Juki LU-562 skipping stitches when top stitching a thicker John Deere type of seat material vinyl...

[JukiFan]

I have had a Juki LU-562 for over 10 years that never skips stitches when top stitching vinyl material.  However, I started sewing a thicker version of vinyl like what would be used to reupholster a John Deere tractor seat.  The supplier who sold the vinyl to me said that another upholstery shop said the material was impossible to top stitch without skipping stitches.  So, what would you tell me to adjust on my machine other than replacing the needle?  I like the material and would like to finish using it as I bought three rolls due to the price.  Basically, I have no formal training on my machine or how to adjust it.  I have tried to review all the Youtube videos on the Juki LU-562/563.  Thanks in advance!!!

[kgg]

59 minutes ago, JukiFan said:

I have had a Juki LU-562

Before you get some suggestions you need to tell use a couple of things. 

i) What size of needle are you using? 

ii) What size of thread are you using as a top thread and in the bobbin?

iii) What system of needles are you using?? Typically for fabric type materials 135 X 17 X (needle size) and for leather 35 X 16 X (needle size). That said sometimes with certain types of vinyl you would use a leather needle.

iv) How thick is the thickest part you are trying to sew??

59 minutes ago, JukiFan said:

So, what would you tell me to adjust on my machine other than replacing the needle? 

The changes could range from incorrect top thread path, wrong size needle for threads, incorrect system of needle, dull needle or wrong needle for the type of material all the way up to replacing worn parts or re-timing the machine. 

If possible post a couple photo's of top thread path from the spool of thread to the eye of the needle and what you trying to sew.

kgg 

Edited January 19 by kgg

[friquant]

First let's see if your machine actually skips any stitches when working with this new fabric..

I would cut some scraps of this new material for practicing, and make them 5 layers thick. (I imagine that's the max number of layers you will see as crossing seams during the topstitch.) Try stitching on them--both straight and in curves.

If no skipped stitches yet, mock up some joints like you will have on the seat, stitch them together, and top-stitch. The goal is to encounter the same situations as you will when you're actually doing the seat, without gouging a big piece of fabric.

If you do manage to get some skipped stitches, then we'll have something to talk about :

[Constabulary]

I´d check the needle bar height (needle hook timing) after 10 yrs the needle bar could have risen a bit and maybe you have to lower it a bit but that's just guessing. But needle bars rise with the time, that happens and is not unusual.

[JukiFan]

Sorry for the delayed response...

My needle is a brand new 135x17 size 20

69# Nylon thread for bobbin and top

Material is 1/16" thick.  So, 3/16 for the two pieces and a top stitch.

The first two photos are of five pieces of material sewn at once 5/16" with no skipped stitches.  Top and bottom

The third and fourth photo is of a top stitch with only missing once.  Top and bottom

The fifth photo is of an example of tons of missed stitches with the same setup. 

[friquant]

Ok, congratulations are in order for missing some stitches. Especially that last photo of the prototype cushion! 🌠

An informative exercise would be to put something like that cushion seam back under the machine so you can see some skipped stitches as they form. With the material under the presser foot, tilt the machine head back so you can see the underside of the machine. Get a good light or a flashlight, and reading glasses if they help. Then turn the handwheel by hand to make slow stitches, but watch what's happening from underneath. Pay attention to what it looks like when it actually makes a stitch, and to what happens when it skips. Let us know what you see!

(More to come)

[kgg]

3 hours ago, JukiFan said:

My needle is a brand new 135x17 size 20

69# Nylon thread for bobbin and top

My thoughts:

i) #20 needle is for V92 thread not V69. reference chart ( https://www.tolindsewmach.com/thread-chart.html ). An incorrect sized needle for the thread size can cause skipped stitches as the loop sometimes does not form properly which gives you skip stitches.

ii) With a fabric backed material I would try a 135 x 16 x 18 to cut through the vinyl rather the 135 X 17 x 20 rather then punching through with an oversized hole. Think of it more like trying to punch a hole in piece of paper with your finger rather then a needle. The fabric needles are meant to push apart/separate fibres so as not to weaken the fabric where as the fabric on your vinyl is probably more for stability to help it from over stretching.

kgg 

 

[Constabulary]

just an other option - a thread oiler / lubricator may help too. 

[JukiFan]

9 hours ago, kgg said:

My thoughts:

i) #20 needle is for V92 thread not V69. reference chart ( https://www.tolindsewmach.com/thread-chart.html ). An incorrect sized needle for the thread size can cause skipped stitches as the loop sometimes does not form properly which gives you skip stitches.

ii) With a fabric backed material I would try a 135 x 16 x 18 to cut through the vinyl rather the 135 X 17 x 20 rather then punching through with an oversized hole. Think of it more like trying to punch a hole in piece of paper with your finger rather then a needle. The fabric needles are meant to push apart/separate fibres so as not to weaken the fabric where as the fabric on your vinyl is probably more for stability to help it from over stretching.

kgg 

 

So, the Juki has been in my possession for 10 years.  I have used it probably 40 hours in making covers for gym equipment. 

Normally, I would use the 69# Nylon with a 135x17x18 needle.  It never skipped stitches with my previous material which was thinner.  With the newer 1/16" material, it happens.  I switched to a 20 size needle before I came onto this forum.  

It could be that I am not pulling both sides of the seam tight enough before trying to apply the top stitch???  Like I mentioned before, the shop who sold me the vinyl told me that another upholstery professional told them the material was impossible to top stitch.  I asked for more info and they had little to say.

My O.C.D. tells me that I am missing an adjustment or something.  

So, if I switched to the 135x16x18 needle, would I need to adjust the timing?  Vinyl is the only material that I will ever sew with this machine.

[kgg]

20 minutes ago, JukiFan said:

So, if I switched to the 135x16x18 needle, would I need to adjust the timing? 

Simple answer, No. The difference of going from a fabric needle (135 x 17 ) to a leather point needle (135 x 16 ) is the tip of the needle. The fabric needle (135 x 17 ) will attempt to push a hole through rather then slice a hole in the material. You will have to check the top thread tension, bobbin tension and presser foot tension. Also a bonded polyester thread would probably provide better UV protection then Bonded Nylon thread.

kgg