Wizcrafts

My bad. I forgot that your motor always spins at 1725 rpm. So, you've pulley'd it down to 1100 rpm at the machine. A 3:1 reducer will bring that down to about 400 spm, which is about 6 per second. You should be able to feather the clutch to 1 per second. If there is any problem doing that, replace the brake on the motor. After the burn-in period it should let you feather it with ease.

Actually, I think that a curved needle would need to be at least 2mm diameter to withstand the shock of piercing sole leather without breaking on impact. It would still run 8 to 10 cord thread.

Okay, I see your problem now. Since neither of us know how the needle number correlates to the thread sizes, I'd wait for the machine to arrive, then try various sizes of waxed linen thread. You can buy them in skeins from various suppliers, including Hobby Lobby and Tandy. My rough guess is that if the needle is a medium size, you'll want to use somewhere around a 6 or 7 cord linen thread. What I don't know is if it needs to be shoe machine right twist, or if the standard left (Z) twist is okay. When the machine arrives, measure the diameter of the needle. Since the needle on the Junker punches the hole without an awl, it needs to be about 2x the diameter of the thread it uses (to account for the lockstitch knots). Thus, a 1.7mm diameter needle (at the eye end) can easily manage 1mm thread without difficulty. That equates to either #554 bonded, or 8 cord linen thread (.83mm D). This needle is double the diameter of the thread.

I used to do the same thing, way back when I started in the biz. My first industrial sewing machine was a Singer 96k40 (I think) straight stitch machine. When I learned its limitations I bought a 31 class spring foot machine. I found that all I had to do was shift the knee lever to hit the foot lifter tang in different positions and slightly adjust the motor position to account for the slight difference in height of the handwheel pulleys. Not happy with that setup, I won a Pfaff 138 at an auction and made it fit on the same table, with a little tweaking. Going completely bonkers, I then acquired a Juki LU-563 and got it to fit the same table and knee lever. The table had a Singer 1/2 hp clutch motor. The oil drip pan was steel. I sure got a lot of use out of that one table! Four machine dropped in with very little tweaking.

You can buy a 3:1 speed reducer setup and new belts to match. You'll have some cipherin' to do to install it next to the slot on the underside of the table and two new v-belts to go from the motor to the reducer's big pulley and from its small pulley to the machine. I am afraid that by the time you run a reducer from your small pulley on the motor, that the machine will only turn over at about 1/2 stitch per second, pedal to the metal. You will be there all day if you have to sew around a long belt or strap.

Is there any reason you didn't ask Henry to send a spool of the correct size and twist of thread?

The Cowboy sewing machines are shipped from Toledo, Ohio. The rate is cheaper if you have access to a loading dock and pick it up there, rather than residential delivery requiring a lift-gate truck.

Almost any compound feed walking foot machine will sew not only 10, but up to 20 - 24 ounces of medium temper leather and webbing. Mind you, the typical maximum thread size is just #138, but each stitch would have 22 pounds breaking strength. Walking foot machines are available in both flatbed and cylinder arm models, from a wide range of brand names and manufacturers. The thing about buying a used walking foot machine is a combination of the wear in the moving parts and the speed that the motors are typically setup to run at. Many leather crafters who buy used machines will discard the old clutch motor and buy a new servo motor, equipped with a very small diameter pulley. This lets the machine sew very slowly and still have punching power.

Ken, if that Bull was based on a Juki TSC-441, it would use the same bobbins as the 441 clones. If based on the big Seiko, they use the same bobbins as well.

