Techsew 5100 back stitch problems

[ZacharyR]

I’m trying to sew 2-3 layers of 2 oz leather which I know is pushing my machines limits. I’m using #92 thread and #20 needles. I’ve read the stickies and tried to follow them but my problem is that it will sew it won’t backstitch. It sews fine forward but when I try to back stitch at the end it misses the bottom thread almost every time. I’ve tried adjusting tension and everything I can think of but it still does it. What am I missing? Thanks 

[MtlBiker]

21 minutes ago, ZacharyR said:

I’m trying to sew 2-3 layers of 2 oz leather which I know is pushing my machines limits. I’m using #92 thread and #20 needles. I’ve read the stickies and tried to follow them but my problem is that it will sew it won’t backstitch. It sews fine forward but when I try to back stitch at the end it misses the bottom thread almost every time. I’ve tried adjusting tension and everything I can think of but it still does it. What am I missing? Thanks 

2-3 layers of 2 oz leather shouldn't be pushing that machine at all!  Even my 2750 has no problem with that thickness of leather.  Is your machine working the way it should with other materials?  Is it only with the leather that you have a problem?  Are you using leather needles?

[ZacharyR]

I’m no expert by any means but if I switch to #138 thread and a #23 needle it sews the same leather fine. I got the needles from techsew. They’re a round point needle instead of a chisel point. 

[JayEhl]

I have the same problem.  I heard from a friend who suggests leaving enough tail on both ends to allow for hand back stitching until I get it figured out.  Granted I'm still very much a novice with this machine so I know its something I've screwed up. I just need to spend more time on it is what I was also told.   Was hoping for a better answer but unless it's mechanical, e.g. the machine isn't working to stitch back, then it's definitely something to do with thread type, thread size, needle size, or tension as far as I can tell. 

Was also told that once it's set, don't mess with it!!  

[ZacharyR]

I hadn’t thought about trying that. Mine sews everything else just fine with bigger thread and needles 

[MtlBiker]

11 minutes ago, ZacharyR said:

I’m no expert by any means but if I switch to #138 thread and a #23 needle it sews the same leather fine. I got the needles from techsew. They’re a round point needle instead of a chisel point. 

Round point needles are not leather needles. 

Okay, I suspect your stitches (with the needle and thread you're using) aren't correct.  Can you post a photo of the forward stitches, both top side and under side?  Since you say there is no problem when you're using #138 with a 23 needle, I suspect the tension adjustment is off and showing us the stitches would help us help you.

(Do you know how to adjust the tension on the bobbin carrier?  Certainly changing from 138 to 69 would require readjusting that.)

 

[ZacharyR]

I can try to get some pictures later. I know how to adjust the tension on the bobbin. I usually just adjust it so the knot is in the center and it seems to be there so I haven’t messed with that tension yet. Maybe I should try it with my bigger needles and see if it changes anything. 

[ZacharyR]

Here are the needles I’m using with the #92 thread. It says they’re for leather but I don’t know that much about it. 

[MtlBiker]

@ZacharyR - While you can use those universal needles on leather, they are not ideal.  You should be using these:

I still wonder if your thread tensions are correct.  There's no doubt in my mind that when you change from 138 thread to #69, you must readjust the bobbin tension as well as the top thread tension.  I also think what you're using is at the lowest end of what the machine is capable of using and that ideally that machine uses thicker thread and bigger needles.

[ZacharyR]

I have some of those needles as well I just can’t find them as small. I know I’m going about as small as this machine can do and that’s not helping. I’ll try it some more this evening and adjust the tension on the bobbin and try a different needle and see if that helps. I appreciate your help and information. 

[Wizcrafts]

I think you guys need to buy the narrow throat plate/feed dog from @RockyAussie

[ZacharyR]

I have one ordered! I hope that helps. 

Edited May 5, 2022 by ZacharyR

[RockyAussie]

Posted yesterday Zachary. The smallest leather point needle be it 794x4 Dia or Lr or S will only go down in size to 23. Anything less will be a fabric round point needle. If the leather is soft/spongy then it can be easy with a fabric needle for the thread to miss the hook due to the elastic nature of that leather. Try using the size 23 needle with the #92 thread instead as the holes don't show much on soft stuff generally. The tension will need to back out a few turn on top. With these very long needles a fine needle is super easy to deflect away from the hook with anything but the most practised hands doing the job. The hook spacing from the needle is generally set up for the larger needles and if you want to stick with the smaller threads then you may want to get a fine shim spacer that moves the hook closer to the needle. Ask the seller there first and if no luck get back to us. I am fairly sure Jess has some in stock. Question......are you using an open toe centre foot?

[Thescandall]

I love my 5100.. got the narrow dog and it’s a stitching machine now. Thing will poke holes in diamonds now. 

