Techsew 441

[Silverd]

Hi All,

 

I have a two year old Techsew 441 that periodically will make a cluncking noise, skip a stitch then break off the needle.  Typically this is when sewing thick leather,  10oz or so but has also done it on lesser material.  I understand it has to do with how the needle path into the hook zone is influenced by the material but the problem appears to be getting worse not better.  A recent project resulted in 8 or 10 broken needles and remaking of several components.  Ive checked the timing using the Uwe system and it's spot on. I have renewed the hook assembly but have not made any lateral adjustmentso or shimming.

Is anyone familiar with this behavior and its causality?

 

Silverd

[Wizcrafts]

Make sure you have sufficient foot pressure to fully hold down the leather as you sew. If it is too loose the leather can lift with the needle and cause problems like skipped stitches and bent needles.

Take the cover off the end and handwheel slowly, watching the needle and hook for actual contact. The hook should just miss the scarf in the needle on the upstroke. If the needle touches the hook, the needle bar needs to be checked for looseness at the top and re-positioned, then tightened in place. There's a tapered pin holding the needle bar in place and set screw on top the locks down the lateral position of the needle bar pin.

How often do you remove the faceplate and oil every crank and oil hole in the left end of the head? While you're doing that, check all set screws for tightness. Raise and lower the feet with the hand lifter to ensure that there is no binding or excess slack.

If these simple things don't make any difference, contact Ron at Techsew. Make a video, with audio, to show what is happening.

[kgg]

Which model of Techsew? I can't seem to find any reference to a Techsew 441.

kgg

[Wizcrafts]

9 hours ago, kgg said:

Which model of Techsew? I can't seem to find any reference to a Techsew 441.

kgg

A 441 machine is a general description of a clone of a Juki TSC-441. In this case, the current Techsew 441 clones are the models 4100 and 5100. The OP may have forgotten the model number, or the machine is in a different location than his home at the time this was posted. My machines live in a shop that I am not in when I do my posting on this forum (too busy sewing).

[RockyAussie]

Another thing may be worth a check is that the 2 screws with springs that hold the shuttle race body are not screwed in all the way or too far. The springs should be just showing visible and the shuttle can be pulled in and out a little by hand. Also check that the bobbin is unwinding smoothly and not catching intermittently.

[Silverd]

Great advise.

Techsew model 5100

Presser foot presser does not appear to be a causality.  I keep it as light as possible but normally dont allow the work to lift.

There is a gap between the needle and hookI as you describe.  But I have not measured the gap.  Machine normally sews well.

I'll check set screw tightness and hand lever presser foot lift mechanism as suggested.

Two shoulder  screws with springs that retain the hook shuttle into the casting are tight.  I can loosen them a bit.  That said.  The shuttle assy does not freely translate in the arm casting at least on this machine. You are suggesting is not normal?  I'll work on this to free it up.  

Bobbin appears to operate normally.  Thread pulls evenly.

 

Many thanks.  I'll follow up a little later.

 

Siverd 

 

 

 

 

[DrmCa]

Does it correlate at all with the wear on the needle? I.e. does a new sharp needle work better than an older dull needle?

[Silverd]

No.  I've never put so many new needles in a machine!  

I'm thinking the work piece is a contributing culprit since the machine will sew perfectly on another piece of leather immediately before and after a breakage.

Silverd

[RockyAussie]

5 hours ago, Silverd said:

Two shoulder  screws with springs that retain the hook shuttle into the casting are tight.  I can loosen them a bit.  That said.  The shuttle assy does not freely translate in the arm casting at least on this machine. You are suggesting is not normal?  I'll work on this to free it up. 

For the screw tightness check this Solar Leather link                         

 

[Silverd]

Hey

 

Great video!  Typically,  shoulder screws like the ones with the springs holding the hook assembly in place are designed with sufficient shoulder length such that they can be fully seated.  Not the case here apparently as you have pointed out.  Definitely I'll loosen mine as they are installed tight.  

 

Thank you

 

Silverd