Standard Class "P" help, please
 

I've been lurking lately, trying to get back into sewing machines, and I picked up a pretty little Standard Class "P" treadle. The table and irons were in great shape, but the head was filthy. I got it cleaned up, but it won't sew. Or rather, it won't as long as there's fabric under the foot. Testing it without fabric and the shuttle picks up the top thread from half to most of the time; try to test sew on fabric and it's none of the time.

It looks like, when the needle starts to rise, the thread doesn't make enough of a loop (or any, with fabric) for the shuttle to pick up. The shuttle fits tight against the slide, so it's not missing the thread, the thread just isn't coming out of the thread groove on the needle far enough to be picked up. As far as I can tell there's nothing to adjust (although I may be wrong about that), so now I'm at a loss. What am I missing, or what should I adjust?

I don't know much about these, but I have 3. Sometimes my thread is too big, and I polished the bobbin holder, and I used 0000 steel wool to polish the slide part, so it's just try and try. Sometimes the thread doesn't slide over the bobbin holder when it should too.

I don't know anything about that machine specifically, but here are the first things I would check:
Is your needle inserted correctly?
Is your needle threaded the correct direction?

If your machine is a vibrating shuttle machine, maybe the needle and thread go the same way as in my Singer vibrating shuttle machines. On Singer vibrating shuttle machines, the flat part of the needle faces to the right, and the needle is threaded from left to right.

Other things to try:
Make sure you are using high quality thread like Coats & Clark or Gutermann, since it will form better loops than cheap thread. Try a size 14 needle, if you weren't already using that size. Also make sure you are using a new needle - a bent needle would cause problems.

Is it the correct type of needle for the machine? Not all machines take a 15x1.

Check out Victorian sweatshop forum.

I'll give that a try today. The really frustrating thing is that it sewed fine utterly filthy, but won't now that it's clean!

The needle is in correctly, according to ISMAC's needle list it's the correct needle size, and it's threaded properly. I normally use Gutterman, so that's what I'm test-sewing with. When that didn't work, I tried everything from cheap poly-cotton to fuzzy serger thread. Still nothing.

Why a size 14 needle though? I thought you were supposed to test with what you typically sewed with?

Ooh, thanks! I didn't know about that site! I'll definitely see what they have to say!

I remembered reading somewhere that size 14 needles were the most common needle size used in the past, so vintage sewing machines were designed to work best with that size. I can tell you that my Singer 328 skips stitches like crazy on knits unless I use a size 14 needle, regardless of the fabric weight. Different sized needles are slightly different lengths, so I just thought it was worth a try.

This is incorrect. Different size needles are slightly thicker as you go up in size, not longer.

Cari

I checked the three brands I have, and I guess the needle length only changes with size for some brands. Singer needles are the same length regardless of size. A Schmetz size 10 needle is 0.7 mm shorter than a Schmetz size 14. An Organ size 11 needle is 0.7 mm shorter than an Organ size 14. The tops of the eyes are all approximately the same distance from the upper end of the needle for all sizes and brands, so the difference in length is down below the eye. Singer needles are 0.3 mm shorter than Organ and Schmetz size 14 needles. I know some sewing machines work better with one brand of needles over another, but I don't know if the length is a factor - maybe it's just the slightly different needle shapes.

Hmm. I knew that there's a slight difference in length between Singer and other brands but I've never used Singer needles and never had a reason to measure my needles so I never gave it any thought.

Cari