Wizcrafts

The only part I will address is that you have bought what appears to be a dedicated edge binder machine. This is a special setup that has a moving plate on top of the arm to which a material folder/binder should be attached, but isn't. The visible presser foot is single left toe to allow the binder attachment to get really close to it. This is to make the edge binding flow more evenly over the edge of the material. The required inside foot is missing! The feed dog is made to work with the binder and only moves forward and backward without dropping and raising like a normal feed dog. This means the feed dog will fight against feeding material without a binder. There is no standard needle plate. Unless those parts are included in a parts drawer or box, in order to use this for standard sewing you will need to buy the missing parts and disable or remove the synchronized moving plate. This may cost you some serious money. OTOH, if you wanted a binder machine, this one is perfect. If the binder is missing you can buy one that screws onto the moving plate. Here are some previous discussions about synchronized binder machines: https://leatherworker.net/forum/topic/82285-walking-foot-with-synchronized-binder/ https://leatherworker.net/forum/topic/45986-pfaff-335-binder/ https://leatherworker.net/forum/topic/70162-pfaff-335-binder-attachments/ https://leatherworker.net/forum/topic/88856-is-this-a-synchronized-binding-machine/ https://leatherworker.net/forum/topic/66497-adler-69-pfaff-335-binder-options/ http://leiflabs.blogspot.com/2011/08/pfaff-335.html

You could drill a hole in it and a hole in the table directly under that hole, then connect it to a floor mounted foot pedal with a chain. Or, you could fashion a tapered latch that sits on the table out of the way until you lower the reverse lever and rotate the latch to hold the lever down. You could probably print out such a thing on a 3D printer.

The outside foot connects to the "presser bar," which is connected to the lifting mechanism by one or two screws Loosen those screws and the bar can be rotated. It is also possible that there will be an alignment tab at the upper end of the bar that rides inside a split shaft. That tab has a set screw too that can be loosed to rotate the bar.

My Father owned a tailor shop from the time I was born until long after I left home. I learned to sew and adjust an industrial sewing machine by the age of 12.

The Singer (and Adler and Claes) patchers are all lockstitch machines with bobbins. The bottom thread is feeding the bobbin winder, which winds fresh bobbin loads, not the bobbin in use. That bobbin lives in the left end of the cylinder arm, just to the right of the needle and is inside an oscillating shuttle that picks off the top thread loop formed by the needle making a down>up>down jog. The bobbins are extremely tiny and aren't normally threaded with anything larger than #92 bonded thread. That isn't to say one couldn't wind a bobbin with #138, or #207 thread, but there wouldn't be very much of it on that bobbin. During the Ice Age of sewing machines, when Singer came out with the Universal Feed mechanism (UFA, 29-2, 29-4), meant for shoe cobblers, there was no bonded nylon thread. They used cotton or linen thread. Some of that thread could have been up to 3 or 4 cords. The reason those machines could actually sew with heavy thread back then was because linen thread is soft and very flexible. If wound tightly, you can get a lot more linen thread in a small bobbin than modern bonded nylon. Also, linen thread didn't require as much tension to pull up the knots, thus was not as tough on the take-up mechanism. I still have a spool of 3 cord thread I occasionally use in my patchers for special jobs.

If the machine uses System 7x3, 7x4 and 794 needles, the smallest I've found is #18 in 7x3 round point. That size is used with #69 thread, top and bottom. Those needles are very long and thin. They bend easily if the thread is too tight. They are also easily deflected by irregularities in the layers. If I was sewing with #138 on top and #92 in the bobbin I'd use a #22 needle, not a #23. The "knots" will be loose in the holes poked with a #23 needle. A #22 will grab the locked stitches (knots) tighter. There are people who believe in running smaller thread in the bobbin to make it easier to pull up the knots in leather. That is their preference. Other needle trades use a thick top thread for appearance only. They back off the top tension so that a thinner, less expensive thread can be used in the bobbin, which is usually prewound. This practice is popular in car seat upholstery where they use a thicker top and thinner bobbin thread for a bold top appearance. These scenarios favor looks and ease of sewing over strength. Every stitch in a mismatched combination is only as strong as the smaller thread. This may not matter much on a seat cover but is could be the difference between life and death if a handgun holster lets go because of the stress of drawing and holstering when one thread is under-rated for the shear load. If you want to use a larger top thread, make sure the bobbin thread is strong enough to hold things together under stress. When I sew holsters and double leather belts I use the same size thread on top and in the bobbin. You can find the breaking (shear) strength of various sizes of thread on this page. It also shows the range of needles that are commonly used with each size of thread. When two needle sizes are listed, use the larger needle when the same size thread is used on the top and bottom, or when the material is very tough or dense.

Be that as it may, the OP asked about sewing machines for leather and this sub-forum is about leather sewing machines.

The thread size determines the best needle size, not vice versa. The rule of thumb is that for every thread size there will be a basic minimum thickness that can reliably hide the lockstitch knots. For 6 ounces that might only be #92 thread.The best needle for that thread is a #19 (metric 120). A #20 (125) can also be used to poke a slightly bigger hole. The needles you listed, 160 (23), 180 (24) and 200 (25) are for use with thread sizes 138, 207 and 277, top and bottom. To bury the knots with #138 thread you would need about 7 to 8 ounces thickness. I'm not saying you can hide them in 6 ounces, but it will take a lot of dialing in the top and bottom tensions. #207 thread is 50% bigger than #138 and takes a #24 needle. I recommend using that size when sewing about 10 to 12 ounces. #277 forms fairly large knots and is best used when sewing 1/4 inch up to about 1/2 inch. For holsters exceeding 1/2 inch you should use #346 thread with a #26 needle, or 415 thread with a #27 needle.

