about an 1840's lathe.
Machines of that era were quite capable of holding close tolerances and doing excellent work.

Machinist apprenticeships are multi-year, like the one I completed.

- Leigh

[ic-racer]

I have seen Chinese lathes with thread-chasing carriage for a little over $1200. However, that amount of money would supply a lifetime's worth of SK Grimes flanges for me.

[Leigh]

Learning how to use it will cost a lot more than $1200 in scrapped parts, time, and aggravation.

- Leigh

[Steven Tribe]

I do many wood and brass working activities. But I have too much respect for the size of machine required, the specialised tooling needed and the need for an experienced machinist, to ever think about cutting these very different threads.
Just think about the stock you would use? Would this rough cast brass form or cut out from a 5mm thick plate of brass?
I think most of the threads we admire in early flanges - and in even earlier telscopes - were hand cut using specially made taps - rather like the way that threads were cut in wood for table legs before IKEA. The entry rate was controlled by the tap having at the other end the same thread pitch that was turned in a female thread.

[Jim Jones]

http://www.harborfreight.com/ sells a $1000 Chinese-made lathe that might suffice. It might not cut all the threads one will encounter. It cost less than that to get my ancient Craftsman lathe outfitted. A few years ago I saw a nice 6" Craftsman outfit bring only $400 at a live auction.

The indexing lip on many flanges is not necessary. Material, brass and otherwise, might be found in a plumbing supply store. A lens flange doesn't have to be metal. Enlarger lens adaptors were sometimes plastic. A couple of aluminum drip pans might end up as flanges or flat lens boards someday. An indexing table shouldn't be necessary. One can do the layout on a computer and transfer it to the flange.

I agree with Leigh that DIY flanges will be expensive. However, there may be enough satisfaction in learning a new art to make it worth while. It is indeed an art.

[Jay DeFehr]

I would recommend designing a kind of universal flange that can be printed by a 3D printer. Imagine something kind of like one bracelet of a handcuff, closed by an allen screw. Just thinking out loud.

[winterclock]

Lindsay publications http://www.lindsaybks.com/ carries several lathe manuals as well as old course books on lathe operation. You might want to do some research on this before you buy the lathe, cutting threads can be tricky, it takes some math to return the lathe bit to the correct location to start multiple passes. And remember: never part all the way through!