Rookie issue with Techsew 5100

[TES]

Thanks for any assistance you might offer in advance.

I am very new to leatherworking. Two weeks in actually. 

Last week I purchased a used Techsew 5100. I watched about 15 videos of various topics from threading to adjusting. I loaded up a few bobbins, threaded the machine and off I went to practice with the machine. All started out well and then I started to get a couple of issues. Here are the problems:

1. Initially, the top stitch looked somewhat twisted and the knot was almost popping up through the needle hole. The thread is Techsew Tex207 and the needle is Grosz-Beckert ?25....I can't make out the exact numbers as the label has faded. I also had two or three occasions where there were multiple threads coming from the bobbin when I would finish a stitch line. I took the bobbin out and had to remove the mechanism that holds the bobbin to clear it. This may have been a mistake. I put the bobbin mechanism back in, checked the timing based upon the video and all seemed lined up correctly.
2. Now, the top thread seems to get caught up in the presser foot and the same thing is happening with the bottom thread. The bottom thread will have multiple threads coming from the machine.

I did place a call to Techsew for support. I was informed that the warrantly did not apply to me and that any questions should be directed to info@techsew.com. I did send an email to Techsew asking for a copy of the manual for the machine which they did send about 1.5 days later. I am waiting on the manual for the motor now. I didn't mention this problem to the tech support person because I really don't even know the correct terminology just yet. I had to Google what the inner foot was called just to write this email.

I hope that this is something you might be able to comment on to get me in the right direction.

 

Many Thanks,

Tom

 

[MtlBiker]

I think that in order for anyone here to be able to help, you should post some photos of your exact thread path from the big spool right down to the needle.  Chances are good that something isn't right in the way you have it threaded.  Also it's important to hold back the top thread as you start sewing.  Finally, you should put a new needle in... your saying that the size on the needle can't be read implies it's old.  Needles are cheap and should be replaced often (VERY often).

We'll all try to help but we need to see photos.

[Wizcrafts]

A #25 needle is too large for #207 thread. The hole will be too loose to grip the knots. Move down one size to a #24. Use leather point system 794 (7x4) when sewing leather, and round point 7x3 when sewing cloth, webbing and bio-synthetics.

I don't know how you've threaded the machine on the top, but, make sure that the thread isn't rising up in the top tension disks as you sew.This may call for re-positioning the thread guide just below the disks. Also, it helps to wrap the thread counterclockwise around the top and bottom holes in the top thread post. I feed in through the top inline hole, wrap CCW, and feed out the bottom inline hole. This provides needed back pressure on the top thread which helps keep the thread from twisting and lifting out of the business part of the disks.

Whatever needle you install, make sure the rib is facing due left and cutout scarf is facing due right.

If the bobbin thread tension is too light, the knots will come out the top to easily. Reverse the direction of the bobbin so it makes are sharp turn and feeds against the direction of the path to the spring outlet hole. If it's too tight, feed straight in and reduce the spring tension. These machines need a fair amount of bobbin tension to offset the big spring in the tension system.

[TES]

1 hour ago, Wizcrafts said:

A #25 needle is too large for #207 thread. The hole will be too loose to grip the knots. Move down one size to a #24. Use leather point system 794 (7x4) when sewing leather, and round point 7x3 when sewing cloth, webbing and bio-synthetics.

I don't know how you've threaded the machine on the top, but, make sure that the thread isn't rising up in the top tension disks as you sew.This may call for re-positioning the thread guide just below the disks. Also, it helps to wrap the thread counterclockwise around the top and bottom holes in the top thread post. I feed in through the top inline hole, wrap CCW, and feed out the bottom inline hole. This provides needed back pressure on the top thread which helps keep the thread from twisting and lifting out of the business part of the disks.

Whatever needle you install, make sure the rib is facing due left and cutout scarf is facing due right.

If the bobbin thread tension is too light, the knots will come out the top to easily. Reverse the direction of the bobbin so it makes are sharp turn and feeds against the direction of the path to the spring outlet hole. If it's too tight, feed straight in and reduce the spring tension. These machines need a fair amount of bobbin tension to offset the big spring in the tension system.

Thank you for your replies.

I don't know exactly what needle is in the machine....I can only make out two numbers as the packaging has faded....I also have two additional packs of needles that came with the purchase...both are mfg'd by Organ Needles...One is 160/23 and the other is 140/22. I can get the needles you suggest in a day or two.

 

The first picture below represents what I see when finishing a stitch line. Thread is wrapped through the presser foot and there will be three or four pieces of thread coming up from the bobbin with only one of them actually leading to the bobbin. Pictures two and three are the top and back of the stitch. 

