BEC Posted December 13, 2005 Author Share Posted December 13, 2005 Michael, I charge $15.00 to install the diaphragms and just go ahead and align the magnet assembly if it needs it. That is if I don't know in advance that the magnet assembly needs alignment. In that case I charge $20.00. Don't glue the horn back on. No reason to do that. Bob Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted December 13, 2005 Share Posted December 13, 2005 "Don't glue the horn back on. No reason to do that. " Huh? I HAVE to, the whole kit n kaboodle hangs from the horn, it has to be sturdy, right? Guess RTV wouldn't do for it. I'll try superglue as long as I'm glueing stuff up. I really aim to get this down myself, it's just a major pain and I can see how you earn your keep. Once I get the hang of it, should be a snap. Seems like half the job is just getting setup. I've got three to do right now, and the K52. Then IndyKlipschFan has another 3-4 down. So I hope to get proficient. Thanks for posting the 'how-tos' Michael Quote Link to comment Share on other sites More sharing options...
BEC Posted December 13, 2005 Author Share Posted December 13, 2005 Michael, At the risk of repeating myself. DO NOT GLUE THE HORN ON. No reason to do that. The horn is held on fine with the 4 screws. Also use very little glue on any other parts. You may want it apart again. Bob Crites Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted December 13, 2005 Share Posted December 13, 2005 oh, yeah, DUUHHH, there's four threaded holes. I was wondering how those little glue dots kept the magnet from falling off. So if the VC is totally disintegrated and the magnet separate from the pole piece, permission to buff em up real good to remove all VC residue? It's gotta be spotlessly clean, right? M Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted December 13, 2005 Share Posted December 13, 2005 Bob, one more, I've got the magnet 'pack' built up and the pole piece in the round carrier. Instead of the 'one shot' method with super glue, would it be possible to use another glue like RTV so that you could have a chance to align the gap precisely, then let it cure and do finish assembly later? Or must it be the superglue adhesive? Or how about wrapping some material around the pole piece, like the business card stock or thin plastic, that would serve as a spacer, then be removed after assembly? M Quote Link to comment Share on other sites More sharing options...
BEC Posted December 13, 2005 Author Share Posted December 13, 2005 Michael, There should not be anything really adhered to the pole piece. Should not need any extensive cleaning unless you are unsuccessful in getting it togeher the first time and then have glue to clean off. I can't think of any way to really use a shim. You might say the silly plastic washer is a shim. It perfectly positions the pole piece in the gap. Use very little glue on any of the parts. A full drop of super glue is probably too much for the whole thing. Bob Crites Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted December 13, 2005 Share Posted December 13, 2005 it was like whatever the 'form' material for the voice coil (more phenolic) was melted to the pole piece, a little scraping and some green scotchbrite make it almost completely smooth. VC was like disintegrated in this one, it came apart in scraps literally. Now that I think about it, this single unit came to me pre-blown when I bought those CWII parts for my center cabinet from CA ebay guy who 'parted-out' two CW's. Who knows what abuse these went through. Am I possibly wasting a diaphram on this setup? Think I'll move over and do the Alnico one that's neat. I need a confidence-booster. Gap is fine on it, just clean, solder, reassemble.... M Quote Link to comment Share on other sites More sharing options...
Jay L Posted December 14, 2005 Share Posted December 14, 2005 i just rebuilt two k77s, everything went ok, but the pole piece seems to not be perfectly flush with the top plate. maybe 1/2mm off, but it is centered. i think i used too much glue to break them back apart. i used 2 part epoxy too. Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted December 14, 2005 Share Posted December 14, 2005 okay, back to the naughty one with displaced pole piece and welded on vc. Got her cleaned up and on third round of magnet snap, finally put a thick card stock in the gap to help with alignment. Seemed magnet was so strong it was pulling the core out of the holder (cheap plastic thingie #*^%(*%*^%#^%^) Is it okay if the gap isn't perfectly consistent, so long as it passes the 'business card test"? In other words mine's not as perfect as the one below, but far from touching. Or can I dry fit the diaphram and see how easily it moves? thanks guys. it's definitely a chore. Michael Quote Link to comment Share on other sites More sharing options...
BEC Posted December 14, 2005 Author Share Posted December 14, 2005 Michael, I would say that if the gap is not perfectly consistent all the way around, time to start over. The stupid plastic washer could not be in the proper place if the gap in not consistent. Bob Quote Link to comment Share on other sites More sharing options...
