problems pfaff 335

[martine2005]

i am sewing with a pfaff 335;

treath nr 20 (european size) under and upper, no backtack used

needle 120 pcl or s

i have problems with the tension, on the bottom small knots are visible, when using two different colors it is very noticable.

i tried already to lower the bottom tension and higher the upper tension, , problem is still there no matter how high or how low the bottom tention.

leather is soft, but not thin, and there is a very light reinforcement used in between the two layers.

 

thanks for any help

[Northmount]

15 minutes ago, martine2005 said:

i am sewing with a pfaff 335;

treath nr 20 (european size) under and upper, no backtack used

needle 120 pcl or s

i have problems with the tension, on the bottom small knots are visible, when using two different colors it is very noticable.

i tried already to lower the bottom tension and higher the upper tension, , problem is still there no matter how high or how low the bottom tention.

leather is soft, but not thin, and there is a very light reinforcement used in between the two layers.

 

thanks for any help

Moved to leather sewing machines, so you will likely get more response here.  Help wanted is like newspaper classifieds advertising for employment purposes.

Tom

 

[mikesc]

Knots on the bottom..( top thread showing on the bottom, but not so bad as to be "bird's nesting" ? ) Normally you would not touch the bottom tension until you have tried adjusting the top tension..So..Firstly, get your bottom tension back to "normal"..So that the thread doesn't bind or pull back at you when you pull on it when it is on a bobbin inn the bobbin case..it also does not want to be too loose when you pull..

Then look at the thread path of the top thread, anything broken, anything loose ?..Without putting the thread through the needle eye does the thread have tension on it when it is threaded correctly on the thread path ,..if yes..tighten the thread tension discs 1/4 turn ..and try to sew with the needle threaded and the bobbin in place in the case..if OK..then great..if not tighten the top thread tension discs ( and only touch the top thread tension, leave the bobbin tension alone if it is OK ) another 1/4 turn ..test again..repeat until it is OK..

Most tension problems are not from bottom tension, but are from the "balance" between top and bottom tension..usually you rebalance by adjusting the top tension..

You are sewing chrome tan ? What thickness is it ( each layer ) ( in mm ) and what is the middle reinforcement layer made from ? and how thick is it, what is the total thickness of the "sandwich" ? do you have enough pressure on the foot ?

Edited August 14, 2016 by mikesc

[Northmount]

Usually more top tension required to pull the knot up.

Make sure the thread is between the tension disks, that it hasn't jumped out and riding on top.

Try a larger needle size if the top tension is already quite tight.  Need a large enough hole to be able to pull the thread up.

Tom

 

[dikman]

I'm with northmount, I reckon the needle is too small for T20 thread. I've been experimenting with my 335, trying to get it to sew T20 (138) thread and I finally got it working using a 140/22 needle.