feed tracking theory needed

[rlevine]

Hi folks,

I think I need a basic theory lesson about what affects feed tracking for a compound machine. 

I have a Tacsew 206RB look-alike that I've brought back from dead; it sews very well. The only issue that I'd still love to fix is that it feeds slightly to one side. If I angle anything I'm feeding a couple of degrees to the left, it sews perfectly straight. I've experimented with all the usual suspects: timed the needle to the presser feet, adjusted the foot timing and height, rotated the presser foot bar slightly, replaced the dogs and feed plate, angled the feed dogs slightly one way or another, tried angling the inner foot slightly, tried reducing or increasing tension to see if stitches might pull it to the side, and probably some other experiments I'm not remembering. But it still tracks consistently to the same side; the feed isn't parallel to the visual landmarks on the machine. I've added some tape indicators, and again, it sews dead straight if I just angle the feed. I'm running TKT 69 bonded nylon thread in canvas and leather, and it behaves the same for both.

Anyone up for providing some tips on what affects feed tracking?  @Uwe, @RockyAussie, @DonInReno?

Or just tell me to live with it?

Thanks!

Rick

[trash treasure]

It would seem to me, that it's the interaction of the feed dog with the inner foot, that determines the tracking.  So that's where I would look.

You might try some different feet, and feed dogs - Aftermarket parts combinations, on a clone machine, might offer all kinds of possibilities ........

Some good, some not-so-good.

[rlevine]

Thanks, @trash treasure. Ya, I’ve tried multiple feet; it seems like it’s consistent across the feet I’ve tried. And I’ve swapped  feed dogs, with no change. I’m running smooth-bottomed feet, and serrated dogs. 
 

Rick

[nylonRigging]

Your needle bar does very slightly pendulum/swing on it's Up/Down, but all 3 bars are in alignment ( Outer, inner and needle ) .. but like  ( TrashTreasure ) saying, Only contact for feeding direction is center Presser Foot and Dog . With that moving centered between the 2-toes of your Outer Presser Foot, and it is only moving a up/down to hold material utilizing the Needle Plate to do this when the center foot is feeding with Dog's .

OK .. Are you sure this is not just an optical illusion that the material is Not feeding straight as it's sewn  ?
You push materials into your Machines Feed . but Many times when sewing materials on machines . The materials being sewn will draw to one side ( curve ) with the added top/bottom thread, and tension of it being sewn . Only appearing to be moving off-center on the feed direction as you watch it leave your machines feed .
.
 

[RockyAussie]

A close up picture showing how parallel your feed dog is as against the back presser foot may help. With pressure on and with the foot not quite touching. My first suspicion is needle size to thread and overall top and bottom tension. Will the next size up needle fix it. If you lower your bobbin tension a 1/4 turn and back off your top tension does it improve?  Is your presser foot tension way more than need be? I run as little foot pressure as possible to keep the needle from lifting the work as possible. Is your back foot swivelling back and forth? Sometimes the back foot little tabs at the top don't snug up to the presser bar tight enough. I generally take them feet to the anvil and hammer them in But make sure when you close them in that you dont have the foot angling up at the front when you put it in. Hammer the front tab? back a bit first then look for the parallel between the feed dog and foot.  I just did a search and found this video at about 4 mins in shows the sloppy back foot I am talking about -  https://www.youtube.com/watch?v=G6jfIaf3aww

Other than that I am out of ideas....best of luck.

Edited August 18, 2022 by RockyAussie

[rlevine]

Thanks folks! Apologies for the delay in answering. I accidentally plowed through a vislon zipper, and had to retime before I could experiment more, and did some other tuning as well.

@nylonRigging, it was definitely not an optical illusion! I wish!

@RockyAussie, thanks for the presser foot tension suggestion. I think backing off both tension adjustments did the trick. I wasn't paying enough attention to foot pressure. I also tried winding bobbins with less tension, and I think the resulting reduction in bottom tension helped not pull as much. Thanks also for the trick of peening the tabs on the outer feet! I always check to level the outer foot before I lock it down, but easing in the tabs makes changes a bit easier. Nice catch on the sloppy back foot on the video - eagle eye to spot that in the middle of a random movie!

Rick

[RockyAussie]

32 minutes ago, rlevine said:

Thanks folks! Apologies for the delay in answering. I accidentally plowed through a vislon zipper, and had to retime before I could experiment more, and did some other tuning as well.

@nylonRigging, it was definitely not an optical illusion! I wish!

@RockyAussie, thanks for the presser foot tension suggestion. I think backing off both tension adjustments did the trick. I wasn't paying enough attention to foot pressure. I also tried winding bobbins with less tension, and I think the resulting reduction in bottom tension helped not pull as much. Thanks also for the trick of peening the tabs on the outer feet! I always check to level the outer foot before I lock it down, but easing in the tabs makes changes a bit easier. Nice catch on the sloppy back foot on the video - eagle eye to spot that in the middle of a random movie!

Rick

Good news Rick. Them little things can make a big difference