Forum member MW magnet repair tool set

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  • pitdogg2
    pitdogg2 Posts: 25,549
    edited July 2023
    Gardenstater wrote: »
    Back in April March he said he had some problems and was sorry and would be sending it on in a week or two. Since then silence.

    Time to drive over....
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  • Gardenstater
    Gardenstater Posts: 4,497
    edited July 2023
    He has had it for around 15 months.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
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  • msg
    msg Posts: 10,111
    Man, you guys are rough. Everyone knows it takes 16 months.
    I disabled signatures.
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  • Gardenstater
    Gardenstater Posts: 4,497
    edited July 2023
    msg wrote: »
    Man, you guys are rough. Everyone knows it takes 16 months.

    Maybe you are right. It is only 12.5% (1/8 th) of a DECADE. Not really that long in that context. :)
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
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  • plastic_avatar
    plastic_avatar Posts: 708
    A blink of your eye in geologic time.

    Maybe I missed a message [goes to look].

    Nothing in my inbox.
    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * custom 5B on a system for my Dad * Ye Olde college stereo in the garage
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  • Tony M
    Tony M Posts: 11,158
    I hope the guy gets it back to you but it seems he might be in jail, prison or he had to bail from where he was living and left it.

    There's NOTHING else it can be used for and anybody finding it and doesn't know a thing about it or why he came into having it will never understand its purpose. It probably will forever be a mystery what happened to him and it.

    SAD! UNLESS.... o:)

    I really! enjoyed fixing a few woofers and will always be grateful for the opportunity to have had a chance to borrow it. It's a beautiful work of art and your machining skills are second to none. I actually had fun using it and saving those woofers from the trash bin.
    Most people just listen to music and watch movies. I EXPERIENCE them.
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  • xschop
    xschop Posts: 5,000
    Loaner jig #2 being sent out Monday to @MrGeology
    Don't take experimental gene therapies from known eugenicists.
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  • MrGeology
    MrGeology Posts: 83
    Picked up three 6500's. All are seized but ohm out good. Will see how it goes.
    "One great object of the Constitution was to restrain majorities from oppressing minoritites or encroaching upon their just rights."
    -James K. Polk, 11th President of the United States
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  • MrGeology
    MrGeology Posts: 83
    edited August 2023
    A quick update.
    Received the jig Friday (thanks @xschop ). After figuring out how to use it properly began using it on the three drivers Saturday.
    These drivers are all new to me as of last month. You can see the considerable mag shift on each.
    Driver#1 = MW6500 dated 02/81
    jd15872q6frl.jpg
    Driver#2 = MW6500 dated 05/81
    zatjnag19aat.jpg
    Driver#3 = MW6500 dated 11/79 (silver basket)
    g1cand4t9at7.jpg
    After considerable toying with how to use the jig, the first driver was easy to set. However while removing it form the jig heard a very quiet 'creak---snap!' and sure enough it had re-seized. Re-set it using the jig again and played some bass oriented music through it (hooked to an old crossover I had laying around) and after about 15 minutes decided to more gently remove from jig.
    This time it was good for about 30 seconds just sitting on the work bench, but as I was looking for the glue heard that same quiet 'creak---snap!'. Checked and sure enough it had seized again.
    Went through this about half a dozen times late Saturday evening, noticing that each time it lasted a little longer before re-seizing.
    Decided to re-set, and leave in jig for 24 hours playing some bass oriented music at about 45W.
    Came back Monday, released from jig, cleaned and glued with no problems.
    opi4xrrg3828.jpg
    Driver #2 will not set properly (suspect pole piece/VC not plumb).
    Driver #3 was set in about 10 minutes, what a breeze. However it did the same thing as driver #1, would not stay set.
    This time let sit in jig playing music from late Monday evening until early this morning (about 9 hours). It is now glued, curing and has not budged.
    fen0z6e55msa.jpg
    Glue is Loctite Power Grab Ultimate Clear and looks pretty much the same around the perimeter on both finished drivers.
    fynykydexxwv.jpg
    Now looking into making a sleeve for the jig so can remove PP/Magnet from driver #2.

    Post edited by MrGeology on
    "One great object of the Constitution was to restrain majorities from oppressing minoritites or encroaching upon their just rights."
    -James K. Polk, 11th President of the United States
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  • xschop
    xschop Posts: 5,000
    If it is shifted, you can pull the magnet off by hand.
    Don't take experimental gene therapies from known eugenicists.
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  • txcoastal1
    txcoastal1 Posts: 13,299
    Look man if a caveman can do it

    https://www.publicdomainpictures.net/pictures/170000/nahled/cave-man-chiseling.jpgsvo55cx7o98n.jpeg
    2-channel: Modwright KWI-200 Integrated, Dynaudio C1-II Signatures
    Desktop rig: LSi7, Polk 110sub, Dayens Ampino amp, W4S DAC/pre, Sonos, JRiver
    Gear on standby: Melody 101 tube pre, Unison Research Simply Italy Integrated
    Gone to new homes: (Matt Polk's)Threshold Stasis SA12e monoblocks, Pass XA30.5 amp, Usher MD2 speakers, Dynaudio C4 platinum speakers, Modwright LS100 (voltz), Simaudio 780D DAC

