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E1 HANDSET SERVICE TIPS

Started by bingster, September 09, 2008, 04:42:57 PM

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Bill

#60
This is becoming what a movie reviewer would call an Epic Struggle Between Good and Evil!

I have only one strap wrench. Thought about buying another, but considering the amount of force I am using here, I'm not sure I could control two wrenches, even with the help of a burly neighbor.

As suggested, I baked the unit in a 200-degree oven, then plunged the aluminum cylinder into ice water and strap-wrenched it. I was hoping the thermal shock would loosen the bond between the aluminum and the brass. In addition, aluminum expands/contracts more than brass, so I was hoping the aluminum would shrink away from the brass. Good idea. No result.

I baked the unit again in a 200-degree oven, then poured a pool of penetrating oil on the joint and set it on the bench to cool overnight. The hope was that as it cooled, it would draw some oil into the corrosion. Good idea, no result.

I have a good solid bench vice. I used a couple hardwood blocks in the vice to pad the threads, and gripped the aluminum cylinder in the vice. No matter how tight I cranked down the vice, the cylinder slipped when I really leaned on the strap wrench on the bakelite cap.

Repeated the vice trick, using several thicknesses of shirt cardboard in place of the hardwood. Bunged up the threads some (I can touch them up with a small file), but the cylinder still slipped, and nothing else happened.

I am cranking so hard on this thing that I can hear the diaphragm ping as the parts deform under pressure. But I still can't get it off.

The thing that seems least controlled is my ability to grip the cylinder tight enough to prevent it from turning when I apply the strap wrench. Since it doesn't have grip holes, I drilled a couple, then put a "pin" (an 8-penny finish nail cut to length) across the cylinder. The hope was that the pin would stop the
cylinder from rotating. No good - the ends of the pin simply bent over. Lots of force here!

Dry ice is probably the next step, if I can find some.

Stay tuned. This turning into a real challenge, and I'm not done yet. But I'm growing fearful enough that I have ordered a set of replacement parts from OPW. By the way, I also ordered an F-1 transmitter capsule - on re-reading the posts above, do I need some sort of adapter in order to use it? Or does it just drop into the aluminum cylinder (625A) that holds the bullet transmitter capsule?

Bill

cihensley@aol.com

Use MaxFilm instead of Liquid Wrench or some other oil.

Chuck

rp2813

You'll need to order the adapter and "grid" as well as the F1 transmitter.  The "bullet" assembly is a single unit, whereas the F1 assembly has three components:  the adapter, the capsule, and the "grid" or transmitter cover as shown in the exploded view.

Just to be sure, when you're using the vise to hold things in place, are you then heating the cap with a hair dryer before attempting to remove it with the strap wrench?  That's what worked for me, but yours seems to be really stuck.

Recently Dan/Panther posted that he had good luck using lighter fluid to get two stuck parts separated from each other, so you might give that a try.
Ralph

Bill

#63
An old friend used to say to me "If force doesn't work, you haven't used enough." I had reached that point, and was prepared for the thing to break if I went further. It finally came apart, but I can't believe what it took.

I've got a good solid bench vise, bolted to my workbench. I've been squeezing the aluminum cylinder in that vise, using wood or cardboard padding, but no matter how hard I leaned into the vise handle, I couldn't get the vise tight enough to keep it from slipping. So I discarded the wood and cardboard, borrowed a pair of thick leather straps from my neighbor, put it all in a vise, and used an 18-inch cheater bar on the vise handle to get a really good grip on it. I'm surprised that the aluminum didn't deform, but it held solid.

Then I got my strap wrench on the cap, and leaned into it. You guessed it, the strap wrench began to slip. I cleaned both the wrench and the cap with alcohol, and tried again. Nope. Still slipped.

My neighbor watched all this, and as he wandered away, he jokingly suggested a pipe wrench. We agreed that it would certainly break the bakelite, but after thinking about it for a few minutes, I realized I was out of ideas, so I put in a couple thicknesses of shirt cardboard, put my 18-inch pipe wrench on the thing, and heaved. Very grudgingly, it begain to turn - and I got it off.

