Seiko STW-8B (Consew 266R) - presser foot height and reverse issues

[michaelcbarr]

Hi all!

I'm brand new to machine leather sewing so please excuse any stupid questions

I bought a Seiko STW-8B  - which I have since found out is often sold as a Consew 266R. It was sewing OK but had some issues with reverse stitch length which I think I solved by replacing an after market bolt which was fouling on the main shaft. I now have forward and reverse hitting the same holes - which took hours but was worth it I think.

I have also fitted a servo motor as clutch control is apparently wAY beyond my skill level :D 

I still have a few issues which I would really appreciate some advice on. I'm going to list them all in one topic but happy to split if moderators prefer:

1. Presser foot height and needle bar interference
   1. From watching @Uwe's brilliant video series I can see that it is possible to sew through 3 layers of 8/9oz veg tan - I would love to try this but I cannot get the presser foot adjusted high enough to even fit the material under. I have tried all the adjustments I could find on this site and elsewhere but it seems to be maxed out at around 9-10 mm on the knee lift even though the manual suggests it should be 0.5 inches - i.e around 13mm.
   2. Even when I do get 10mm of leather under the presser foot, when I try to cycle the needle, the needle bar fouls on the vibrating foot - I'm only using hand power to test this but it seems there would be interference and damage if I tried to run it under power. I have the standard 135/17 needle - do I need a longer needle and then adjust the needle bar higher and reset the timing?
       
2. The vibrating presser foot seems to be off centre in relation to the needle. The needle sits dead centre in the feed dog hole but if I line the vibrating foot up straight in the middle of the lifting foot, then the needle is very, very close to the left edge of the vibrating presser foot hole. I can remedy this by rotating the vibrating foot slightly to one side so it does not run true from front to back -  but surely that isn't correct?
    
3. The timing seems to be correct (seems!!) but in reverse it is skipping stitches every time - and I'm pretty sure the top thread is just being missed by the hook. Is there anything obvious i could have messed up or do I just need to check the timing again?

Thanks so much for your help - I only discovered this website a few days ago and I am hooked - so many helpful folk out there!

Mb

  

 

[DonInReno]

 

23 hours ago, michaelcbarr said:

The timing seems to be correct (seems!!) but in reverse it is skipping stitches every time - and I'm pretty sure the top thread is just being missed by the hook. Is there anything obvious i could have messed up or do I just need to check the timing again?

Welcome to the site!

Hook timing needs four things - if any of these four things are not right you’ll skip stitches.

From the lowest position, raise the needle the thickness of a US nickel.   We are talking 3/32” - not 1/8”, not 1/4”, not 1/16” and not a US quarter.  In metric or inches, this amount is almost universally recommended.   If someone won’t or can’t get this right the rest won’t matter.

Second, at that needle position the point of the hook should be inline with the needle and 1/16” above the eye.  This is so important in the past many of us insisted on a photo before giving any additional advice because it must be human nature to screw this up and think it’s ok when it’s not.

Third, the point of the hook should be as close to the needle as possible without actually touching it.  Literally, at most a piece of paper should barely slide through the gap, and literally the hook should not be deflecting the needle!   Again, many of us don’t believe someone has actually set this gap correctly unless they can prove it with a close up photo.

Fourth, the hook as to be correct.  The sharp point of the hook has to be a sharp point.   A blunt damaged point will not cleanly reach behind the thread as it should.   A hook that’s been bent inward and someone has chosen to adjust it closer to the needle rather than replacing the hook is asking for trouble.  A cheap replacement hook may not ever work correctly - I saw one on eBay that didn’t even have a needle guard.   I often don’t believe people when they say the hook is in good condition unless they have a good quality photo.

Good luck with your machine!

[michaelcbarr]

Thanks so much Don!

I had another crack at the timing based on your advice and noticed that the needle was actually being deflected by the shuttle - more so in reverse than forward. On closer inspection, this seemed to be caused by the hook being in line with, or slightly inboard of the edge of the shuttIe. This had the effect of very slightly pushing the needle away from the shuttle at the point of bobbin thread catch, if the needle height was correct as stated. 

i very gently applied some pressure to the hook and moved it a tiny fraction out - we are talking 1/2 a mm at the very most. This allowed me to set the hook closer to the scarf of the needle avoiding the deflection, and it seems to have fixed the problem:

 

 

That line on the right shows forward and reverse hitting the same holes perfectly with no missed stitches!

Thanks again @DonInReno.

Now I just need to look at the max presser foot height and the weird rotated vibrating foot issues!

Mb

[DonInReno]

Awesome - glad that helped!

[Uwe]

Please post some pictures of your machine. That model apparently went through multiple versions and castings over the years. There are surprisingly few pictures of this Seiko model available online. Suggested pictures: whole machine front and back, remove left cover plate on head and show internal bits, underside of machine with close-ups of hook gears, head near take-up lever and tension unit, close-ups of needle area, rear of machine near lift lever.

