my Pfaff 34 industrial treadle machine

[amateursewing]

I am using a size 16 leather needle and a size 35 high quality German polyester leather thead for alterng bikers leathers, on

my Pfaff 34 on thicknesses of over 3 layers of leather the thread in the needle seems to ravel up insteadof locking the underthread and making a good stitch. Then I do  the same

work on my Signer 20 electric machine and on this machine it NEVER loops the needle thread, in fact it only gently has to be handwheeled over the 3-4 think seams and then

sews beautifully

 

What is going on here? I supsoect it is somehing to do with the Pfaff 34 treadle, but this WAS a saddles machine, I am using DPx5 leather needles in

each machine size 16 needle.

 

Laurecne

[Kohlrausch]

Hi,

 

can you please specify exactly what kind of Singer machine you are referring to? There are at least five different Singer 20s: The Singer Serenade 20, the Singer Prima 20, and the Singer Samba 20. Those three are household sewing machines. And then there is the Singer 20 artisan machine as described in this blog: http://keay3.blogspot.de/2012/05/new-to-me-singer-20u-33-sewing-machine.html There would also be a Singer 20 toy sewing machine, but that I don't think you were referring to that ;-)

The Pfaff 34 also is an artisan's machine, not a specific leather or even saddler's machine. It can be adaptated to a wide range of uses though, either at the factory as specified by the subclasses, or by the user. What subclass is your Pfaff 34?

Have you tried a bigger needle? Please check everything in the threadpath for sharp edges. The Pfaff 34 is about 100 years old. If it has been used in a saddler's workshop it will likely show extensive wear. Threads may have cut deeply into guides causing sharp edges. Maybe shine a light at all the parts and look for bright reflections with a strong loop. I once had a similar problem on a Pfaff 130; polishing threadguides, especially close to the needle, resolved it. Also specifically check and if necessary change the tension disks. About 40 percent of threadwear occur at this place.

If you read German you might have a look at Renters, "Der Nähmaschinenfachmann". Here you can find the Renters - Der Nähmaschinenfachmann-books as downloadable scans: http://www.occaphot-ch.com/bernina-startseite/industrie-masch/ Vol. 2 covers Central-Bobbin-machines (Bahngreifermaschinen). The Renters books contain tons of info 'bout repair and adjustment of all kinds of (from todays point of view) older sewing machines.

As usual, pictures would make the diagnose a little easier.

HTH

Greets

Ralf C.

Edited May 25, 2016 by Kohlrausch
r

[amateursewing]

Hi, it is actually a Global ZZ machine which is actually a singer 20U artisan machine with an induction motor  mounted in an industrial table.

the Pfaff is a 34-6, but the Pfaff 34 works fine with the size 16 needle on two layers of leather but with 3 layers it is the needle thread that is looping on the top of the leather, as though the thread is not being dragged around the shuttle at all, but on the Singer 20U (Global machine) it works fine, these are photos of the machines.

Laurence

[Kohlrausch]

Hi,

 

just a couple of ideas: The Pfaff 34 is a central bobbin machine. The original bobbin cases had a fairly strong spring. Afterkmarket bobbin cases often have a much weaker spring with the additional problem of a wasp waist, which allows the spring to turn sideways, thereby causing an uncontrolled oversized threadopening. Also lint or thread remains may have accumulated under the spring, thereby rendering it unfunctional (remedy: clean it), and the spring may have weakened over time or have been bent.

I must admit I have never seen a Pfaff 34 in real life, but my first impression was that the topthread tension might be assembled wrong. The checkspring (red arrow) will be blocked by the post (green arrow). I think, the checkspring should be positioned under the post.

 

The Pfaff 34 is the same generation as my Pfaff 38 (zigzag). My 38 had considerably less pressurefootpressure than my other commercial machines; it was more in line with a good homesewingmachine. My Pfaff 145 has about 40 pounds footpressure, my Adler 5 about  50 pounds, my Singer 29 about 30 pounds and my Pfaff 38 about 10 pounds. You might try to increase the footpressure by adding a second spring. Also on my Pfaff 38 the feeddog mechanism was less efficient than on my other machines, even than the similarly built Pfaff 138. My 38 needed a good teflon foot to transport leather and PVC reliably. I ended up selling my 38.

-6 is Pfaff's way to say standard model, it is no specific leather or even saddler's machine.

 

HTH

Greets

Ralf C.

Edited May 25, 2016 by Kohlrausch
o

[amateursewing]

thanks I am not at home with the Pfaff machine right now but will check the position of the upper tension spring, I think it is OK and I bought two new bobbin cases for it off a UK wholesaler, it was practically IMPOSSIBLE to find this bobbin case with the "finger" that points a different way to all other bobbin cases. I dont think its a promblem with the bobbin case though as it sews perfectly on two layers of leather, in fact it sews perfectly on a thick layer of a leather belt but only looped the upper thread when doing the three layers of bikers leather pants. (this is the old original bobbin case - I got two new ones from a UK wholesaler) and this is a photo of the current top tension set up. I looks the same as the way your marked photo set up looks?? thanks, it came with all these amazing feet!!!

Laurence