Project: My voice coil winder

Discussion in 'The Completed Projects Collection' started by R!f@@, May 3, 2010.

  1. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    It's been long time since I wanted but haven't been able to get my hands on one, and after resent losses I decided it's time to make one, since I have the resources and knowledge and last but not least, our old faithful, AAC members :D.

    And so the journey begins.....
    feel free to comment and ask any thing
    I will update as the work progresses
    Now that project is approved let me get some details.
    Coming up......
     
    Last edited by a moderator: Dec 27, 2011
  2. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    Well.. I got some new pics and I will start how I came to build this.
    As you all know what this machine is for I'll skip that.
    I do not have a machine shop now and it is really hard to do metal work, I can just cut simple rods and metal with a hand grinder. That's all.
    I checked to buy one and the cheapest are around 1000 bucks to my doorstep. And these are hand operated device.
    Which is something I do not want, so I thought why not try to make since I have the knowledge and members like you to comment.

    The optimum choice for me was to use plastic. Thicker ones, so I went to the shop and almost fainted when I got the price for 10mm acrylic plastic sheets.These are strong and really tough. price was more than 3000.
    For tht price I'll be better off with ready made one.

    Next I thought of a simpler solution and I found out that they sell 6mm to any size I want. Why not use double that. I will get 12mm. better and cheaper.
    Next task was to find the shaft. My voice coil bobbin has a 10mm hole, so I thought I'll go for 10mm SS rod.
    Guess what, every store was out of ss rods. :mad:.
    Next choice is a threaded rod and I found what I was looking for, so with that I bought the bearings and the butterfly nuts.
    To hold the bearing in place, I came up with real good idea. I used two nuts with lock washers on both sides of the bearing to hold it and it works perfectly.
    Now I had the motor and the gear mach already made as you can see from the picks.
    The tough job was to bolt the main gear to the shaft so it won't slip.
    Again same principle. I found a large gear with compatible teeth spacing as the gear assemblies, drill a 10mm hole in the center and bolted it too.
    Perfect.

    Now to make the frame. Since cutting plastic is no biggie for me, cause I have access to a lazer cutter.
    A quick Coreldraw sketch and a slight brain storming with the measurements I took of to get the plastics cut.
    The cutting was precise so the bearings were perfectly fit.

    I use acrylic super glue to bond the sheets and for the time being normal screws are used to hold the frame work. After a completing, counter sunk ones will be used, but after my counter sunk head bit arrival. it is on it;s way. I got that from ebay :p.

    As I have not planned a procedure for this and this being made quite fast, the order is a bit odd.

    I have dismantled the whole thing after the above post to do some more cutting and the shaft too seems to be a bit wobbly, there is a bent in it. so I am off to get a new piece.

    The pics are labeled, just in case any one have a question.
     
    Last edited: May 4, 2010
  3. retched

    AAC Fanatic!

    Dec 5, 2009
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    I have to say, I LOVE the pink workspace, but can you crop your FEET out of the pic next time? ;)
     
  4. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    you of all people noticed that.
    It was in the middle of the night and the pink sheet is my bed silly.
    no jokes on that.
    I am going to remove that pic
     
  5. retched

    AAC Fanatic!

    Dec 5, 2009
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    You are doing a beautiful job Rifaa. I really would like to have unrestricted access to a laser cutter.

    Gotta put that in my budget.

    Remember to keep all of the corelDraw files so we can duplicate your design if it turns out great (Which it will ;) )
     
  6. Wendy

    Moderator

    Mar 24, 2008
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    I'll look for that PIC counter project posted in the completed projects. I've thought of doing something similar, for regular coils and tesla coils, where count's are important.

    A thought, use a long screw with a variable speed to help lay the wire out neatly and precisely. The threads will move the wire across the coil surface neatly.
     
  7. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    retched.
    Yes, I am lucky to have access to a lazer engraver, but do you know it cost around USD 60,000.
    As for corel draw, there is nothing much to it, as most were in my head, just a rough outline of the plastic cutting dimension that were needed to feed the cutter. It uses corel outline to cut. Quite easy.
    This winder is not really a project I though of before but under the circumstances I had to make one in a hurry.
    Don't worry, If any one need to know, just ask, I'll be more than happy to discuss what I did.
    As for the use of this, I don't think I would need it in a second time soon, as big woofer jobs are not that common, Me being the only one who is capable of winding a voice coil in Maldives as far as I know, not many knows about me as I do not advertise or go searching for these jobs.
    This were from my customer who never want any one else to touch their items but me.
    Although there is a seller who imports these, they are too expensive and they do not repair them this way as they don't have the skill, they just replace the complete basket assembly and charge a hefty price. Their main customers are resorts who do not think of spending too little. But from time to time they cannot do cause they always run out of stock it seems. I know this cause in order to get this done faster I went to them twice in between months to buy these parts and both time they say they were out of stock.
    I will be posting the repair procedure of these woofers soon.

    The thread Idea is really good. It will provide a smooth coil winding., but as you see I do not have the resources to do much.

    Here is a mid assembly pic. I am encoding a video and upload it so that you guys can see how well the motor performs. I too am surprised with it. :)
     
  8. R!f@@

    Thread Starter AAC Fanatic!

