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pfaff 545 thread tension problems

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Hi everybody! 
I have a problem with old pfaff 545 (I believe, because front model plate was lost)- on single leather layer upper thread tension is not enough (needle thread №20, bobbin thread №30, tensioner kit is new, and screwed at max., needles 134-35 №120 LR, foot lift on low position, stitch lenght is about 4.5mm max).
I tuned timing - needle 2.5mm up from lowest position, hook 1.6mm above the scarf of needle... 
I hope you can help me!)  *sorry if my English was bad...


IMG_20170323_131337.thumb.jpg.01e3a62e6200fdb52c2e6722f261b4bc.jpg

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Welcome to Leatherworker.net Stanislav!

There are MANY possible reasons that top thread tension may not working properly.

Please post some pictures of the back, hook area and underside of your machine - it may allow us to narrow down what model your machine is. It's not a standard Pfaff 545 - of that I'm quite certain.

Your machine looks like a two-needle machine that was converted to single-needle. Your thread tension assembly is also a dual needle tension unit with parts removed. The thread tension unit on my single needle Pfaff 545 looks like this (also Pfaff 145 and Pfaff 1245):

IMG_7590.jpg

 

On the two-needle thread tension units the tiny pins inside the post that push the tension disks apart are NOT the same length. If the tiny pins get swapped or the wrong length is used, they will not work right (I just worked on a two-needle Pfaff 120 where exactly that was a problem.) Make sure your tension disks are not permanently pushed apart by a pin that is too long. The tension disks have to press against each other to put tension on the thread. 

Make sure the threading is correct and that all the thread tension parts actually work the way they are supposed to work.

The top thread may get caught somewhere and cause it to get pulled and loose tension. Open the right slide cover and turn a few stitches by hand. Observe the thread getting wrapped around the hook - it should be smooth, not snapping.

I made a video with a Pfaff 1295 post bed machine recently. The Pfaff 1295 post bed machine has a different bed than yours, but the top portion of the head and the hook are the same as the Pfaff 545. The threading, bobbin loading, and thread tension release (pushing the tension disks apart when lifting the presser feet) should also be the same as your Pfaff 545. Some tension release parts on the back of my Pfaff 1295 are customized, but the effect of pushing the tension disks apart and letting them close again is the same (see 7:58 mark in the video below.) Make sure your tension unit works the same way when you lift the presser feet - your tension disks may be stuck apart for some reason.

Here's my Pfaff 1295 video - compare top and bobbin threading, thread tension release, and hook movement to your machine. 

 

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On 12.04.2017 at 7:06 AM, Uwe said:

Welcome to Leatherworker.net Stanislav!

There are MANY possible reasons that top thread tension may not working properly.

Please post some pictures of the back, hook area and underside of your machine - it may allow us to narrow down what model your machine is. It's not a standard Pfaff 545 - of that I'm quite certain.

Your machine looks like a two-needle machine that was converted to single-needle. Your thread tension assembly is also a dual needle tension unit with parts removed. The thread tension unit on my single needle Pfaff 545 looks like this (also Pfaff 145 and Pfaff 1245):

On the two-needle thread tension units the tiny pins inside the post that push the tension disks apart are NOT the same length. If the tiny pins get swapped or the wrong length is used, they will not work right (I just worked on a two-needle Pfaff 120 where exactly that was a problem.) Make sure your tension disks are not permanently pushed apart by a pin that is too long. The tension disks have to press against each other to put tension on the thread. 

Make sure the threading is correct and that all the thread tension parts actually work the way they are supposed to work.

The top thread may get caught somewhere and cause it to get pulled and loose tension. Open the right slide cover and turn a few stitches by hand. Observe the thread getting wrapped around the hook - it should be smooth, not snapping.

I made a video with a Pfaff 1295 post bed machine recently. The Pfaff 1295 post bed machine has a different bed than yours, but the top portion of the head and the hook are the same as the Pfaff 545. The threading, bobbin loading, and thread tension release (pushing the tension disks apart when lifting the presser feet) should also be the same as your Pfaff 545. Some tension release parts on the back of my Pfaff 1295 are customized, but the effect of pushing the tension disks apart and letting them close again is the same (see 7:58 mark in the video below.) Make sure your tension unit works the same way when you lift the presser feet - your tension disks may be stuck apart for some reason.

