Wizcrafts

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.

Sewing machines do not form saddle stitches. They are either lockstitch - with overlapping knots that need to be buried inside the material, or chainstitch - with a looper forming a thread chain on the bottom. The latter is only useful if you can't see the bottom of the work and heavy duty chainstitch machines are not easy to find. Briefcases were sewn with Puritan chainstitch machines back in the day. Everything else is done on lockstitch machines. The type of sewing machine you need to sew leather depends on a number of factors. It could be a flat bed, post bed, or cylinder arm. It all depends on how the work needs to be stitched. Belts, straps and flat items are best sewn on a flat bed. Hats and bags are better sewn on a post bed machine. Sleeves, cylindrical items and things the hang down on the bottom are best sewn on a cylinder arm machine. Many cylinder arm machines have accessory table attachments for sewing flat work. The things you describe don't require a super heavy duty machine. Show us some pictures of the things you are making and we may be able to recommend specific machines.

The belt may be bad. Try another belt.

Oooooooo!

Do NOT run this machine a high speed without oil in it. It could seize. You may run it very slowly by feathering the clutch.

That's where I buy my motors and reducers.

LOL Order from CowboyBob. He is an industrial sewing machine dealer. His phone number is in his signature under his name.

I am currently using Barge all purpose, clear, TF, quick dry cement in a 32 ounce can with a brush. It is available in larger containers too. But, it costs less to try a quart!

Try Masters quick drying cement and/or Barge super speed toluene free contact cement.

JRM Clips makes them as the 3000 series, in New Jersey. I recommend calling them rather than submitting the contact form.

I bought my inline feet from Toledo Industrial Sewing Machines. Their number is: 866-362-7397.

That is a Union Lockstitch Machine, from 1910. They built them that way so they could handle the heavy stacks of leather used in the harness trade. It easily sewed 3/4 inch with extremely thick thread (#415 bonded nylon or 7 cord glazed linen). The stack in the photo is only 24 ounces. Not much of a challenge for a ULS.

Use a larger needle, like a #140/22

450 pounds