Page 1 of 2 12 LastLast
Results 1 to 35 of 69

Thread: Butyrate Bobbins

  1. #1
    Supporting Member JGundry's Avatar
    Join Date
    Jul 2006
    Posts
    1,049

    Butyrate Bobbins

    Here is a quick photo of the first pickup with the Butyrate bobbins Belwar and I had done. They took FOREVER to get done but I am glad we did it. Belwar made up Solidworks drawing from original parts he and I had. And I found a plastic molder just outside of Kalamazoo to do the work. I have spent at least 20 hours going to his shop for test runs etc. I still have to head to Kalamazoo to check the final run when we do it. These bobbins are from the last test run. We need to run them with a little higher temperature to get rid of the flow lines. But the flow lines on this batch actually match a Pat# paf I have.

    This pickup has slugs I had custom made from the correct vintage allow. I had two batches of slugs made on two different Brown and Sharpe screw machines. These slugs were done on a 00-G Brown and Sharpe. I just placed an order Monday for USA made baseplates and once that is done every part will be USA made!

    This pickup does sound different than the same pickup wound with the same wire spools, on the same machines but with All Parts bobbins. And yes it does sound better IMO. The differences are the Butyrate bobbin pickup has a more pleasing high end and midrange than the on Butyrate pickup. There seems to be a bit more dynamics also. I think the plastic is part of it but the slugs are fractionally smaller in diameter with the Butyrate as per vintage specs and the coil former sizes are a fair amount different with the Butyrate as per vintage specs. There are some other vintage details that are not in the All Parts bobbins that we did with the Butyrate bobins that I think effect tone. I don't think you can chalk it all up to the plastic but these do sound noticeably different in a good way. I think some part of the tone has to do with the softer plastic since these are unpotted.

    They don't make them like they used to... We do.
    www.throbak.com

  2. #2
    Old Timer Possum's Avatar
    Join Date
    May 2006
    Location
    Planet Mongo in the country of PAF
    Posts
    3,937

    ....

    Looks great, but the tone differences between a PAF coil design and AllParts bobbin coil design are night and day because they don't make the same type coils. Dimensions are radically different. You can't make a true PAF replica on StewMac/AllParts bobbins. I call those "Korean tone buckers" and pretty much abandoned those years ago because they all sound the same to me. Good job, congratulations. Where's the creme version?
    http://www.SDpickups.com
    Stephens Design Pickups

  3. #3
    Supporting Member JGundry's Avatar
    Join Date
    Jul 2006
    Posts
    1,049
    Thanks Dave.

    The dimensions do make a difference for sure. You get a fatter shorter coil. The distance from the wire to the screws and slugs is different also. The screw and slug spacing is not the same on both bobbins. For some reason almost everyone has missed this detail in the Butyrate repro bobbins I have seen.

    I'll take a picture of the cream. I just wound only back ones today.


    The original All Parts bobbins are Japanese not Korean.
    They don't make them like they used to... We do.
    www.throbak.com

  4. #4
    Old Timer Possum's Avatar
    Join Date
    May 2006
    Location
    Planet Mongo in the country of PAF
    Posts
    3,937

    ....

    Actually there isn't one set of dimensions, I've found 3 radically different versions so far, and know why they changed, but none of them are the same as from the land of whale killers (go Sea Shepherd!!!)
    http://www.SDpickups.com
    Stephens Design Pickups

  5. #5
    Tone Mechanic
    Join Date
    Dec 2006
    Posts
    1,086
    They look nice. I have to commend you and Matt for taking on this endeavor. Putting in a lot of time, energy, and cash to get these done....not to mention all the stress that goes along with doing something like this to ensure that the molder includes all the details. The good thing is is that it will pay off and be very gratifying when they're done.

  6. #6
    Supporting Member belwar's Avatar
    Join Date
    Jul 2008
    Posts
    1,066
    Well I have to say that Jon did the lions share of the work particularly near the end - He's close to the molder so it worked out well for us. Jon and I work well together, and it probably wont be our last project together.