Dear Uwe, thank you very much for detailed answer. Yes, probably some parts was installed from different pfaff models. There was an old tensioner kit on my photo above, I installed another one now (black, on the photo below) because of the broken nut on tensioner discs, It is from two needle pfaff with some modifications and unfortunately it china made, but it works. Now I think everything is ok with those little pin in tensioner discs, I saw it and disassebled all parts of tensioner plate and spring. At first I thought that problem was in wrong needles and timing, but now I guess something wrong with hook or with another parts of machine... As you noticed there is something like snapping. Also I observed that backtack is shorter than normal stitching length. I'll capture a video tommorrow

IMG_20170413_171111.thumb.jpg.ba4759e9cc41d3948792ff094a8df932.jpgIMG_20170413_171245.thumb.jpg.fa26d261a6cf5a09f3e2b64b0cfa2b96.jpgIMG_20170413_171142.jpg.3478b951bc4359e69650f3a4a48784d0.jpgIMG_20170413_171606.jpg.77f65085b8f0ef2a711a453dee33f792.jpgIMG_20170413_172019.jpg.9c5b7f87600599e3a0062c8d82dfcf3e.jpgIMG_20170405_214526.thumb.jpg.59c60611604fd905da38fbe705535a61.jpg

IMG_20170413_171229.jpg

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Has this machine ever worked in this configuration? Perhaps the previous owner sold it in frustration because he couldn't make it work.

Your machine is very likely is a Pfaff 146/546  class machine (Flyer: pfaff-0546.pdf) and was designed as a dual needle machine. This means it had special feed dogs, throat plates, needle holders and various other two-needle specific parts. I'm not convinced that this two-needle design can be made to work properly if all the two-needle parts are replaced with single-needle parts. Hopefully I'm wrong and it will work, but sometimes mix-and-match parts combinations add up to a no-go configuration that cannot be adjusted to work properly. The partially removed automation parts are adding to challenge. 

The parts manual for the Pfaff 146/546 (Pfaff 546 Parts List.pdf) has a whopping 132 pages, hinting at the complexity and number of variations covered by this general design.  You might be able to narrow down what subclass your machine is by looking for tell-tale odd parts (e.g. that bent-looking horizontal manual foot lift lever).

The Pfaff 146-546 users manual (Pfaff 146 546 User Manual.pdf) may help answer a few key questions, too (needle system etc.)

That bobbin and cap in your picture don't quite look right. Are you sure you have the right size bobbin? The bobbin+cap should fall into place inside the bobbin basket and the center lock tab should flip down to hold the cap in place.

Edited by Uwe

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This machine looks like it had trimmers for thread cutting at one time.  Uwe, like you, I believe somethings are not quite right on this machine.

glenn

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Hi all. I am new to this forum and to leather upholstery and I managed to get a walking foot pfaff 546, originally with 2 needles, but converted to work with only 1 needle, exactly as the one the initiator of this topic has.

The machine is in good shape, but I have some issues with it. I have followed the above discussion, but I cannot figure how to fix my issues. The main issue is that the outer presser foot is not lifted during the sewing. The inner one walks just fine, but the outer one just stands, without lifting. I have attached a couple of link for photos  and 2 videos (because of the image size requirements), maybe I have to tighten a screw or something.

Also, it has a clearance of material of around 7mm. Isn't that too small clearance?

Thank you in advance for the answers.

 

LE: The machine sews, but I have to drag the material by hand (as it's pressed by the outer foot), so it's in working condition.

 

https://www.dropbox.com/s/ba6o5ypl3vj4yqg/VID_20170523_132515.mp4?dl=0

https://www.dropbox.com/s/erjfr6k1dkcimwg/VID_20170523_132005.mp4?dl=0

https://www.dropbox.com/s/vnk3zrlue9w6wrk/IMG_20170523_132117.jpg?dl=0

https://www.dropbox.com/s/yv94icfi7u9atk3/IMG_20170523_132056.jpg?dl=0

https://www.dropbox.com/s/24l39hszte4ssa3/IMG_20170523_132035.jpg?dl=0

https://www.dropbox.com/s/i4c1nd3fu4ltm7v/IMG_20170523_132017.jpg?dl=0

Edited by olariuciprian
I forgot to mention extra infos

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First of all, machine as a single needle is not threaded correctly.  As it comes off the tension discs, it goes over the little pin.  Put the thread under the pin.  I would look  at getting a single needle thread controller and take up spring instead of the double ones that are on the machine.  I plan to pickup a used 767-65-FA-273 long arm Adler.  I want to convert it to a single needle machine so I know what you are going thru.

glenn 

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