    erat interfectorem cesar et **** dictatorem dicere a
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  • Gardenstater
    Gardenstater Posts: 4,497
    edited August 2023
    You could stuff some soft stuff through the windows propping up the cone so the voice coil is out of harms way too. Wrap some Armacell around a couple wood dowels?
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
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  • xschop
    xschop Posts: 5,000
    edited August 2023
    ^^^I used Dacron on a couple of 6500's that I clearanced Base Plate ID's without removing the dust cap.^^^
    Don't take experimental gene therapies from known eugenicists.
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  • xschop
    xschop Posts: 5,000
    txcoastal1 wrote: »
    Look man if a caveman can do it

    https://www.publicdomainpictures.net/pictures/170000/nahled/cave-man-chiseling.jpgsvo55cx7o98n.jpeg

    https://youtu.be/T_wS0Kw6k9c
    Don't take experimental gene therapies from known eugenicists.
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  • MrGeology
    MrGeology Posts: 83
    Magnet came off so easy by hand.
    First thing visible was some corrosion that was rubbing VC/baseplate. After cleaning it discovered the real problem was the VC coming through at an angle similar to @Gardenstater 's. No mater how you push the cone, the coil would rub (at about 120 degrees clockwise from the corrosion in the pic).
    8n5qz4t4gtjo.jpg
    So took @xschop 's advise and Dremeled the baseplate ID out to 1.086"
    9s4kf0b03lfu.jpg
    And voila! no more coil rub.
    lk8qquuhejve.jpg
    And because the original glue made a mockery of trying to remove it with acetone.
    s0bg21ya6xyj.jpg
    Only problem is that its so slippery now you can move the magnet around between the two plates by hand. Simple to align, but having trouble with keeping alignment when releasing set screws. Currently aligned in jig now, will get back to it later today.

    "One great object of the Constitution was to restrain majorities from oppressing minoritites or encroaching upon their just rights."
    -James K. Polk, 11th President of the United States
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  • ratpin
    ratpin Posts: 85
    Are you still sending these out? As far as post count, I was previously username "G-force" on the forum before losing my email and having to start a new account. Join date 2006.
    Polk: / SDA-CRS / SDA-1C / M-10B / M-7B / M-5 / M-5jr / RTA-11T / LSIM703 / LSIM704 / LSIM706 / RTI8 / CSI3 / CSI5 / RTI4 / RTI-A5 / CSI-A6 / RC80i / RC85i / RC6s / PSW300 / Atrium6 / Atrium4 / About a dozen pair of Atrium45 lol.
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  • xschop
    xschop Posts: 5,000
    edited August 2023
    Great job and driver save. You can clearly see from the pic how bad that one was off-axis. That'd be the only resolution short of file 13 with these drivers doing their corrosion process over time. Seen quite a few with this issue.
    BLUE Loctite the PP to magnet first using alignment dowel to confirm concentricity of the two. After they set, reset them to the base plate in the jig with Blue Loc-Tite also.

    No need to glue perimeters unless youre OCD.
    Post edited by xschop on
    Don't take experimental gene therapies from known eugenicists.
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  • pitdogg2
    pitdogg2 Posts: 25,549
    Why would you not use red (271 or 262) to permanently glue the magnet?
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  • MrGeology
    MrGeology Posts: 83
    xschop wrote: »
    Great job and driver save. You can clearly see from the pic how bad that one was off-axis. That'd be the only resolution short of file 13 with these drivers doing their corrosion process over time. Seen quite a few with this issue.
    BLUE Loctite the PP to magnet first using alignment dowel to confirm concentricity of the two. After they set, reset them to the base plate in the jig with Blue Loc-Tite also.

    No need to glue perimeters unless youre OCD.

