Wizcrafts

That is the wrong size needle for #138 thread. You should use at least a #22, if not a #23 leather point needle.

How thick are the collars at the widest point? This will determine the type of machine needed to sew them.

Use a #18 needle with #69 thread in leather or webbing. Number 16 is for cloth and vinyl.

From the model number I suspect that it is a clone of an Adler 69 series machine. Call Bob Kovar (primary Cowboy dealer in the USA) to get more info on that machine. His toll free number is: 866-362-7397. Let us know what you learn.

I own a second hand Techsew 2700 (deprecated). It is identical to the Cowboy CB227R. These compound feed walking foot machines use a standard G size Singer bobbin which is often referred to as 1x capacity. They are best limited to a maximum thread size of #138 (22 pounds test), which works best with a #22 or #23 needle (depending on the density of the material). The maximum thickness they can sew is 3/8 inch if properly adjusted. My machine seems happier running #69 or #92 thread. The smallest thread I have run on it is #33 bonded nylon. The reverse function is part of the spring loaded stitch length lever. You have to pull and hold the lever down to back stitch. The holes will line up as long as you hold the lever all the way to its stop. When you let go the lever springs up into forward sewing mode. The cylinder arm is about 2.5" diameter, or so, (I'm not in the shop as I type this) and easily gets inside bags, cuffs and sleeves. The bobbins drop in from the top on the right side of the needle, under a sliding cover plate. My machine came with an optional table top attachment. The Cowboy has a similar table attachment and also can also have a drop down edge guide installed at an additional cost. But, I found a work around. There are spring loaded edge guide feet for sale with spacings from 1/8 to 5/16 inch from the guide to the needle. Problem solved! One final note is to make sure you get a mechanical dial controlled servo motor with the machine. Mine originally shipped with a push button controlled servo that started with a jolt at about 200 RPM. I replaced it with a Family Sew servo that starts at zero and increases smoothly to whatever maximum speed I set on the rotary dial. The motor is foot controlled. There is also a foot lifter for the feet that gives more lift than the hand lifter on the back of the head. IHTH

I suspect that the machine models you listed a 335, not 355.

There is a big adjuster cap screw on top that controls the foot pressure. It can be backed out until the marks are minimized.

My guess, based upon my ebaying, is that the much cheaper parts are usually shipped to you directly from China, Honk Kong, Taiwan, or elsewhere in the Orient. It could take a month to arrive. The higher price parts are usually in-Country. I would check the location before hitting the Buy Now button. Another reason for price discrepancies like that are when you buy authentic replacement parts from a brand's manufacturer, vs aftermarket parts from the Orient. The accuracy of the AM parts may vary widely.

I have added 3:1 speed reducers to most of my machines. That usually does the trick for me and should for you too. The question is what type of reducer to buy and who is going to install it? Then there's the question about your motor. Does it start up with a jolt at a couple hundred rpm? If so, does it have pushbuttons to control it? That type of servo is very hard to control and I have removed any like that and replaced them with this type of knob controlled servo motor. This motor starts at zero and speeds up to the preset limit of the knob. Heck, you may find that you don't really need a reducer with this motor. Note that when you change motor types, or add reducers, the v-belt length/lengths will change too.

The Class 26, et al, is a compound feed walking foot machine. All of these machines are designed to sew medium density materials, like vinyl, chrome-tan and thin veg-tan leather, draperies and denim. Light cloth tends to get pushed into the hole/slot in the feed dog. It also lifts with the inside foot on the upstroke which caused puckering and skipped stitches. You probably will need a flat bed straight stitch machine to sew thin linings.

