Old fashioned camera spools

[fatoftheland]

Hi all.
I am trying to work out a way of hold a 120 film spool in my lathe so I can turn the diameter of the flange ends down about 2mm. Then I would be able to use the film in my very old camera. Any ideas would be appreciated. I am not (at the moment) worried about the core diameter.
Regards
Jon

[naffsharpe (Nathan)]

Could you do it with a split cylinder around the axle and cut a step at one end to the diameter you wish the flanges to be ?
Nathan.

[ieezitin]

Not quite sure what a film spool looks like so people may be pressed in answering your question on holding it on the lathe, any pictures?

Anthony.

for some reason the attachments were not showing, i see them now .......  dismiss my first statement..

[chipenter]

Do it between centres with a half centre at the tailstock , I have done this for 135 spools but I only had turn the outside of the flange .

[fatoftheland]

Is the picture not visible? It's the first time I have posted one.
Between centres is a good idea but being a newbie I'm not sure what a half centre is!
Thank you for the replies.
Jon

[ieezitin]

he means this..  its halved so you can get your cutting tool up close and the center does not get in the way, if you buy one get carbide tipped, they are not expensive and a really handy tool to have you will use it often.

Anthony.

[fatoftheland]

Thank you all for the help
Jon

[DMIOM]

Jon,

I'd be a little wary of using a dead centre (half or otherwise) on such an flimsy ended-spool, as the end of the spool will be rotating around the point of the dead centre, and I suspect the pressure would spread the pressed hole in the spool end.

If you're going to turn it between centres, I'd be inclined to suggest turning a little button up first, slightly smaller than the target diameter, with a spigot on one face to locate in the end of the spool, and centre-drilled pop in the other end to locate over your tailstock centre.  In fact, if you made the 'button' a centimetre or two long, it might give you sufficient clearance that you could use a normal running centre.

At the headstock end, if you're using another centre, then make your button long enough that you can pop a pin or dowel or studding through which you can use as/with a drive dog.

Dave

[vtsteam]

I remember those film spools from my first cameras. They are very light sheet metal stock, and I think it would be hard to run them between centers, as DMIOM said, and hard to drive them as well without damaging the cheeks or the keyhole at center

My own direction would be to try to support the ends if I had to do it on the lathe by gluing one end at a time for turning to some thick aluminum sacrificail block chucked up in the four jaw. Since you are only turning the outer edge of the cheek down, you could just do one cheek (the glued one), release it from the block, glue the other cheek, and do that. Each cheek would be well supported by the backing and the center hole untouched.

What kind of glue and how much, might take some thought. working with a washer, for practice, would probably give you the info and experience.

I've used superglue for similar kinds of things. If tacked on lightly and carefully, it can be knocked loose with a sharp rap to the edge with a soft drift. Turners cement is traditional, as is shellac, I believe. Again, working out the amount and type, and method of release is important, and practice with a washer should reveal what is needed.

[vtsteam]

This also seems like it would be a good job for a toolpost grinder. Even a makeshift one from a dremel glued to some 1/4" keystock, to hold it in the toolpost. Going gently and slowly shouild reduce the flanges without damaging anything. This would not be for the glued block method mentioned above, but for a conventionally held spool. It's not actually necessary to spin the lathe for this. you could turn the lathe by hand.

[fatoftheland]

Well I couldn't think of a single way to do it! Now I have a load of different options. Thank you all.

[NormanV]

Modern 120 spools are made of plastic, so very easy to cut. They can be trimmed freehand with a scalpel and finished with sandpaper.