put big bobbin case in small bobbin case machine?

[zanepurcell]

I wonder if you can take a singer 11w, or a consew 225 etc and put the larger bobbin in it. Some aspects make me think it can be done. Specifically, can you put the adler 167 large bobbin in an adler 67 with small bobbin?
Zane, known modifier of stuff.

[sofadoc]

It's been discussed here before. I think I remember the general consensus being that......while technically, it can be done...... it's more trouble and expense than it's worth.

I guess if you feel confident enough to save a shop fee by doing it yourself, and you have countless hours on your hands, then it might work out for you. But if you have to hire a SM mechanic to do it, it would make more financial sense to just trade up to a big bobbin machine.

[zanepurcell]

i learned to rebuild these machines because of the repair cost beinh prohibitive so many times. I can time them and change bobboins and whatever else, It seems to me from diagrams that the adler 67 and 167 seem to be the same machine save for the bobbin size. An issue I see with consew for instance is that the large bobbins on later machines are loaded underneath and are horizontal shaft. The old ones are top load. I have seen singer 11w's on occasion that have a large bobbin upgrade. The main issue on an adler will be fit and room, the bobbin case assembly would have to be moved over about 1/3 inch to go from g to m bobbins.

[JuneC]

I own 2 Singer 111W155 machines, one large and one small bobbin.  I bought the small bobbin machine for a backup so it wasn't really a consideration when buying, but after the fact, asked here about upgrading the hook to a large hook.  Gregg (Keystone Sewing) said it could be done, but was a lot of work and lots of parts beyond the hook. 

June

[gene]

Sorry for the lack of technical knowledge about sewing machine parts:


The bobbin allows thread to go up through the needle feed hole at a certain tension. It does this in such a way that the looper arm can go around the bobbin thread, carrying the top thread with it, and this makes the stitch.

Why can't you put a full bolt of thread on the floor, pass the thread up and through the tension part of the bobbin, and run the thread out the needle hole?

If you had guides for the thread why would this not work?

How would this be any different than having the thread come out of the bobbin case as it does now?

Inquiring minds want to know.

gene

[zanepurcell]

genem the top thread goes down and completely loops around the bobbin thread to make a lock stitch . The entire top thread would have to come down, loop the entire spool under the machine and then come back up on the other side of it and the thread takeup level would have to be about 8 feet long

[Mojo]

Gene:

I have asked myself this question a million times. Why hasn't some engineer designed a machine that uses a spool of thread on the bobbin instead of a bloody bobbin with very little thread.

I need to get Bob Kovar on this.

Chris

[zanepurcell]

with a lock stitch, the two threads twist around each other. one must completely go around the other from end to end for every stitch. you would have to get the top thread to go entirely around the spool on the bottom.
I think a chain stitch machine operates differently and therein might be the solution to sewing with two large spools

[gene]

zane p: I just got it. I can see what you're talking about. The top thread has to go around the entire bobbin of thread. It can't go around the bottom thread unless it goes around the entire bobbin of (bottom) thread.

I wonder how many guilds and tensioners you would need to have the top thread going all the way to the floor. Wow! And could you ever get the entire thing fine tuned?

I had assumed that there was no easy way to make a bigger bobbin or else it would have been done by now.

gene

[zanepurcell]

again, the next factor to a giant bobbin would be the take-up lever. It comes down and makes enough slack to get the top thread looped around the bobbin by the hook. when the take up comes back up, the thread is up and the needle is up, thats why you put the take up lever to the top to remove work.
so lets theorize chain stitch, we might be able to re-engineer it. I know that a chain stitch is working differently because with a bag closer for instance, you can just grab the thread on one size and remove it like a zipper- that would incinuate that there is no real looping action going on but rather a multi step twist with a curved needle

[zanepurcell]

june, do you see a difference in size of your two singer 111w's take up levers? I know consew went from top load to front load bobbin when they went to a larger bobbin so they might have solved their issue differently.

[zanepurcell]

gene,

singer 300w is your answer. I have seen some nice double stitched boat covers made by these, just four large spools on top, no bobbin and youre off.

http://www.youtube.com/watch?v=2eATurVK-Gc

[Toledo Mach. Sales]

The only problem is a machine w/o a bobbin makes a chainstitch on the bottom side & can get caught & break the thread & then the whole seam will open up.
We have done alot of Adler 67 large bobbin conversions in the past & can do it if you want to send the machine to us.I est around $400.00 which isn't to bad since a small hook if yours needs replacing cost almost $200.00
HTH
Bob