Wizcrafts

I recognize the size 16 needle. This is used with US size 46 or 69 bonded nylon thread. I don't know what #10 nylon equates to. That is not a US measurement. As a reference, the standard #50 cotton or polycore thread used in home sewing machines is slightly smaller than #69 (T70) bonded nylon. Buttonhole thread is usually a little thicker than #69. My guess is that #69 thread is about .25mm thick. Most heavy leather sewing in the USA is done with #277 bonded nylon thread, using a #25 needle, which is a #200 metric. The machines that sew with this heavy thread are usually clones of the Juki 441, or Adler 205, or the ancient Singer 45k. #277 thread is about .5mm thick. Whatever size thread you want to use, the eye of the needle must pass it freely, without binding.

Kev; What size thread are you trying to use? Can you see any readable number on the needles you have, like this: 90, 100, 110, or 14, 16, 18, etc? Use a magnifying glass if necessary, to read what is engraved into the upper shank of the needles. What type of feed mechanism does your machine have?

Okay. Here then is the procedure I follow to change to the flat slotted throat plate, on my CB4500. Turn off the power and press the speed pedal to ensure that the motor is totally off. Rotate the wheel to get the needle up. Unscrew the standard throat plate, storing the two screws in the two threaded holes in the top-center of the arm. Remove the bobbin cover. Unscrew the two screws that hold the shuttle onto the end of the arm. Set the screws aside and carefully pry off the shuttle and bobbin assembly and set it aside. The bobbin case can fall out, so handle it carefulloy, or remove it from the shuttle race. At this point all you have left is the shuttle driver and feed dog. Roate the shuttle driver to move it out of the ay of the feed dog screw. Use a large flat bade screwdriver, with a big handle, to unscrew the feed dog screw. It may take a few hits with a mallet to get the Lock-Tight to give up. Remove the feed dog. You can replace its screw in the hole for safe keeping, with just moderate tightening. Reinstall the shuttle race and bobbin case, exercising caution to align the bobbin case with the shuttle driver. Install the flat slotted throat plate You will now be sewing without bottom assist. This will change the stitch length in both directions, but more so in reverse. You can try reducing the pressure spring pressure to alleviate the force on the leather. This will allow it to feed a little smoother with just dual feed. Just don't reduce the pressure to the point that the leather lifts with the needle.

What exactly do you need me to explain?

That Super Bull has been for sale at least three times over the past two years. It was a prototype machine for sewing heat tiles onto space shuttles. The tiles were glued instead of sewn, making this machine unnecessary. The weak link may have been the available types of thread that might not stand up to the heat of reentry into the atmosphere.

I own a Singer 15-91 and have tried to sew leather with it. My findings are as follows: The biggest needle available is a #20, but it is hard to find in leather point. The heaviest thread that the #20 needle passes is #92 bonded nylon or bonded polyester. Number 18 leather point needles are available from most sewing machine shops. They are the right size for #69 (T70) bonded thread. This thread is rated between 10 to 11 pound test. It is best limited to wallet interiors, or combining the edges of soft leather or leatherette belts. It is also good for seat covers that won't be under a lot of strain. The maximum thickness I can get under the standard foot, set to its normal height, is 1/4 inch The motor needs to be helped with the hand wheel when trying to sew 1/4 inch of leather, or a soft wooden ruler covered in chap leather. This is even when I used a #18 needle, with #69 thread. The leather tends to lift with the needle, so I had to turn the presser foot pressure screw all the way down. A fully tightened pressure screw adds to the strain on the motor and machine and makes it harder for the feed dogs to move the material. When the motor bogs down under the strain, it makes an unhappy sound and gets quite hot. When it does feed leather, it sews it nicely, albeit with very thin thread and smallish stitches. Adding an even feed foot (fake walking foot) reduces the available clearance to about 3/16 inch. It does improve the feeding of two layers without the separation caused by the standard foot. However, these fake walking feet don't have real grip and if you hold back the leather, is slips under the foot.

Try moving the needle sideways, to distance it enough that the foot misses it when spun 180. A well timed machine with a good check spring will continue to form loops and sew no matter which way you move the needle mount. OTOH, if rotating the bell crank changes the lateral relationship between the needle and foot, something has been drilled off center, or has not been fully tightened into its housing. Check the screws that secure the head to the body. If you have a right angle flat blade screw driver, try gripping the two screws that are on the bottom of the bell crank and see if they are really tightened all the way.

Try Toledo Industrial Sewing Machines for system 134-35 needles. Or, ask Gregg at Keystone Sewing, or Ron at Raphael/Techsew. Finally, there is Nick-O-Sew, in Tenn-o-see

I used to have one that was used to sew Velcro onto reflective vests and evidence bags. I loved the resounding CLANK it made at the end of each tacking cycle!

No, it is and always will be a bartacker machine.

You must thread the top thread through whatever post or multi-hole guide comes before the upper tensioner. But, this is of little help if the thread is acting like a spring coming off the spool. Is the spool sitting on a thread stand cup and feeding straight up, through a guide eye, then on to the top of the machine? Is this black bonded nylon thread (he asked knowingly)?

I have the same type of machine, just a different name. My bobbin case is sometimes tricky to get back in. It is the moving feed dog bar that covers the opening where the bobbin case has to be pressed in that causes this issue. As mentioned by the previous responder, simply rotating the hand wheel will move that feed bar into a position where the bobbin case can be popped in with less effort.

The Singer 20U is a light duty, bottom feed zig zag machine, not suitable for leather. Is is great for light drapery and garment sewing.