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    Here's the video clip
    This is the second shaft, the first one was worse, the whole thing tried to run away when I increased the RPM. :eek:
    Still this one is a bit wobbly but for now it will do, and I don't have a SS rod to lath. :(
    The max voltage I presumed were 60V as the motor can handle it, but after the check, 12V is more than enough for the intended job. Nominal voltage is 5V.
    I am still trying to PWM the motor but this is yet to implemented and as bill suggested, a counter will be nice as I did thought of this but I got to finish these woofers with in days.
    So I guess after that I can complete this rig.
    What do you think of the performance. :D
     
    Last edited: May 4, 2010
  9. beenthere

    Retired Moderator

    Apr 20, 2004
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    If you can't count turns, you might premeasure the wire so the coils turn out all the same.
     
  10. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    tht's a problem, since I do not get the original low voltage copper enameled wire.
    I tried to get this but the company did not respond.
    I have used up all I have tonight and threw them all away since the glue's I have does not seem to adhere to kapton.
    Right now I am lost, by the time I found out how to adhere them to kapton, I am out of wire. So tomorrow I have to get some more, but these a high voltage insulation and I have to make adjustment to the whole thing to make it work.
    The wire I used to have was perfect but since I moved I lost the reel.
    No matter how many turns, I have to get 8 ohms and I have to make it fit in to the air gap. I can do this now, Since I have used almost 4 different type of glue and a few hundred turns of wire and whole lot of patience.

    The main problem is the cheap crap adhesive that most of the damn shops sells, most of them don't even stick and I cannot buy them all.
    We do not have genuine sellers like you do, I got to find a way with what I have. None of you will survive here I think. If you came here and start to live like me :D
     
  11. eblc1388

    Senior Member

    Nov 28, 2008
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    Why 8 ohms? How do you measure it?

    Is it based on markings on the original speaker 8 ohms, xxx W ?
     
  12. R!f@@

    Thread Starter AAC Fanatic!

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    8 Ω is the speakers impedance at continues power of 300W.
    The wire I got was a bit thick, on visible from a micro meter. so the resistance drops.
    The Z is measured as the resistance of the wire. low resistance results in Z imbalance when this unit is wired in parallel with other sets in the setup.
    But low Z results in much higher power dissipated by the coil, and burn can be prevented if the user avoids sound clipping, but this is seldom the case, they will crank up and won't care if the amp clips, resulting in all of them blowing.
    But this is rather good, more work for me. :D.

    The glue I have is killing me as they don't want to stick to the kapton and the coil tends to come out, and the tight winding makes it impossible to yank the coil out of the drum, I had one hell of a time with it last night.
    I wound all the coil I have around 10 times and still I got no lead in pulling the coil without bending it or destroying the turns. :(
    I am thinking of making the whole unit automatic so I can keep both hands free and also leave the coils tight without touching until the recent glue I am going to use dries up plus I figured out a new way to pull the coil in a jiffy :D
     
  13. retched

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    3000psi of compressed gas? ;)
     
  14. Wendy

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    Mar 24, 2008
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    OK, this is meant for brainstorming, which means it isn't practical but it might inspire other ideas. Use a cardboard tube with a balloon or a bag filled with gas. When it is done relieve the gas pressure.

    That or use something like dowels inside the tube, when it is done start pulling the dowels out from the middle, which will relieve the outside pressure and allow the tube to slide easily off.
     
  15. R!f@@

    Thread Starter AAC Fanatic!

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    My turn to make you guys brain storm
    Remember how tight the winding is, well it still is ...but My hard work paid off.

    Here is the winding procedure.
    The kapton is taped to the barrel and from below pic you can see the first layer. Before the winding starts, I applied a thin layer of epoxy.

    [​IMG]

    The Second picture below show the second layer done. As before epoxy is applied to top the first layer and the coil is wound.
    Since the epoxy needs to harden before any attempt to remove the coil, I applied a low voltage to slightly heat up the winding ( since my work space is like at 26°C) so that the hardening time can be decreased.
    the meter shows the current through the coil.

    [​IMG]

    Slight increase in current

    [​IMG]

    a close up

    [​IMG]

    The next pic shows the unwanted area of the kapton cuttoff

    [​IMG]
     
  16. R!f@@

    Thread Starter AAC Fanatic!

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    OK guys . This is the start of the removal procedure.
    the pictures are shown in order.
    Does any of you know how I did it.

    [​IMG]

    Note the screws

    [​IMG]

    Screws a tighten one at turn each at a time

    [​IMG]


    And Viola

    [​IMG]

    What do you think :D
     
  17. Wendy

    Moderator

    Mar 24, 2008
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    Heat the before winding, then use ice to cool the metal form to shrink it.
     
  18. R!f@@

    Thread Starter AAC Fanatic!

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    [​IMG]

    A comparison between an original and mine
     
  19. retched

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    Your sucks.

    Just kidding. VERY good job. I also like how quickly you went from idea to completed project. (A counter would still be nice :) )
     
  20. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    I know. Still It will be on the bench or in the store. After these woofers I don't think I would be needing it any more. If a I am to add a counter I would like to first make the shaft, the thread is wobbly.
    Like you said everything always sprung up suddenly for me and always are based on some work I get.
    I donno.. may be I will complete this winder after a while..
    I am using the supply I started to build to drive it. that thing also is halfway.
    at this rate I don't think I will ever finish anything i start...too much work on my head.
    After this there is a couple of LCD to fix from a resort, well around 30 I think.
    Next week I think I'll be at Srilanka for a week or so.
     
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