Wizcrafts

I've been sewing leather since 1984. My Father had a tailor shop for over 6 decades and he only owned one sewing machine: a Singer 31-15. Once he set the tensions, he was good to go. But, he only sewed cloth. Armed with this history, my first industrial sewing machine was a straight stitch Singer 96k40. I bought it to sew a leather vest that i was constructing from a pattern and leather that I bought at my local Tandy Leather store. After gluing the varipus pieces together I began sewing across some back seams. The moment the foot encountered a new layer, it stopped in its tracks. When I used the knee lever to lift the foot, the stitch tension got screwed up, then the needles broke. I went back to that dealer with the vest in hand and he sold me a Singer walking foot head only. It dropped into the same table. That machine sewed the vest without any hiccups or readjustments. It was the old style spring foot mechanism with an oscillating horizontal hook. Decades have passed since then, and I now have a shop full of walking foot machines. The absolute best one for climbing up and down while maintaining good knot placement is a Cowboy CB4500. The next in line is an Adler 30-7 patcher with a top feed walking foot that turns 360 degrees to feed the work in any direction. The rest of my machines are compound feed walking foot machines. Some have issues changing to different layer and others are not so bad. All of my machines have check springs with adjustments for tension, stopping position, and importantly, slack. When sewing thick seams, it is best to give the top thread more slack via the check spring adjuster. Most of my machines have a common round disk covering the check spring. There is a curved slot on the top area with a set screw that can be loosened and tightened to control the amount of slack in the top thread. If you are going from a single layer to a double layer, preset the adjuster for the maximum slack, then adjust the top tension to hide the knots well inside the single layer..You should get them drawn up to about the same depth when you come to the new layer. While this holds true for moving UP to a new layer, it may or may not be the same going down. Sometimes, the first stitch or two will draw the knots right up on top of the bottom layer because the foot is not directly pressing down around the needle. Here's where using a compound feed machine excels. It has an inside alternating foot that pressed down directly around the needle. As long as that small foot makes hard contact with the bottom layer, the stitches should be properly buried. Another bad thing that can happen when transitioning from a higher level to a lower one is that, without intimate presser foot contact, the bottom layer may lift up as the needle ascends. This not only throws off the knots, but causes skipped stitches because the thread loop on the needle dissolves before pickoff time..

I have dealt with images since the start of Web 2.0. Back in the days when you connected to the 'net through a dial-up modem, image filesze mattered a lot. So, I researched some Windows programs and bought into Paintshop Pro, which is now owned by Corel Corp. One of the features of Paintshop Pro is that, after any resizing, cropping, sharpening or effects, you can save as both a file TYPE and QUALITY. If you save the photo as a common JPG file, you can choose the amount of compression to apply to reduce the file size. I find that I can save jpgs at 80% quality and still make out all of the details unless you enlarge the photo a lot. Another program that does this is called FastSone Photo Resizer. It does everything from one interface and is made for Windows computers. If you don't have a Windows computer, there are photo resizing Apps available for most smartphones...

That spring pushes down on the inside foot, which pushes down on the material under it. Under that is the feed dog with its hole or slot for the needle. If you get prominent pock marks on the bottom from the hole in the feed dog, back off that top screw and let the main pressure spring on the back exert most of the foot pressure. I've attached a manual for the Singer 111w155 and 156 that shows the various views of the parts, including the rear pressure spring. It also contains valuable usage details. 111W156.pdf111W152_W153_W154_W155.pdf

No, it isn't. But, it does have a strong effect on the force needed to turn the machine it it is all the way down. That spring and screw affect the inside alternating/vibrating foot. The spring I was talking about runs along the back side of the machine. It is a long, flat bar, about 1/8 inch thick, 1/2 inch wide and maybe 10 to 12 inches long. There is a screw about half way along the back side that pushes down to add pressure to the outside foot.

I have a 211G156. The foot pressure is adjustable via a screw over the long pressure spring. Try backing off that screw and the foot pressure should ease up.

You can buy 1/4 inch diameter leather belting and a steel C clip and cut it to size. Order a 64 inch length and you should be golden. You'll need a tiny hole punch, like for poking a hole for a hand stitching needle. Most revolving punches have this size in them.

Thanks for posting this data with the tpi and equivalent screws.

@Agent319Contact Bob Kovar, at Toledo Industrial Sewing Machines, in Ohio, or Ralph's Industrial Sewing Machines in Denver. Both are long time Singer dealers. I believe that Ralph's bought all of the remaining parts when Singer went out of the industrial sewing machines business. Finally, there's Hoffman Brothers in Des Plains, Il. They were also Singer sales and service going waaaaaaay back.

This is very good advice. It might not be obvious to some people who haven't worked on disassembling sewing machines before.

That's a first for me. I have never had a machine that threaded the bobbin retainer tab like that.