  7. #7
    Member
    Join Date
    Feb 2009
    Posts
    22
    Looks great Jon!

  8. #8
    Supporting Member JGundry's Avatar
    Join Date
    Jul 2006
    Posts
    1,049
    Thanks.

    I think finding the right molder is pretty important. The guy that did these for us also restores muscle cars as a hobby and he totally understood the importance of all the details that functionally make no difference but you would want if you are doing Butyrate bobbins. We did the circle in the square hole twice and the molder id not put up a fuss. The main down side of getting most parts like this done is it takes a long time to get a quote, get the material, make a change, get a test part.....
    They don't make them like they used to... We do.
    www.throbak.com

  9. #9
    Supporting Member belwar's Avatar
    Join Date
    Jul 2008
    Posts
    1,066
    Oh course it didnt help that he got the flu, the bubonic plauge, his car wouldn't start, his grandma died, and his dog ate his homework either.. Ok so only two are true.

    so whats next jon?

  10. #10
    Supporting Member JGundry's Avatar
    Join Date
    Jul 2006
    Posts
    1,049
    Quote Originally Posted by belwar View Post
    Oh course it didnt help that he got the flu, the bubonic plauge, his car wouldn't start, his grandma died, and his dog ate his homework either.. Ok so only two are true.

    so whats next jon?
    You forgot he threw his back out too.

    I'm heading down to Kalamazoo Tuesday to run all of them. Fingers crossed.
    They don't make them like they used to... We do.
    www.throbak.com

  11. #11
    Supporting Member belwar's Avatar
    Join Date
    Jul 2008
    Posts
    1,066
    Quote Originally Posted by possum
    What year PAF bobbins did you model these on?
    Several different specimens were measured ranging from 1958-1960 (I think we looked at 10+ bobbins). When drawing, my reference was a 59. Beyond minor shrinkage differences they were uniform.


    There were alot of difficult decisions we had to make including - do we factor in 50 years of shrinkage, or do we make it as it was?

  12. #12
    Old Timer Possum's Avatar
    Join Date
    May 2006
    Location
    Planet Mongo in the country of PAF
    Posts
    3,937

    ....

    I don't think they shrank over the years much at all, you are forgetting that injection plastics shrink right out of the mold, you have to account for that when specifying what material you are using and oversize the mold by that amount. I tried to find out what shrinkage for butyrate is, I think its around 1%, but it also depends on proper pressurizing and correct temperature. You can clearly see in the core where shrinkage happened at manufacture by the large dimples, and also dimples on the top in some, more in later years...
    http://www.SDpickups.com
    Stephens Design Pickups

  13. #13
    Supporting Member JGundry's Avatar
    Join Date
    Jul 2006
    Posts
    1,049
    The shrink is factored in during the tooling of the mold. The place doing the tooling applies that shrink factor for a particular material to your original drawing. They would have done the same in the 50's. The pressure or how much they "pack" the plastic in is part of the tweaking that any molder does after the mold is made. Packing the material in more will increase the overall dimension in length by about .004" on this part. Not much at all. The raw material comes with the temp and shrink specs.. Apparently Butyrate has a fairly wide working temperature range. there is actually a fair amount of fine tuning that has to be done once the mold is in the machine. That is what I'm going to the molder on Tuesday for. I want to make sure everything is dialed in ad approve it before a bunch of expensive Butyrate is shot through the machine.

    The variation in sink on the top of the bobbins and the coil former is just due to different runs of the same part at different times. My molder even pointed this out to me how the sink can be tweaked a bit. The original molder might not have had the same settings for every run. Gibson might have even brought the mold to different injection molders to get the best price.

    Unrelated I brought this molder a 50's P-90 bobbin and the took a lighter to it to smell it. He said it is Styrene. You guys may have know that but evidently a trained nose can identify plastic by the smell it makes when it burns.
    Last edited by JGundry; 03-15-2010 at 05:43 AM.
    They don't make them like they used to... We do.
    www.throbak.com

  14. #14
    Senior Member
    Join Date
    Oct 2007
    Posts
    196
    Ahhh! Beauty-Rate bobbin!