Every time I sew a Western drop loop gun belt with bullet loops, or a large weigh lifters' belt, I morn my choice of the 4500 rather than the 5500. I bought mine brand new and picked it up in person, from Toledo Industrial Sewing Machines (Bob Kovar, owner and a paying supporting member here (aka: CowboyBob)). He always takes care of any problems with my machines or motors and sends parts out for next business day delivery. I never worry about support with machines I buy from him. The 25" arm makes this a truly impressive machine. The pedestal stand is much heavier than the one I got for my CB4500. One thing I would like to remind all Cowboy machine owners to do is to open the face plate occasionally and put oil in the tiny oil holes in all the crank shafts in the business end of the head. Use a precision oiler with a needle tube. You will have some oil drops to wipe up, but the machine will operate quieter and not seize up from lack of oil in these critical components.

Strip the old paint off and lay down a fresh coat. That machine will be good for another hundred years. I have a 1920s Singer 42-5 getting repainted right now. It is an excellent chaps machine.

My old cast iron Singer sewing machines from the early 1900s can sew canvas with #69 thread. They all are portables with motors on the back than be be swapped out if necessary. The baddest of them all is a 1902 model 27, which has a bullet type shuttle. Any upholstery grade walking foot machine will do an excellent job of sewing canvas, duck cloth, vinyl, denim and leather. I used to have a National 300N walking foot machine that could sew 3 to the inch, with #138 thread, into more than 3/8 inch stacks of stuff. It was much like the modern Consew 206RB-5, with a stitch length rotary dial and a large push down reverse lever. My only problem with it was the body was too short for the work I was taking in. I now use a long body Singer 139 to sew things that are wide and need to be spun around a lot.

Now Ron; stop tempting me!

The specs on the 602 look really good for thicker fur and moc work and thread. It appears that this machine starts where the standard model leaves off. Hmmmm....

I think that any 441 clone will do the job. The question is how much room will you need on the right of the needle? There are machines in this class with 9", 10.5", 16.5", 25" and even longer arms. All will sew 1/2 inch and most, more. Personally, I think that my 16.5" arm on my Cowboy CB4500 is barely adequate for some jobs.It sews over 3/4 inch. I wouldn't consider a shorter arm myself. Other folks are happy enough with a 10.5 inch arm model, like the CB3200, which sews up to 1/2 inch. One consideration you may want to ask about is if you can get what is referred to as a blanket foot and feed dog set. These items have teeth that help move blankets, furs and such. I have these feet for my CB4500, but have yet to use them. Still, I'd rather have them in the drawer in case they are needed. Harness feet are not ideal for fur.

To add to what Uwe said, bonded nylon thread is a combination of several monofilamint strands that are twisted and bonded together. The overall strength of the resulting bonded package is a known factor that is available in various thread size charts, including this needle and thread size chart. You can look at the tensile strength for each listed size of thread and make your own determinations about which size will work best for your various sewing jobs. For example, #69 (T70) bonded nylon thread has a tensile (breaking) strength of about 11 pounds of pull. That is about what a medium sized bass might exert when you try to reel him in and he is fighting you. If your line has too little tensile strength the fish may break it and swim away. But, it was easier to cast because of its light weight and you got more yards on the spool you bought that a heavier line that had less thread for the same price. This is false economy. So, while a compound (triple) feed walking foot machine is rated at a guaranteed maximum thickness of 3/8 inch, or 10mm, and that machine can be fitted with a #18 needle, and that needle threaded with 11 pound test #69 bonded nylon thread, three 8 ounces pieces of veg-tan leather might have more flex force than the thread can withstand. A couple of bends in the wrong direction, or a sharp fold may break the thread and let the project fall apart. My shop has several sewing machines that do different jobs, based on their best capacities, not their worst. I don't sew 24 ounces of leather, Biothane, or webbing on my upholstery grade walking foot machines. I use my Cowboy CB4500, or my buddy's Cobra Class 4. I don't even consider using #69 thread in those machines, even though it "can be done." Rather, I'll use #277 bonded thread, with a #25 needle to sew 3/8 inch of dense leather or webbing. This size of thread has 44 pounds breaking strength, per stitch. This is inline with the thickness and possible stresses that belt, case, sheath, strap or holster is likely to encounter. A leather crafter who owns sewing machines may eventually go into the repairing things business. Those things may include zippers, patches, cuffs, hems, purses, backpacks, holsters, seats, saddles and more. If you already own a patching machine and you can't say you will never get into doing repairs, do not get rid of that machine if it works. If it needs a little tweaking, pay someone to tweak it. Repairs that call for a patcher are innumerable! I use my patchers almost every day for some job that cannot be sewn on the other machines. When the thickness exceeds the patcher's ability to feed and sew it, I move the work to a walking foot machine. I sew patches onto bikers' vests all the time. I sew the backs and shoulders on a flatbed walking foot machine, then move it to a patcher to sew over pockets, or on sleeves of jackets. Of course, if you are unhappy with your Adler patcher, Uwe or I will be happy to give it a new home.

