ValkyrieEquine Report post Posted March 18, 2019 (edited) Sewing two layers of leather cemented together with my Cobra 4 and on the up-stroke, the needle is sticking and lifting the leather. This is causing the thread to pull up and not catch the bobbin thread and/or cut the thread completely. Very frustrating to say the least. I was wondering if I could use wax or silicone on the needle to keep it from sticking? Has anyone else had this problem and fixed it? Thanks. Edited March 18, 2019 by ValkyrieEquine Quote Share this post Link to post Share on other sites
buzzardbait Report post Posted March 18, 2019 Check the tip of your needle it may have a tiny bend or curl that is catching, if not you may need to give your cement more cure time. Quote Share this post Link to post Share on other sites
ValkyrieEquine Report post Posted March 18, 2019 I did change the needle out earlier, in case that was the problem, so unless the second needle has a bent tip, that isn't the problem. The leather has been sitting for two days, but my shop has been cold, so cure issue is definitely a possibility. I will let it sit some more and see if that helps. Thanks! Quote Share this post Link to post Share on other sites
chrisash Report post Posted March 18, 2019 Can you put more pressure on the feet to hold it down a bit more Quote Share this post Link to post Share on other sites
Bob Blea Report post Posted March 18, 2019 How thick is your leather? Have you sewn this leather before without any problems? Is there any chance that your timing is off and the shuttle is nicking the needle and either bending it slightly or putting a burr on it? You could try waxing the needle with beeswax to see if it has an effect. The wax would wear off quickly but it might tell you if friction is the problem. For the ultimate in non-stick if you have non-stick cooking spray in the house try spraying some in a cup and then using a q-tip to apply some on the needle. Quote Share this post Link to post Share on other sites
Northmount Report post Posted March 19, 2019 @ValkyrieEquine Moved your post to leather sewing machines. You'll get more participation from this group. Tom Quote Share this post Link to post Share on other sites
Mark842 Report post Posted March 19, 2019 The name for what is happening is called flagging. The usual culprit is incorrect needle/thread size for the leather or glue that is not completely dry. What size needle and what size thread are you using? What type of leather and how many oz total? Is your glue dry all the way? Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted March 19, 2019 If you have a lube pot on top of your machine, buy some liquid silicon lube and run the top thread through it. Most industrial sewing machine dealers have quarts in stock. Quote Share this post Link to post Share on other sites
chrisash Report post Posted March 19, 2019 Sorry i don't see where i am wrong, surly the only job of the pressure foot is to hold the leather down tight until the needle tip has passed the leather clear on the up stroke so the leather can be moved for the next stitch, if the needle sticks and raises the leather with the needle, then the problem lies with the pressure being to week Quote Share this post Link to post Share on other sites
Sonydaze Report post Posted March 19, 2019 Sometimes I sew two layers of glued together 16 oz. sole bend. Is it is very dry and hard, the needle tends to stick. (good needle, right needle thread combination & max pressure foot tension.) My experience is that rubbing beeswax on the needle helps. It doesn't last for long but it seems that after awhile the needle polishes to become slicker and then you don't need the wax as often. Quote Share this post Link to post Share on other sites
ValkyrieEquine Report post Posted March 19, 2019 22 hours ago, chrisash said: Can you put more pressure on the feet to hold it down a bit more I have been trying that, but it doesn't always work and ends up messing up the stitching when it doesn't. :/ Quote Share this post Link to post Share on other sites
ValkyrieEquine Report post Posted March 19, 2019 21 hours ago, Bob Blea said: How thick is your leather? Have you sewn this leather before without any problems? Is there any chance that your timing is off and the shuttle is nicking the needle and either bending it slightly or putting a burr on it? You could try waxing the needle with beeswax to see if it has an effect. The wax would wear off quickly but it might tell you if friction is the problem. For the ultimate in non-stick if you have non-stick cooking spray in the house try spraying some in a cup and then using a q-tip to apply some on the needle. Leather is two layers, 10-12 oz skirting. I've never had a problem with the thickness before. Needles are 25s I believe and can't remember thread off the top of my head, but it was ordered from Leather Machine Co specifically for the Cobra 4 and what I am doing. I checked both needles and neither have burrs. I've also sewn through test pieces with no issues, the cement seems to be the catalyst. I have the pieces sitting out in the sun to see if lack of cure was the issue. 16 hours ago, Northmount said: @ValkyrieEquine Moved your post to leather sewing machines. You'll get more participation from this group. Tom Thank you! 4 hours ago, chrisash said: Sorry i don't see where i am wrong, surly the only job of the pressure foot is to hold the leather down tight until the needle tip has passed the leather clear on the up stroke so the leather can be moved for the next stitch, if the needle sticks and raises the leather with the needle, then the problem lies with the pressure being to week Not sure if someone else said you were wrong, but I didn't. I'll look into seeing if that is something that will help. Quote Share this post Link to post Share on other sites
ValkyrieEquine Report post Posted March 19, 2019 1 hour ago, Sonydaze said: Sometimes I sew two layers of glued together 16 oz. sole bend. Is it is very dry and hard, the needle tends to stick. (good needle, right needle thread combination & max pressure foot tension.) My experience is that rubbing beeswax on the needle helps. It doesn't last for long but it seems that after awhile the needle polishes to become slicker and then you don't need the wax as often. Thank you, I will try that. Where do you get your beeswax? Quote Share this post Link to post Share on other sites
shoepatcher Report post Posted March 21, 2019 Running thread thru a thread lubricator with silicon lube should cure the problem. glenn Quote Share this post Link to post Share on other sites
nylonRigging Report post Posted March 21, 2019 Are the Ti-nitride coated needles slicker than standard needles ? always used silicon on the heavy thread cord and works great . But I ( have not ) tried the Ti coated needles yet and wondering if anyone uses ? . Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted March 21, 2019 35 minutes ago, nylonRigging said: Are the Ti-nitride coated needles slicker than standard needles ? always used silicon on the heavy thread cord and works great . But I ( have not ) tried the Ti coated needles yet and wondering if anyone uses ? . I use titanium coated needles in all of the machines that accept systems DBx1/16x257 and 135x16. They cost about $2 more per pack of 10 and are less likely to stick in the material from heat or basting tape. Quote Share this post Link to post Share on other sites