    Just like Venice in Summertime - velly beautiful - velly smelly.

  15. #15
    Old Timer Possum's Avatar
    Join Date
    May 2006
    Location
    Planet Mongo in the country of PAF
    Posts
    3,937

    ...

    There is too wide a variation in bobbin cores to be shrinkage or different batches. I wonder why butyrate is so expensive, maybe because its not so common anymore? Its a smell I remember as a kid, I think alot of toys were made out of that stuff, I love the smell of butyrate in the morning, ok gotta go toke on some styrene...suuuuuuuuuuuuck
    http://www.SDpickups.com
    Stephens Design Pickups

  16. #16
    Supporting Member JGundry's Avatar
    Join Date
    Jul 2006
    Posts
    1,049
    The sink varies from how the part was run batch to batch. Whenever the mold was reworked to change the core height the pieces of the mold that make the coil former would be redone. Measuring an original part is tricky because some things that might seem like poor tolerances in the finished piece are drafts built in to allow the part to eject from the mold.

    There is room for interpretation when having these made. One example is the slug spacing on a PAF does not match the screw bobbin spacing. Matt and I kept this mismatch in spacing. But if you get the original parts to an experienced molder they can interpret just about every mark on the part accurately from a manufacturing standpoint and duplicate the process.
    They don't make them like they used to... We do.
    www.throbak.com

  17. #17
    Old Timer Possum's Avatar
    Join Date
    May 2006
    Location
    Planet Mongo in the country of PAF
    Posts
    3,937

    ....

    I've been fortunate to know the exact specs Gibson designed but can't say more than that.

    There do seem to be two different sets of bobbin mold numbers, and all the Patents I've examined have identical core measurements, so yes there is room for interpretation but the master design was aimed at one tone.
    I did a little research on dielectric ratings of CAB and ABS....
    The dielectric of ABS plastic at 1 megahertz is from 2.8-3.8
    CAB (butyrate) 1 megahertz = 2.5-6.2
    You have to get up to radio frequencies for anything much different to show up. Having experimented with my "darkening" potting fluids at audio frequencies of course that range of difference is inaudible and keep in mind I am entirely soaking the interior of the coil, not just having someting butt against the core and top and bottom. Any differences you're hearing are due to design differences from these and what you were using before. And BTW I did find the ideal potting liquid, non-hardening, darkens coils, but was too hard to control how much saturation inside the coil so pretty much abandoned that idea and found better ways.
    http://www.SDpickups.com
    Stephens Design Pickups

  18. #18
    Member
    Join Date
    Mar 2009
    Posts
    97
    wow
    JGundry an Belwar, this bobbins look real nice

  19. #19
    Supporting Member JGundry's Avatar
    Join Date
    Jul 2006
    Posts
    1,049
    The original PAF mold is a 4 cavity mold. When the coil former bit was remade they would have etched new cavity mold numbers. The suffix on the number indicates the cavity of the mold. The original parts are still at the molder but I'm pretty sure the font is a little different on one of the original parts. I will check that when I am at the molder today. The different font would probably indicate a different bobbin core height.

    Any original specs. would have been adjusted with the Butyrate shrink factor applied by the place making the mold. They would also include any draft etc. needed for making the part. Things like the circle in the square pin were hand done and vary from cavity to cavity.
    They don't make them like they used to... We do.
    www.throbak.com

  20. #20
    Member
    Join Date
    Jan 2009
    Location
    Home
    Posts
    76
    Wow, those look great! Fantastic job, guys. I actually like the dimples / flow marks in the bobbins, all my original butyrate bobbins have those and it looks much more authentic to my eye. I suppose the discerning customer might prefer a 'perfect' bobbin, though...