I did check the needle timing with the hook and changed to a new needle. It appears to be timed properly according to the video and after changing the needle, the stitches appeared to get uglier....long groove is facing left.

Thank you again for any input.

 

Tom

[TES]

1 hour ago, Wizcrafts said:

I don't know how you've threaded the machine on the top, but, make sure that the thread isn't rising up in the top tension disks as you sew.This may call for re-positioning the thread guide just below the disks. Also, it helps to wrap the thread counterclockwise around the top and bottom holes in the top thread post. I feed in through the top inline hole, wrap CCW, and feed out the bottom inline hole. This provides needed back pressure on the top thread which helps keep the thread from twisting and lifting out of the business part of the disks.

 

The system will not let me upload the photos of the threading...says I can only upload 1.46mb and the files are actuall 900kb...I assume it is a daily limit.

The thread guide on the top tension disk is at the bottom of the disk. The thread coming from the top thread post actually is so low that it hits the lifting mechanism of the foot. The thread enters the thread post in the top hole and exits towards the top tension plate through the bottom hole. 

The first few stitches with this machine did give me twisted threads on the top stitch. I found that I had it threaded incorrectly, corrected it and the twisting disappeared, but this other mess appeared at that time.

 

Thanks again,

Tom

[Northmount]

1 hour ago, TES said:

says I can only upload 1.46mb and the files are actuall 900kb...I assume it is a daily limit.

I don't believe there is a daily limit.  But it is possible.  Reduce file sizes 800 or 1024 pixels wide and you will have lots of room.  Will also be a big favour to people on the fringes of the internet with low speed connections.

[kgg]

3 hours ago, TES said:

The thread guide on the top tension disk is at the bottom of the disk. The thread coming from the top thread post actually is so low that it hits the lifting mechanism of the foot. The thread enters the thread post in the top hole and exits towards the top tension plate through the bottom hole. 

The following topic may help with threading.

kgg

[TES]

Thanks for all of your replies.

Here is what I have done/found:

 

Thanks KGG for the thread. Mine appears to be threaded as per the video reference.

 

I confirmed the bobbin hook timing with the needle. The problem exists exactly at the second stick everytime. It appears that the bobbin thread is being either pushed into the bobbin by the needle or something is causing the bobbin thread to loop back into the bobbin. The attached picture is what happens each and every time I sew....it always starts on the second stitch.

Back stitches look fine. You can see the loop pulling through the needle holes on the top side of the stitch.

[Wizcrafts]

4 hours ago, TES said:

The problem exists exactly at the second stick everytime. It appears that the bobbin thread is being either pushed into the bobbin by the needle or something is causing the bobbin thread to loop back into the bobbin.

Are you holding back the starting threads for a few stitches? This is a necessity! When you start sewing, can you confirm that the top thread is going inside the inside foot and exiting out the back of that foot? If the top thread is fed between the inside and outside foot, there will be trouble.

How much swing/travel does the check spring have? It must hold the top thread taut until the needle has penetrated the top layer. and must stop moving down before the needle reaches BDC. If your chec spring travel is too short, there will be too much slack in the top thread as the take-up lever moves down. This could lead to the thread getting caught by, and wrapping around the feet.

[Burkhardt]

2 hours ago, Wizcrafts said:

Are you holding back the starting threads for a few stitches? This is a necessity! When you start sewing, can you confirm that the top thread is going inside the inside foot and exiting out the back of that foot? If the top thread is fed between the inside and outside foot, there will be trouble.

How much swing/travel does the check spring have? It must hold the top thread taut until the needle has penetrated the top layer. and must stop moving down before the needle reaches BDC. If your chec spring travel is too short, there will be too much slack in the top thread as the take-up lever moves down. This could lead to the thread getting caught by, and wrapping around the feet.

Without having pictures of how it's threaded isn't there a guide that's missed to get a angle like that to the needle with the thread?

[TES]

12 hours ago, Wizcrafts said:

Are you holding back the starting threads for a few stitches? This is a necessity! When you start sewing, can you confirm that the top thread is going inside the inside foot and exiting out the back of that foot? If the top thread is fed between the inside and outside foot, there will be trouble.

How much swing/travel does the check spring have? It must hold the top thread taut until the needle has penetrated the top layer. and must stop moving down before the needle reaches BDC. If your chec spring travel is too short, there will be too much slack in the top thread as the take-up lever moves down. This could lead to the thread getting caught by, and wrapping around the feet.

Good morning sir....Thank you again for your help.

