Wizcrafts

3.2 mm = 8 ounces = 8/64 inches = 1/8 inches Most domestic sewing machines max out with #B69 (T70) bonded nylon thread and a #18 (110) leather point needle. Leather that is 8 ounces thick is usually very tough; too tough for most home type sewing machines to handle. So, even though the presser foot may let you clear 1/4 inch of "material," it probably shouldn't be anything harder than Denim jeans or maybe vest leather. Dense belt and strap leather tends to grab the needle and lift up with the ascending needle and thread. This causes skipped stitches and possibly broken needles and other parts. You will probably knock the timing out after the leather lifts with the needle a few times. In my own experience, using several different ancient Singer cast iron body home machines, an 8 ounce belt, sewn with #69 bonded thread, using a #18 leather point needle, was the practical limit. To even do that I have to crank down the presser foot pressure spring screw on top. This kept the leather from lifting with the needle, but reduced the length of the stitches to an almost useless distance of about 8 or 9 per inch. Changing the presser foot to a Teflon foot helped reduce drag and allowed slightly longer stitches. Forgetting to keep the Teflon foot raised when the material is out of the machine ruins it by pressing the feed dog teeth into it. If your New Home is a Janome plastic body, multi-stitch machine, I have one of those also. It is only made to sew light cloth; maybe denim. You will break the machine if you sew leather on it.

The sewing machine in the Hadley Roma video is a plain old straight stitch Singer 31-15 or equivalent, with a roller foot conversion and an inline edge guide screwed onto the body. These are slow speed, manually oiled tailors' machines. My Dad used one and I have one at home. They have a sewing capacity of 1/4 inch, or 6 mm. The thread handling maxes out at #69 (T70) or maybe #92 (T90) bonded nylon or polyester. The largest practical needle size is #140 (Singer #22). My guess is that those straps were being sewn with high quality B46/T50 thread, using a #75 or 80 needle. You should be able to find a complete Singer tailors' machine, with motor and table, for about $500. Another $150 to $200 gets you the servo motor conversion. The roller foot conversion will cost you about $40 USD and consists of three parts: the roller foot attachment, single row feed dog and a matching single slot throat plate. You will need to adjust the presser bar up to install the roller foot attachment, then move it sideways to line up the roller with the slot and feed dog. Some dealers will convert a straight stitch slow speed machine into a roller foot machine. This saves you a lot of dinking around and possibly bad mistakes. These machines normally come with a 20" x 48" x 1.75" table, mounted onto a "k-legs" steel stand. There is a big floor pedal that connects to an industrial motor and a knee lever under the oil pan that lifts the presser foot and releases the top thread tension. There should be a thread stand that holds two or more large cones and a bobbin winder attachment screwed onto the right side of the long slot for the v-belt that powers the machine. The bobbin winder has a big wheel that you push into the belt to load a bobbin. There is an adjustable metal tang that moves out as the bobbin loads. When the bobbin is as full as you can safely load it, the tang pops up, disengaging the bobbin winder wheel from the v-belt. Don't make the mistake of buying a new high speed self oiling machine. You will never spin it fast enough to distribute the oil to the extremities, sewing watch bands

The only upholstery grade machine in your list appears to be the Rex. As long as you stick to chrome tan leather it will do a good job. However, if you use it to sew veg-tan or bridle leather it will mark the top pretty badly with the teeth on the feet.

Yes, the 1541 is a standard walking foot machine, with triple feed. The standard presser feet are smooth on the bottom. Ones with teeth are just accessories. Make sure you get smooth presser feet. There are many accessory feet for this type of machine. You may benefit from an edge guide foot for your straps. This foot has a thin spring loaded steel plate that is hinged at the back. The guide normally sits all the way down on the right side of the work and keeps your stitch line a fixed distance inside the edge. They are available in different spacings from the guide to the center of the inside foot. You might want a set that places the stitches about 1/8 inch from the edge, or maybe a little closer. Alternately, you could purchase a left toe only outer foot and a swing-away edge guide (mounted on the right, on the body). This would let you run the stitch line any distance inside the edge you want. Make sure you order leather point needles! Regarding the servo motor; try to get one with a very small motor pulley (e.g. 50mm). This gives more slow speed range, with higher punching power. Normally, many of these motors lost torque at their slowest speeds. The smaller pulley will get some of that power back, at the expense of the top end speeds.

