Yet another question about my Pfaff 545 - tension.

[LePoisson]

With the help of this group I have equipped my new-to-me machine with a servo motor, got thread and needles, and the right foot, and even fired it up and got teh first few stitches out of it... but it hasn't been a pretty process. Now I return, head hung low with yet another question... tension.

Thread tension on my machine seems wonky. on the 545, I'm coming off the "pre-tension" top post with the thread and going around 2 holes in the tension plate, clipping on to a little button guide, then feeding the thread between the tension plates before going over the spring guide and on to the arm/needle. My thread seems to be jamming on both the tension plates and the button guide. The only way I could the machine to sew without just eating through the thread was to remove the tension spring altogether, and use the adjustment screw to barely support the plates. I got it working, but after a bit the thread jammed again, this time in the button guide. 

Should I fart around and try to replace all these various parts, or is there a whole package that just replaces the plate and everything on it? To be honest, I haven't been able to figure out what the thread is jamming on between the plates - despite taking them apart and cleaning and pondering, and the button guide I have no idea at all what to do about. Any tips or sources are welcome. 

FWIW - this video has the same threading as my machine, it may be helpful to see teh parts I am referencing.

[Gymnast]

Can you inform us what exact type of thread, that you use? It needs to be for a sewing machine and of a reasonable thickness.

[kgg]

A few photo's of your thread path along with the type and size of needle and thread would be helpful in figuring out what is happening.

kgg

[LePoisson]

Good questions everyone. 

I got T70 #69 210D/3 thread off amazon for a first test. It is thinner than I expected. 

Thread path is in photos below - but the white thread is tough to see. I am aware that I am missing the thread guide that goes ahead of the needle (there is a screw there, but no guide) apparently it has been like that for some time since the paint is all worn off the touchpoints where the thread meets the face of the machine.

Thread Path 1: 

Thread Path 2: 

Needle Pack:

 

[Gymnast]

The Pfaff 545 should be able to handle a Tex 70 thread all right. But I would not risk to buy an unbranded thread from Amazon. Do you know if it is nylon or polyester, bonded or not bonded? Normally a size 16/100 or 18/110 needle size would be used for a Tex 70 thread. A 21/130 needle is too thick.

You think you got some problem with the needle thread tension. At lowest tension setting, I think you should be able to set a thread tension below 1.5 Newton just before the take-up lever. At some place of the thread guides you may have some metal damage that creates unregular tension. Try to thread the machine one step at the time and at each step try to feel the thread tension by hand when you pull the thread. It should feel smooth with little variation. Also the thread stand can be the problem - how do it look like? One common beginner mistake can be to have a heavy thread spool turn around a vertical pin, or the thread drops down under the spool.

You got both bobbin thread tension and needle thread tension to worry about. While you are not experienced in sewing, it can be nice to be able to measure thread tension (it still is for me). This is a video about measurement of thread tension: https://youtu.be/kINRgj42GnI

[Constabulary]

For what ever reason you may have a top tension release. Do you have a knee lifter you ever so slightly push the knee against when sewing? Or pedal for lifting the foot you rest your foot on when sewing? That MAY cause a tension release. Just a guess...

Just to try something... You see the black disc right behind the thumb nut - remove it and put back on the beehive spring and thumb nut and try again. This way you disable the tension release entirely. There is a tiny pin behind the black disc - don´t loose it. Is just to see if there is a change when sewing, it reversible in a few seconds.

Have you checked the needle hook timing? Just to make sure the machine is set up for 134-35 needles. Needle scarf is facing toward the hook right?

[shoepatcher]

17 hours ago, LePoisson said:

With the help of this group I have equipped my new-to-me machine with a servo motor, got thread and needles, and the right foot, and even fired it up and got teh first few stitches out of it... but it hasn't been a pretty process. Now I return, head hung low with yet another question... tension.

Thread tension on my machine seems wonky. on the 545, I'm coming off the "pre-tension" top post with the thread and going around 2 holes in the tension plate, clipping on to a little button guide, then feeding the thread between the tension plates before going over the spring guide and on to the arm/needle. My thread seems to be jamming on both the tension plates and the button guide. The only way I could the machine to sew without just eating through the thread was to remove the tension spring altogether, and use the adjustment screw to barely support the plates. I got it working, but after a bit the thread jammed again, this time in the button guide. 

Should I fart around and try to replace all these various parts, or is there a whole package that just replaces the plate and everything on it? To be honest, I haven't been able to figure out what the thread is jamming on between the plates - despite taking them apart and cleaning and pondering, and the button guide I have no idea at all what to do about. Any tips or sources are welcome. 

FWIW - this video has the same threading as my machine, it may be helpful to see teh parts I am referencing.

Not threaded correctly to start

[shoepatcher]

It is not threaded correctly in the video to start. If sewing with #69 thread. #18 or #19 needle is best.  One thing not mentioned here is the take up spring.  Pfaff made a heavy and light spring.  You are using #69 thread, I would go to the lighter spring.  The one in the machine is for heavier threads.    Check to make sure the take up spring is threaded correctly in that when going around the tension mechanism that after it, you hear a click when you pull the thread around it.  That tells you the thread has cleared the curved finger in back.

glenn

Edited March 30, 2022 by shoepatcher

[kgg]

On 3/30/2022 at 2:52 AM, LePoisson said:

Should I fart around and try to replace all these various parts,

My take on the threading of your machine. I zoomed in on the photo's of your machines threading. What I noticed was:

1) The top thread post pin on top of the machine seems to have been replaced with a short two hole post a long while ago. This shorter pin has allowed the thread too cut a groove into the paint. This could on thin or soft thread rub /cut the fibers. 

2) You are not threading the thread through the top vertical thread guide.

3) Since the bottom horizontal thread guide just before the needle has been missing for some time a groove has been cut into the paint.

4) The thread guide at the top of the needle appears to be missing.

5) The needle size is incorrect for V69 (Tex 70 / Tkt40) thread.

Before replacing major items I would try:

1) Replace the top thread post pin on top of the machine with the longer 4 hole pin so the thread clears the body of the machine. If not, re-thread the pin in reverse so the thread enters the pin from the bottom hole and exits from the top to the first guide. Then enter the thread guide on the tension assembly through the top hole crossing over the guide so the thread enters the second hole in the direction of the button tensioner. I could not tell from the photos but I would venture to guess that there is a slight burr / groove cut in the second hole of the thread guide on the tension assembly.

2) Install a bottom horizontal thread guide. If you don't one a DIY guide made out of a piece of smooth wire like a large paper clip may work to protect the thread and keep it away from the body of the machine.

3) Install the thread guide at the top of the needle. Without this thread guide to keep the thread in the vertical position along the shaft of the needle you will never get good stitches.

4) Change the needle to a size 18 (110) or 19 (120).

5) Change the spool of thread as it maybe defective particularly if it is a cheap no name thread.

kgg