joker Report post Posted February 3, 2015 Hey guys I know this has probably been beaten to death but I need some advice. I need to buy a sewing machine in the next week or so. I have been looking at the Cobra 4S. I need it to be able to sew at least 3/4", leave little or no marks on the bottom side. I will be doing holsters, knife sheaths, horse tac, ect. Any help would be great! Thanks guys Joker Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted February 3, 2015 At 3/4 inch your Cobra will need all the pressure you can apply to the presser feet. This is to hold the leather down as the loaded needle comes up with the knot from the bobbin thread. The pressure is divided equally between the inside and outside feet. The inside foot directly surrounds the needle and pushes the leather down hard into the big slot in the feed dog on the bottom. You are going to have deep puckers on the bottom, surrounding the needle holes. If you use the supplied S point needles, the top stitches will look much better than the bottom, which will appear shorter from being drawn in to the oval holes. You can get around this by ordering diamond point needles in the proper sizes for the thread combinations you plan to use. Diamond points produce a better matched top and bottom stitch. But, the puckers will be visible on the bottom. The only way to reduce the puckering is to greatly reduce the foot pressure. Unfortunately, unless you are sewing harness or bridle leather, the low pressure usually allows the leather to lift with the needle, causing skipped stitches. One solution to this, for 3/4 inch sewing, is to use a Campbell-Randall Lockstitch machine, or equivalent needle and awl harness stitcher. Even a Union Lockstitch produces a nicer bottom stitch than any closed eye needle machine I have ever used. They have a jumping foot that is either single or double toe. The immediate radius around the stabbing awl has nothing but air. The hold-down pressure is off to the sides of the slot in the throat plate and bottom puckering is almost non-existent. Top and bottom stitches closely resemble those of a hand stitching awl with a chisel point needle. These are my observations from using both types of machines. Quote Share this post Link to post Share on other sites
joker Report post Posted February 3, 2015 Thanks for the reply! I won't always be doing 3/4". Mainly 3 layers of 8-9oz. What machine would you suggest? Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted February 3, 2015 I guess you first need to define what you meant by "leave little or no marks on the bottom." The Cobra has a totally smooth feed dog when it arrives. There won't be any tooth marks if that's what you meant. Feed dogs help move the leather and maintain a constant stitch length. The dogs on the big Cobra, Cowboy and all other 441 class machines are almost 3/8 inch across and have a hole large enough to clear a #280 needle; just about 1/8 inch. The combination of this elongated hole and the inside presser foot is part of what causes the puckering on the bottom of the needle holes. Please define what you expect, or don't want for the bottom appearance. Quote Share this post Link to post Share on other sites
joker Report post Posted February 3, 2015 Some puckering won't be a problem. Just don't want big cleat marks on the back side. This is a big purchase and just want to make sure I'm getting the right one. I will prob never go over 3 pieces of 8-9oz maybe two 11-12oz. Just want the back of my holsters and knife sheaths nice. Thanks for the help! Joker Quote Share this post Link to post Share on other sites
oltoot Report post Posted February 3, 2015 My vote is for needle and awl if you are thinking about pushing the upper limits of use often rather than ocaissionally. But as Wizcrafts says you need to define your desired results better in order to get a firm answer. Each type has its limits and the users just learn to adjust accordingly. Quote Share this post Link to post Share on other sites
Red Cent Report post Posted February 3, 2015 The Cobra 4 will go through an 8-9 plus a 5-6 easily (lined holster). Double this for the holster seam and it marches easily through the leather. I do not use a welt. Never liked the bulky blocky look it gives. However, I have sewn two layers of 8-9, two layers of 5-6, plus another single layer of 8-9 (welt) carefully. I use 277 top, 207 bottom, and a #25 needle (S). Polyester thread. Quote Share this post Link to post Share on other sites
joker Report post Posted February 3, 2015 Sounds like the Cobra 4 is a good machine. I have hand sewn for years, just about all thicknesses, hands are just getting wore out Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted February 3, 2015 The puckers on the bottom can be rolled or hammered flat. An overstitch wheel will help the bottom appearance. Quote Share this post Link to post Share on other sites
joker Report post Posted February 4, 2015 Sounds like a plan! Thanks to all for the responses Joker Quote Share this post Link to post Share on other sites
