Davidmadd Report post Posted March 30, 2023 Hi - I've been using my Singer 111w155 on and off for some time. Generally I use bonded nylon thread 40S, which I think is V 138. I'm trying to use 20S, size 23 needles,. The machine stitches fine through 1 layer, fine with 2 layers coped with 3 but when I try 4 layers the thread starts to unravel, bunches and thats the end of that. I thought the machine would cope with 4.4mm of leather. With no thread it whops its way through no problem but it seems as if the thread is starting to degrade as soon as it hits that 4th layer. I dont have a lower thread guide that attaches to the needle securing screw as it was hitting the upper side of the walking foot, just but enough to want me to remove it (None fitted when I got the machine, new chinese made item newly fitted) so maybe the angle of the upper thread creates undue friction, but why not with one or two layers. I find this baffling. Can anyone shed some light on why the thickness increase messes up the top thread. Could I have too much tension?, although looking at the formed stitches it needs a bit more top tension, so could the lower tension be too tight????? Any help welcomed. Regards David; Plymouth UK Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted March 30, 2023 A properly timed and foot-adjusted Singer 111w155 can easily sew 3/8 inch of soft to medium temper leather. Those proper adjustments start with setting the timing per the service manual. You don't want the tip arriving too late, or early on the upstroke. Also, make sure the hook passes very close to the largest needle you expect to use. Adjust the deflector tab as needed. It should just brush the needle above the top of the eye, but within the scarf area. Next, adjust the latch opener to pull back on the bobbin case so the thread doesn't get trapped by the little tab that moves in the protrusions under the throat plate. The next important adjustment is the travel and force of the check spring. It has to hold the top thread taut until the needle goes through all the material, but, let go well before pick-off time so a decent loop is formed on the right side of the needle. Open the sliding bobbin cover and watch the loop form as the needle ascends. It must be big enough to get picked off by the hook. If the loop is too small, try reducing the travel of the check spring. Or, rotate the disk around the little screw inside the curved slot in the check plate. It fine tunes the action. Use the best needle for the thread sizes and density of the leather. Move up a size if in doubt. Use leather point needles only in veg-tan leather. Next, make sure you have enough foot pressure to hold the leather down as the needle ascends. Missed and ratted stitches happen when the material lifts with the threaded needle. Oh, make sure the needle is aligned so the rib is facing due left and the scarf is facing due right. This outta get you in the ballpark. Quote Share this post Link to post Share on other sites
Wyowally Report post Posted March 30, 2023 What Wiz says for sure. I was dealing with a similar issue on a different model not long ago. Just for giggles I hand threaded a #23 leather needle with 138 bonded nylon. Then I put the needle butt down on my bench and pushed a couple pieces of 4 oz. veg tan down on the needle point. It took a LOT of force! After it went through I pulled it back a little and put another thread through the loop. Then started pulling the needle back up while holding the leather down. Again, it took an amazing amount of force to pull the needle, loop, and "bobbin" thread back up and into the leather. There is a huge amount of friction - I think the forces involved are much more than at least I was aware. What it all means to me that if the needle is not large enough for the thread, then the thread will suffer. 92 bonded nylon with the same needle was a much better match. Quote Share this post Link to post Share on other sites
Davidmadd Report post Posted March 31, 2023 Many thanks to Wizcraft for his recommendations. I will endeavour to to check out all those points. I have a manual but I think its a user manual, I'll try and find a Service or Adjusters Manual. Also like to thank Wyowally for his additional comments relating to friction... Best Regards David Quote Share this post Link to post Share on other sites
Davidmadd Report post Posted April 5, 2023 Singer 111W155 Fine Tuning Well I've had some success and spent some time checking and adjusting the settings as suggested by Wizcraft. I adjusted the needlebar position to get the correct needle bar height then readjusted the hook timing as it was a few degrees out. I carefully watched the check spring action and made corrections to keep the needle thread away from the point of the needle. I didnt appreciate just what the Bobbin Case Opener function was but now I think I know but it doesn't seem logical, is it possible to be 180 degrees out???? As the hook picks up the thread the case opener moves towards the needle and away from the bobbin case protrusion. The bobbin case doesnt appear to rotate clockwise due to the thread friction as expected so doesn't appear to need a case opener! The hooked thread now moves around the bobbin case and the case opener is now moving back away from the needle (so closing?) and actually abuts the bobbin projection as the hooked thread reaches it. In the initial trials after making all these adjustments the thread was actually catching up on the bobbin case opener and holding it back for a split second or two and when it did release it made quite a loud clacking sound. Now imagine this when the machine is rotating quite fast and it was making quite a noise. Once I spotted it I re adjusted the case opener to leave a gap for the thread and the noise is nowhere near as loud, but I still am not entirely sure the case opener is doing its job. I've never had the bobbin case assembly apart so dont know if it could be be re-assembled incorrectly. Just run some tests and the stitching is good but when I tried on a project I found that for for 5 or 6 stitches there seemed to be too little tension and although stitches were made, they were not correctly formed. So I have two 5/6 stitch lengths of poor stitches which is really annoying and of course I need consistently good stitches. There does seem to be quite a bit of play where the bobbin case sits in its housing so if its assembled incorrectly, it has resulted in a fair bit of wear. I found some very useful info on the internet from :- https://navyaviation.tpub.com/14217/css/Timing-The-111-W-155-Machine-55.htm, this being the US Navy Aviation/Parachute maintenance manual which includes the 111w155 and possibly other Singer info. Easier to read and understand than the Singer manual. So my query is has anyone any experience of the mechanism relating to the Bobbin Case Opener and whether or not it could feasibly be re assembled incorrectly at some point in the past Quote Share this post Link to post Share on other sites
