M Size Bobbin Center Hole Inconsistency Question....

[Bmwmoa67707]

My wife just got a new Juki 1541S and in the process of getting acquainted with the machine, ie, winding bobbins, we have discovered that some of the bobbins supplied with the purchase, have slightly different bores.  Enough so that when sliding the bobbin on the winding shaft, some have a reasonable amount of friction, and consequently, wind the bobbin nicely.  However, several others have larger bores in the bobbin, and when sliding the bobbin on the shaft, it will just spin without any resistance at all.  Those bobbins won't wind at all.....so what's the story on all this...the winding shaft has a split in it that one could jam a screwdriver in and spring it open wider probably enough to hold the over-bore bobbins tight enough to cause them to wind, but doing that would make it unreasonably hard to slip the ones on that presently do fit correctly.   We are new to leather sewing machine, and the new Juki seems to be a wonderful machine, but whats the deal on the bobbins?

Thanks, Steve

[Bert51]

I have found a similar problem with cheap bobbins, some seller think all bobbins of a type, say CB have the same diameter hole..

Bert.

[Pintodeluxe]

Just keep buying bobbins, and get a batch that are the same fit.  Toss the outliers, as those will be maddening.  

Otherwise, invest in a few boxes of pre-wound bobbins.  

[Constabulary]

I had that with bobbins for my former 34K post machine - from a German dealer I bought so extra bobbins made of aluminum and they did fit not fit the winder. Then bought some SEKI made bobbins and they work well! I also has issues with my 132K bobbins I bought overseas then bought some SEKI bobbins from College sewing and they work perfect as well. Sometimes the price really matters - SEKI is more expensive but yet no issues with their bobbins.

[JJN]

I discovered the same problem when I got my 1541S. Wiz suggested a great idea that I now use when winding all my bobbins on all my machines.

Put the thread into the bobbin and out one of the holes on the side like normal. Then feed the thread through the center hole. Press the bobbin on the winder with the end of the thread pointing at you. The thread in the center hole tightens up the loose bobbins to work perfectly. The added benefit is you don't have to hold the tail of the thread while getting it started. Be sure to trim off the extra thread when you remove the bobbin from the winder or you will have trouble in your bobbin case. I now use all the 'cheap' bobbins I have with no problems.

[Bert51]

I have been feeding the thread through the center hole for many years, it saves a lot of mucking around with winding the bobbins.

My biggest problem is with my Singer 31K47, the bobbins are listed as #2996 and every time I purchase bobbins from sellers or ebay for that number, they are way to loose to use on my winder. I have been told that all 31's use CB bobbins.

I think Singer where very clever by making bobbins with different sized centers so they could sell more bobbins.

I also have problems with the center hole size for my Adler 105 bobbins, the seller told me to just spread the bobbin holder on the winder, I did and now I have no problems winding these bobbins then they are worth.

Bert.

Edited January 10, 2020 by Bert51

[toxo]

On the bobbin winder spline that the bobbins go on there should be a split. Tap a screwdriver in the split and the spline will widen.

[kgg]

If this is a new Juki from a Juki dealer call them and ask for the proper replacements. When I purchased my Juki 1541s from a dealer I purchased an additional dozen bobbins amongst other items. All of which were identical to the ones that came with the machine, no problems with any of them not fitting properly on the winder or in bobbin holder. I suspect the ones you got were after market replacements. Others have stated maybe ok, maybe work but you shouldn't have to do work arounds to get them functioning on a new machine. It is the small stuff that drives you crazy.

kgg

[Bmwmoa67707]

Guys, thanks for all the responses....looks like this is a common issue.  Machine was purchased new from a well recommended seller. Have been very happy with his communication and everything else.  Just the dozen extra bobbins, where 6 of them fit correctly, and 6 don't fit tight enough.....oddly enough, they all appear to be from the same manufacturer.  I will call the place we got the machine from and let them know about the problem today, I feel confident they will take care of it.  The idea of shimming the oversize hole with the tag end of the thread had already occurred to me, just hadn't done it.  Expanding the outside diameter of the shaft with a wedge of some sort,  while I know that would work, just doesn't seem right to me.

Steve

[CowboyBob]

IDK how many times we tried different bobbins from different suppliers for the 1541 & finally found some that are consistent.The black steel ones seem to be the worst.