Vintage pfaff 335G-h3 stitching problems

[tibee]

Hello,

 

I bought a vintage pfaff 335G-h3 and I'm having issues getting a proper bottom stitch, especially on thick veg tanned.

I Reckon this machine was made for medium thickness chrome tanned leather but bought it because I though't id be able to handle anything from 1-6 mm veg tanned

It's threaded properly and I've dismantled and cleaned all where the threads travel.

in the picture ( its the bottom stitch) I'm using #92 on Nm130/21 LR needle  on 3 mm veg + fabric. ( tried Nm 120/19 and results are the same)

Also, as I go up in thickness of leather (5mm and above), I have to crank my top tension nearly to the max. I don't know much about sewing machines but it seems weird and

I don't understand why I have to do that so if anyone could elucidate me on that I would much appreciate it.

 

Also I have to change a bunch of screws which are completely mangled, does anyone know if I get regular 335 parts it will fit?

 

I appreciate any help because I've been struggling for the past week,

Thanks!

 

Tib

 

[kgg]

1 hour ago, tibee said:

Also, as I go up in thickness of leather (5mm and above), I have to crank my top tension nearly to the max.

Sounds as through you need to back off the bobbin tension as the thicker leather is creating more resistance on the bottom thread which means you have to have more top tension to pull the bobbin thread into the leather. If possible could you post a couple of pictures of your top thread path from the thread spool to the needle.

kgg

[tibee]

Thanks Kgg , I'll try that. Any idea for the the random bottom loop? 

Also here is the top thread path.

[kgg]

33 minutes ago, tibee said:

Any idea for the the random bottom loop? 

I am not familiar with the bobbin case of your machine but I would check and see if there is any bits of material in the case also if the case is supposed to have a backlash spring it is working ok. I suspect that the odd loops have more to do with tension problems then anything else.

[tibee]

Thanks Kgg

backlash spring still has spring so I guess that means it's good? Could it have anything to do with the check spring, that's the only thing I haven't messed with..or could it be something about how the bobbin is wound? 

It seems like the random loops are less frequent on thinner and softer leather if that helps

 

I have a 100 year old 29k that gives me a good stitch in 1- 6 mm leather without any adjustments whatsoever but this beast of a german engineering is giving me so much trouble its almost comical.

[jimi]

Hi Tibee, could be the little finger not letting the thread pass easy?? the one on the end of the arm??but looks like your bottom thread is catching now and again somewhere??

[tibee]

I'm not sure what you mean by little finger, do you mean bobbin tension spring?

Maybe there is something catching the bottom thread occasionally and creating extra tension but I have no idea what it could be because its not like it travels that much right? 

[kgg]

Stupid question, which way does the thread come off the bobbin. If I am not mistaken in your Pffaf 335 the thread comes off the bobbin clockwise like a domestic machine rather then counter clockwise. Some machines don't really care but others if the bobbin is inserted incorrectly thread slack can occur resulting in poor stitching.

kgg

[RockyAussie]

I'm pretty sure that the thread does not go up over the post at your tension discs. https://www.google.com/search?client=firefox-b-d&q=how+to+thread+a+335+pfaff#kpvalbx=_WSEZXuXLJtXCz7sPoqOQcA24

Also your thread return spring should just start to slacken off as the needle enters the leather. Thick leather check for this. Make sure you leave no thread hanging out when you refill the bobbin and test the bobbin how it rotates in the bobbin case in your hand. If it feels catchy try another bobbin and if still catchy look for burs etc on the bobbin case shaft and that the backlash spring has not been bent out of shape and catching in the bobbin slot when it rotates.

[dikman]

Good catch, Brian, I missed that when I looked. There's been a post or two about this before, it shouldn't go over the little post