Leather Machine Company sells single toe left and right presser feet for the Cobra Class 4. They are listed on the Class 3 and 4 accessories page.

To remove the feed dog, unscrew the two screws holding the shuttle race to the arm, being careful to not lose them or the coil springs on them. Pull the race out with the bobbin case, ensuring that it doesn't fall to the base of the pedestal and get broken. You will now have a direct path to the large screw holding the feed dog in place. Unscrew it and pull out the dog. Now, install the new feed dog and secure it lightly with the big screw. Set the raised height on the dog and lock it down. Then reinstall the race cover and bobbin case. Make sure you leave about 1 turn clearance on the race mounting screws so the springs can let the race float a bit. If you don't get a special feed dog with the attachment, use the spare blanket feed dog that shipped with the CB4500. That dog has teeth.

I have multiple sewing machines in my shop. When it comes to sewing shoes, vests, Cowboy or biker hats, ball caps, or shallow bags, I use a 7 inch post bed machine. I can rotate the work around the post. If I need to sew something long and hollow, like a boot, pouch, purse, or deep bag, I use a boot patcher. I have a Techsew 2700 cylinder arm machine on a U shape table. I use it to sew cuffs, hem pants, sew around the outside of bags, etc. Those items never give me any problem due to the shape of the table. It even came with a flat table attachment. A well equipped custom shop can have more than one type of sewing machine. Mine happens to have 9 with another walking foot machine at home.

You'll have to get the thread unwound from the bobbin case before using the machine again. If there is a stub long enough to grab, try pulling the thread out as you wiggle the hand wheel (unthread the needle first). If the thread won't come out, the bobbin case will have to be removed and that is not really for newbies. If you must do this yourself, have a magnetic pickup tool nearby as you remove the tiny screws that hold the bracket on that secures the bobbin basket in the shuttle. Better yet, magnetize the small blade screwdriver.

Time the hook so it intersects the needle about 1/16 inch above the eye after the needle has risen about 3/32 of an inch above BDC. Also, make sure the needle is aligned with the rib on the left and the scarf on the right. Ensure your needle is the proper size for the thread and proper type of point for the material (round for cloth and wovens, and oval/wedge, tripoint, or diamond for leather). Check the motion of the check spring. It must lift with the take-up lever and keep the top thread taut until the needle fully pierces the material. If it stops moving down too soon the needle will pierce the thread and rat it. Adjust the bottom motion stop bracket up or down as required.

We have a sub-forum dedicated to discussing 3D printers and lasers. That would be a good place to pursue a 3D printed shuttle.

The Singer 20 series are zig-zag machines that can be used as straight stitch by zeroing the side throw.

There is a difference between machine error and operator error. If a machine has been adjusted and readjusted and a thread jamming situation persists, it may not be the machine itself that's at fault. Most top loading (vertical hook) industrial sewing machines are subject to jamming the top thread around the bobbin basket unless you hold back the starting threads for a couple of stitches. It is what it is. Hold back the top and bottom thread for a few stitches and the jamming will probable go away. If you can't grab the bottom thread, at least hold the top thread back and to the right. If the knot is visible on top from a top tension imbalance, pull down on the bottom thread when you are done sewing, before trimming the thread. You will be able to hide the knots after a few tries. Note that this thread jamming can also happen on horizontal hook machines. I have to hold back the starting threads on a Consew 206RBL-18 or I get a jam. It is what it is.

The entire shuttle housing can be raised, but I don't remember the details. I do recall that if you back off the tapered pins that the clearance increases between the driving gear and the shuttle gear.

Before you start turning 4 sided screws, does your ULS have the new gear driven servo motor setup? If so, that may be the sound you are hearing. Those motors are geared high and tight. You can start troubleshooting the binding by raising the shuttle drive compartment a little. This will increase the slack in the shuttle drive gears, but if that was the cause of the noise and grinding, it is a cheap fix. Inspect all paired gears to see if there is foreign material in the teeth. Move some of the gears laterally if they are too tight. I always ran my ULSes a bit loose. They were noisy, but never bound up or gnashed the gears. There was something special about the clashing and clanging of metal on metal when I floored the beasts at 800 spm (15/second)!

I honestly don't know that. I would be concerned about the stress a larger bonded thread would exert on the loopers and the needles. You could buy several small spools of #92 thread and a pack of #19 needles in system DCx27 and see how it works out. There are other sergers made for thicker thread and heavy material, like rugs. But, I think they use a non-bonded, soft thread that is larger in diameter.

Sailrite makes a portable zig-zag walking foot machine with top and bottom feed. Some of our members have and use it.

Contact Toledo Industrial Sewing Machines, at 866-362-7397 about replacement parts for Cowboy sewing machines sold in the USA

They are for school room windows in the event of an active shooter.

I also use an MO-6700 at my second job; sewing blackout window blinds. Initially I set it up with #69 bonded nylon and it sewed it perfectly with #16 or 18 needles. However, I wanted to up the ante and have flame resistant edging so I changed to Tex 40 Nomen thread, using a #14 needle. This thread lies so much flatter and also holds onto the double sided tape I buy from Wawak to hold seams and Velcro in place for sewing. The nylon thread simply doesn't hold onto the tape because it is lubed.

The Cowboy CB2500 is like the GA5 machines. It is available from Toledo Industrial Sewing Machines with either a flat or roller foot.

A Union Lockstitch, or a Number 9 machine produce a bottom appearance almost like hand stitching.