Having pictures eliminates much guesswork and allows us to identify what version of the machine you actually have. Plus, we can mark up your photos with arrows as we try to explain things.

A video clip uploaded to YouTube with a link to it posted here is the best way to show problems in motion. Extremely slow, hand-turned stitches tell the best stories.

The feet on your machine may be cheaply produced aftermarket feet that are simply not to spec, off-center, or with a misaligned mounting hole, causing mis-alignment of needle and foot. If the needle is nicely centered in the hole of the feed dog, then the presser foot itself is a suspect.  

Show us how high the rear foot lifts above the throat plate when using the manual lift lever - hold a small ruler next to the foot.

Show us a picture (or video clip) of the position of the tip of the hook when the needle is precisely at the lowest point. Hook timing variance may cause trouble, even if the machine manages a nice stitch.

Show us a photo of the needle package you’re using.

 

 

 

Edited April 12, 2021 by Uwe

[michaelcbarr]

@Uwe first of thanks so much for taking the time to reply - it is very much appreciated.

I have taken a load of photos and a wee video of a slow hand stitch, along with a video of the needle bar colliding with the presser foot if I force 10mm of leather under it.

I used a small piece of paper with marked measurements to show the max lift height (using hand lift and then knee lift)

Hope this gives you some idea! 

I have created a shared Google photo album as I can't attach the photos here - hope that's OK?

https://photos.app.goo.gl/NEX5wJiNEmeipj146

I have picked one out up to my 1.5MB limit :D

Here is the video clip of a slow stitch:

And this is is one of the needle bar collision on 10mm leather:

 

BTW - please excuse the dirt on the machine - once I make sure it works as required and I am definitely keeping it I will give it a thorough cleanup - promise :D

Thanks again for your help,

Mb

 

 

[Uwe]

Thanks for the pictures and videos. Posting pictures right here in the forum is the best way for easy in-topic viewing and also for archiving purposes. That Google drive link will just not work a year or two from now, and the search engines don’t index the photos unless they’re actually on a web page. It’s a bit of a pain to resize photos to upload them here, but well worth the effort in the long run.

There are quite a few adjustments that are not quite right from what I can tell based on your videos:

Top three issues that need to be corrected first:

1. Hook timing looks retarded, meaning the hook arrives at the needle too late. This causes the needle bar to be set lower than it should be, and it causes the thread to snap around the hook because the hook timing is not properly synchronized with the take-up lever motion. This video shows how to time the hook on this class of machine:

 

2. The walking motion of the feet is not timed correctly. The front/inner foot arrives at the throat plate much too late. 

This video shows how to adjust the walking foot timing on a Pfaff, your machine works the same way:

 

3. Your rear presser bar is adjusted too low. This causes your foot clearance issues. The video below shows a lengthy repair that you DON’T need to do. During the re-assembly steps it shows how to adjust the rear presser bar height starting at the 11:35 mark (use a 1/2” spacer block for your machine) You’ll need to back out the presser tension screw (shown at  1:00) and loosen that clamping  screw I’m tightening in the video to be able to move the rear presser foot bar up and down.  

 

Report back after you’ve made these adjustments and we’ll address the other issues. We’’ll need to see how various parts are aligned with the needle in three key positions:

1. When the descending tip of needle is level with throat plate.

2. Needle at lowest point (bottom dead center)

3. Needle in hook timing position

 

Edited April 13, 2021 by Uwe

[michaelcbarr]

That's brilliant thanks @Uwe! I will get on to that today and see what I can do .

I can also have a look at resizing some of the pics and reposting if you think any of them would be helpful to others?

Mb

[Wizcrafts]

9 hours ago, michaelcbarr said:

That's brilliant thanks @Uwe! I will get on to that today and see what I can do .

I can also have a look at resizing some of the pics and reposting if you think any of them would be helpful to others?

Mb

I use FastStone Photo Resizer. It is easy to use. By lowering the "quality" 15 or 20 percent you get a smaller image file size with very little reduction in clarity. It also has a sharpen function that makes reduced, or even slightly out of focus images sharper. If you also crop out unnecessary portions you can save more bits and bytes. Finally, resizing an image down makes it smaller. I often cut the original file size in half, or close to it, using combinations of functions.

[michaelcbarr]

7 hours ago, Wizcrafts said:

I use FastStone Photo Resizer. It is easy to use. By lowering the "quality" 15 or 20 percent you get a smaller image file size with very little reduction in clarity. It also has a sharpen function that makes reduced, or even slightly out of focus images sharper. If you also crop out unnecessary portions you can save more bits and bytes. Finally, resizing an image down makes it smaller. I often cut the original file size in half, or close to it, using combinations of functions.

Thanks Wiz - I have downloaded and will have a look later or tomorrow - been too busy breaking my machine

Mb