Wizcrafts

I use titanium coated needles in all of the machines that accept systems DBx1/16x257 and 135x16. They cost about $2 more per pack of 10 and are less likely to stick in the material from heat or basting tape.

You're about to encounter the classic what machine can do it all conundrum. The answer is none. You already have a machine type for medium thicknesses with #138 thread. To sew thicker, and/or with heavier thread, you will need a substantially heavier duty machine. This class of machine is sometimes called a harness stitcher, because that's what they were originally designed to sew (as well as thick buffing wheels. There are several machine styles in this category. They are... GA5-1 style, based on/cloned from the Singer 45k models. These are bottom feed only machines that are usually setup to sew between 7/16 and 1/2 inch of leather. The teeth really dig in hard on the bottom. They are best used with thread sizes 138 through 346. Your least expensive option, they sell for between $1000 and $1400. Juki TSC-441 and clones. These machines have triple feed and can sew at least 3/4 inch, with Cowboy, Cobra and Techsew models rated at 7/8. The aforementioned clones have smooth feed dogs. The original Juki did not, but may now have it as an option. A Juki 441 will cost you about $6,000, while the clones go for the mid 2ks through lower 3ks. Cowboy CB3200. This machine has triple feed, a smooth feed dog, sews up to 1/2 inch and can be tweaked for 5/8 inch by giving up the very bottom. It uses the same needles as the bigger brothers from Cowboy and thread from #138 through 415. They sell for $1900 right now. Adler 205-370/374. These machines (discontinued by Adler) sew 3/4 inch and run smoother than the Juki and its clones. The 374 subclass has a smooth feed dog. They were selling for between $6500 and $7,000 until the end. The new Adler 969 ECO. It sews almost an inch of leather and has a built in motor. They are sold by Weaver Leather and cost about $10,000, more or less. Campbell-Randall Lockstitch machines have a needle and awl and produce an awesome stitch that looks great on both sides. They sew 3/4 inch out of the box, with higher lift options available. They can use linen or bonded polyester thread, from 3 cord through 7 or 8 cord (~#138 through #556 bonded), with the proper needle and awl combination. There is a learning curve and they are very expensive (over 6k). Sold in Texas. Union Lockstitch machine, also sole by Campbell-Randall company in Texas. This is a high speed needle and awl harness stitcher that sews 3/4 inch. Handles the same thread types and sizes as the Campbell-Randall. A little less expensive the the CR Lockstitch (~5k).

If you have a lube pot on top of your machine, buy some liquid silicon lube and run the top thread through it. Most industrial sewing machine dealers have quarts in stock.

You could ask the seller if they could sew a 1/2 inch stack of leather with the heaviest thread and matching needle they have, at the maximum stitch length, sending you a photo of the results.

This is a case of bring your own stack of leather and see if it sews that thickness and what the maximum stitch length is at that thickness.

All of the class 153 machines are rated at #138 thread, top and bottom. The stitch length depends on the type of stitch length adjuster used in that particular machine and how you set it up. My Singer class 111 walking foot machines have a threaded rod and knob on the back of the hand wheel. The maximum stitch length is about 4 to the inch. The later model 111w155 was able to eek out 3.5 spi, using a different stitch length system. The Singer 153 uses a standard G size bobbin that does not hold nearly as much #138 thread as newer M style bobbin machines do.

What you have there is a Union Lockstitch machine. I've owned two of them over the years. They are different from Randall Lockstitch machines (now called Campbell-Randall Lockstitch), like apples and oranges.

Search Leatherworker.net for Adler 105-64. There should be a few discussions about the machine and its capacities.

That's a good thing! They really got these motors right compared to the old push button styles. BTW: Did you change the image file in your signature? The usual banner is missing, leaving only a link to your website. The missing file is: kovar.gif

It looks like a clone of an Adler 105-64

Try swapping out the pressure springs for lighter/softer work. You don't need the extra heavy coils until you sew stacks of hard leather. It only takes a minute to unscrew the pressure screw.

The OP already tried backing off the foot pressure, to no avail. Also, there is no separate pressure screw adjustment for the inside foot. Both feet are adjusted together with a big threaded cap screw on top of the machine head.

We can add this to our knowledge base of quick fixes for mystery problems

Let us know how this turns out for you.

There is a spring inside that motor that is supposed to lift the lever all the way up. Something happened to that spring. You can call one of the Cowboy dealers for assistance with your motor. Your closest dealer is Solar Leather in Texas, then in Toledo Industrial Sewing Machines in Toledo, Ohio..