Aside from the pulley difference, when I opened up my motor, I looked at the switch and found that it is populated with small resistors. I'm not into electronics anymore (for 3 decades) and have no meters. But, I'm guessing that someone with the right equipment and good close-up eyesight could figure out how to replace the rotary switch with a suitable military grade, long life, log taper pot (or stacked concentric pots).

One big difference I see is that your motor has a large pulley. Mine has a 50mm (2") pulley, which gives more low speed torque and runability.

My FS-550 motor has a multi-position rotary switch. I wish it could be converted to a log taper pot. Let me know if/how any mods work out for you.

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.

The hook point must intersect the scarf area above the eye of the needle on the upstroke, after about 1/8" of lift. If you can't lower or raise the needle bar to meet the hook, try re-timing the hook. This calls for loosening the screw/bolt/clamp that secures the hook to the shaft that drives it. Using the hand wheel, lower the needle to BDC, then raise it about 1/8 inch and stop. If the point of the hook is rotationally before the needle, advance it. If it has passed the needle, retard it. If your needle is still too high or low, adjust the needle bar to place the hook above the eye on the upstroke. If you have trouble balancing these two items, the hook point may be damaged. Replace the entire unit. Dinking around with old worn out parts is a losing proposition more often than not. There were a couple of system 135 designations. The more common one is 135x16 and 135x17, which is the standard walking foot machine needle. There is/used to be a 135x7, which is not the same needle. Singer no longer makes patcher needles. Patch owners now have to use system 135x16. The difference is that these needles have a cut-out scarf and the old 29x4 are straight all the way down the shaft.

Adjust the position of your needle bar to place the hook inside the scarf area, above the eye of the needle.

After you do the things that Constabulary recommended, check the top thread where it goes around the upper tension disks and make sure it is firmly seated inside the disks when you start sewing. Birdnests in the bobbin case are often caused by total loss of upper tension. Also, make sure the top thread is going through the check spring and take-up lever.

Aw shucks Maam, it twern't nuthin'!

If your 31-15 has an industrial motor, it doesn't matter what type of belt you use. The motor has an adjustable nut and bolt to raise or lower it. You can lower it for more belt tension until your leather belt stretches too much. Then, remove the belt and take out the C clamp from one of the ends. Cut that end about an inch shorter, punch a #0 hole about 5/16" in from the end and bend the C clamp into it. The leather should just touch when the clamp is in position. If you get a v-belt, make sure you get on that will fit tightly with the motor adjuster in the center of its travel. A stretched out 43 inch leather belt, already adjusted to the bottom of the motor adjusting bolt, would probably be replaced with a new 42" v-belt (type 3L only).

Is your machine motor powered, or treadle powered? If motor, is it a big industrial motor under the table, or is it a tiny home style motor on the back of the machine? The reason I ask is because most treadle powered machines use looooooong leather belts, cut to size as they stretch out with age. Industrial motor powered sewing machines are normally equipped with rubber or composition v shaped type 3L belts. These belts don't slip as easily as leather does. They are tightened by lowering the motor via its adjusting nut and bolt.

Just measure your leather belt around the pulleys and replace it with a standard type 3L v-belt of the same length.

Nope and nope. It is a post machine with a roller feed. These are typical machines for the shoe and hat trades.

Servo motors can be bought for about $110.00 + shipping for a Family Sew FS-550s

It looks like a standard walking foot machine from a picture I found. It says that they take system 135x17 needles. This hints that it also takes standard walking foot, type 111 presser feet, including zipper feet.

