Stitching issues on a 3200 with 5-6 oz veg tan

[BDAZ]

One of my product lines, a pouch, uses 5-6oz drum dyed leather. I use either 138 bonded nylon with a 23 needle or 207 with a 24. (Pictures are 207/24)

I purchased a spool of white bonded nylon for this job as all my tread inventory is either black or natural. 

I get perfect stitches when stitching two 5-6 oz pieces but when I reach the flap I end up with knots on the top or if I loosen the top tension the knots move below the surface but the thread appears to bunch on the down stroke and the needle punches through the tread as shown in the pics. Both look like crap!

Any suggestions will be most welcome! I am backed up and I need to solve this issue, whether by changing thread/needles or adjusting the tension or possibly working with the catch spring ASAP.

Thanks!

Bob

[SolarLeatherMachines]

it would help to see pictures of the actual product and views of the stitching about 8" away from the surface. 

[BDAZ]

[Gymnast]

I am not that expierienced here. But I like you to check the operation of your check spring. For my machine - if the check spring is not operating, the top thread may not be tight when the needle hit the fabric.

[Wizcrafts]

I would agree that the likely culprit is your check spring. The spring must hold the top thread taut until the needle pierces the material. If it lets go before that the tip of the needle will pierce the thread.

[BDAZ]

Thanks both for your help!  I have been working on the check spring tension and position of the stop. Bobby from Toledo suggested to move the stop so the hole in the spring is even with the post on the lower tension. Didn't seem to help.This is what happens during a stitch when tension is low enough to move the knot below the surface of a single layer of 5-6 oz.

 

Bob

Edited July 19, 2019 by BDAZ

[BDAZ]

I watched Alexanders video on removing and resetting the check spring. I did pull it apart and all seems normal did make sure the neck of the check spring was engaged in the hook of the check spring tension spring but it made absolutely no difference. I checking Ryan's video of threading the 3200, he demonstrates the action of the check spring but on my setup, upper tension is not enough to move the check spring at all.

 

Bob

[Gymnast]

I did also look at the youtube video

https://youtu.be/MHQBvaNkcRM

I think the upper tension should be high enough to move the check spring at any time. So to me it means the upper thread tension is too low. Perhaps the lower thread tension is too low as well. Do you have any Means of measuring the thread tension?

The Picture you have above, is that from before or after the stop on the check spring was changed? I would like the stop be lower than on the Picture to make Space for more movement of the check spring.

[BDAZ]

I did move the check spring stop back to the middle position and vertical and now the thread runs straight across from the post through the opening in the check spring but it made absolutely no difference. The current tension is the maximum tension I can use and not present knots on the top. The bobbin is set to almost maximum.

[Gymnast]

When I look at your Picture AND the video I refered to above, it seems to me that the thread is not put between the tension discs of the tensioner. I take that from the direction of the thread from the pretensioner. The thread rides on the top. It should be pulled in between these discs.

[BDAZ]

1 hour ago, Gymnast said:

When I look at your Picture AND the video I refered to above, it seems to me that the thread is not put between the tension discs of the tensioner. I take that from the direction of the thread from the pretensioner. The thread rides on the top. It should be pulled in between these discs.

No, it's an illusion. It is exactly the way Ryan demonstrates in the video and the way I have been doing it from Day 1. I get a perfect stitch when stitching 2 pieces of 5oz but having trouble with the single.

 

Bob

[chrisash]

Looking at the photo's it does not look like "bonded nylon" as the individual threads are showing loose all along both images

[BDAZ]

4 minutes ago, chrisash said:

Looking at the photo's it does not look like "bonded nylon" as the individual threads are showing loose all along both images

The first two microscope photos are a new spool that was supposed to be bonded but the subsequent  photos are from my old stock purchased from Bob Kovar and are bonded.

BTW I occasionally used to be the club champion at the Christmas Common Sporting Clay Club when I lived in Berks. Not fun when the temp is 45C and no bacon butty sandwiches to be had! Also lectured in photography at what was Surrey College of Art and Design and also Trent and Derby..

Bob

[Wizcrafts]

The easiest way to set the stopper for the check spring is to tighten the top tensioners on the thread, then loosen the set screw on the stop bracket and lower it as you hand wheel the needle down. Once the needle hits the top layer, add a touch more travel and tighten the set screw. This may need to be fine tuned but will keep the top thread taut until the needles penetrates the top layer.

As for thread tension, I run with just enough bobbin thread tension to require a noticeable pull. Then I balance the knots with the top tensioner and sometimes with the secondary tensioner.

Thread size matters with thin leather. When sewing 5 ounces on my Cowboy, I use a #19 needle with #69 or #92 thread. Anything larger makes it difficult to bury the knots. Also, it is not recommended to sew under 6 ounces on a 441 clone.