Jay L Posted December 14, 2005 Share Posted December 14, 2005 it seems the hardest part is applying the pole piece to the bottom plate while holding still the washer. if the pole piece had a resting point for the plastic washer it could never be off axis. or make the stupid thing one piece and this problem would never occur in the first place. i got an alnico with the weldid ring and you can make it off center as well. i suppose one could demag, refit, then remag that would work easily enough. Quote Link to comment Share on other sites More sharing options...
BEC Posted December 14, 2005 Author Share Posted December 14, 2005 If only EV had done the top plate like this we would never have heard of this problem. I really think every K-77M will eventually have this problem happen. Bob Crites Quote Link to comment Share on other sites More sharing options...
Arkytype Posted December 14, 2005 Share Posted December 14, 2005 Michael, et al There is an ElectroVoice pro speaker manufacturing facility in nearby Morrilton. At the compression driver and woofer assembly stations, the workers use a circular sleeve (paper or maybe plastic) that drops into the voice coil gap. This assures perfect centering when the voice coil assembly is mated to the magnetic gap. We recently had them refurbish the woofer surrounds and replace some tweeter foam on a pair of EV Sentry 100A monitor loudspeakers that have to be 25 years old!! http://www.electrovoice.com/Electrovoice3/files.nsf/Pages/Sentry100A/$file/Sentry100A-eds.pdfBTW, compared to the Klipsch plant, the EV facility is immaculate. Over 40% of their pro products are sold in Europe and the Germans buy the most. Nothing is built unless there is an order for it. Maximum build and ship time for any size order is three days!! Lee Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted December 14, 2005 Share Posted December 14, 2005 Guys, I get everything cleaned up, mag assy with bolts ready and very carefully align the top of pole piece with the top plate and get that (&^*%$&%(*%) plastic spacer inserted as tight as she will go. Following Bob's careful steps, I put a mini droplet of superglue on the back plate, then align the assy's and begin lowering. It seems like the pole piece must get pulled out of the top plate at last instant, or the plastic spacer is worn, because every time the pole piece is misaligned. The bolt holes aren't exactly precision either. Would it be possible to GLUE the pole piece/spacer/top piece together so nothing can jump around when doing the assembly? I've done this one like 6 times and getting better, but never the exact perfect gap that's needed for good VC longevity. I do understand that this needs to be consistent, but there's got to be a better way, I've tried shimming between the pole and top, to little success. Is it just trial an error? Is it how close you get before you let the magnet pull take over? what? And so many of my CW's have the alnicos, which I'm now hearing that they lose their power, are only good to 10K, are much weaker than the ceramics. Does it pay to rework these 'inferior' units? At first I was happy when I saw them in the Klipsches, thinking I was getting the older-but-better models? Which is best to have? Michael- about to start throwing things here. Quote Link to comment Share on other sites More sharing options...
BEC Posted December 14, 2005 Author Share Posted December 14, 2005 Michael, I think now that perhaps you missed the step on the first page of this thread where I said to glue the confounded plastic washer to the pole piece and top plate. Bob Crites Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted December 14, 2005 Share Posted December 14, 2005 thanks Bob, that would make a huge difference. So it goes in the magnetic field as one solid unit. AHA! Quote Link to comment Share on other sites More sharing options...
BEC Posted March 23, 2006 Author Share Posted March 23, 2006 Bump for educational purposes. Bob Quote Link to comment Share on other sites More sharing options...
BEC Posted December 11, 2006 Author Share Posted December 11, 2006 Well time passes and education continues. I have worked out a time an labor saving method for fixing these monsters. I was contemplating the fact that if I could just get the confounded pole piece with ridiculous plastic washer out without completely disassembling the magnet assembly, that would save a lot of time. Getting to the point now where I see more and more of them with slipped pole pieces and I really think it will happen to almost every one of them at some time. Anyway, there is only about 1/8 inch of the pole piece exposed after the top round plate is removed. That is not much to grasp, but thinking back to a Dentistry program I once watched, looks like a similar problem extracting a molar. Large pair of pliers with tape around the jaws to prevent scratching the pole piece. Quote Link to comment Share on other sites More sharing options...
mark1101 Posted December 11, 2006 Share Posted December 11, 2006 Bob, When the pole piece is displaced what do you hear? How do you know when it has happened? Quote Link to comment Share on other sites More sharing options...
BEC Posted December 11, 2006 Author Share Posted December 11, 2006 You would hear nothing. The voice coil would be crushed. You would have to take the tweeter apart to see what had happened. Bob Quote Link to comment Share on other sites More sharing options...
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