10 months of side-shock from a badly melded belt may have warped the bearing on the speed reducer, or even caused some slop to develop in the flywheel pulley on the machine. De-belt the reducer and spin it by hand, checking for side wobble. If there is an appreciable wobble, remove the wheel and try tightening up the flange on the inside of the reducer wheel, if this is possible. The reducer should revolve smoothly, but not wobble sideways. Lineups I go to great lengths to line up my motors > reducers and machine pulleys. The straighter the pull, the less stress there is on the three sets of bearings. Motors can be shifted laterally by loosening the three nuts under the motor mounts, while clamping the cap bots with a vise grip or suitable pliers. Reducers are usually attached to a movable mounting block that can be moved sideways to line the large pulley up with the motor pulley. It may or may not not be as easy to move the machine pulley to line it up with the reducer. I would say to seek out "Gates" brand belts and see if they are properly welded inline. The first thing I do when a new belt arrives it to unfold it and lay it on a flat table. If it lays flat, or almost flat, after a few minutes, it goes into the "for use" hook. If it sits high in one area, I check it out to see if I can flatten it out. I also press it down at the weld joint and check to misalignment. One can shave off a small amount of material sticking out one side or the other, or just throw it away. I always throw away new belts that don't lay flat AND have misaligned weld joints.

Maybe there is a piece of broken thread, or foreign material stuck in the teeth of the worm gears driving the shuttle, or between the shuttle and bobbin basket?

Try running the machine with the top belt off the machine's pulley. See if the variation in speed and thumping exists with just the motor (and speed reducer, if any). In the unlikely event that the thumping continues with the machine out of the equation, make sure that the motor mounts and pulley are fully tightened. If you have a speed reducer between the motor and machine, unbelt it and run just the motor. A mis-adjusted reducer could cause this type of problem. You might have to dink with the bolt securing the reducer, or replace it if it wobbles. If you don't have a reducer between the motor and machine, try running the motor with the belt off. I have thrown away v-belts that were poorly melded out of alignment where they are joined. In fact, it happens more and more all the time. I now only buy top of the line v-belts. It is possible that your belt or belts are not up to snuff and could cause this problem. If everything on the motor is tight and it thumps on its own, with no belt at all, replace the motor. Hand wheel the machine and listen or feel for occasional binding. If you encounter binding, or any unusual resistance, mark/note the position and direction of the needlebar and presser feet and we can investigate further.

Boa; Your first YouTube video is marked Private and cannot be seen by anybody but you.

Greg is right, in that the standard build of the LU-1508 has the same foot lift and sewing capacity as most other walking foot machines. I mistakenly forgot to append the "NH" designation when I mentioned this particular Juki machine. The LU-1508NH has higher lift and sewing clearances and uses system 190 needles. I modified my National 300N to sew just under 1/2 inch, using system 190 needles. Because these needles are 3/16" longer than standard system 135x16 and 17 needles, the bottom of the needle bar, at BDC, is also that much higher. This allows the presser feet to be raised 3/16" higher using the knee lever. The hand lift lever only raises them the standard height.

Something might be wrong with the bobbin case or basket, or the bobbins themselves. Make sure that the shuttle mechanism is fully tightened and not able to slip as you sew. Also, after winding your bobbins, cut off the beginning thread stud flush with the bobbin. An exposed stub can catch and cause intermittent tension problems. Try to watch the bobbin as you sew. See if the thread is twisting as it feeds out of the slot and under the bobbin tension spring. This action would cause sudden changes in bottom tension and cause the knots to appear near the top. If this is happening, troubleshoot the bobbin area and your bobbin thread winding technique. I usually recommend inserting your wound bobbins so that they feed against the direction of the loading slot, making a sharp turn backwards to the spring. Going the other way sometimes results in changes in tension as you sew. You might try altering both the top and bottom tensions to see if there is a happier place for both of them to get along and give a consistent knot placement.

The 1508 is a beefed model, with higher presser foot lift. It was designed to sew leather goods and even some shoes. It can take more pounding than the 1541 before wearing out. Also, it has extra clearance inside the head to allow for longer needles and higher sewing thickness: about 12 mm. Without this extra clearance one cannot sew a compressed thickness beyond 10 mm. Even with these improvements and higher lift (plus longer needles), the 1508 is not a substitute for a harness stitcher, like the Juki 441 or Adler 205 and their clones, that many leather crafters here are using. Highlead is a well respected brand name, Worldwide. If you will have dealer support in your own locality for a Highlead machine, you probably won't be sorry. Also, if you decide you need something stronger, your dealer may allow some value on a trade in.