Tallbald Report post Posted May 13, 2014 (edited) My Cowboy 3500 is a fantastic machine and I'm tickled to have it. I am learning to use it with scrap piece sewing, making some simple key rings and a few other small items. I am learning it's behavior when going from single thickness leather to double and triple thickness. Something I am not sure of is what an ideal bottom stitch looks like. If I leave the top tension as is when changing from multiple thickness to single, the bottom stitch seems to flat out bury itself below the surface of the layer. Should the bottom layer stitch look just like the top surface stitch? Should I learn to adjust top tension as I change thickness on the same piece? I mean like when sewing away from a welt on a holster toward a double thickness and vice versa? Is there a tutorial here that might show me what to aim for? I have looked without success. Thanks so much. Don Edited May 13, 2014 by Tallbald Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted May 13, 2014 The knots should always be buried inside the layers, or at least the bottom layer. If you cannot hide the knots, the thread is too thick for the material thickness. Unlike some fancy home machines, industrial sewing machines are mostly manually adjusted 100% of the time. The amount of thread tension used in heavy leather stitchers, like your CB3500, is enormous, compared to an everyday domestic sewing machine. Those fancy plastic machines use cotton or poly-core thread in sizes 50 and under. The faster machines prefer #27 thread. You would be pushing one of those machines to its limit by running #69 bonded nylon through it. Even if the machine can tension #69 thread, it is usually limited by the mechanism to only sewing 1/4" of soft material. In contrast, real leather stitchers use thread sizes starting at #92 and going up from there. Most 441 clones, like the CB3500, are setup by the dealers to sew into 3/4 inches of veg-tan leather with #277 or #346 bonded nylon thread. I usually set the bobbin tension for a smooth, steady pull. Then I balance the knots by adjusting the top tension as needed. When adding layers, give the knob a turn or two inward. When leaving a layer, back it off, if you see the knots appearing near the top. Quote Share this post Link to post Share on other sites
Tallbald Report post Posted May 13, 2014 Wonderful information to have and it's just what I was needing. I'm taking notes each time I receive help. And I thank you so much. Don Quote Share this post Link to post Share on other sites
Rayban Report post Posted May 13, 2014 Don, this is what works for me. When I told Toledo Bob what I would be doing he told me that any tension adjustments I need to make can be done from the top, leave the bobbin tension alone. I've heeded his message. In the pictures below is a 1/4" thick gun belt I'm finishing up. I've used 207 top and btm for the belt, same for the keeper which is 8oz. I used a #24 needle for the belt, then changed to a #23 for the thinner keeper. Something about the smaller hole it makes creates a better looking stitch on thinner leather. I'm no expert as Wiz is...just want to show you what works for me. When I get into the 1/2" thick range, I use a 277 top thread and 207 bobbin. I may increase the length of the stitch but I leave the tension alone. Quote Share this post Link to post Share on other sites
Tallbald Report post Posted May 13, 2014 Rick those are beautiful stitches. AND, I am well aware of the beautiful items you craft, being the proud owner of one of your custom gun belts. Incidentally I posted a 1 month happy follow up on The High Road gun forum about my belt from you too. I'm a proud member of several special interest forums, and it is help like I have received in response to this post that makes a forum what it is supposed to be. Wiz and Rick, thank you so much. Don Quote Share this post Link to post Share on other sites
