Wizcrafts

You didn't say what the problems are with the Boss machine. But, if they aren't resolved at the factory and you still want a manual sewing machine, there is one called the Cowboy Outlaw. It is sold and services in Toledo, Ohio. Also, Weaver Leather sells a manual sewing machine they call The Cub. For similar money you could get a motorized Cowboy CB2500. It is only bottom feed, but the teeth really pull the leather on the bottom. People using machines like it just rub out the tooth marks on the back side.

There is an attachment that is driven by the needle bar going up and down that sort of passively walks in sync with the feed dog. It was made for quilters and is sometimes called a quilting even feed foot. I had one that I used on a Singer 15-91 I had and it was useless with vinyl and leather. I had better results when I found a roller equipped foot.

Maybe a wallet, or maybe just a wallet interior. The only method of feed is the teeth on the feed dog. Because leather can be dense, more pressure may be needed on the foot to prevent the leather from lifting up with the needle. The higher foot pressure fights against the feed action and may result in uneven stitches. This is especially true if the top grain is sticky, rather than smooth. The foot may just dig in.

You can find these screws on eBay or from any industrial sewing machine dealer in the World. The hook used in your machine is one of the most common in existence. Why not buy an entire new hook, and a new driving gear? Techsew is in Montreal and can help you with parts.

I haven't read every word in the replies, so my apologies if this was already mentioned. Sometimes, when bobbin thread changes tension as you sew, reversing the direction of the bobbin may smooth out the flow. Standard practice is to insert the bobbin so the thread makes a sharp turn against the direction of the windings. This is to keep the thread in the slot leading to the tension spring and to offset the rotation of the bobbin case that could cause the thread to unwind inside the case. Most bobbin cases either include an anti-backlash spring or can have one dropped in under the bobbin. These springs may be a beehive shape or a 5 point star, or round with raised portions. If your bobbin case has one of those springs, try feeding the bobbin thread inline instead of against the natural direction of flow. Note: Changing the direction of flow in the bobbin case changes the tension. You will have to readjust the top and bottom tensions one way or the other.

Three of the four machines you posted pictures of have synchronized binder attachments. These machines are used to sew cloth binding over edges. Because of the way the binders feed the folded cloth, the machines are often set up without a 4 motion feed dog. If the machine you pick only has a sliding feed dog, it may interfere with sewing your sandals, especially if they are leather soled. In effect, the feed dog will be trying to push the work back towards you as you try to sew it. The only machine without a synchronized binder is the one called e-sew. If it has a 4 motion feed dog, it may be a better choice. A 4-way feed dog moves forward and backward and up and down. It is also known as "drop feed."

Buy different thread.

The 1181 has top and bottom feed and a static needle and inside foot. The outside presser foot claws the work in sync with the feed dog. It sews a little over 1/4 inch and has a short needle like the tailoring machines use. This machine is best used on chrome tan leather, vinyl, cloth and webbing. The teeth on the feet will mark veg-tan leather. The 1541 and 1508 are triple feed, with the inside foot, needle and feed dog moving in sync. They can sew 3/8 inch and use walking foot System 135x17 needles. The smooth feet won't dig in and mark veg-tan as badly, depending on the foot pressure you set.

The Adler 30-1 is a short arm, small bobbin patcher that is best limited to #69 (T70) bonded nylon thread. It can sew up to 5/16 inch if so adjusted, but is more comfortable at 1/4 inch of medium or soft temper leather.. The maximum stitch length is 5 per inch if the feed motion cam is not worn down. I have sewn on one with a worn feed cam and was lucky to get 8 to the inch into 6 ounces of leather. A well maintained Adler patcher usually sells for between 800 and 1500. This one is going for only $500. Even if you have to replace the feed mechanism, you will come out ahead.

It really depends on what is actually being powered on the machine. If it is only the motor, you can replace it with any servo or clutch motor you prefer. If the power also actuates the foot lift and trimmer knife, maybe, maybe not.