  21. #21
    Supporting Member JGundry's Avatar
    Join Date
    Jul 2006
    Posts
    1,049
    Matt and I both like the sink and the look of them. Personally that is what I want. I'm pretty sure customers will like it also. The flow marks are on some of the vintage bobbins but not all. I'm going to see if those can go away by tweaking temperature etc..
    They don't make them like they used to... We do.
    www.throbak.com

  22. #22
    Old Timer Possum's Avatar
    Join Date
    May 2006
    Location
    Planet Mongo in the country of PAF
    Posts
    3,937

    ...

    Yes the original specs include shrinkage, there are some features that weren't actually done, the original top flat spec was for radiused top and bottom of the lip, I think they didn't want to pay full price for their drawing spec and deleted certain things that weren't important vs. cost of the mold. I don't see parting lines in the tops of the originals though...
    http://www.SDpickups.com
    Stephens Design Pickups

  23. #23
    Supporting Member JGundry's Avatar
    Join Date
    Jul 2006
    Posts
    1,049
    I checked today and the shrink factor is .004" per 1" for Butyrate.

    The mold for the top of the bobbin is 1 piece.
    They don't make them like they used to... We do.
    www.throbak.com

  24. #24
    Member
    Join Date
    Mar 2009
    Posts
    97
    Quote Originally Posted by JGundry View Post
    I checked today and the shrink factor is .004" per 1" for Butyrate.

    The mold for the top of the bobbin is 1 piece.
    that's 0,1 mm right? 2,54%
    i was thinking it is less, like 0,8%

  25. #25
    Old Timer Possum's Avatar
    Join Date
    May 2006
    Location
    Planet Mongo in the country of PAF
    Posts
    3,937

    .

    I don't think there is only ONE formula for butyrate and probably the colorant might be involved. I remember someone saying there are CAB plastics that are real soft and some that are harder. There's probably going to be some slop no matter what you do, I've seen enough Gibson pole screws stripped from them forcing through stuff that didn't match up. I see a line in the middle of the slug bobbin going all the way across, thats not a parting line?
    http://www.SDpickups.com
    Stephens Design Pickups

  26. #26
    Member
    Join Date
    Mar 2009
    Posts
    97
    Quote Originally Posted by Possum View Post
    There's probably going to be some slop no matter what you do, I've seen enough Gibson pole screws stripped from them forcing through stuff that didn't match up.
    is this maybe possible because of baseplates holes? or becasue of keeper bar holes, i stripped some screws because smaller holes on keeper bars i made

  27. #27
    Old Timer Possum's Avatar
    Join Date
    May 2006
    Location
    Planet Mongo in the country of PAF
    Posts
    3,937

    ....

    Who knows, could be the keepers most likely. I make my own keepers and there is definitely a certain amount of slop I can get away with and some I can't. Pole screws don't always thread in perfectly straight when you drive them in either. Generally my buckers are very tightly fit together for best magnetic transfer...
    http://www.SDpickups.com
    Stephens Design Pickups

  28. #28
    Old Timer RedHouse's Avatar
    Join Date
    Jun 2006
    Location
    Pacific NW - USA
    Posts
    1,761
    Quote Originally Posted by clown_luthier View Post
    wow
    JGundry an Belwar, this bobbins look real nice
    +1

    Good work gents

    When you get it all rolling, are you going to keep 'em locked-down in house, or offer 'em up for consumption?

  29. #29
    Supporting Member JGundry's Avatar
    Join Date
    Jul 2006
    Posts
    1,049
    These are just for Belwar and I.

    There are a bunch of things that come into play with the shrink. The size of the gate, temperature and even additives like talc effect the sink.

    I'm not sure on this but I think Gibson had a machine that drove all 6 pole screws at once. I have seen some other old Gibson multi tool air driven machines at Heritage. I would think they might have taken the same approach for putting the pole screws in.

    The shrink is .004" per 1". That is inches. So for screw spacing that is .008" of shrink more or less.
    They don't make them like they used to... We do.
    www.throbak.com

  30. #30
    Member
    Join Date
    Oct 2007
    Posts
    47
    "These are just for Belwar and I."
    What a big teaser
    I am sure there are many here who would like to try these bobbins too!
    bajaman

  31. #31
    Supporting Member belwar's Avatar
    Join Date
    Jul 2008
    Posts
    1,066
    I understand, but you have to understand the research and the time that went into these. Not just our own research, but from other forum members as well (thank you velly much by the way!). There's only a handful of makers doing this and it makes it a little special.. If everyone had it, it wouldnt be special anymore!