Yes, I am holding the starting threads back for the first few stitches. Yes, the thread is going through the inside foot and exiting out of the back. I have measured the travel on the check spring, nor even looked at it when starting to sew.....I have videos but they are too large to post here.

Could this all be due to thread tension being incorrect? The top thread is very tight and the bobbin thread is MUCH more loose.

I was thinking about the situation last night.

This all started after I got the machine home and threaded up to start sewing. The only initial issue was that the top thread was twisted and some of the knots were slightly showing on the top side. I did get a thread tangle in the bobbin area ; so much so that I had to remove the plate holding the bobbin shuttle in place to remove it......This is when my problems began.

I videos online was a Techsew 5100, but clearly a different vintage and did not look exactly like my machine. It took a couple of days and Techsew did send me the video for my exact machine. I found that I had spooled the top thread incorrectly when watching that video. I rethreaded it correctly, but I am thinking that I may have screwed up the tension when removing the plate holding the bobbin in place....

Based upon the video, the needle/bobbin timing is correct.

Question:

Could this be a thread tension issue? The top thread takes considerably more pressure to pull thread than does the bobbin thread. When I removed the bobbin shuttle plate, did that release the tension for the bobbin thread?

I don't know enough about these machines to diagnose. I do know that the loop being formed in the bobbin area is happening on the second stitch and if I let go of the top thread and pull the bobbin thread very tight it does not happen. 

I am going out there this morning and put some more tension on the bobbin thread and see if the problem gets better or goes away.

 

Thank you again for your responses. You have been extremely helpful....much more so that the manufacturer. 

Tom

[Wizcrafts]

@TES

When you removed and replaced the shuttle retainer plate, did you leave some slack in the spring covered retainer securing screws? They need room to float as the top thread goes around the bobbin case. I back mine off 1 full turn for #277 thread and above, or 1/2 turn for smaller thread sizes. If you tightened the screws all the way down, there's no room for the thread to push out the shuttle as it goes around. This adds tension to the top thread and can actually pinch or jam it.

[kgg]

59 minutes ago, TES said:

Could this be a thread tension issue? The top thread takes considerably more pressure to pull thread than does the bobbin thread. When I removed the bobbin shuttle plate, did that release the tension for the bobbin thread?

If your timing is correct and the machine is timed properly I would figure your dealing with a tension problem. Since you removed the bobbin assembly to clear a tangle I am going to assume the problem lies with the bobbin tension. When you removed the bobbin shuttle plate you may have screwed the two screws in tight, which would be incorrect. Screw them in fairly snug and back off about, I think, a 1/4 - 1/2 turn. Since this is a used machine another bobbin problem could be the actual bobbin tensioner spring has at some point been over tighten (will decrease the tension on the thread as it will cause the tensioner to bend away from the bobbin body), has been bent outward by incorrect bobbin threading, the bobbin has been installed incorrectly and the spring in the bobbin case has been damaged.

Even through the following video's are for the Cobra Class 4, which is basically the same machine, it will provide better instructions on installing, threading and tensioning the bobbin thread.

 

kgg

[Northmount]

2 hours ago, TES said:

I have videos but they are too large to post here

Post them on YouTube and in link to them from a post here.  Videos take up a lot of space!

 

[TES]

1 hour ago, Wizcrafts said:

@TES

When you removed and replaced the shuttle retainer plate, did you leave some slack in the spring covered retainer securing screws? They need room to float as the top thread goes around the bobbin case. I back mine off 1 full turn for #277 thread and above, or 1/2 turn for smaller thread sizes. If you tightened the screws all the way down, there's no room for the thread to push out the shuttle as it goes around. This adds tension to the top thread and can actually pinch or jam it.

KGG

If your timing is correct and the machine is timed properly I would figure your dealing with a tension problem. Since you removed the bobbin assembly to clear a tangle I am going to assume the problem lies with the bobbin tension. When you removed the bobbin shuttle plate you may have screwed the two screws in tight, which would be incorrect. Screw them in fairly snug and back off about, I think, a 1/4 - 1/2 turn. Since this is a used machine another bobbin problem could be the actual bobbin tensioner spring has at some point been over tighten (will decrease the tension on the thread as it will cause the tensioner to bend away from the bobbin body), has been bent outward by incorrect bobbin threading, the bobbin has been installed incorrectly and the spring in the bobbin case has been damaged.

Even through the following video's are for the Cobra Class 4, which is basically the same machine, it will provide better instructions on installing, threading and tensioning the bobbin thread.

BINGO!

I tightened those screws tight. 

I'm headed out there in a bit, watch the two videos above and adjust the shuttle retention screws, check it and see how it sews...might need to adjust thread tension....I will follow up.

