Type 66 bobbins

We have two 99k, a 185k and a 201k, and my daughter and her husband have a 66k and a 201k. What these machines have in common is that they all take the type 66 bobbins.

I am lucky enough to have aquired 3 authentic vintage type 66 bobbins with my 4 machines, and of course these work perfectly in all 4.

But 3 into 4 leaves a gap, so early on I bought 4 new type 66 bobbins at the local haberdashery (what a lovely word). These are the ones that most suppliers have, domed both sides and 4 holes on each side. One hole is smaller than the others, and this is to register on the pin on certain types of bobbin winder (on the 201k and the 99k13, which have the autostop and the moving thread guide).

These bobbins work perfectly in most bobbin carriers, and sew perfectly. But the problems start when you try to wind the bobbins. The authentic vintage items have a centre hole which is about 0.246″ in diameter, and this is a close fit on the various bobbin winder shafts. The shop bought items have an internal diameter of 0.241″, which is smaller than the diameter of the bobbin winder shafts. And they don’t stretch to fit!

The second issue is that even if you hold your face right and manage to squeeze one onto the shaft you were a bit exhuberant polishing when reassembling the machine, the pin on the bobbin winder does not register with the little hole, so the bobbin won’t go all the way on. The pin expects the hole to be closer to the center.

The fix is really easy. First take a small grinding tool in your rotary tool (aka a Dremel) and relieve the central hole at both ends just a tiny bit, and run it through the centre to to polish the middle a bit too. Do this in small increments until it fits a bobbin winder. I took the belt guard with the bobbin winder attached off my 99k so that I could take it to my shed easily.

Second, take a tapered pointy grinding tool, and grind the bottom of the small hole on each side to that it is elongated towards the centre of the bobbin.

There is a third problem, and that is they do not work correctly in the 201 bobbin carrier. I thought they did, but they seem to bind in some way, causing a very high bottom tension, which no amount of top tension will counter. Put an authentic type 66 bobbin in and it works fine. The brand in this case is Birch, but I am willing to bet that these are a generic cheap bobbin being sold all over the place.