Wizcrafts

Is there a reason why you posted this topic 5 times in a row?

Check your check spring threading.

The 31 class are for tailors, seamstresses and decorative shoe uppers. Some later models can be tweaked to use #92 and possibly even #138 thread (mine cannot). But, they are very light duty machines with bottom feed and soft tension and pressure springs. You need to move up to a different class of machine to sew rugs and tack. Check out the CB2500.

I found this: " Same as 31-15 except fitted with reversible drop feed. For cloth. (10/1952) "

As long as those feet are advertised as fitting compound feed, Singer 111 type walking foot machines, yes. That class of machines uses the same diameter bars for the inside and back feet and have the same mounting system (slotted rear and narrow round front bars). Note, most, if not all Pfaff and Adler walking foot machines use different foot mounting systems and will not be compatible with Singer style machines.

If I was in the market for a portable walking foot machine, I would not hesitate to buy a Sailrite. The price may be higher than the Asian clones, but the quality offsets the difference. Sailrite has optional knurled feet and feed dogs for sewing veg-tan leather. The feed is not as efficient as a triple feed machine, but is better than just bottom feed. Best of all, if you overstress one of their machines, Sailrite will sell you replacement parts, many of which will be beefier than the originals from a decade ago and more. The Ultrafeed machines were discussed at great length about a decade ago on this forum. Use our site search for Sailrite and read through the results. Or, use Google search with the phrase: site: leatherworker.net sailrite ultrafeed - where you will find fascinating discussions like this topic about modding a Sailrite.

According to this needle and thread chart, 0.6mm falls somewhere between #277 and #346 bonded thread. The minimum needle size would be a #25/200 and the maximum would be a #26/220. To use these combinations requires a harness stitcher class of machine, like the Cowboy CB4500 and the Cobra Class 4. If you don't need to sew 3/4 inch, a Cowboy CB3200 is a less expensive alternative. If these machines are beyond your budget, the CB2500 and similar GA5-1 type machines, like the Techsew 3650HD can handle #277 thread and sew up to 7/16 inch of leather. These are clones of the ancient Singer 45k series and are bottom feed machines only with a fixed presser foot. The teeth on the feed dog are substantial. You can forget about any of the upholstery class machines if you want to use #277 or #346 thread. Furthermore, the lockstitch knots formed by such heavy thread are very prominent and require at least 12 to 16 ounces of leather to completely bury them. Note: most modern lockstitch machines cannot use waxed linen thread. They must be operated with bonded nylon or bonded polyester, or another synthetic, or dry, glazed, left twist linen thread (5 or 6 cord).

Please define "thicker thread."

If the bobbin anti-backlash spring is missing, AND if the bobbin is inserted so it feeds in the same direction as the shuttle is rotating, AND the bobbin tension is a little on the loose side, extra thread can be pulled out when the OP makes a right angle turn. Personally, I would tighten the bobbin tension, then balance the knots with more top tension, then pull the bobbin out and turn it over so it feeds against the rotation of the shuttle. I've been know to do weird shit like that.

I think the previous responders were thinking that the loops were on the top side. The OP stated that the loops are the bobbin side, not the top. Let's assume this is a fact. If the bobbin thread forms a loop under the material, the bobbin might be inserted so that it's feeding the wrong way, or the anti-backlash spring is missing, or the bobbin tension spring may be too loose. All of these, but especially a missing anti-backlash spring can allow the bobbin thread to continue feeding when you stop suddenly.

I made the mistake of buying an off brand portable walking foot machine couple years ago from an eBay seller. The box was dropped on the handwheel end during shipping. When I unpacked it, the machine was seized. I tried to free it up for one day, then mailed it back and got a refund. The crank shafts were made of soft metal that had bent from the rear impact. The casing was crude and had jagged edges when I opened the top cover to check the damage.

It is my understanding that only the Sailrite brand machines have been regularly upgraded as flaws or weaknesses are discovered. They say as much on their website and in videos they produce. This is important if one intends to continue using the machine for an extended period of time. They have beefed up cranks and bearings. While not on par with a full blown industrial dual feeder, they are more than a step above the majority of Chinese clones.