First of all, I see thread that is bound onto the bobbin hold down tab. Free that thread before you do anything else! There should never be thread trapped like that! After freeing the thread from the tab, check the hook timing vs the eye of the needle on the upstroke. A properly timed hook will intersect the needle about 1/8 inch above the eye and sill be within the scarf cutout. Many times, a late hook will cause that snapping sound. Advance the hook a bit the loosen the thread loop. The check spring comes into play here. If the travel is too long, the top thread stays taut longer than necessary. Before you change the bottom stopper, try moving the screw in the curved slot to the right end of its travel. If that doesn't help, loosen the screw under the bottom stopper bracket and move it so the spring only moves a little past when the needle makes contact with the top of the leather. This adds slack thread and reduces the tension as the thread goes around the bobbin case.

I agree with your assessment. I got my Cowboy cb4500 in 2011 or 12 and haven't had any mechanical problems or failures yet. It has more than paid for itself over these years. I will mention that it is necessary to keep it well oiled to ensure a long life. This involves removing the left faceplate occasionally to oil all the little holes in the crankshafts.

What kind of motor is it? Can you take a small resolution picture of the machine and the motor under the table and upload it here? Use the lowest setting on the camera, like 1x1 or 3x4. If you need a new motor, consider this type, which I use.

@Lostranger When I have problems with patchers, and the timing is as close as it can be set and the bobbin thread is not getting picked up, I look at the following things. The top threading. Make sure you've gone around the top tension disks and that they apply sufficient tension when the foot is down. Make sure you are feeding it through the hole in the check lever on top, then down the snout. The needle system. Make sure you are using either System 29x3, 29x4, 135x16, or 135x17. Make sure that there isn't a broken needle shaft stuck inside the needle clamp and that the needle is all the way up in it. The needle orientation. Make sure that the rib side is facing left and the scarf cutout is facing due right. The needle position. You can move the needle clamp to the left or right to get as close to the hook as possible. The paddle spring. This often overlooked spring is inside the needle bar, just above the needle clamp. It's job is to hold onto the top thread as the loop is formed when the needle makes a down>up job. If this spring is bent, gouged, or missing the thread loop will dissolve before the hook can pick it off the scarf of the needle. Check the driving gear inside the gear box to see if it has come loose. This gear is directly under the shuttle. There is a small screw inside the gear that secures it to its shaft. There is a hole on the back of the arm, inline with the gear. Rotate the wheel to bring the screw into view in that hole.You'll need a narrow blade precision screwdriver with a flat blade and good side handle to tighten it if it's loose. A loose drive gear throws off the timing. Finally, adjust the spring tension and travel of the check lever on top. It's possible that the spring is pulling it up too much and overpowering the paddle spring as it tries to secure the loop at pick-off time. If all of this fails, get rid of it. I fought with a blue body Singer long arm patcher for years and it never sewed reliably. I got rid of it and bought an Adler 30-7 and haven't looked back.

Good find! Now, have you figured out how to keep this from happening again?

There is a screw going into the housing that holds the check spring shaft in place. You should see it on the right side behind your arrow. Loosen it and wiggle the shaft out. The screw's job is not just to hold the assembly in place. It also is used to adjust the spring force. You would loosen that set screw, then rotate, then use a screwdriver blade to rotate the shaft to the left or right for more or less force. Once you are happy with the spring setting, lock the shaft down with the set screw.

I'd start feeling and looking at the thread guides for burrs. You didn't mention whether or not the thread is bonded. If it isn't, you're supposed to run it through the wax pot to bond the strands. If you don't have Sellari's stitching wax, order some online.

It is not difficult to add a speed reducer later. However, you will need to buy two new V belts: one from the motor the the large pulley on the reducer, and the other from the reducer's small pulley to the machine's pulley.

@JWfur If you intend to use a 441 clone to sew thin or soft materials using thin needles and thread, you'll probably need to upgrade the stock feed dog and throat plate to a narrower set that resists the tendency of some materials to get shoved down into the cutout in the throat plate and the oval hole in the feed dog. These aftermarket feet and throat plates are made by one of our members. His website is here. I use some of his items.

I use the servo motor and speed reducers listed on this web page.

Sailrite does offer smooth and a knurled foot set for their leather sewing machine variant. The pebble grain pattern is a little friendlier to veg-tan ;leather than the stock feet, which have angled teeth. The totally smooth set will have less pull on the top layer and could slip instead of feeding slick material.

The 5100 can sew fur items if you install the blanket foot set made for it. This set has teeth on the feet and feed dog that help grab slippery material.

The O.P. hasn't responded since he posted this, on April 14, 2024. I suggest that you start your own topic. If you upload photos, keep them as small as possible and in .jpg format.

@Pinto, sometimes the only way to obtain replacement parts that aren't available from dealers is to buy another machine of the same make and model and salvage parts from it. In your case, you could hunt for another Singer 15-91 in antiques shops, or Craigslist. Or, buy one from Ebay and pay through the nose.

I have used Barge TF with good success. But, lately I've been using Master Cement and it is a permanent bond. Master is usually sold to shoe repair shops, which is how I learned about it.