More Techsew 2750 Issues.

[Gulrok]

I've seriously had it with this machine. I want to throw it off a cliff.

We've never had great sewing with it. I'll mess with it for hours. It'll work nicely, and then it won't again.

In September/October we had a lot of tensioner issues until we just bought a genuine JUKI tensioner. In Feb I had an issue with jamming. In March we learned we needed leather sewing needles 135x16 instead of 135x17. We fixed our problems.... In April we had the control box pop a capacitor. It was nearly a month before we had another control box.

We had a wonderful few months from May to now, where the sewing machine was totally reliable. It was fantastic. It would sew fine.

Last week it started skipping stitches. I didn't have any projects that needed to be done with the machine until this week, so I figured I'd wait since we were going to be out of town.

Today, won't even sew anymore. Threading gets jammed in the bobbin area that will bind the whole machine or It'll pickup the thread for a stitch or two and then nothing.

I'm lost for words. I really just want this thing to work. I feel like its a constant problem.

--

Looking through the manual that comes with the book... it doesn't quite help me. There isn't a lot in the book about this machine.

[Matt S]

23 minutes ago, Gulrok said:

I've seriously had it with this machine. I want to throw it off a cliff.

We've never had great sewing with it. I'll mess with it for hours. It'll work nicely, and then it won't again.

In September/October we had a lot of tensioner issues until we just bought a genuine JUKI tensioner. In Feb I had an issue with jamming. In March we learned we needed leather sewing needles 135x16 instead of 135x17. We fixed our problems.... In April we had the control box pop a capacitor. It was nearly a month before we had another control box.

We had a wonderful few months from May to now, where the sewing machine was totally reliable. It was fantastic. It would sew fine.

Last week it started skipping stitches. I didn't have any projects that needed to be done with the machine until this week, so I figured I'd wait since we were going to be out of town.

Today, won't even sew anymore. Threading gets jammed in the bobbin area that will bind the whole machine or It'll pickup the thread for a stitch or two and then nothing.

I'm lost for words. I really just want this thing to work. I feel like its a constant problem.

--

Looking through the manual that comes with the book... it doesn't quite help me. There isn't a lot in the book about this machine.

I think that all of us who own a sewing machine have gone through this at some point, especially if we're self-taught. Don't despair, you CAN fix it, or find someone who can. Luckily you're in the right place for help.

Sewing machines are devices that need a surprisingly precise and yet nearly unquantifiable amount of "just right" to work, and they can and will "walk out" of their settings over time, especially if they have a crash. Sometimes just a stubborn thread jam can throw it all out of goose. It's also quite easy to adjust them out of balance, perhaps inadvertently or perhaps in order to cope with a different combination of leathers, and either forget or not be able to set it back to "right". However with time (massively reduced by access to the centuries of machine mangling experience available to you on this forum) it will soon become second nature to you.

There's a few different things that could be playing up with your machine right now, probably something to do with the hook timing, but those are never the first things to check. First action if your machine goes screwy is always to completely unthread your machine and install a new, fresh needle, checking that it's the correct type and size (made that mistake a few times!). Then rethread the machine from scratch, making sure to follow the manufacturer's instructions exactly (especially with regards the bobbin orientation). Use contrasting colour needle and bobbin threads if possible. Set the stitch length somewhere in the middle of its range. Turn the machine over a few times by hand, making sure to give a gentle pull on the thread tails away to the right. Does it still have problems? If it jams don't force your way through the jam as this alone can cause the machine to come untimed. Leave it as is, take a photo of what's going on around the bobbin case and post in this thread (or better still, another video). Remember also that your machine will behave a little differently with material/leather in it and without.

It doesn't really surprise me about the manual -- industrial sewing machines are primarily intended for use by people in factories who have trained technicians available to do routine maintenance, make any adjustments needed and to fix problems as they arise. The manuals tend to give you a few tech specs, some basic maintenance and operating instructions and that's about it. It's the same reason why your car's manual probably doesn't tell you how to change its oil or do a 10,000 mile service. As owner/operators it's on us to learn to be a technician/mechanic, or to pony up and pay a real one for their expertise. Just the way it works I'm afraid!