    I'm sure someday, some company will make butyrate bobbins for public consumption - but until then i'll use it to its full advantage :>

  32. #32
    Member
    Join Date
    Oct 2007
    Posts
    47
    oh okay - it's a secret handshake closed shop then
    I am used to shared information not boasting
    No need to read this thread anymore - lol
    bajaman

  33. #33
    Supporting Member belwar's Avatar
    Join Date
    Jul 2008
    Posts
    1,066
    Quote Originally Posted by bajaman View Post
    oh okay - it's a secret handshake closed shop then
    I am used to shared information not boasting
    No need to read this thread anymore - lol
    bajaman
    There's a difference between shared information, and shared labor/parts.

    I quite gladly give up vintage/rare pickup information publicly (i.e. Dearmonds, Wal Bass Pups, Tele p/u's, etc). Hell I destroyed almost $1000 worth of lane poors and posted all the results publicly with photos, measurements, etc. I even sell very good quality keepers to a few forum members too, but bobbins - i dont know - thats just different to me. I dont think its boastful at all, its a marketing tool and it would be foolish not to take advantage of that. I should also mention im an OEM and dont sell pickups to the public.

  34. #34
    Supporting Member JGundry's Avatar
    Join Date
    Jul 2006
    Posts
    1,049
    Actually I gave some specifics that will be helpful for anyone who decides to get Butyrate bobbins molded.

    The truth is there are a bunch of nitty gritty specifics that never get mentioned on this forum. Coming by some specifics can be pretty pricey. Those are usually not for public consumption.

    I should probably add that there are a lot details that are open to interpretation and are dependent upon how attentive and patient the molder is with what probably seem like silly details to the molder. Getting original parts to reference is a the main thing to start with and that is not cheap. And even at that the bobbins Belwar and I did just are not going to look like the bobbins someone else does because of all of the variables. Although both might be very accurate to the originals.
    Last edited by JGundry; 03-18-2010 at 03:01 AM.
    They don't make them like they used to... We do.
    www.throbak.com

  35. #35
    Member
    Join Date
    Dec 2006
    Posts
    32
    Quote Originally Posted by bajaman View Post
    oh okay - it's a secret handshake closed shop then
    I am used to shared information not boasting
    No need to read this thread anymore - lol
    bajaman
    Kinda knew this would come at some point.....

    Perhaps better than having something like this supplied to you via others hardwork that you pay a premium for, go out, problem solve, and you can end up with some pretty cool pieces on your own. This forum is full of boasting, but I don't think you will find it in this thread - they decided to show you the product in test run stages and let it be critiqued by people who really know what they are talking about. I would think that is pretty open and definately not some secret handshake society....

    This thread was intended to show the fruits of some pretty serious effort and labor, and I think it is kinda immature to get upset that you can't buy them

    But maybe I overreact - but you knew sniffling like this would come up!

Page 1 of 2 12 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. butyrate color (pigment)
    By clown_luthier in forum Pickup Makers
    Replies: 30
    Last Post: 11-09-2009, 05:09 AM
  2. More Butyrate questions - Which would you choose?
    By belwar in forum Pickup Makers
    Replies: 34
    Last Post: 06-16-2009, 09:21 PM
  3. New member - with butyrate bobbin questions
    By belwar in forum Pickup Makers
    Replies: 13
    Last Post: 08-07-2008, 05:10 PM
  4. Making taller bucker bobbins out of existing bobbins...
    By Zhangliqun in forum Pickup Makers
    Replies: 11
    Last Post: 08-23-2007, 09:10 AM
  5. Butyrate Humbucker coils--from where?
    By CL-10 in forum Pickup Makers
    Replies: 9
    Last Post: 12-12-2006, 02:25 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •