Bobbin tension on leather machine

[Massive]

Been having problems with my bobbin tension being too low and not adjustable.

- How I thread it:

I stick the bobbin in the case, and pull the thread through the angled slot until it pops in the horseshoe notch in the spring, that is recessed into the bobbin case.  I adjust tension with the obvious screw.

- How it works now:

I am having problems with the tension adjustment in the lower end/bobbin.  When I got the machine from the original owner, it showed pretty much zero signs of use or wear.  The tension adjustment did not work that well, however.  I found lower end tension was light, and not reasonably adjustable.  The original owner had tightened the screw to about the bottom out position, short maybe 1 turn.  He had also scarred the screw slot a little showing signs of some kind of force.  Probably he was having trouble adjusting/getting the tension also, and resorted to force.  At some point the tension actually peaks as the screw is backed off, but there isn't any reasonable range of adjustment.

How I test it:

I have the bobbin case and hook removed from the machine.  My test involves getting a piece of loose 277 thread, and clipping it in to the tension adjustment, and then hanging the whole assembly from it.  I use the thread, because I don't have to rewind it, and the bobbin wants to eject all the time.  The tension with the free thread seems to be the same as with thread on a bobbin.

- My results:

With this test, the bobbin and hook would just fall to the ground if I didn't catch it.  At the one point where it has some tension, but no range of adjustment the tension is just sufficient to stop the assembly on the thread, a little jiggling will allow it to go down.  That is an OK adjustment for some uses.

- What i need to know:

I'm just wondering, what one can do to tweak the spring or case to have better contact.  There is a large slot in the case that the spring fits into, and I could tweak that with a screw driver.  Or try flattening the spring curvature, or bending more flex into the end that is retained by the screw.

I think the original user used one size heavier thread.

Maybe I need new parts, but before I go there, I might as well try tweaking the parts I have.  No down side.

I am going to put up a video later.

[Camano Ridge]

What machine is it? If you don't get the help here that you need I would call the manufacture or rep before taking a screwdriver to it. Most are very helpful and have probably dealt with your problem and most will help wether it is a machine you bought from them or one of their machines you bought used.

[Massive]

They are very helpful, but it will take a few days till they get back to me, and they may or not have a solution, so I thought I would try here.  i wouldn't blame them if they thought it was a case for new parts, but I would like to go at it from a repair direction first. 

Also, I think it would be beneficial if the collected wisdom on bobbin setting were available here.  Lower bobbin setting is pretty basic to getting the machine working, so if anyone has some wisdom it would be great to have it in the archive we have here.

Most of the advice one gets on tension with machines has to do with setting the upper tension, and ballancing the two out for different stitch performance, or getting it the right overall level.  I have only come across one source that deals with setting lower tension, on domestic machines, to a baseline.  But since finding that, I try to find a calibrated setting for lower end tension for all my machines.  Then it is really easy to change up the setting in any way one wants to later, because lower end tension is basic, and needs to be set to a standard. 

Don't worry, I am not going to go at it with the screwdriver, I thing someone doing that to the screw is part of the problem I have.

[Slamfire]

I'm with ridge, need to know what machine you have.






      Hootnix.

[Slowhand Bob]

Which machine, which model and do you have an original owners manual?  I can tell you that one of my original problems was wanting the bobbin thread to tight BUT no it should not be free falling either.  I would also say that tension afforded by having the bobbin in place would be significant enough to matter on your final setup.  It helped me a great deat when I talked with a couple of ladies who had much experience with general sewing machines.  The bobbin tension was so much lighter than what I expected and the upper thread was adjusted to accommodate this.   Are we also sure that you are dealing with the bobbins thread tension screw and not an adjustment lock down screw?