Double needle machines are used in upholstery for topstitching across previously sewn seams (that were sewn together inside out). They are also used in the construction of jeans and work clothing to secure and reinforce folded down seams. These are normally flatbed machines with large bobbins with fast clutch motors (time is money in upholstery) driving them at 2000 rpm and above. Turning sharp corners is tricky with twin needles. You won't usually find these machines in hobbyists' leather shops. They are factory machines used by auto seat cover makers and professional upholsterers. Any flatbed machine gives better support to flat work than a cylinder arm machine. Sitting down at a full size table is much better than trying to fit flat work onto an add-on table attachment on a stand up cylinder arm. Cylinder arm machines are a must have if you sew things that cannot be held flat on the bottom. This includes shaped holsters, pouches and cases with belt loops and clips sewn or riveted on the back, hats, cue stick bags and round objects and preformed curved straps. Cylinder arm machines are usually built to sew at the very left edge of the arm, allowing shaped work to move below the throat plate level. You cannot do this on a flatbed machine. Clothing often takes multiple types of sewing machines to assemble. Some jeans require at least 5 different sewing machines. Backpacks and some bags can take two or three machines (flatbed, post bed and cylinder arm). You will no doubt find that you need more than one machine to do professional work. Some will be light duty and some may be heavy duty. Different builds of machines accept different ranges of thread. You have much to learn and a lot of money to set aside to experiment with. The simplest way to begin is with a common flatbed walking foot machine and build your inventory as the need reveals itself. Some members here start with a cylinder arm machine and construct or buy a slide or bolt on table attachment. But, if you really need a cylinder arm to sew a part, nothing else will do the same job.

The welt size on the foot equals the diameter of the covered cord. If your cord is 3/16" and the covering material is 1/16", the combined diameter is 1/4". That's the size of welt foot you need for that combo. Most double welt feet are 1/4", but others are available. Singer 111 feet refers to a style compatible with a Singer 111w155. Since Singer has been out of the industrial sewing machine business for a long long time, the only actual Singer feet for sale will be used, or new old stock. Good luck finding authentic Singer feet. If you hunt long enough, some will show up. otherwise, buy what's available in the market. Ask local upholstery shops if they have an extra set of "Singer" double welt feet. I scored mine with a machine I bought from an upholstery shop. It was in the drawer.

Anybody who may be interested in these machines should know that they are located in the Asian country Sri Lanka (an island nation south of India in the Indian Ocean) and the seller does not know if he is willing or able to ship them. If you live in, or near Sri Lanka, these machines could be a good deal. He has not stated what voltage and phase the motors are either.

I bought some brown and black calfskin that I use for wallets. It is about 2 ounces thick. I also have some dark brown and black haircell pigskin that is about 1 ounce thick, which I sometimes use for interiors. PM me if you want to discuss your wallet project with me.

It might be best to find an industrial sewing machine mechanic or dealer who has done this before. Otherwise, you are on your own.

It sure looks like the post screws need to be loosened, then unclamp something underneath holding the gears in place, then move the entire post to the right until the hook clears the needle. This movement might change the hook to needle timing slightly, maybe for the better.

What type of feet came with your Cobra 26? Post a picture of them. If your machine uses standard Singer 111 style feet, buy a wide outside foot, or a complete extra wide inside and outside set. The wider the footprint, the less it digs into the leather. There are dozens of different presser feet for standard walking foot machines based upon the Singer 111w155. Second, try backing off the top pressure screw. It only needs enough spring pressure to hold down the leather until the needle has cleared it on the way up. Less foot pressure results in less marking. If none of the above work, try taping a thin piece of hard leather next to the left side of the stitch line. This will act as a buffer between the outer foot and top grain and won't interfere with your edge guide on the right. If you are using a right toe foot, tape the buffer piece on the right side of the stitch line. Leave enough clearance for the inside foot to make full contact with the top grain.

There was a discussion about this model during 2016, in this topic. Maybe it will answer your questions about this long obsolete machine with many parts made of unobtainium.

Call your technician and tell him that he sold you the wrong part. It should be on the installer to install a correct part.

It looks like nobody has yet told you that Ferdco is long out of business. There is a sewing machine dealer in Chicago that bought some of their remaining stock. But, you probably won't find any authentic, official support for these machines. They modified the mechanisms on various Bull models and some parts were custom made by Ferdco.

You can buy a brand new Consew P-1206rb for under a thousand dollars. It is similar to the 206 mechanism, but is self oiling and lacks the safety clutch button. If you remember to hold back the starting threads and maintain proper threading and top tension you won't need a safety clutch.

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