 

I can't tell you how much I appreciate your help. Very thankful.

Tom

1 hour ago, Wizcrafts said:

 

 

[TES]

I thought that I had erred by overtightening the two screws holding the bobbin shuttle. I bumped them snug and backed off 1/2 turn, and no real luck. The top thread has a lot of tension...fyi.

I uploaded some videos to youtube so you can see what is happening.

 

 

[kgg]

2 hours ago, TES said:

I uploaded some videos to youtube so you can see what is happening.

I looked at your video's and here are my comments:

1.) Your top thread should come directly from the top guide above your thread spool to the second hole in the vertical guide and wrap backwards coming out the fourth hole to the top tensioner.

2.) Your thread at the head appears to be correct.

3.) The shuttle plate appears to be dry and needs a drop of oil inside.

4.) The feed dogs appears to have rust which may indicate other rusted parts which maybe rubbing and cleanup.

5.) When removing an item from under the needle pull out a few inches of top thread first so you are not causing strain on the needle and possibly cause a bucket in the needle.

I would recommend removing the hook to inspect it and the surrounding area as there maybe a burr, needle may have struck the hook at some point, the tip of the hook maybe worn or filed back and need replacement. I would recheck and re-time like they do with the Cobra Class 4. 

A couple of photo's of the hook maybe helpful.

kgg

[AlZilla]

Is the tension arm all the way up when you stop?  Early on in my sewing, I'd have thread seemingly tangled like that and I was just not paying attention to the tension arm position.

[TES]

Thank you all for your comments.

Yes, I didn't loop the top thread through the top guide twice...I was trying to lessen the tension. I have corrected that now.

I have been at this machine all day attempting tension adjustments, videoing and attempting to sew.

I am touching the piece inside the bobbin shuttle that the top thread is looping around on the second stitch every time I sew. It looks like some sort of cam or similar. 

I also have knots showing through the needle holes. I went through the tightening process for the bobbin and got to the point where there was no more takeup in the screw...meaning I could not increase the tension on the bobbin any more and I still had the same knots showing.

I spent two hours loosening/tightening the tension on top and bottom and nothing really corrected my issue with the top thread getting caught on the second stitch...I did get a little improvement on the knots showing throught the needle holes.

I changed needles twice to see if that was the issue, and it did not help.

 

Thanks Al. I'll check that position next time I go out to the machine. 

 

Thanks again for all of your help. 

[Wizcrafts]

On my Cowboy CB4500 and my friend's Cobra Class 4, both of us can back off the top tension disks spring to the point that there is no tension at all. This is the same lack of tension we get when we lift the feet all the way with the hand lifter knob, or foot lifter pedal. When you lift the feet does the tension drop to, or close to zero at the disks?

If the tension can be set to zero at the top disks, can the same be done by backing off the beehive spring on the bottom roller? Standard procedure is to wrap the thread around the bottom roller 1.5 turns. Check the tension as the thread exits the bottom roller.

Move on to the check spring. Is the spring able to move up and down as the take-up lever moves up and down? Inspect the inside of the loop at the end of the spring to see if it has a burr, or is somehow pinching the thread.

Inspect the thread hole in the take-up lever for burrs.

Inspect the lower thread guides, including the thread hole on the needle mounting clamp.

You need to figure out where along the thread patch the tightness is coming from. Maybe it is the spool itself. Is it cross-threaded? Once you are able to set the path to zero tension, balance the top and bottom. You should be able to back off the bobbin tension to a bare minimum and balance the knots.

Make sure you're using the best thread and needle combination. Consult this needle and thread chart.

[TES]

15 hours ago, Wizcrafts said:

On my Cowboy CB4500 and my friend's Cobra Class 4, both of us can back off the top tension disks spring to the point that there is no tension at all. This is the same lack of tension we get when we lift the feet all the way with the hand lifter knob, or foot lifter pedal. When you lift the feet does the tension drop to, or close to zero at the disks?

If the tension can be set to zero at the top disks, can the same be done by backing off the beehive spring on the bottom roller? Standard procedure is to wrap the thread around the bottom roller 1.5 turns. Check the tension as the thread exits the bottom roller.

Move on to the check spring. Is the spring able to move up and down as the take-up lever moves up and down? Inspect the inside of the loop at the end of the spring to see if it has a burr, or is somehow pinching the thread.

Inspect the thread hole in the take-up lever for burrs.

Inspect the lower thread guides, including the thread hole on the needle mounting clamp.

You need to figure out where along the thread patch the tightness is coming from. Maybe it is the spool itself. Is it cross-threaded? Once you are able to set the path to zero tension, balance the top and bottom. You should be able to back off the bobbin tension to a bare minimum and balance the knots.

