E 140 dust cap replacement, advice please

[Ruediger]

I want to replace the dust cap of an E 140. I have got a spare and the glue, both from JBL. I searched this forum for advice, found some and read it. But I am still a bit unsafe and would like an expert's advice before I continue.

Please see the attached picture. I removed the dented dust cap. What is left is the voice coil former and a bit of the old dust cap. Only once I cut into the voice coil former, You can see that on the picture at 14:45 hrs.

What bothers me id the rest of the old dust cap. The edge is not absolutely plane, and I do not see how I can seal that air tight. Where must I place the glue? How much of the glue should I use?

Thanks in advance
Ruediger

[Ruediger]

Finally I did it the only way which seemed possible to me, and it worked!

I used aceton to soften the glue. Aceton worked well for this driver, it does not work so well for another driver which I have.

The remainder of the old dust dome was a strip of aluminium about 1,5 mm wide. Actually it was a ring of aluminium. If I had to do it again I would not remove so much material when cutting away the dust dome. I would leave maybe 3 mm of material.

I looked for a proper spot where I could insert a knife between the voice coil former and that ring of aluminium. I could manage to make enough room to insert one blade of a pair of nail scissors.

I cut the ring so that it had two open ends. I used some pliers and very very slowly and carefully I pulled the aluminium strip off the voice coil former. Befor pulling I softened the glue with acetone. I worked on 90 degrees or less at a time.

Finally I tried to remove the left-over glue with acetone. That was not a good idea as the glue turned into a mess which was hard to handle.

I used a weight on the new dust dome to keep it in place. To carry the weight I used a small disk cut from plastic with 4 feet made from rubber foam.

I first put the dome into place, then applied the weight, and finally applied the glue.

I had an old monitor stand which I used as a turntable. Never throw things away :)

Regards Ruediger

[Earl K]

Very Nice Work Ruediger :thmbsup:

Necessity is truly the "mother of invention" ! :applaud:

I learn something new everyday / I thought the little ridge-edge of the dome fit onto the inside of the voice-coil former / now I see it fits on the outside . ;)


>< cheers :)

ps; Great Pictures ! BTW

[jcrobso]

I have a couple of D140Fs that I'm going to have to replace the center dome.
You have just save me a lot of time figuring out how to do it! Thank you again!:applaud::applaud::applaud::applaud::D