[RockyAussie]

First thing is to check that the long needle groove is on the left. After that as @Matt S rightly said ...change the needle as a little bend is all it takes to do the above. If that don't work then you are looking at timing perhaps. As best you can watch the needle take the thread down and when it starts coming back up the hook should be coming around to grab the loop in the thread somewhere in the scarf of the needle area. If you have no loop forming then find out why. That would mean your thread is being held up by something that it should not be. If the hook does not come around as the needle scarf area is there then you have got a timing issue. If so check first that the needle bar has not been knocked high. If it is correct then you need to loosen the hook and align it so that it will come around just when the thread loop is looking nice and open. Rough I know but it will get you out of trouble.

[Gulrok]

21 hours ago, Matt S said:

I think that all of us who own a sewing machine have gone through this at some point, especially if we're self-taught. Don't despair, you CAN fix it, or find someone who can. Luckily you're in the right place for help.

Sewing machines are devices that need a surprisingly precise and yet nearly unquantifiable amount of "just right" to work, and they can and will "walk out" of their settings over time, especially if they have a crash. Sometimes just a stubborn thread jam can throw it all out of goose. It's also quite easy to adjust them out of balance, perhaps inadvertently or perhaps in order to cope with a different combination of leathers, and either forget or not be able to set it back to "right". However with time (massively reduced by access to the centuries of machine mangling experience available to you on this forum) it will soon become second nature to you.

There's a few different things that could be playing up with your machine right now, probably something to do with the hook timing, but those are never the first things to check. First action if your machine goes screwy is always to completely unthread your machine and install a new, fresh needle, checking that it's the correct type and size (made that mistake a few times!). Then rethread the machine from scratch, making sure to follow the manufacturer's instructions exactly (especially with regards the bobbin orientation). Use contrasting colour needle and bobbin threads if possible. Set the stitch length somewhere in the middle of its range. Turn the machine over a few times by hand, making sure to give a gentle pull on the thread tails away to the right. Does it still have problems? If it jams don't force your way through the jam as this alone can cause the machine to come untimed. Leave it as is, take a photo of what's going on around the bobbin case and post in this thread (or better still, another video). Remember also that your machine will behave a little differently with material/leather in it and without.

It doesn't really surprise me about the manual -- industrial sewing machines are primarily intended for use by people in factories who have trained technicians available to do routine maintenance, make any adjustments needed and to fix problems as they arise. The manuals tend to give you a few tech specs, some basic maintenance and operating instructions and that's about it. It's the same reason why your car's manual probably doesn't tell you how to change its oil or do a 10,000 mile service. As owner/operators it's on us to learn to be a technician/mechanic, or to pony up and pay a real one for their expertise. Just the way it works I'm afraid!

 

16 hours ago, RockyAussie said:

First thing is to check that the long needle groove is on the left. After that as @Matt S rightly said ...change the needle as a little bend is all it takes to do the above. If that don't work then you are looking at timing perhaps. As best you can watch the needle take the thread down and when it starts coming back up the hook should be coming around to grab the loop in the thread somewhere in the scarf of the needle area. If you have no loop forming then find out why. That would mean your thread is being held up by something that it should not be. If the hook does not come around as the needle scarf area is there then you have got a timing issue. If so check first that the needle bar has not been knocked high. If it is correct then you need to loosen the hook and align it so that it will come around just when the thread loop is looking nice and open. Rough I know but it will get you out of trouble.

Yeah. I'm a little bit on edge about it. It makes you want to rip your hair out. At least me. I'm a pretty technical person. I've rebuilt numerous motorcycle engines, lawnmowers,  and other mechanical things. No problem at all. If I get stuck. I can find a parts diagram or a manual somewhere.

But these sewing machines. Ugh.

I have the scarf in the right spot. Replaced the needle as well. I have the hook approximately 0.5m to 1mm from the needle (in the scarf) although I'm using a business card to measure that. (When I removed the jam, I removed the hook and bobbin assembly). 

I spent time polishing the hook because it did have a burr on the end. 

The timing has the hook crossing the needle at the bottom of the needle stroke. 

I still will go good forward, but now I get the occasional skipped backstitch. 

It is now catching the thread again. But ocassionally it'll 

[RockyAussie]

5 hours ago, Gulrok said:

The timing has the hook crossing the needle at the bottom of the needle stroke.

That sounds wrong to me. Normally the hook comes across the needle when it is on its way up and somewhere in the needle scarf area. As you have had the hook off I would guess that you need to loosen your hook and turn it to the right enough so that it comes across the needle when the thread loop has formed properly. As for the hook to needle gap if you put in the largest size needle in that the machine can use and set your hook so that it almost touches it, it should be alright for the other sizes.

