Fabricating Diaphragms - Plastic?

[dusin1]

I have a Toman Reproducer that has a 2-½" diameter diaphragm. It's blown, has corroded holes in it. And also replacements don't appear to be available. It also appears to be just flat aluminum. So I'm going to have a new one milled out of .016" thick aluminum. To support the stock material it has to be sandwiched between thicker plates to cut it out. While doing this I can add other layers/materials and have them cut at the same time.

Has anyone tried using plastic diaphragm material? If so, what did you use and what was your experience?

[52089]

A dealer friend experimented with using plastic cut from the lids of margarine tubs as a replacement for Diamond Disc diaphragms. I was not wild about the results. I know some people have also used various kinds of cardboard for this, again with mixed results.

Please post your results either way!

[edisonplayer]

I remember Jerry Donnell using lids from Swiss Miss Instant Cocoa for diaphragms.edisonplayer

[Henry]

IIRC, someone on the board once mentioned using coffee can lids, i.e., the kind that pull off with an integral tab. The material is a very thin aluminum.

[larryh]

In my early days of designing diaphragms for the Edison I found one version of plastic that had some pretty fair sound. It was a total accident. My mom had some old dog flared plastic collars used when a dog needs to be kept from biting at a wound or sore or from an operation. That material was too thick for the edison but it would work none the less. The plastic butter tubs was a total dud in sound. So evidently as with anything there is a very wide range of sound in plastic products. Even the foam meat trays I use for the True Tone diaphragms vary in quality of sound widely and only certain ones will produce high quality sound.

Larry

[gramophone-georg]

In my early days of designing diaphragms for the Edison I found one version of plastic that had some pretty fair sound. It was a total accident. My mom had some old dog flared plastic collars used when a dog needs to be kept from biting at a wound or sore or from an operation. That material was too thick for the edison but it would work none the less. The plastic butter tubs was a total dud in sound. So evidently as with anything there is a very wide range of sound in plastic products. Even the foam meat trays I use for the True Tone diaphragms vary in quality of sound widely and only certain ones will produce high quality sound.

Larry

Mica Monster made a comment in a thread about rebuilding reproducers that the amount of pressure the seals exert on the diaphragm is just as critical as the diaphragm itself, which makes total sense to me. Wonder if you could have improved that even more that way.

[JerryVan]

I snipped one out of a pie tin once. Actually sounded pretty darn good.

I think if you just marked out a piece of aluminum with a compass or divider and carefully cut it out you'd do just fine, and the exact center would already be marked by the compass point. I'm also thinking, .016" may be a bit too thick.

[Curt A]

I have cut apart modern soda cans and used dividers to cut them, as Jerry suggested, and they work well... extremely thin aluminum.

[Henry]

I snipped one out of a pie tin once. Actually sounded pretty darn good.

I think if you just marked out a piece of aluminum with a compass or divider and carefully cut it out you'd do just fine, and the exact center would already be marked by the compass point. I'm also thinking, .016" may be a bit too thick.

As a matter of fact, the aluminum coffee can lids I'm familiar with already have a very small hole in the center, which allows the can to "breathe" with changes in temperature and pressure. One could use this hole as the center for scribing the circle.

[Curt A]

Coffee cans are too thick... a Coke or Pepsi can is perfect... the sides, not the top or bottom...