Diy AMT

[båndsei]

I had forgotten that measurement.Here it is:
[IMG][/IMG]
Green is covered 20mm at each end.
Very small difference.
I made a test with my new tool.Plates are too thick.2mm gives a spacing off 4-5mm.,and it have to bee app.2,5mm.
The fixture with the diaphragm has to be in the oven 20min. at 175 c.
Plexiglass gets soft and bendy at that temperature.

Bernt.

[båndsei]

I have made a new diaphragm with 1mm. alu plates for the tool
[IMG][/IMG]
[IMG][/IMG]
It is very symetrical .And it keeps shape,meening i have to drag a bit to fit 32mm.with.

Bernt

[solhaga]

Impressive!

So you have alufoil across to keep the shape?

[båndsei]

No.Not nesesery.The mylar keeps shape as it is warmed up and cooled again.The stripes is there because tape is double there .My tape is 50mm.wide and i use 4 to get 160mm.

Bernt

[solhaga]

So you have 50 mm wide mylar tape? How thick?

The mylar keeps shape as it is warmed up and cooled again.

Yes of course. That´s how it used when making wings and fuselage for air plane models. In fact, I order my mylar from a micro flight diy supplier here in Sweden.

How do you heat it up, bake the whole package in the oven?

[båndsei]

Mylar is the same as polyester or PET.My tape is 12my with 8 my adhesive.I place it all in a oven for 20min. at 175' c.

Bernt.

[solhaga]

Thanks, Bernt.
Do you buy the tape or make it yourself?

When I saw your method I thought of nail strips. They have predrilled holes, can be down to 0,7 mm thick and can be cut in any length:

[båndsei]

I bought it here:Specialtape & klæbestoffer
Nail strips might do it.

Bernt

[solhaga]

Great. I´ll check if it can be obtained in Sweden.

Looking at the site it says:
"We can supply tape in standard widths as indicated below or in widths according to specifications."
and according to the data sheet:
"Widths from 1/4” to 15.5"

So then you can have the tape oriented along with the gap and you don´t need to overlap.

[jay53]

Originally Posted by båndsei

Mylar is the same as polyester or PET.My tape is 12my with 8 my adhesive.I place it all in a oven for 20min. at 175' c.

Bernt.

Bernt,

This is very interesting. I just bought AMT diaphragms to build the Tweeters.

Are you using the Photoresist to develop the aluminum traces on the PET or using Aluminum adhesive backed tapes ? I presume the Mylar 3M tapes are to protect Aluminum traces.

Jayant