Pfaff 193

[jpt]

A couple of weeks ago I bought a Pfaff 193 post bed machine. It was missing a bobbin case, but luckily there was a used one in a sewing machine shop close by. After getting it I noticed that the bobbin base was broken. I'm a complete novice with sewing machines, so I didn't notice it earlier. I ordered a new one and I got it today. The case and base didn't fit together, but a little bit of filing solved that problem.

A bigger problem is that the base doesn't move freely, and that almost jams the whole machine. If you look at the picture, the part A goes into a slot in the top plate. The slot seems to be too narrow. Actually the part B was broken in the old base, so I guess the problem was the same with the old base. I don't know if the top plate has been replaced at some point.

Can I just file the slot wider, or would that create some additional problems?

[Constabulary]

What sewing machine shop will sell a customer a broken part?

If you have bought the correct parts you don´t have to use a file but maybe you have bought wrong parts so thats most likely your problem! Do you have a manual and parts list for your machine? If not get them - they will help you to find the correct parts.

Furthermore - remove the entire hook and check if some old thread has clogged up the hook. Not sure if you know but the Pfaff bobbin case needs a cover and that cover has the spring for the lower thread tension. Machine will not work properly w/o it. In what condition is your machine? Maybe it needs a thorough cleaning and oiling? Maybe some sewing dust / oil clumps have to be removed from the mechanics.

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BTW - if you have filed on your hook parts you will have some rough surfaces (they have a smooth surface for a reason) and since the parts are moving with high speed the parts will probably wear out much faster and the rough parts will collect more sewing dust than smooth parts. So you probably have to replace the entire hook sooner or later and that will cost some $$$. The file idea was a bad one in general.

Edited September 10, 2014 by Constabulary

[jpt]

Constabulary, thanks for your input.

I guess I should have specified that both the bobbin case (the cover with the spring) and the base are the correct parts according the the Pfaff parts manual. Both have the Pfaff name and the part number on them. So I cannot blame the shop, as it seems that the quilty part is Pfaff. I only filed the case so that it fits on top of the base. Neither the thread nor any other moving part touches the filed part.

Also the top/cover plate, where the slot is, has the correct part number. So I don't know where the problem is. All I can do now is the study how the mechanism works, and it seems that I have to file a fraction of a millimeter out of the other side of the slot. I just tested the machine and is sewing nicely if I let the top plate to move a bit.

[Constabulary]

Can you lower the feed dog / feeding wheel if it rubs on the cover plate? if it is an older machine probably some old oil is gummed up.

[jpt]

There is definitely some dirt/gummed oil in the machine as the stitching length is not constant. I'll try to clean it tonight. Hopefully it'll work for the problem I described above.

This is a roller feed machine. I don't see/hear anything rubbing the cover plate.

[jpt]

Problem solved. When taking the machine apart for cleaning, I noticed that I can adjust the movement of the lever C (in the picture). No need for filing

[Dignitas1980]

I have the same Pfaff 193 roller foot and i want to sew with a large stitch than my machine usualy can sew(2-4 mm). There is something i can do, like changing the feed dog or something else? Any ideas?