Thread tension gauges are expensive, so I'd thought I'd share a simple project with you that works very well and can save you a lot compared to buying one if you can find one.
If
you are looking for one to use, make your own, but this will not be a small pocket sized portable, but it works with almost any machine. And it isn't huge.
Make a small wood "base"
of say 3X10X3/4 inch (approx). It might not seem like a "base" yet, but it will. Drill a small hole (about 1/16th of an inch)
1/4 of an inch in from one of the base's long sides and centered from left to right. The hole should be perpendicular to this base while it lays flat on a work surface.This long edge with a hole drilled vertically has become the back edge of the gauge.
Make a "back panel" five inches
wide by eight inches tall of something like "foam-core" or thin
plywood. This back board should be glued to the base's back edge,
vertically, with the 1/16th inch hole centered left to right with the backboard. A piece of heavy white paper is glued to the inside
surface of the "L" if needed and will serve as a surface to mark on using a
pencil later on.
You
need a piece of music wire (from a hobby shop) of about .045 thousandths of an
inch diameter and seven inches long. Bend a little (tiny) loop or hook
(curly-Q) into one end, this will become the top of the wire when finally set in place. Glue the plain end of the wire into the hole you've drilled and let the glue cure/dry.
To use: Get a bobbin case that is known to be "set" properly. form a
loop in the 3 inch tail of thread coming from the bobbin case and catch the thread loop in the loop/hook at the top end of the wire. Pull gently, the wire begins to bend and keep pulling until the bobbin just starts to turn within the bobbin case. At that point note how far the wire bent and mark on the
back board (a little tick mark) how far the wire bent until the bobbin within the bobbin case just began to turn. Make your mark toward the top of the wire. Then let things relax. Release the thread from the hook you formed in the wire and with a finger tip pushing from the top of the wire bend the wire over to the Mark you made on the backboard. Then press the wire against the backboard, holding it there from the hooked end of the wire and use the wire as an edge to draw a more distinct slightly curved line. Try the bobbin case from several machines if you can, all from machines that are behaving themselves. You'll notice the marks start falling within an average zone or
range. Were you to measure this "average" it will come out at about 2.6
Grams. It's a primitive little gauge that will cost about fifty cents to
make and take an hour to make. It is every bit as accurate as the
$189.00 big name machine gauges and can be just as fancy as you want it to be if you want to embellish it.
To use the tool, form a loop in the thread coming from your bobbin case and as above pull on the thread, holding the bobbin case to do so. Note when the bobbin begins to turn and if it is to one side of the line you have made, or the other, you will need to adjust the bobbin case accordingly. If the bobbin begins to turn before the wire reaches the line, tighten the adjustment screw of the bobbin case. If you are pulling beyond the mark and the bobbin case is not turning, loosen up the adjustment screw a little at a time.
Once you see what I'm up to with these words you can work-out your own design improvements and
it will work fine. I told you .045 diameter wire, but it can be a little
larger in diameter or smaller but I would not suggest a big departure. It's just how much it bends when pulled
on, consistently, that matters. But don't go real heavy or thin just
because you had a problem finding some rational sized wire.
And please use music wire from a hobby shop as it is good spring steel and not like coat hanger wire that bends and stays bent.
If when using your gauge you come quite close to the line....that's good enough. This is a very sensitive gauge and close is good enough.
