Questions about a Pfaff 545-H3-6/01 CLPMN

[Elcheatobandito]

Hello. I have some experience with domestic sewing machines, but this is the first industrial machine I've used. Picked it up sight unseen from a barn pull. Got it looked at, and cleaned, at a local shop. Owner said I got a great deal on it, all things considered. Slotted in some replacement parts, and it was sewing. I have some issues though.

The needle the machine is using right now is bigger, and longer, than the needles I bought. The gauge of the needle isn't such a big deal, but the length has got the timing way off. First things first, do I have the correct needles for this machine? It looked like these were the ones.

Second, the stitch length adjuster only goes from about 3 to 6. I fiddled with it, tried to take the faceplate off (but the plate itself is connected to the shaft, or something), and couldn't really tell how to get it to adjust to shorter lengths, if I can. Would this be a problem?

 

Third, I took some time to see how the smaller "correct" (to my knowledge) needles would fit into the machine, and I'm unsure if I can get the needle to go as low as I need it without spinning, and setting,  the needle bar in a different orientation from how it was returned to me? Can I do this? I'm kind of in over my head with this one, and any help would be appreciated.

Edited June 1, 2023 by Elcheatobandito

[kgg]

53 minutes ago, Elcheatobandito said:

The needle the machine is using right now is bigger, and longer, than the needles I bought.

I think the repair shop installed a 190 needle system needle which I think is what is recommended for the H4 sub class and the 134-35 are for the H3 subclass. The 190 needles are about 1/4" longer so the timing will not be correct. The needle needs to be installed so the two groves on the needle are on the left and you thread the needle from left to right completely opposite to a domestic sewing machine. The stitch length is changed by turning the thumb nut on the lever. 

Here is a manual for the PFAFF 545 the manual covers models from 141 to 545.

kgg

545.pdf

Edited June 1, 2023 by kgg

[Elcheatobandito]

I have actually read through much of the manual. I know you adjust stitch length by turning the thumb nut, but that's as high as she goes. I've messed around with it a bit, and can't figure out how it would go higher without a different thumb nut. Can I re-time the machine without it being on zero? I assume the shop didn't have to, or maybe I'm missing something.

[Uwe]

 

Your threaded stud may not be seated all the way in, making the thumb screw thread bottom out too early. The bits inside the thumbscrew (red arrow) are not supposed to stick out that far. 

 

The Pfaff 145/545 parts (https://www.diamondneedle.com/documents/Pfaff Parts Manual/145_545.pdf) manual shows how the parts of the lever fit together. 

The threaded rod (blue) in the screen shot below is the part that may stick out too far. That threaded rod is probably held in place by a set screw. Getting to that set screw may not be easy. The little bushing (red) sometimes breaks (if plastic) or goes missing altogether. If you remove the thumbscrew, be mindful that there’s a spring in the assembly. Things may pop out unexpectedly.

Edited June 2, 2023 by Uwe

[Elcheatobandito]

I got to the set screw, took it out, and tried to get the threaded stud pushed in further, with no luck. Also tried taking it out, and only got it out a tiny bit, it only has a little bit of play. Is there something else holding that thing in there, or can I try to yank on the thing? Also, why is that spring inside the set screw under tension anyway?

Edited June 2, 2023 by Elcheatobandito

[AlZilla]

I have a SWAG.  Does the blue piece slide back and forth inside the red piece? Or at least supposed to? Because that looks like a great place for gum and/or varnish to have built up. Assuming that's all metal I might drip sewing machine oil down there. I might even be tempted to drip rubbing alcohol.

Also, if I'm looking at it right, I think the blue piece inserts into the little hole in the end of the piece to the left, identified as either 91-009 602-02 or 91-009 702-02. That piece also appears to insert into 91-009 604-05 and 91-009 603-45 and rotate with the lever. That little tangle of parts looks like another haven for gummy crap and looks like it's supposed to raise/lower with the stitch length lever. I could see that being problematic.

That whole area reminds me of old domestic zig zag machines I've unfrozen with all sorts of twisty turny little parts. It can take a lot of patience, oil, wd-40, PB Blaster and heat to free them up.  Sometimes a week or two of tinkering on and off.

Just some observations from someone who's never even seen a machine like you're working on.

Edited June 2, 2023 by AlZilla

[kgg]

2 hours ago, Elcheatobandito said:

Is there something else holding that thing in there

Looking at the photo of the thumb nut it appears to me that the body is split as the result of someone at some point screwed the thumb nut in to far. My suggestion would be to remove the center screw and the part the center screw screws into. With those items removed you should be able to unscrew the thumb nut from the threaded rod. Those threads inside the thumb nut are probably striped or cross threaded. You are more then likely going to have to replace the thumb nut with a new one. The installation of a new thumb nut may solve your stitch problems.

kgg

[fibersport]

The blue shaft just lifts up and down.  The pink part has a curved edge to allow it to be locked onto the numbered plate that indicates the stitch length.  The spring inside the knurled knob is there to keep the knurled knob under a little tension, probably to make adjustments a little easier.  The blue shaft doesn't go in or out any more than it is.  The split nut on the end is supposed to be that way, it's not broken.  I believe the set screw is just there to limit the knurled knob from going in too far. The knurled knob and the pink part slide on the blue threaded rod.  It's been a few months since I had mine apart so this is from memory.  It's really a wierd design, you would think they could have designed it a little simpler which they eventually did.

[Elcheatobandito]

Well, adjuster issues aside, am I able to re-time this machine successfully without having the stitch length set to 0?

[Elcheatobandito]

I successfully got the machine zeroed out, and re-timed the machine correctly. I am now sewing, but am running into upper thread issues. About once every 10-20 stitches or so, I will get a loose loop of upper thread. The lower thread looks fine. I know on domestic machines this is often a tension issue, is it the same for these industrial machines?