[ZacharyR]

RockyAussie I got the email that my package is headed my way!  I appreciate the information. I’m using an open toe presser foot but I haven’t had time to try it with the bigger needle yet. I’m hoping to experiment some more this weekend and see if I can figure it out. 

[shoepatcher]

i have at times put a machine in reverse to time it especially if it is missing stitches in reverse.  The Needle is in a different position in reverse.  Also, make sure your hook is as close as it can be to the needle without touching it.  If it is too far away from need, hook will miss the the loop and and that means a missed stitch.

glenn

[Wizcrafts]

I time my CB4500 with the stitch lever in the zero motion position. This is the recommended position for timing 441 type machines.

There is another factor that comes into play when using thin needles and thread with thin leather on a 441 clone. This factor is the check spring. Normally, one sets and forgets the check spring (or never changes it from how it was setup by the dealer). This usually works out for the best when you use thread sizes 207 and larger. It gets a tad iffy with #138 thread and can be disastrous with #92 or smaller thread. This is because the standard setup has a lot of tension on the check spring to control heavy thread during the take-up lever's downstroke. This heavy tension completely overpowers thin thread and can cause the loop to dissolve before pick off time. I would back off the check spring tension until it just drops all the way down to the bottom stopper The stopper itself should stop the downward motion when the spring is horizontal. It may have been set a little lower for heavy thread.

[RockyAussie]

1 hour ago, Wizcrafts said:

I time my CB4500 with the stitch lever in the zero motion position. This is the recommended position for timing 441 type machines.

There is another factor that comes into play when using thin needles and thread with thin leather on a 441 clone. This factor is the check spring. Normally, one sets and forgets the check spring (or never changes it from how it was setup by the dealer). This usually works out for the best when you use thread sizes 207 and larger. It gets a tad iffy with #138 thread and can be disastrous with #92 or smaller thread. This is because the standard setup has a lot of tension on the check spring to control heavy thread during the take-up lever's downstroke. This heavy tension completely overpowers thin thread and can cause the loop to dissolve before pick off time. I would back off the check spring tension until it just drops all the way down to the bottom stopper The stopper itself should stop the downward motion when the spring is horizontal. It may have been set a little lower for heavy thread.

Very good point there @Wizcrafts No accounting for experience and thank God and you we have this forum to help and gain assistance with these issues these days. Might have to have a look for some good  instructions on loosening the spring pressure on the check spring yet. Lets hope not for now.

 

On 5/6/2022 at 9:42 AM, Thescandall said:

I love my 5100.. got the narrow dog and it’s a stitching machine now. Thing will poke holes in diamonds now. 

Good to hear. Now tell me ...can you see any reason to change back to the standard set? I have not yet myself.

I get messages nearly every day asking me how much the narrow foot needle plate set costs and I will take this opportunity to say that due to different costs of postage around the world it differs but as most sell into the USA the cost all up is $110 US anywhere there. If you are after a set you can pm me on here and please leave me your full postal details and an email to send the invoice to and I will get back to you normally with in 24 hours or sooner. 

[Thescandall]

I have no reason to go back to the original set. It’s in a drawer somewhere now. I’m sewing from #69 thread to 277 and I know I can go bigger if need be. I noticed my 111w155 has a similar set of dog and plate style and I’m able to do the same work on my 5100 now. 

[Gymnast]

More things can cause skipped stitches. I remember a video by Uwe, on a Juki 441 class machine that can have a problem with skipped stitches in reverse. Perhaps it can help:
 

 

[catskin]

I find that it depends on where the needle is when you change from forward to reverse. Make sure the hook has caught the thread on the last stitch before changing to reverse. If you change directions at the wrong time it will miss catching the thread for the first reverse stitch.  Or it does on my CB 4500.

[ZacharyR]

I appreciate all your help and advice. I played with the check spring some. I’ve gotten it to be able to back stitch some of the time but not reliably. I’m starting to think that small of thread is just not going to work very well. 

[Wizcrafts]

39 minutes ago, ZacharyR said:

I appreciate all your help and advice. I played with the check spring some. I’ve gotten it to be able to back stitch some of the time but not reliably. I’m starting to think that small of thread is just not going to work very well. 

For small size thread the check spring travel is also important. If the spring holds onto the thread too long the loop might dissolve before pickoff time. The bottom stopper can be raised to stop the spring earlier. This adds more slack that might help the loop.

Another thing is thread twist. If the thread is twisty it might turn away from the hook. You can offset clockwise twist by wrapping the top thread counterclockwise through two holes in the top thread post. I use the top and bottom holes to do this.

[Gump]

I had this problem and it was the hook timing. Roll the machine forward and note where the hook and needle meet, then put machine in reverse and see if the hook and needle meet in the same position as forward. For some reason mine was way late in reverse. When hook timing matched in forward and reverse I had no more problem with skipped stitches.

[Wizcrafts]

Hook timing on machines with reverse should be done with the stitch length position set to zero movement.