That is not a 1541, even though it says that on the label. The 1541 has a horizontal hook with an end loaded bobbin accessed under the sliding plate on the left of the machine bed. This is a Juki DNU-1541:

Most people who sew leather, vinyl and canvas use synthetic thread that has been coated in a polymer or resin that bonds the filaments together so they don't untwist as you sew. Some threads are more heavily bonded than others. But, any bonding is better than none. Glazed thread is smoothed out and the little cotton or linen fibers don't stick out. It is better than just mercerized, but not as strong as synthetic bonded thread. Here is a definition of Mercerized thread.

Those threads are glazed, or mercerized, but not bonded. You will have a hard time using cotton or linen thread is a normal sewing machine. The shoe threads are usually waxed before you sew. In the case of a sole stitcher, the wax is in a pot that feeds to a barbed needle. This strengthens the fibers. If you run this thread through a standard sewing machine, without wax, it will probably break during the take-up cycle. At least that was my experience with Barbour's Irish Linen glazed thread when I last tried it.

Regarding the "shoe thread," ask the seller to check the label to see which way it is twisted. Most single needle sewing machines with hooks spinning clockwise require left, or reverse, or Z twist thread. But, some shoe sole stitchers require right twist thread. If you use right twist in a standard sewing machine it may unravel as you sew. Note, some twin needle machines may require right twist for the outside needle if that hook spins counterclockwise..

$1500 will get you a Consew 206RB-5. It won't sew 7/16 inch out of the box, but it can use #207 thread top and bottom. The machine might could be altered to sew higher by a dealer.

You have a couple of options to sew 7/16 inch with a flat bed machine. Juki LU-1508 NH (high lift version that accepts #207 thread out of the box). Adler 696 ECO (Not a flat bed. Cylinder arm, sold by our advertiser, Weaver Leather) Cobra Class 20 (sews up to 1/2 inch. Flat bed, 207 thread.)

There are a couple things you should know about those machines. First, they are all compound feed walking foot machines. Your Mercury is a dual (top and bottom) feed machine. Second, they may lift higher with the foot lifter, but are still limited to sewing 3/8 inch of material. Third, if you start sewing without holding back the starting threads, you will have an instant thread jam. In your video you started sewing without holding back the starting threads. Fourth, These machines have a normal upper limit of #138 bonded thread, top and bobbin. You may be able to get the Juki and Thor to sew with #207 on top, but not the Singer. How thick do you need to actually sew? What materials will you be sewing at this thickness?

It could be. I got an extra heavy spring for my Cowboy CB4500 for use with hard and extra thick leather. The stock spring was too weak in some leather, but not in others. Note, that an extra heavy spring leaves extra deep tracks in the leather! I use bonded nylon 99% of the time and bonded polyester 1%. I have none of the problems your machine is giving you. Have you tried contacting the seller/dealer? The thread shredding can be caused by a burr on the hook, or throat plate, or feed dog. The hook may be too far from the needle, or the timing advanced or retarded. If the machine was purchased from a dealer I would be on the phone with them.

Nothing in these photos is of any help.

Consult this thread and needle chart to find the range of needles best used for a particular size of thread (top and bottom). If you run smaller thread in the bobbin, use the smaller needle listed. If you use the same size thread on both sides, use the larger needle listed.

I take issue with this recommendation. That size needle pokes a hole that is much too large for the combined size of the overlapping lockstitches. I normally use a #19/120 needle with #92/T90 thread. Sometimes I use a #20/125 for difficult material or sewing through double sided tape. I would not use a #23 needle unless I was sewing with #138 thread, top and bottom and the leather is medium to hard temper.

I know of several clone brands that are top quality. But, their availability depends on your location. You are in the Netherlands so you may not have dealers selling and supporting the brands I am familiar with. I recommend buying any brand you like from an authorized dealer who will setup and service the machine as needed. Chances are good that unless you make a rookie mistake and jam up the bobbin case and shuttle, the machine could outlast you. Talk with your industrial sewing machine dealers!

FYI, a type 3L v-belt is 3/8 inch wide at the wide top side. Most auto belts are type 4L, which are 1/2 inch wide. There is a big difference in applied pressure between the two sizes. With the proper length 3L belt you can probably tighten it back up to 1/2 inch deflection.

I would still replace the belt.

Your assumption is correct. If you leave a thread sock on while sewing, adjust the top tension to compensate for any additional drag on the thread.