Wizcrafts

Yeah, I Grok your pain. There is a little flat blade screw inside a hole in the bobbin case, forward from the tension spring screw. The screw inside that recess locks down the tension screw. Use the small screw driver that came with the machine to loosen the set screw, then adjust the tension screw for more bobbin tension. When you are happy with the back pressure, tighten the set screw to keep the tension screw from backing out.

If the photo is taken from the top of the leather, either the top thread is wrapped incorrectly around something it shouldn't be wrapped around, including itself, or a post, or one of the 2 disk sets, or the bobbin thread has come out from under the bobbin tension spring. If the photo represents the bottom of the leather, either the top thread has come out of the tension disks, or is not feeding through the take-up lever, or the bobbin thread is too tight, or the needle is too big, or the thread is too big for 6 ounces of leather.

Make sure that the thread doesn't bind in the eye of the #14 needle. This might be a tight fit for #69 thread, unless it is wound and bonded tightly.

I had to re-acquire all of my current stock of sewing machines from scratch, starting in 2009. My first good machine was a National 300N flatbed walking foot machine, made in Japan. It is similar to the Consew 206RB and Chandler 406RB. While it "can" sew with #207 thread, it does so with some difficulty, compared to #138. It simply cannot sew with #277 thread. The machine is good for slightly over 3/8 inch of material, including leather. The walking foot came with a clutch motor, which although I could feather it down to 1 stitch per second, it was stressful on my ankle. So, I replaced the motor with a SewPro 500GR, from Toledo Industrial Sewing Machines. My next important purchase was a Singer long arm, large bobbin 29K172 patcher, on a treadle base. I use it every week to sew patches onto motorcycle gang vests. My third best machine purchase was my Union Lockstitch Machine. It sewed 3/4 inch as is, but I modified it to sew 7/8 inch. It is thread-agnostic, as long as I have the right size needle and awl. It is currently set up with #346 thread. My fourth and truly best machine acquisition was my Cowboy CB4500. It is now in my leather shop and is used every day to sew anything from cuffs on jeans, to zippers in jackets, to belts, gun belts, weight belts, to holsters and sheathes. I just sewed together a 3/4 inch thick knife sheath, with #277 thread, top and bottom, using a #25 S point Schmetz needle. My next purchase was a Singer 31-15, which I use for flat work and material.

I'm glad to have helped you Andrew! Sew On!

Manual, schmanual. Try balancing the reverse ratio yourself. Here's how I do it... On the back of the head you will see a crank protruding and clamping into a slotted block. That crank's position in the long slot sets the amount of lift of the alternating feet. There should be a 6 sided slotted bolt on a shaft protruding from the right side of the slotted block. If you loosen that bolt the presser feet can be moved up or down manually. What I do when the stitch length doesn't match in fwd/rev is to lower the inside foot a bit, so it hits the top of the material at about the same time as the needle point makes contact. This causes the stitch length to increase both ways, but more so in reverse. You will have to try different contact timings until you find the best one for bi-directional sewing into the same holes. It may be that you have to set the inside foot to make simultaneous contact with the top of the feed dog itself, without any leather under the feet.

Here are a couple of things you should check, or readjust for problems sewing with #138 thread. Needle size: Use a #22 or #23 maximum needle size with #138 thread (aka, T135). Too large of a needle makes too big of a hole, which lets the loop dissolve before it can be picked up. Thread post: Wrap thin thread, like #138 around the top thread post one full turn before feeding it into the the upper tension disks. This provides some back pressure to keep the thread from lifting/twisting up in the disks and out of the primary tension position. Check spring: You may have to alter the tension and maybe even raise the starting position of the check spring to ensure that the check spring is not destroying the formation of the loop in the eye of the needle. Needle orientation: Sometimes it helps to slightly rotate the needle counterclockwise to aim the loop towards the oncoming hook. This tends to help more when the timing is very close, or other factors are interfering with the loop. Needle brand: Use a Schmetz needle if at all possible. They tend to produce the best loop under any given configuration. Needle point: Leather point is preferred Timing & Needle bar: You may be able to find a better vertical orientation of the needle bar by lowering the needle in its mount very slightly. If the thread pickup improves, the needle bar should be lowered in its clamp, inside the head. It is secured with two screws. Constant pounding can cause the needle bar to slip upwards, throwing the timing off (especially in reverse). Horizontal separation between the needle and shuttle may be to great. This is not so easy to fix. There is a spacer that goes into the end of the arm, before the shuttle mounting plate. If the spacer was designed for very large needles, like #25 and larger, a #22 needle may be too far away for a marginal loop to get picked up by the hook point.

Keep the machine oiled. Open the face plate every now and then and using a precision point oiler, place oile into all little oil holes on the moving cranks. Also, pop open the two rubber caps on top of the head, over the needle and inside foot bars and add some oil to those ports.

On production runs, you should wind a full, tight bobbin, then count the pieces as you sew them. When you do run out of bobbin thread count how many complete items were sewn before the one that needs splicing. That's what I do, other than opening the bobbin case every now and then.

You would certainly become familiar with it quickly, as it crushed most of your bones. Puritan machines are made of American iron and steel and weigh a LOT.

You will need a powerful servo motor if you go that route. Get at least 3/4 to 5/6 horsepower. For a clutch motor a solid 1/2 horsepower is the minimum. A 3/4 HP clutch motor is better.

I spray my belts with the belt no-slip sold at auto parts stores.

The 223 is a light duty machine. A #120 needle is only good for #92 (T90) bonded thread. If you want to sew with #207 (T210) thread, you'll need a #24 needle (metric 180). It is probably beyond the machine's ability to tension such heavy thread. The machine has a vertical hook and standard G size bobbin, which is not ideal for anything over #138 thread in the bobbin.

I have both spring guides and compensating feet. They serve a different purpose. The spring guide presser foot can be used as an edge guide, as long as the material is at least 1/16 inch thick. I find them useful on my walking foot machine which has a swing away roller guide, where I need to go around an edge that is on top of another layer (e.g. a rifle sling where the body and lining captures the tail). The compensating feet are better used for top stitching, as Eric pointed out. The sprung toe or toes are not as square on the bottom as a leaf spring and tend to run up onto the upper level if you're not careful. I use the compensating feet on my straight stitch machine and spring guide feet on the walking foot machine. Normally I just use a left toe foot and my swing away edge guide. None of these apply to 441 or 205 type machines.

It was: his machine head

I believe you can forget about using that machine for sewing anything heavier than a leather vest or your pants and shirts. Here are its specs.

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!