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Thanks again for the photos. They REALLY help. I'll go back and give it another whack. Maybe it's time to bring out the small sledge hammer and a heavy duty socket to place on the back of the pin to bang on?
There seems to be a round flat cap on the back of pole piece (see photos). I don't see it in the photo of yours. Does that also get pounded through the hole or do you somehow have to pry it off or remove it somehow first? So far I have not seen ANY movement.
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State, Province, Country: Indiana
It will help, and I think Terry will agree, that if you use a hammer to beat it out instead of a press to press it out, that you should remove the pot from the speaker frame. Otherwise the frame could be damaged. The pot is held onto the frame by three unusual pins that come out easily when hit a few times with a hammer and a pointed instrument.
Of course, for everyone else reading this,
the cone and spider must be removed before any of this is done! Mark, I know you've already removed your cone...I believe you said it was damaged?
A long time ago, I removed the pole piece from the pot of a Philco 70 speaker by hitting it multiple times with a hammer and blunt instrument. I never finished the project. In multiple moves since then, I have lost track of the parts. It was after I separated the pole piece from the pot the hard way, that I learned that I could have had a machine shop press it out for me, and press it back in.
Terry - I went to Photobucket and viewed your other photos of your Philco speaker. Great job!
I assume you made the hole in the pole piece with a drill press? I don't see how you could get an accurate hole otherwise.
--
Ron Ramirez
Ferdinand IN
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The spyder and voice coil on my cone are OK. The cone itself has a couple of repaired tears in it but overall I think it is useable. I removed it carefully.
I still have had no luck figuring out what the round "cap" on the end of the field coil pole/pin is. I'm not sure if it has to be removed somehow or does it just get pressed through the hole along with the rest of the field cole pole piece?
Central Arizona is not exactly a hotbed for machine shops. I called a couple of automotive machine shop places with no luck so far...
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City: Marion Il.
Hi Ron,
Thanks for the compliment. I took 107 Pictures of my restoration.
I did take the pin to work and put it on a drill press. It looks off a little but it got kind of distorted with my caveman antics. In hindsight I should have also put the pin on our hydralic press but I had not ever used it before. It would be a good idea to set the frame aside.
Mark:
Here are a couple more pictures to help I hope.
[Image:
http://i220.photobucket.com/albums/dd137...ure016.jpg]
[Image:
http://i220.photobucket.com/albums/dd137...ure036.jpg]
I don't really see any difference in the two. Maybe somebody else can see something we are missing.
Terry
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If you look closely at the photo of the end of my field coil pin, it looks like there are three small slits or vents around the perimeter of the pin. That is why I thought it might be a cap of some sort but I'm really not sure.
My search for a small hydraulic press will continue. Brute force doesn't seem to be working except for smashing my finger...
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SUCCESS:--I was able to remove the three pins holding the field coil frame to the speaker shell. Then I was able to use an automobile gear puller to remove the field coil pin (see photos).
Now I need to find someone to rewind the field coil with about a pound of 36 Ga wire and I can move on to the next step.
I'm not sure how I'll get the pin press fit back in place yet but one step at a time.
Thanks for all the photos and suggestions.
Mark
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Hi Guys
Tnx from the other Terry for all the pic's. I was wondering how all that came a part. I've got a speaker out of model 21 that has a open field coil and was thinking about rewinding it but didn't have a clue how to. It might be worth opening a section on the list so other can exsess it easily and add their experiences too.
Terry
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
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City: Marion Il.
Hi Mark,
Thats great you got it out. Pretty ingenious using a gear puller! If you were like me I coaxed it along with some kind words (right). Now you can start on winding the coil. I'm sure you can come up with a better arrangement than I used. There is always a way to build a better mouse trap. If you got the pin out you can wind the coil! Take your time and do some research. Don't be afraid to try it. I took it one problem at a time.
Hi Terry,
That sounds like a good idea. I'm sure that other folks would have something to contribute. Glad my pictures helped.
Terry
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I just weighed my field coil. With the plastic form it weighs about 9 1/4 ounces. So, I'm thinking about a half pound spool of 36 ga wire should do the job? I found a supplier online (PowerWerx.com) which says that's about 6185 feet of wire...
Does that sound about right?
Terry, in the photo of your field coil winding setup you have a digital VOM showing a reading of something.... What was that VOM measuring?
Thanks...
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Hi Mark,
1/2 lb won't be enough. 6185 ft will give you about 2565 ohms. You can use this calculator to get what you need.
http://www.cirris.com/testing/resistance/wire.html You will need around 8000 ft. That will give you 3318 ohms. I measured the resistance on my other 90 and it came out to 3.2k ohms. There is about 414 ohms/1000ft. One pound has about 13000 feet in it. I have some old wire and I think it came from my rebuild. It mikes out between #36 and #35. I said you need a pound and I made a mistake. I think they sold me 3/4 lb and I didn't get it all on. I came up with 2.7k and had to install a wirewound under the chassis to make up the difference. It's been 5 1/2 years since that project and there has been a lot of water under the bridge.
I don't think the meter was hooked up to anything. It does that in the idle mode. Looks impressive though doesn't it?
Terry
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That reminds me, I need to come up with a way to reproduce a voice coil, less wire to deal with but I am still thinking about what to use to make a form out of. The reason is that I have several speakers where the voice coils use a paper form and the form has a kink in it that rubs on the pole piece, some are also torn. Getting back to removing a pressed in pole piece a hydraulic press like a mechanic or machine shop would have would work, it was how thet installed it in the first place only you are doing the reverse. I never though of a gear puller to remove it, I don't think I would try that to get it back in though.
Regards
Arran