First thing I noticed is that the aluminum is threaded directly into the bakelite. There is no brass insert, at least on this one (date code 230). So there was no aluminum-brass corrosion, and all the corrosion dissolving chemicals in the world weren't going to help. In addition, it was threaded so tightly into the bakelite that no oil was ever going to get into it. In fact, when the aluminum cyclinder finally came loose, the peak of each thread in the bakelite sheared off and stayed with the aluminum. It is possible that dry ice might have shrunk the aluminum enough to release its hold on the bakelite, but refrigerator ice wasn't anywhere near doing it. And heat just made it worse, by expanding the aluminum and driving it deeper into the bakelite.

To my surprise, the magnet seems quite strong. I have no real experience with how strong it should be, but I can hang a 5/8-inch Craftsman combination wrench from the pole pieces. So it may turn out that the problem was simply a gunked-up diaphragm, as was suggested earlier. If so, there was no way I was going to clean it up without getting the whole thing open, so it was worth it. The diaphragm, incidentally, looks perfect. So I will reassemble, clip it into a 500-set, and try again. If volume is still low, I will try the rare-earth magnet trick, and report back.

I have reported all this simply to let others know that the thing can be REALLY hard to get apart, but that if you get desperate, a bit of excessive force might not be such a bad idea.

You can be sure I will put a thin coat of Vaseline on the threads before I reassemble it ...

Bill

LarryInMichigan

Bill,

Congratulations on your success :)  All of the E1 handsets I have seen have bakelite caps screwed onto aluminum.  It seems that your cap was somehow fused to the aluminum.

Chances are, that if you clean all of the surfaces well and make sure that the diaphragm is perfectly flat, the receiver will work well after it is reassembled.  Make sure that all of theelectrical contacts are clean from any dirt ans oxidation.

Larry


bingster

Wow, that was quite an ordeal! I once had one that (I'm guessing) must have been stored in a very humid environment, because all the aluminum had corroded to a point at which it was covered by a thick white powder and the steel had rusted. I wound up having to use a dremel and little nippers to cut/break the receiver case out of the cap.   

Incidentally, the only major brass parts on an E handset are the two threaded pieces molded into the handset handle.  Everything else is aluminum. 

= DARRIN =



Phonesrfun

It seems that your magnet is quite ample and not demagnetized.  It might be that the cap, while very tight on the aluminum body was still not screwed down all the way to achieve clamping of the diaphragm edges along the cup of the receiver.  I know that is not what you wanted to hear, because I don't know how you could screw it on any more than it already was!  You have probably already checked for signs that someone had screwed in on cross-threaded before.  You may want to try just putting the diaphragm on the receiver cup and hole it in place with your fingers without the cap.  Either put the receiver unit back on the E-1 handle and hold the diaphragm in place or use the clip lead routine.  See if you get ample volume out of it that way.  If so, it was probably not being held against the cup by the cap.

-Bill G

GMF

You should be able to remagnetize your element using neodymium magnets, available from guitar repair supply stores online, or wherever google leads you. You can adapt the instructions for remagnetizing guitar pickups

Bill

Bill G, you were right. I got the thing apart, cleaned up the diaphragm and the magnet poles, reassembled it, and it was fine. I was excited.

Unfortunately, the next step was to disassemble the transmitter, which made not a sound. Like the receiver, it was really stuck, so I put the force to it - and broke the cap. Not a real smash job, but broke a piece out of the side. I may be able to glue it, but it will never look quite right. I got a replacement from OPW, to be used whenever I get the thing apart. But for now, it is sitting in a box where I won't see it for 6 months - I have moved across the country for the summer.

Incidentally, my plan is to modify my bench vise into a pin-type phone disassembly wrench. Should be a simple mod - if it works, I'll post with pics. The price of a real pin wrench seems a bit out of my reach.

Bill

deedubya3800

The situation I have is that the receiver cap is stuck onto the receiver element, and the diaphragm really needs to be adjusted. I've tried chemicals and tools and even a serpentine belt as something of a hand-held strap wrench, and I can't budge it the least bit. I've already done negligible damage to the threads that the ring goes on and I'm one step away from getting desperate and asking to send it to someone to have them try.

Quote from: BOB BONCHAK on October 17, 2008, 08:06:58 PM
Harbor Freight Tools has a two piece set of stap wrenches (Item 94119) on sale for $2.99 until 10/27.  Work great in removing the round parts of handsets.
BOB

I'm going to order these. They're still $2.99, and today is the last day to get 20% off any one item, making them $2.39, or $4.79 with tax shipped to me.

deedubya3800

Quote from: Bill on April 04, 2011, 05:27:27 PM
An old friend used to say to me "If force doesn't work, you haven't used enough." I had reached that point, and was prepared for the thing to break if I went further. It finally came apart, but I can't believe what it took.