[Gulrok]

57 minutes ago, RockyAussie said:

That sounds wrong to me. Normally the hook comes across the needle when it is on its way up and somewhere in the needle scarf area. As you have had the hook off I would guess that you need to loosen your hook and turn it to the right enough so that it comes across the needle when the thread loop has formed properly. As for the hook to needle gap if you put in the largest size needle in that the machine can use and set your hook so that it almost touches it, it should be alright for the other sizes.

I think we're onto something..

EDIT: Yes I know this isn't a 225, but the concept should be similar.

Edited June 29, 2020 by Gulrok

[Matt S]

Yep that could be it. Generally you want the hook crossing the centreline of the needle after BDC. Machines vary but most similar machines need the hook to cross after the needle has risen roughly 2mm past BDC.

Looks like the Techsew 2750 is a clone of the Juki 341. Check out this page of the 341 manual for timing information: https://www.manualslib.com/manual/917750/Juki-Ls-341n.html?page=9#manual

[CowboyBob]

15 hours ago, Gulrok said:

 

Yeah. I'm a little bit on edge about it. It makes you want to rip your hair out. At least me. I'm a pretty technical person. I've rebuilt numerous motorcycle engines, lawnmowers,  and other mechanical things. No problem at all. If I get stuck. I can find a parts diagram or a manual somewhere.

But these sewing machines. Ugh.

I have the scarf in the right spot. Replaced the needle as well. I have the hook approximately 0.5m to 1mm from the needle (in the scarf) although I'm using a business card to measure that. (When I removed the jam, I removed the hook and bobbin assembly). 

I spent time polishing the hook because it did have a burr on the end. 

The timing has the hook crossing the needle at the bottom of the needle stroke. 

I still will go good forward, but now I get the occasional skipped backstitch. 

It is now catching the thread again. But ocassionally it'll 

Run the needlebar all the way down(BDC) turn the handwheel towards you so the needlebar raises 3/32" or 2.4 mm & the point of the hook should be @ the needle for it to be timed correctly.Here's the Engineers Manual

JUKI 341 engineers manual.pdf

Edited June 29, 2020 by CowboyBob

[Gulrok]

On 6/29/2020 at 6:12 AM, CowboyBob said:

Run the needlebar all the way down(BDC) turn the handwheel towards you so the needlebar raises 3/32" or 2.4 mm & the point of the hook should be @ the needle for it to be timed correctly.Here's the Engineers Manual

JUKI 341 engineers manual.pdf

We're sewing like a dream again. Thank you.

[MelAnn]

I have the same issue with skipping stitches. Since I bought the machine almost a year ago, I've had constant problems. I have become adept at changing and testing the timing and needle position because that's what the technician (when I called and we video chatted) taught me to do. (As a side note, I can't believe that they don't give you better insight online how to do this - they just give a measurement of how far the needle post needs to be and if it's off by 0.1 mm then you're screwed. They could have had an instructional video to show people where it needs to be when it hits the bobbin.) Anyway, that TechSew service guy was grouchy and condescending, and would say things like "make a video of yourself threading the machine and then send that to me and then I'll talk to you". When he finally saw this issue about the needle timing, he told us the logical way how to do it (when I say 'us' I include my husband who could also not figure it out, and we both are PhD engineers who are quite good at all things mechanical!).  

Anyway, if anyone can help, we have checked timing, needle size, new needles, etc, and the machine skips a stitch about every 3rd stitch. I cannot find anything helpful online about this. I have resorted to my $200 Singer Heavy Duty machine for lighter leather projects because it's reliable.

[kgg]

18 hours ago, MelAnn said:

I have the same issue with skipping stitches.

Any chance of posting a couple of photo's or a short video showing:

i) How you have the machine threaded.

ii) How you have the needle inserted in the needle bar.

iii) Are you using 135x16 or 135x17 needles?

iv) What are you sewing Fabric or Leather?

v) How thick is the item you trying to sew?

vi) What size of thread?

vii) What size of needle?

kgg

[MelAnn]

Dear kgg - thanks so much for your response. I am 100% sure that the machine is threaded correctly (I do it exactly as the instructional video from techsew and anyway it was working fine before), and that the needle is inserted properly (with the scarf on the right, aligned perfectly perpendicular to the direction of stitching). I'm using size 92 thread, with 135x17 needle, size 18/110.  I'm sewing leather (mid-weight, 1-2 mm) and the skipping stitches problem started about a month ago (before that, the timing had to be readjusted frequently which was very frustrating). I have re-checked the timing and I'm sure that's good. The video above by Gulrok (posted 6/28/2020) was super helpful for that. After all this checking and fine-tuning yesterday, the skipping is less frequent, but now like every 10th stitch instead of every 3rd. It's so frustrating. And advice you have would be greatly appreciated!