[BDAZ]

46 minutes ago, Wizcrafts said:

Thread size matters with thin leather. When sewing 5 ounces on my Cowboy, I use a #19 needle with #69 or #92 thread. Anything larger makes it difficult to bury the knots. Also, it is not recommended to sew under 6 ounces on a 441 clone.

I was waiting for someone to post this! I remember this vaguely when I got  started. Plan A is to move to a heavier leather. Plan B is to keep painting the knots black with a Sharpie, looks great if you don't get too close. My latest batch of drum dyed purchased for this production run is noticeably thinner than usual. I was hoping I could make some changes in setup that would help. This is the main headache, again only on 5-6 oz. 

[BDAZ]

1 hour ago, Wizcrafts said:

The easiest way to set the stopper for the check spring is to tighten the top tensioners on the thread, then loosen the set screw on the stop bracket and lower it as you hand wheel the needle down. Once the needle hits the top layer, add a touch more travel and tighten the set screw. This may need to be fine tuned but will keep the top thread taut until the needles penetrates the top layer.

Did this and it's the first improvement I've had. Not perfect but better than the above pic.

 

Thanks! BTW I picked up an EUB a year or so ago..FUN!

[BDAZ]

I want to thank you all for the input. It seems there was no one issue but a combination of tuning the catch spring stop, changing back to a 23 needle with 138 thread, reworking the bobbin tension seems to have corrected the problem. I will give it some more attention tomorrow but as of tonight I am a happy camper and will be able to complete my order with confidence.

 

Thanks again!!

Bob

[Wizcrafts]

There is a trick you can try that uses larger thread on top and thinner thread on the bottom. In your sample, you seem to like #277 on top. Tyr this. Load #277 white or straw thread on top.  Install a #24 needle. Load the bobbin with #92 or #138 black thread and tighten down the bobbin tension spring. Back off the top tension disks to let the bobbin thread pull the knots down low, but inside the flesh side. If you use black thread on the bottom, the visible, semi-buried black knots won't need a Sharpie to bring them out visually.

Adjust the check spring as necessary to keep the top thread taut.

[BDAZ]

Thanks! I have done that in the past, using a lighter black bobbin thread but it wouldn't work for this application. Also, I have used 207 with a 24  for these tests but switched back to 138 with a 23.I am still not sure I have the check spring operating properly. It certainly doesn't seem to keep the tension on the thread as the needle is piercing the leather. I'll shoot a video tomorrow..

 

Bob

[RockyAussie]

In your picture above showing the thread check spring the stopper is set to the top and it should be way lower. You have found that out but have a look and make sure the the thread check spring is not rubbing against the cover as that can act to stop the proper and full travel. You may need to get in and make sure its clearing and it may need to be positioned to be tighter as well. There is a nut inside the cover to reposition the tension if I remember correctly. You undo turn the tension shaft stud and do the nut back up.

[BDAZ]

Thanks Rocky! I do have a feeling the check spring is a bit rough. I don't get much movement in the spring and sometimes none if the tension is a bit slack. I did pull the check sprin gand check for rubbing and also lubed the check spring tension spring, but I agree it needs attention. Am I supposed to get full travel of the check spring with every stitch?

 

This is the latest test which is pretty close to acceptable.

[RockyAussie]

33 minutes ago, BDAZ said:

Am I supposed to get full travel of the check spring with every stitch?

Yes ...until it hits the stopper every time. I would consider opening up a slot in the middle foot (shown below) as you can see better and it makes the threading a whole lot easier.

[Wizcrafts]

If the check spring is not able to bottom out all the way to the stop bracket's lowest position, the coil spring that returns it must set be too light. There is a nut on the back of the housing where the check spring shaft is mounted. You'll have to wrangle a really narrow wrench behind there to loosen the nut, then turn the split screw until it pulls the check spring all the way down. Tighten up the locking nut and set the stop bracket as needed. Don't be afraid to try different angles to get more travel.

[Gymnast]

10 hours ago, BDAZ said:

No, it's an illusion. It is exactly the way Ryan demonstrates in the video and the way I have been doing it from Day 1. I get a perfect stitch when stitching 2 pieces of 5oz but having trouble with the single.

 

Bob

Yes, it is some kind of illusion to me :). I think I watched 5 other videos on youtube regarding this subject now, and they all looks equal and as on your machine. They all seems to me like the thread do not go between the discs on the main top thread tensioner. So I hope I can learn something too.

With the pretensioner Ryan in the video clearly indicates, that the thread must be pulled in between the discs. But he do not show the same regarding the main tensioner. Are the tension discs different on the main tensioner? Do the thread go around the discs near the outer perimeter of these discs? I normally see the thread commes in around the post, that may be only about 1/4" diameter, and I do not see this happen here.

[RockyAussie]

This video should be of help here I reckon -