wilsonintexas Report post Posted March 9, 2019 I have a consew (non walkingfoot) sewing machine. I am using 2100/3 polyester thread (and have tried other heavy duty threads as well) I have tried size 16 and 18 needles I am testing the machine before I start some leather work. I can sew 3 layers of canvas successfully at full speed as soon as I add a 4th layer the top thread frays and breaks. I can rotate the machine by hand and all is fine. If I sew very slow (I am still getting familure with the machine, and have trouble controlling the speed) the thread is fine If I get any speed at all, the thread breaks I am considering changing out the pulley on the machine to slow things down. Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted March 9, 2019 When you sew fast the thread flops around the take-up area more so than at slow speeds. You may have to adjust the check spring setting, or lengthen the throw of the spring by moving the stop bracket down. Consult your owners' manual to see these parts. Quote Share this post Link to post Share on other sites
nylonRigging Report post Posted March 9, 2019 (edited) What (wizcraft said ) .. slow down the rpm on moving through the thicker thicker materials and trying small adjustments like recommended . ( i no expert ) and It really hard to diagnose stitch problems without actually having hands-on and sitting in front of machine . So I will throw my guess in the mix . unless I missed it somewhere ? . your saying it just a 'Bottom-feed' Consew ? , but what model is it ? , and the needle 135x5 or a 135x17 or bigger ? You saying with 4 loose pieces of material, the top thread breaking, but how thick of a stack is it with 4 pieces ? this--> Assuming you already have proper Pressure-foot tension and thread tensions on Top and Bobbin thread ? , and also using the proper Needle size/length for your material ? I think your statement ..." I can rotate the machine by hand and all is fine ". is the giveaway . Your just asking your Machine to do to much . You may just be pushing the machine and needle to it's design limit, Plus . If just Bottom-feed model and not Needle-feed or Walk . with stacking the 4th piece of material on ? . And Nothing wrong with Bottom-feed and I still run 2 of them daily . Sometimes it is just plain hard for a Bottom-feed with keeping good tension and stitching on thick multi-layers . that is where a needle-feed or walk shines . hold multi layer materials firmer with stitching motion for no deflection and holding proper presser and thread tensions . . Edited March 9, 2019 by nylonRigging Quote Share this post Link to post Share on other sites
brmax Report post Posted March 9, 2019 Can you take a gander and look at the thread spool again, what size is being used. Maybe the needle is thin and bending a bit. Its tough in these diagnostics for anyone. Csn you say this is just during straight sew runs. Good day Floyd Quote Share this post Link to post Share on other sites
Colt W Knight Report post Posted March 10, 2019 Sounds like the needle is getting hot and breaking tearing up the thread - my first thought Quote Share this post Link to post Share on other sites
Pintodeluxe Report post Posted March 10, 2019 Needle bar thread guide in place and intact? Quote Share this post Link to post Share on other sites
Constabulary Report post Posted March 10, 2019 On 3/9/2019 at 5:48 AM, wilsonintexas said: 2100/3 polyester thread what therad size exactly is this - have you mistyped? And what machine model are you using? Probably a problem with the thread path? Thread keeps hanging somewhere? Burr in needle eyed on on some thread guides? Too much thread tension (top and bottom)? Needle bar probably a tiny bit too high? Have you checked the needle hook timing? Needle insert correctly? Do you have a manual for the machine? Quote Share this post Link to post Share on other sites
tofu Report post Posted March 10, 2019 15 hours ago, Colt W Knight said: Sounds like the needle is getting hot and breaking tearing up the thread - my first thought Agreed. This happened to me. Couldn't figure it out. Rotating by hand was fine, but as soon as I got on the electric, thread would fray and break. It was heating up so much that I saw smoke coming from the needle area when I shined light on it Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted March 10, 2019 If, as is being speculated, the top thread is overheating and burning, it can be run through a silicon lube pot that sticks on top of your machine (magnetic base). Factories with high speed machines have forced air tubes that they aim at the needle and blow cool air constantly as the machines spin at 90 stitches per second. Finally, you can buy titanium coated needles that are much more heat resistant than plain steel. I use these needles in all my walking foot and patch machines, not because of heat, but to resist the grab of the 3M leather tape I use to hold things together for sewing. Quote Share this post Link to post Share on other sites
wilsonintexas Report post Posted March 31, 2019 I WANT TO THANK EVERONE FOR THE REPLIES. It is a bottom feed, non walking foot. I suspect that the spring at the top tension is not set correct or is deformed, the thread does not seem to be pulling on it. I will look into that soon. I will also look at some of the mods that I have seen (here I think) and put a lager pulley on the machine. I have trouble controlling the speed of the machine, and do not want to sepd the money on a new motor. When I get back to it, I am also going to go through the machine and adjust it from scratch, there was a good video that I saw, if I can find it again. Quote Share this post Link to post Share on other sites