[kgg]

24 minutes ago, MelAnn said:

I'm using size 92 thread, with 135x17 needle, size 18/110.  I'm sewing leather (mid-weight, 1-2 mm)

For leather you should use the 135x16 needles as they are designed to pierce / cut through leather where as the 135x17 are for fabric where they separate the fibers rather then cut through them. The needle size for V92 should be a #19 / 120 or #20 / 130 needle. A good thread size to needle size chart can be found at ( www.tolindsewmach.com/thread-chart.html ). You may find in thicker / tougher leather or multi layers of fabric you may have to go up another needle size above the recommended. This is so the hole that the needle punches is large enough not to allow the thread from being grabbed by the material which will affect how the loop is formed. If the loop isn't formed properly the hook can't catch it.

A good source for needles can be found at Wawak.com. I personally find the Schmetz needles to work the best in may machines.

Also the quality of thread can play an important role. Buy a brand name thread like A&E (made in Canada and the USA) as the consistency / quality is always dependable where as the cheap Chinese stuff is just a frustration generator with overall poor quality. Also I find the 1 LB spools of thread have less problems then the 4 or 8 oz spools. Remember you need 2 1/2 times the height of the thread spool too the thread stand thread guide hole.

kgg 

 

[MelAnn]

thanks! I'm not sure it's 135x17; I'm using the needles that came with the Techsew and it says "D8x17" (18/110). In fact ALL of the needles they provided were D8x17 (some with size 110 and some 120).  Therefore I thought this was appropriate. Also, I looked up another thread chart that said for 92 you can use either 110 or 120. I'll try the 120 but can this really be the problem? and finally, i'm not sure what you mean by "you need 2 1/2 times the height of the thread spool" - can you please clarify?

thanks so much!
Mel

[kgg]

9 minutes ago, MelAnn said:

it says "D8x17"

I think the printing on your pack of needles is probably a bit blurry and it says DP x17 which is the same as 135 X17. The 17 denotes that the needle is used for fabric. Your machine requires 135x16 ( leather) or 17 (fabric) needles otherwise the needle will be too short or long to allow the hook to pickup the top thread properly which will give you skipped stitches if it does manage to pickup the top thread.

When you measure the height of the spool, a 1 lb spool is about 7 inches tall from the base to the top. So you need the guide hole on the thread stand to be about 17.5 inches above the base of the spool of thread to allow for the thread to properly unwind / unkink. The problem I find with the commercial thread stands is that this can give a fairly serve angle from the thread stands guide hole to the first thread guide pin. I like to keep my top thread as close to horizontal to the top hole of the first guide pin on the top of the machine.

The example is of a Kobe LS-1341 (setup for binding) which is the same as your Techsew 2750 that are clones of the older Juki LS-341 just different clone name.

kgg

[MelAnn]

kgg -- I can't thank you enough for all this invaluable advice! I was using the Groz-Beckert needles and you're correct, it''s DPx17. I will buy the DPx16 and see is that helps. You mentioned that you prefer Schmetz - i use those for my other machines, but do they fit in the Techsew  2750 or Juki LS-341? 

thanks again!

[Wizcrafts]

2 hours ago, MelAnn said:

I will buy the DPx16 and see is that helps. You mentioned that you prefer Schmetz - i use those for my other machines, but do they fit in the Techsew  2750 or Juki LS-341? 

Yes. Both machines use standard walking foot needle systems 135x16 and 135x17.

[kgg]

9 hours ago, MelAnn said:

You mentioned that you prefer Schmetz - i use those for my other machines, but do they fit in the Techsew  2750 or Juki LS-341? 

Yes I prefer the Schmetz needles and never have had problems with them in any of my machines but have had problems with other manufactures needles in the past. I'm sure other people find other manufacturers needles just as good as well. Schmetz is a manufacturer of needles for a wide variety of both domestic and industrial sewing machines. All the sewing machine manufacturers (clone or brand name) have recommended a needle system and a min / max needle size that works for their machines. So as long as your needles are the same needle system and in this case 135x16 (DPx16) or 135x17 (DPx17) from a #18 to #24 needle they will fit quite a number of machines whether they are flatbed or cylinder bed configuration. 

