Making a flanged lens

kenlilly106 · Post by **kenlilly106** » Sat Apr 02, 2011 8:47 pm

Got a little project going on that needs 4 lenses made, I've found the perfect sized lens and barrel material (lipstick tubes w/o the center mark) but I need to make a riveted flange on one end.

My first idea was to cut out 4 rings in styrene and glue them onto the end of the barrel and then glue a strip of styrene around the barrel and sand and putty as needed.

Course the big problem is cutting out 4 identical holes and getting them aligned properly.

Then I tried bending Plastruct angle into a ring but it doesn't work since there's too much material to compress.

I thought about plunge forming some but I think cutting out the hole and getting it centered properly would be a problem.

I'm back to cutting out rings and gluing them on as my solution, it's important I get the rings centered on the lens or they won't look right and I'm not sure I can do it any other way.

Ken

Andrew Gorman · Post by **Andrew Gorman** » Sat Apr 02, 2011 10:50 pm

Gasket punches have worked for me- there are some available with a center point that makes concentric rings a snap. Or if you can find a metal washer the right size, use it as a pattern for your plastic version.

kenlilly106 · Post by **kenlilly106** » Sun Apr 03, 2011 9:26 am

Never thought about using washers for the pattern, you're a genius!

Ken

Sluis Van Shipyards · Post by **Sluis Van Shipyards** » Sun Apr 03, 2011 7:04 pm

What size rings do you need? Plastruct makes ABS rings that are really handy for all kinds of things.

kenlilly106 · Post by **kenlilly106** » Sun Apr 03, 2011 7:47 pm

Looking for something 11/16" nominal OD and around 1/2" to 9/16" ID, ideally .040" thick or thinner.

I didn't know about the Plastruct rings, I looked at what they had, they do make 11/16" OD rings but the ID is a shade smaller than what I need, plus the thickness is way too thick, thanks for pointing them out to me, I didn't know Plastruct make anything like that.

Ken

Mr. Badwrench · Post by **Mr. Badwrench** » Mon Apr 04, 2011 1:15 am

You could still heat form them as you mentioned, just make the center hole part of the buck. At the center of the tool you're using for a buck, put an additional small, raised disk. Then after forming, when you cut your flanged rings from the sheet, cut the center raised area off. It will always be in the same place.

Mark Yungblut · Post by **Mark Yungblut** » Mon Apr 04, 2011 11:59 am

I don't know how much help this will be but I have successfully created multiple custom size flanges using a lathe. There are several methods that can be used. So if you know someone that has one available I'd look at that as a possibility...

Mark