Bags like to be sewn on cylinder arm sewing machines. Ask them! The next question is: which is the best cylinder arm machine fits my $2500 budget? If you are buying used, anything you can afford and don't mind dinking with when things go out of wack. But, if you buy new and the dealer offers (and provides) free support, you will easily spend $2500 (shipped). This could buy you a Cowboy CB341 or Cobra Model 26, which are clones of the Juki LS-341 (now superseded by the improved LS-1341). Here is a video of a Cowboy CB341 being demo'd: https://www.youtube.com/watch?v=zVJ9_3AbmO4 There are other brands available used that cost twice as much new as the above mentioned clone machines. Adler and Pfaff come to mind, as well as an actual Juki LS-341, or the current LS-1341.

I was being facetious ;-). Nobody who knows anything about industrial sewing machines is going to pay anywhere near that amount. Maybe if it was cleaned up it might fetch $250. This model 111w153 is a triple feed walking foot, but with low foot lift. It can sew a maximum thickness of 5/16 inch unless it was highly modified. They use standard G size walking foot bobbins and can just handle up to #138 thread, but is better limited to #92. I had one for a while.

If somebody is willing to pay $500, go for it! Sell it on Craigslist to a budding upholsterer.

The maximum needle size is determined by one or more factors, including: the diameter of the hole in the feed dog or throat plate and the position of the hook in relation to the scarf in the needle and how far it can be moved and remain in time. Those are physical limits. Additionally, there are thread handling limits that apply to any given sewing machine. Some machines have stronger or weaker take-up levers and crank shafts in the head. Some, if not most upholstery grade walking foot machines are built with an upper thread size limit of #138 (T-135) bonded thread, which has a breaking strength of 22 pounds. If that machine is threaded with #138 thread on top and in the bobbin, that is its safe design limit. Coincidentally, that thread combination calls for a #23 (Metric 160) needle. While those machines will operate with #138 thread using a #23 needle, they are happier running #69 or 92 thread with a #18 or 19 needle, respectively. All of the stresses are reduced with thinner thread and needles.

If you aren't already doing so, use a #23 needle with #138 thread, top and bottom.

What you want is a leather belt hook, like this one.

You can use the freeware Faststone Photo Resizer to reduce the file size for use on forums with filesize restrictions.

Try to increase the slack thread using the check spring adjuster, There are three adjustments available, depending on what type of check spring system your machine has. The style with the most adjustments has the spring inside rotating disks under the top tension disks. They allow for spring tension (loosen a set screw and use screwdriver blade to tighten or loosen the spring), spring travel (via a curved stop bracket on the bottom of the spring) and a curved slot adjustment to fine tune the amount of extra thread that is allowed on the downstroke. By playing with the check spring adjustments you can get a larger, longer lasting loop for the hook to pick off.

No. I use a #25 needle with #277 thread. A #24 needle hole is too tight to let the knots come up easily in veg-tan leather. You would have to really crank down the presser foot pressure screw and crank up the top tension, and/or lower the bobbin tension.

I would only use an oversize #230 needle if the bottom of the hole healed up before the knots can be pulled up. This might happen on Biothane harness or heavy webbing straps. For instance, I occasionally get hired to sew vehicle tow straps that are 2 inches wide and about 1/4 to 5/16 inch thick along the overlap. I use #346 thread with a #26 needle to offset the hole bottom closing up. This makes it easier to pull up the knots and center them in extremely dense material.

If you advertise the Singer 251 as a tailoring/dressmaker's machine it may sell fast. Dressmakers like to sew fast and that machine sure can lay down fast stitching.

The double needle walking foot machine can be operated with one needle and is capable of sewing leather, vinyl, canvas, denim, webbing and fire hose. The 251 is a bottom feed tailoring machine and not for leather or hoses. If you bought the 251 you made a mistake.

They will be metric thread. Contact an industrial sewing machine dealer to get the right parts. Don't ruin the threads to save a few bucks on local, wrong pitch parts.

If you are hoping for replies to your leather sewing machine question, a photo or video of it trying to sew would be more useful than the landscape photo you posted. As beautiful as the scene is, it doesn't show the machine. A close-up of the hook as the needle begins its upstroke would be most useful.