I've got a good solid bench vise, bolted to my workbench. I've been squeezing the aluminum cylinder in that vise, using wood or cardboard padding, but no matter how hard I leaned into the vise handle, I couldn't get the vise tight enough to keep it from slipping. So I discarded the wood and cardboard, borrowed a pair of thick leather straps from my neighbor, put it all in a vise, and used an 18-inch cheater bar on the vise handle to get a really good grip on it. I'm surprised that the aluminum didn't deform, but it held solid.

Then I got my strap wrench on the cap, and leaned into it. You guessed it, the strap wrench began to slip. I cleaned both the wrench and the cap with alcohol, and tried again. Nope. Still slipped.

My neighbor watched all this, and as he wandered away, he jokingly suggested a pipe wrench. We agreed that it would certainly break the bakelite, but after thinking about it for a few minutes, I realized I was out of ideas, so I put in a couple thicknesses of shirt cardboard, put my 18-inch pipe wrench on the thing, and heaved. Very grudgingly, it begain to turn - and I got it off.

First thing I noticed is that the aluminum is threaded directly into the bakelite. There is no brass insert, at least on this one (date code 230). So there was no aluminum-brass corrosion, and all the corrosion dissolving chemicals in the world weren't going to help. In addition, it was threaded so tightly into the bakelite that no oil was ever going to get into it. In fact, when the aluminum cyclinder finally came loose, the peak of each thread in the bakelite sheared off and stayed with the aluminum. It is possible that dry ice might have shrunk the aluminum enough to release its hold on the bakelite, but refrigerator ice wasn't anywhere near doing it. And heat just made it worse, by expanding the aluminum and driving it deeper into the bakelite.

To my surprise, the magnet seems quite strong. I have no real experience with how strong it should be, but I can hang a 5/8-inch Craftsman combination wrench from the pole pieces. So it may turn out that the problem was simply a gunked-up diaphragm, as was suggested earlier. If so, there was no way I was going to clean it up without getting the whole thing open, so it was worth it. The diaphragm, incidentally, looks perfect. So I will reassemble, clip it into a 500-set, and try again. If volume is still low, I will try the rare-earth magnet trick, and report back.

I have reported all this simply to let others know that the thing can be REALLY hard to get apart, but that if you get desperate, a bit of excessive force might not be such a bad idea.

You can be sure I will put a thin coat of Vaseline on the threads before I reassemble it ...

Bill

Oh, my gosh! I think I have your receiver's identical twin. I'm needing to adjust (i.e., fiddle-fart with) the diaphragm to get a better sound, and it's stuck in the cap worse than anything I've seen before! I've tried hot, cold, loosening sprays, and right now it's wrapped in a serpentine belt and secured in a vise waiting on me to take it to work with me tomorrow and borrow a pipe wrench to do almost exactly what you described here. I also have some strap wrenches on the way, but if they arrive too late for this project, I know I'll have countless others.

HarrySmith

One of the members of ATCA came up with an easy to make wood jig to disassemble E1's. I have a file at home, I will try to find it and post it here.
Harry Smith
ATCA 4434
TCI

"There is no try,
there is only
do or do not"

Bill

Harry -

This must be a jig similar to the one in Ralph Meyer's book. I plan to fab one in the next couple weeks. Wish I had seen it before I broke my second E1. Anyway, we'll see if it is similar to the one you mention. ANYTHING should be better than a pipe wrench.

Bill

Bill

As noted in the other E1 thread, there is a pretty simple wooden disassembly jig described in Ralph Meyer's book. I plan to fab one within the next week or so, and we can see how it works. In the meantime, don't break anything!

Bill

deedubya3800

We got it apart, but we scratched the cap a little bit somehow. It's not bad, but I may try to restore it later. I have some other scratched and chipped Bakelite items that I would like to... I digress. The problem here is that the cap was screwed on way too tightly. I'm thinking that is what was causing the poor sound: The cap was so tight it was restricting the free vibration of the diaphragm. Now everything sounds great!