Funny thing is my partner and I, as a custom shop, do occasionally make strange items from time to time. It's not my specialty, but if it needs to be sewn, I can do it. How much weight it takes before it slips off the boys; that's another matter.

Huh?

I actually would have a use for a curved needle and awl machine. I guess I am also one of the idiots that don't know when to leave well enough alone.

Sewing machines used in our type of leathercraft tend to be run at a turtle's pace, compared to a garment making machine. These slow speed machines are usually manually oiled, whereas the high speed cousins have a sump pump like a car. There are very few self oiling machines that can efficiently pump oil to all the extremities at speeds under 2000 stitches per minute (33 per second). There are very few types of leather sewing operations that need or use than kind of speed. The exceptions would be upholstery shops and leather garment factories, where time is money. Garment and upholstery leather can usually be sewn very fast (33 sps+) without the needle smoking and melting the thread and burning the inside of the leather. Veg-tan leather, unless it is soft, will burnish inside and grab the needle at rates much faster than 12 to 15 stitches per second. I can usually get away with sewing belts at 10 per second with little or no smoke. The heat actually fuses the knots inside the leather. Chaps, like upholstery leather, can be sewn very fast.

My first attempt at sewing a garment leather belt on a 441 machine resulted in the leather getting squished down into the throat plate feeder cutout, then eaten by the huge slot in the feed dog. The flat slotted plate solved that instantly. Other peoples' mileage may vary. Just sayin'

I can't ID that machine from the photo. You would be smart to take some of the shoe upper leather with you and see if the machine can hold it down, feed it without binding, use #69 bonded thread and sew slowly. If you see a glass oil bubble, it indicates that this is a high speed self oiled machine with a pump. It is supposed to run at several thousand rpm to distribute the oil. The 243 is definitely a very high speed machine, made to run at over 4000 stitches per minute.

I have posted several replies to questions like yours in reference to Cobra and Cowboy 441 clones. One lengthy reply is in the topic asking if a Cobra 4 can use #69 thread. In a nutshell, a qualified yes. But, you will have to reconfigure the machine, remove the feed dog and install a flat slotted throat plate. All springs, including the check spring, will need to be backed way off and the machine re-threaded with #69 or #92 thread. You will need to buy #19 needles, which are the smallest available and then, only in round point, not leather point. The flat plate is an optional accessory that you may or may not have received with your used machine. I have performed this changeover on my Cowboy CB4500. It takes about 1/2 hour each way (downgrade/upgrade), then more time to balance the knots. Make sure you have plenty of small needles on hand, as they are very easily deflected by inconsistencies between layers or its feeding. You will probably have a few bent and broken #19 needles. Also, the stitch length will be shorter and forward and reverse will no longer match up.

The most you can hope for is that a shoe repair shop may offer to haul it away for the price you'd get at a scrap yard. But, you never know. Somebody, somewhere may be reading this and thinking: "I wish I had that machine!"

You are asking for old parts that appear to be made of unobtanium. A drill bit should take care of that problem. Be sure you use Emory cloth afterward to remove burrs. You may have to move the shuttle to allow a much larger needle to clear it on the downstroke.