You can get this kind of chain at Lowes, Home Depot or Menards.

My Cowboy CB4500 came with an add-on table attachment. It has four long bolts under it that go into matching holes in the pedestal table top, on the front and back side of the machine. It takes about two minutes to install or remove it. The table will support most flat work. I also got a drop-down roller edge guide that I find invaluable. It sews everything I put under the feet, from about 6 ounces to 3/4 inch.

I have a walking foot machine that is similar to your Juki. These are really upholstery machines, not built to penetrate and properly sew hard or thick leather, or to use heavy thread. So, I got a Cowboy CB4500 to handle the heavy work. It sews like a champ. I can go down to #138 thread, or even #92, by using smaller needles. Normally, it is threaded with #277 on top and either #207 or #277 in the bobbin, depending on what is being sewn. Cowboy machines are distributed and sold by Toledo Industrial Sewing Machines.

Sometimes, just raising or lowering the needle bar a fraction of an inch can help or hinder your timing and thread breakage problems. It is possible that after repeated pounding, the needle bar can get pushed up a little, which changes the timing position of the eye. You can test this by loosening the needle screw and lowering the needle in its mount, by 1/16 inch. Tighten it up and see if this makes matters better or worse. If lowering the needle improves the stitch reliability, the needle bar itself may need to be lowered to compensate for slippage. There are two Allen socket screws that secure the needle bar in its bracket. The faceplate needs to be removed to access them.

Search the Interwebs for a manual for the Consew 227R. They are very similar machines.

Singer of Japan made a blue body zig-zag industrial sewing machine: the 29U. It allows you to set the position of the needle for straight stitching, or to zig-zag, using two levers (needle position : zig-zag width). It should be adequate for marine upholstery, seat covers and even some light weight drapery. Do not attempt to sew leather on one of these machines! Pfaff also made/makes industrial zig-zag machines. Contact our dealers to see who has what in a zig-zag machine. with a motor and table.

The number after the RB- designates the generation of that machine. The current generation is RB-5

Right from the get-go I can see that not only is the top tensioner being doubled up un-necessarily, but the thread coming off the thread check spring is not going under the J-shaped thread-check bar, before going up to the take-up lever. This means that there is no slack in the top thread, which is going to cause skipped stitches and other tensioning problems.

This is very thin thread for a 30-70. Everything needs to be tweaked if you previously set it up with #138 thread. Start by moving the needle mount to the right. Loosen the upper screw in the oblong cutout and push the needle mount to the right, then tighten the set screw. This places the needle closer to the hook. Next, back off the forced lift setting, inside the left end of the trapeze. Loosen the thumb screw, move it down, from Dick (thick) to Dorf (thin), then tighten it in the lower position. Try some stitching. If you have any skipped stitches, look at the leather as the needle ascends. Is the leather lifting, or puckering under the foot? If so, increase the pressure spring thumb nut pressure. Your combination of a #18 needle and #69 thread is as good as it gets with 332LG needles. But, leather point LR needles work better than rounds and Schmetz needles work better than GB or Organ. Make sure that the foot has enough lift to allow a full-length stitch to form, at 5/inch setting on the sliding stitch regulator puck. When you load the bobbin into the case, make sure the thread is pulled through the tension spring and that it has enough tension to hold back the thread a bit. Then, feed it though the tiny hole, then through the hole in the center post of the bobbin case. This affects the stitching considerably. Finally, there is a paddle shaped spring inside the needle bar, just over the needle mounting bracket. Shine a flashlight on the spring and see if it is still making good contact with the flat area on the inside, where the thread passes on its way down to the needle. This is the check spring, and will cause skipped stitches if irt is broken, twisted, or bent away from the thread at the paddle end.

I used type 332-LG needles when I operated an Adler 30-70. They are considerably longer than standard industrial needles. If Bob says they are 2 1/8 inches long, I believe him (he probably has a pack of them in his office). My Singer patcher uses the same length needle as the type 135x16, which is just shy of 1 3/4 inches long. If your needles are closer to 1 3/4 than 2+ inches, they are the wrong ones for the 30-70.

Yes. It is the same as how my ULS works: punch a hole with a chisel pointed awl, then bring up a barbed needle through that hole. In your case, bring down a closed-eye needle through the same hole. If you intend to use your Cowboy 441 clone to sew holes into plastic, do tighten both needle bar screws first, as much as possible. Install a #26 or #27 diamond point needle, or make an awl out of a hard steel rod that has the same shank diameter as a 794 needle, by 2 3/4 inches long. Prepunch the holes with the awl in the machine, then install the correct needle and sew through them. If you are going to sew with a #25 needle, make the stabbing blade a little wider (like a #26 or @27 needle). Bob Kovar sells these huge needles and might be willing to build you an awl. It should be either a chisel or diamond shape at the blade, with a quick taper to round in about 1/8 to 3/16 inch. If you have a friend nearby with a Union Lockstitch or Campbell-Randall machine, ask him or her to sew the plastic for you. It would be safest to use a combination of a #4 needle and #5 awl, with #346 or #415 thread. The #5 awl pokes a big hole and is very strong. Smaller awls may bend. The size difference between the needle and awl allows the needle to cleanly enter the possibly ragged hole from the bottom, pushing its way into the hole. A #4 needle is also very hefty and less likely to get deflected by exit wounds on the bottom of the plastic.

My Union Lockstitch machine might be able to penetrate that plastic. But, it isn't worth it to find out otherwise. Use a drill.