    Loctite 243 or is 242 OK? Haven't got any 243 and haven't seen it locally. One of the industrial supply shops may have it, but that takes a bit of running around to check.
    "One great object of the Constitution was to restrain majorities from oppressing minoritites or encroaching upon their just rights."
    -James K. Polk, 11th President of the United States
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  • xschop
    xschop Posts: 5,000
    Blue 242 is what I use.
    The red 271 does not give much work time.
    Don't take experimental gene therapies from known eugenicists.
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  • MrGeology
    MrGeology Posts: 83
    Never mind, Loctite 243 available at local Napa...
    "One great object of the Constitution was to restrain majorities from oppressing minoritites or encroaching upon their just rights."
    -James K. Polk, 11th President of the United States
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  • MrGeology
    MrGeology Posts: 83
    edited August 2023
    Ran into a small problem with the centering tool. The hole in the end fits the PP to perfection. However it won't fit through this particular magnet.
    Micrometer read 1.2735" in one orientation and 1.270" in the other. Too hard to hold calipers on magnet and operate camera, so modified a piece of sched 40 PVC (3/4" flange) that was laying around to verify fitment. I forget what the centering tool measures.
    s0nh20npj0o2.jpg
    ee61lory2umg.jpg
    eqq97qcuifzu.jpg
    Figured @xschop may be interested in these numbers for future reference.
    "One great object of the Constitution was to restrain majorities from oppressing minoritites or encroaching upon their just rights."
    -James K. Polk, 11th President of the United States
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  • Gardenstater
    Gardenstater Posts: 4,497
    Yeah it doesn't fit the MW6500s in my experience as well. I was going to make one out of PVC on my lathe but haven't gotten to it yet.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
    · Share on FacebookShare on Twitter
  • xschop
    xschop Posts: 5,000
    I spun the dowel off the CNC program from previous batch.

    If one of you guys want to chuck it on a manual lathe and index it to the 6500 ID @ 0.200 depth, then the dowel would center 6500's and newer drivers as well.

    Hind sight is still 20/20
    Don't take experimental gene therapies from known eugenicists.
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  • Gardenstater
    Gardenstater Posts: 4,497
    @Kryten could you do this ^^ to yours as well? 🤣😜
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
    · Share on FacebookShare on Twitter
  • xschop
    xschop Posts: 5,000
    edited August 2023
    It was everybody's here on the forum, now it belongs to somebody in Manasshat, VA.
    Don't take experimental gene therapies from known eugenicists.
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  • MrGeology
    MrGeology Posts: 83
    On Saturday I managed to negotiate a deal for a pair of M5jr (circa May 1989). The drivers are pristine and did not need reset via the jig so they are now glued. They feel like they aren't even broken in yet.
    "One great object of the Constitution was to restrain majorities from oppressing minoritites or encroaching upon their just rights."
    -James K. Polk, 11th President of the United States
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  • MrGeology
    MrGeology Posts: 83
    edited August 2023
    Just got back from a rather long road trip which yielded a pair of M5B's (I believe) with the 8" passive, MW6502 and SL2000's, circa 1985.
    Massive corrosion (?) has this 6502 locked up for the most part. Pics of it, as well as an update on the MW6500 driver #2 upcoming, once I have caught up on some sleep...
    "One great object of the Constitution was to restrain majorities from oppressing minoritites or encroaching upon their just rights."
    -James K. Polk, 11th President of the United States
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  • xschop
    xschop Posts: 5,000
    Good score. 5Bs respond well to all the mods, don't require much power for amplification, and fill any space with big sound stage.
    Don't take experimental gene therapies from known eugenicists.
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  • MrGeology
    MrGeology Posts: 83
    As far as MW6500 driver #2 goes, not sure it is salvageable after all. Actually wondering if something went wrong from the factory after closer inspection.
    -Before I pulled it apart (the first time) had it freed up and played music through it to see if that would help VC rub (it didn't). While doing this noted that it sounded a few db quieter than the other two 6500's on the bench and hoped it was just due to VC rub.
    Turns out it was not. DATS confirms after re-assembly it measures a few db lower than any other 6500's I own (six drivers in total).
    The impedance chart looks all wrong too.
    The VC also measures 40% less induction (Le) than any other 6500's I have (0.3 mH vs the usual 0.5+ mH). It also measures 6.3 ohms.
    Luckily Blue Loctite was used on re-assembly. So used a heat gun on magnet and plates while rotating on a lazy Susan. Kept an eye on temps with an IR thermometer. Once it was above 250 degrees, set the jig back on and used it to break the plates loose from the magnet. So easy. Re-centered then let cool and pulled magnet off by hand again.
    zffi7iq1c93v.jpg
    The plates mic out at 0.250" and the magnet mics out at 0.545".

    -The first time it was apart noticed that the VC former was curled over (to the inside) on the end under the dust cover, so gently (as possible) straightened it out.
    After second disassembly cut the dust cover off to inspect. The VC former protrudes 0.100" from cone (not sure what it should be).
    You can see where the former had to be straightened. Also not sure if the cone is supposed to look like that around where it is attached to the former. (Pics of others on the forum do not look like this)
    39kvypdevi8m.jpg
    Upon further inspection, the spider has a convex shape (instead of flat or concave like the other drivers) when in resting position. The other drivers also have noticeably more cone length at the base where the spider is glued to the former than this one.
    mn6gneehhbiw.jpg
    Not sure where the resting VC position should be, but it measures 0.170" recess from baseplate.
    eg3z380mcg30.jpg
    Contemplating doing a Wu-coil overhaul on this since there is nothing to loose.
    In the meantime moving on to the 5B MW repair.
    "One great object of the Constitution was to restrain majorities from oppressing minoritites or encroaching upon their just rights."
    -James K. Polk, 11th President of the United States
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