When you order your needles also order a brand name spool of thread either bonded nylon or bonded polyester depending on what you are sewing.

kgg

[Sewman]

On 6/27/2020 at 10:40 PM, RockyAussie said:

First thing is to check that the long needle groove is on the left. After that as @Matt S rightly said ...change the needle as a little bend is all it takes to do the above. If that don't work then you are looking at timing perhaps. As best you can watch the needle take the thread down and when it starts coming back up the hook should be coming around to grab the loop in the thread somewhere in the scarf of the needle area. If you have no loop forming then find out why. That would mean your thread is being held up by something that it should not be. If the hook does not come around as the needle scarf area is there then you have got a timing issue. If so check first that the needle bar has not been knocked high. If it is correct then you need to loosen the hook and align it so that it will come around just when the thread loop is looking nice and open. Rough I know but it will get you out of trouble.

I'm new to this too, and have certainly felt the same about "throwing my machine off a cliff" as well. Tech support from Techsew is a joke. However the needle scarf needs to be on the right side not on the left side. I am assuming that needle groove and needle scarf are the same thing. But what is important is that the long needle scarf/groove needs to be on the right side. Mine has done the same though. Sometimes it works and then, bam, it is not sewing again. It took me almost a month to get it going. Finally, I took it to a local shop and spent $170.00 to get it timed and a few other things the tech said he had to do. Brought it back and used it for about 4 hours and it was back to where it was before ...not sewing again! I think these things are sensitive to the timing, and it goes out frequently. The guy that said look at the Juki instructions helped me because I couldn't take it for the $170.00 fix every week. I think that there are better machines to buy. Wish I had bought a different brand.

[Northmount]

1 hour ago, Sewman said:

I'm new to this too, and have certainly felt the same about "throwing my machine off a cliff" as well. Tech support from Techsew is a joke. However the needle scarf needs to be on the right side not on the left side. I am assuming that needle groove and needle scarf are the same thing. But what is important is that the long needle scarf/groove needs to be on the right side. Mine has done the same though. Sometimes it works and then, bam, it is not sewing again. It took me almost a month to get it going. Finally, I took it to a local shop and spent $170.00 to get it timed and a few other things the tech said he had to do. Brought it back and used it for about 4 hours and it was back to where it was before ...not sewing again! I think these things are sensitive to the timing, and it goes out frequently. The guy that said look at the Juki instructions helped me because I couldn't take it for the $170.00 fix every week. I think that there are better machines to buy. Wish I had bought a different brand.

You need to look at the anatomy of a needle.  The scarf and groove are on opposite sides.  The scarf lets the hook get closer tot he needle to pick up the loop that is formed as the needle rises.  The the top thread comes down the groove.  It reduces the drag as the needle is descending, and thread is protected from shredding that would otherwise occur.  See the link below.

https://www.schmetzneedles.com/blogs/blog/sewing-machine-needle-anatomy

 

[kgg]

2 hours ago, Sewman said:

But what is important is that the long needle scarf/groove needs to be on the right side. 

Like @northmount said you should checkout that link and NO the groove side of the needle needs to be on the Left.

You never said what type or size of needle you were using with what size thread in how thick of material, leather or fabric.

If you are sewing leather you need the correct size of needle a 135 X16 in the correct size and for fabric you use 135 x 17 needles. There are a lot of other factors that can cause a machine to not sew or sew properly, top threading path to the needle, thread tension, how the thread comes off the bobbin, incorrect needle installation to name a few.

It would be nice to see some photo's of how you threaded the machine from the thread spool holder to the tip of the needle.

Chances are this is a simple problem that you should be able to solve yourself with the help / suggestions of members here.

You should download a copy of the JUKI LS-341 engineering manual as the Techsew 2750 is a clone of the Juki LS-341.

kgg

[Sewman]

17 hours ago, Northmount said:

You need to look at the anatomy of a needle.  The scarf and groove are on opposite sides.  The scarf lets the hook get closer tot he needle to pick up the loop that is formed as the needle rises.  The the top thread comes down the groove.  It reduces the drag as the needle is descending, and thread is protected from shredding that would otherwise occur.  See the link below.

https://www.schmetzneedles.com/blogs/blog/sewing-machine-needle-anatomy

 

OK, thanks for the info !