Make sure you're using the best thread and needle combination. Consult this needle and thread chart.

Partial victory!

I went out this morning and took the bobbin shuttle out and cleaned everything. I polished all of the surfaces with 2000 grit and finished off with 2500 grit sandpaper. I could definitely feel the corrosion when rotating the bobbin shuttle....No more though....it is now polished up and smooth as silk.

I made the first stitch and it did the same thing (top thread looping around), but it was a much, much looser loop. I loosened the two top tensioners and changed the EPS to stop in the needle UP position. It has worked flawlessly ever since...Flawlessly in that the top thread doesn't catch or loop in the bobbin shuttle.....I still can't figure out completely why the little knots are showing. I have the bobbin thread as tight as it can go and the top thread is now no as tight as it was. I think that the tightness was caused by this: on the tensioner where you make 1.5 turns the last half turn of thread was laying on TOP of the bottom thread. I rethreaded and passed the half turn INSIDE the first turn....now the thread tension seems to be much smoother. All of the tension issue I think was from the bottom roller (1.5 turns)....

When you lift the feet does the tension drop to, or close to zero at the disks?   Yes sir, when I lift the foot, most all of the tension on the top thread is gone. 

I thought that tightening the bobbin tension would pull the knots down toward the back of the work....

I am going to order new needles and thread today. I did change the needle yesterday to a 23....but I only have the Tex207 for thread (machine thread).

The back stitches look perfect....front stitches have the knot showing...please see below.

My preference is that I like to see the stitches, meaning I like a heavier thread when possible....The thread I am using now says Techsew Tex207. Based upon the chart, I should be running a size 23 needle.

What brand of thread and needle do you recommend? I'm brand new at this...

 

I thank you all again for your help.

 

Tom

 

[AlZilla]

Looks like your sewing a single layer. I wonder if the bottom thread disappears when you sew 2 layers together?

[TES]

5 minutes ago, AlZilla said:

Looks like your sewing a single layer. I wonder if the bottom thread disappears when you sew 2 layers together?

That is two layers....but they are probably two -three oz layers.

[kgg]

41 minutes ago, TES said:

What brand of thread and needle do you recommend?

I find Schmetz needles work the best in my machines. Buy a brand name like A&E and stay away from the cheap Chinese stuff particularly the 8 oz spools. Buying a brand name thread will save you a lot of frustration. I use A&E (www.amefird.com) thread in either bonded polyester or bonded nylon.

28 minutes ago, TES said:

That is two layers....but they are probably two -three oz layers.

I think this is just to thin of leather to allow proper seams appearance for a Class 441 machine. If this is the thickness you are going to typically sew I would suggest getting the narrow feed dog and needle plate that @RockyAussie came up with and also refer to @Wizcrafts article on dumbing down a Class 441 machine (  Dumbing down a Cowboy CB4500, Cobra Class 4, or similar harness stitcher ( https://www.rw-leatherworks.com/blog/2019/02/dumbing-down-a-cowboy-cb4500-cobra-class-4-or-similar-harness-stitcher.html )).

41 minutes ago, TES said:

The thread I am using now says Techsew Tex207. Based upon the chart, I should be running a size 23 needle.

No, for V207 thread which is Tex 210 the needle should be a #24 and in thick / tough / sticky materials you may have to go up to a #25 needle. The #23 needle is for V138 (Tex 135).

kgg

Edited May 28, 2023 by kgg

[TES]

43 minutes ago, kgg said:

I find Schmetz needles work the best in my machines. Buy a brand name like A&E and stay away from the cheap Chinese stuff particularly the 8 oz spools. Buying a brand name thread will save you a lot of frustration. I use A&E (www.amefird.com) thread in either bonded polyester or bonded nylon.

I think this is just to thin of leather to allow proper seams appearance for a Class 441 machine. If this is the thickness you are going to typically sew I would suggest getting the narrow feed dog and needle plate that @RockyAussie came up with and also refer to @Wizcrafts article on dumbing down a Class 441 machine (  Dumbing down a Cowboy CB4500, Cobra Class 4, or similar harness stitcher ( https://www.rw-leatherworks.com/blog/2019/02/dumbing-down-a-cowboy-cb4500-cobra-class-4-or-similar-harness-stitcher.html )).

No, for V207 thread which is Tex 210 the needle should be a #24 and in thick / tough / sticky materials you may have to go up to a #25 needle. The #23 needle is for V138 (Tex 135).

kgg

Many thanks for this information....EXACTLY what I needed. 

 

Thanks again for all of your comments.

 

Tom