More Techsew 2750 Issues.

[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