Play hide the knot?

[sportycliff]

On 1/31/2023 at 12:27 PM, kgg said:

If I'm not mistaken this machine has the same capabilities as the PFAFF 335 and similar clone machines. Most of the 335 machines are really only capable of sewing with V92.

 

It shares the same bobbin case, bobbins,  and looks like the same hook as my Sailrite Fabricator.

That machine has zero problems with 138, nothing is shredding, so I assume clearances are ok, I'm going to try adding a pre-tensioner.

 

 

 

[kgg]

1 hour ago, sportycliff said:

I'm going to try adding a pre-tensioner.

To add a bit more tension to the top thread try:

i) top thread entering through the top hole of the post guide wrap it around to the back side and out the bottom hole in the post guide located on the top of the machine

ii) top thread through the first hole in the vertical guide located on the main tensioner wrap it around and out the second hole and then onto the underside of the little guide pin.

kgg

[DonInReno]

On 2/1/2023 at 4:17 AM, sportycliff said:

Any other thoughts?

I’m out of ideas - it appears that there is roughly enough top tension to mostly pull the knot up, but that lower thread looks crazy and appears to have varying amounts of tension.   I’d guess it’s partially whatever brand and type of thread and partially something underneath it’s hanging up on giving the inconsistent bottom tension.

The finger that keeps the bobbin case in alignment has to have enough clearance for thicker thread to pass around easily.  There is no bobbin case opener to adjust, but clearance is adjusted with careful metal removal and polishing.

If this machine was made to only sew thinner thread, in addition to a tight area at the bobbin alignment notch, there may also be resistance from a tight spot somewhere else around the bobbin case that would have to be clearanced.

Thats about all I’ve got.

 

 

 

 

[sportycliff]

9 hours ago, DonInReno said:

I’m out of ideas - it appears that there is roughly enough top tension to mostly pull the knot up, but that lower thread looks crazy and appears to have varying amounts of tension.   I’d guess it’s partially whatever brand and type of thread and partially something underneath it’s hanging up on giving the inconsistent bottom tension.

The finger that keeps the bobbin case in alignment has to have enough clearance for thicker thread to pass around easily.  There is no bobbin case opener to adjust, but clearance is adjusted with careful metal removal and polishing.

If this machine was made to only sew thinner thread, in addition to a tight area at the bobbin alignment notch, there may also be resistance from a tight spot somewhere else around the bobbin case that would have to be clearanced.

Thats about all I’ve got.

 

I've tried two different types of bonded nylon. Both run fine on my other machine.

 

Number 24 has a finger on the bottom side which fits a notch in the hook assembly

which stops the center section of the hook from spinning, is that what you mean?

I don't mind a little mod work, just want to mod the correct items.

 

9 hours ago, DonInReno said:

 

 

[Constabulary]

maybe its just the hook that is a bit close to the needle so the gap between hook notch and position finger is too tight. You can move the hook a tiny bit (maybe 0.5mm or so) to the right (if not already flush with the machine arm) by loosening the 2 or 3 set screws on the hook body. Better check the needle hook timing after doing this.

[sportycliff]

On 2/4/2023 at 4:28 AM, Constabulary said:

maybe its just the hook that is a bit close to the needle so the gap between hook notch and position finger is too tight. You can move the hook a tiny bit (maybe 0.5mm or so) to the right (if not already flush with the machine arm) by loosening the 2 or 3 set screws on the hook body. Better check the needle hook timing after doing this.

I never considered that the closer the hook to the needle the tighter the notch clearance as well, I'll play with the gap some more...Thanks

 

[DonInReno]

I’d suggest taking off the end cap so you can watch the thread as it goes through a stitch - modifying something that doesn’t need to be modified is just guessing.

[sportycliff]

On 2/4/2023 at 12:22 PM, DonInReno said:

I’d suggest taking off the end cap so you can watch the thread as it goes through a stitch - modifying something that doesn’t need to be modified is just guessing.

Everything seems perfect. Can easily slide 207 through the notch no hangups anywhere, tried multiple gap hook/needle gap and timing changes, it does seem that sewing speed changes quality from maybe ok on some stitches to loops on others, no consistency at all. I'm down to size 92 and still having the same issues. I don't think it's a tension issue any longer, this machine (by feel) is running MUCH higher tension on 92 than my other is running with 138 or 207 and still loops on the bottom, with shitty stitches all the way around. I'm waiting on slow boat for another feed dog, but now I'm playings part replacer instead of proper diagnosing and doing it right. #Frustration

Edited February 9, 2023 by sportycliff

[sportycliff]

On 2/4/2023 at 7:29 AM, sportycliff said:

I never considered that the closer the hook to the needle the tighter the notch clearance as well, I'll play with the gap some more...Thanks

 

No difference.

[sportycliff]

Found a repair shop only a couple of hours away, going in next Monday.