The Type Of Sewing Machine You Need To Sew Leather

[Wizcrafts]

Content to be added and updated on an ongoing basis.

Welcome to the Leatherworker.net Leather Sewing Machines Forum! If you are new to this forum and you are seeking information about the right type of sewing machine you'll need to sew leather, you're in the right place. Everything stated below is either my honest opinion, or the honest opinions of other members of this forum. We all have personal hands-on experience sewing a broad range of leather projects on a broad range of sewing machines. Most of us have worked our way up, trying different machines, fixing up old ones, modifying them, tricking them out, all in usually fruitless efforts to sew something they are simply not capable of sewing. This is especially true when it comes to sewing leather.

Leather varies in texture, weight, stickiness, thickness, density, dryness and chemical composition. No doubt, some of you have seen pictures and videos online, showing this or that machine sewing leather. Those pictures are uploaded by the seller of the machine, to broaden their purchasing audience. What many first time sewers don't realize, is that just because a particular machine is said to be able to "sew leather," that does not mean it will do it well for the types of leather the buyer wants to sew. Leather varies, as stated above. The machines that can sew garment weight leather may not be able to sew chaps, belts, tack, holsters, or saddle bags. Just because a machine is large, or metal bodied, or or even industrial, does not make it a true leather sewing machine!

First, I will address the machines seen on eBay, sold as Industrial Strength sewing machines. Most are all metal and proudly state that fact. The sellers talk about the "powerful" 1.2 or 1.5 amp motors that are attached. Some even have ribbed drive belts and gear reduction, to eliminate slippage when sewing thick material. No doubt these are strong machines. I have a few myself. I have 2 old iron body Singers and a metal body Kenmore, even an ancient White Rotary machine. Will they sew leather? Yes, two layers of 2 to 4 oz garment leather. Will they sew leather with nylon thread? Yes, but no bigger than #69 nylon. Will they smoothly feed garment leather as it is sewn? Yes, as long as it is fairly small in size and weight and not stitcky on the top grain. If the top is sticky, no way, Jose. Sticky vinyl and leather usually gets dragged back by the top pressor foot and the stitches are either too short, or filigree the material, or skip frequently.

Sticky material, like smooth top grain chrome tanned garment leather and Naugahyde (vinyl), does not feed evenly unless the pressure on the "pressor foot" is reduced significantly. All of the feeding is done from the bottom, by the teeth in what are know as "feed dogs." The pressor foot has to apply enough pressure to the top of the material to keep it from moving between stitches and also to prevent it from lifting with the needle, as the needle begins its ascent. This is when the thread in the needle's eye forms a loop for the rotating or oscillating "shuttle" pickup point to grab. The grabbed top thread is then pulled around the bobbin case and bobbin thread, which is pulled up by the lifting take-up lever, to create the lockstitch inside the material. If the top pressure is insufficient for the thickness and density of material being sewn, the material will lift with the ascending needle and top thread. When this happens the loop may not be formed and there will be skipped stitches. Even if the material is held down by the foot to form the stitches, the spring pressure may not be enough to hold down dense veg-tan leather when the take-up lever lifts up. If the leather lifts during the take-up phase the stitch length will vary wildly, the layers may slide out of alignment and the needle may deflect and break. This can also cause skipped stitches.

In an effort to overcome the problem of feeding sticky vinyl and leather, sewing machine companies and aftermarket manufacturers produce add on pressor feet to make it easier to feed these materials. Some dealers sell replacement feet with little rollers inside them (roller feet), or teflon plastic feet that claim to allow sticky material to feed better that steel feet. Others sell actual rolling wheel pressor foot attachments and sets, where the foot, feed dog and throat cover plate are replaced as a group. Finally, you can usually find a replacement foot called an "even feed" foot, or "walking foot" attachment. It contains an inner and outer pressor foot, which alternate up and down as the needle moves up and down. This is done by a lever that is hooked on top of the needle screw on the needle bar. The inner foot presses down and moves as the needle lifts out of the material and the feed dogs pull the material back. When the feed dogs reach the preset stitch length they drop down (drop feed) and the inside foot lifts up with the raised needle bar and snaps forward. The outer foot then drops to hold the material in place until the needle has penetrated the work again and is ready to form the next stitch.

This is not a true walking foot, as is used in true walking foot machines. It is an effort to improve the feeding ability of the wrong machine for the job. An add-on walking foot will not actually help you feed heavy garments or chaps through the machine, but it will allow the leather or vinyl to move and stitch without stitcking to the bottom of the pressor foot, allowing you to increase the pressure to prevent lifting, shortened stitches, or skipped stitches. If the material being sewn is long and wide, or heavy, your machine will have trouble pulling it back to form the stitches, despite having the even feed attachment installed. There are no teeth on the bottom of the pressor feet and the material can slide easily with a little tug, or from the weight of the work folding over the front of the work table.

I have learned that these even feed attachments usually reduce the clearance under the feet. This means you cannot sew as much thickness as with the standard foot. If you raise the pressor foot bar for more clearance, the needle bar, or top thread guide on the bottom of the needle bar will hit the inner pressor foot. They are a compromise feed system.

Even if you are able to feed the material through an industrial strength sewing machine, you are going to be limited in the thickness that it can sew, as well as the size of thread it can handle and the sizes of needle it can use. Number 69 bonded nylon thread is fine for leather vests or small vinyl projects, but is not so good for upholstery or chaps, or anything thicker, like belts and bags. For these projects, you'll want to use at least twice the size of thread: #138. At this point, most home machines drop out of the picture. Even a lot of actual industrial machines will not sew with #138 or larger nylon thread. They might be able to sew soft polyester or cotton thread in larger sizes, often sold a button or topstitch thread.

To properly sew leather you need an actual Walking Foot sewing machine. In my next installment I will define the various types of walking foot machines and what makes a dedicated leather stitcher different from a leather-capable sewing machine. I have to go earn my keep now, but maybe some other members will add to this topic.

Later!

Barra; Joanne; can this become a Sticky topic?

Edited July 11, 2010 by Johanna
turned into a sticky- thanks Whiz!!!

[outcast]

This is good stuff. I look forward to more.

[Wizcrafts]

When I left off my last post in this thread, I said that I would define the various types of "walking foot" sewing machines. So, here I go!

The home and industrial strength sewing machines I wrote about yesterday all come equipped with flat, static "pressor" feet (the foot shaped steel plate that presses down on the material and applies pressure). I detailed about how a steel pressor foot drags sticky material, causing shortened stitches and showed some optional replacement feet that assist the machines in moving leather and vinyl material properly. This ended with my statement that I recommended a true walking foot machine for sewing leather, rather than a converted flat foot, straight stitch machine. A straight stitch machine does not have zig-zag capabilities and is usually equipped with a flat pressor foot and the work is driven entirely by the bottom feed dogs.

The difference between flat foot, bottom feed (feed dogs), straight stitch machines and walking foot machines is profound. A walking foot machine may have any of the following drive configurations and still fit the walking foot classification.

1. Compound/triple feed: the feed dog, needle and inside pressor foot all move together, in synchronization. BEST OVERALL SYSTEM
2. Double feed: The feed dog and outer pressor foot move together in synchronization. GOOD FOR VINYL & NON-MARKABLE LEATHER
3. Jump feed: The needle moves the work as the slotted pressor foot lifts (with or without a dull tooth or smooth feed dog). BEST FOR HARNESSES, HALTERS AND HOLSTERS
4. Pressor foot feed: Used by all shoe patchers, the pressor foot has teeth on the bottom that move the work. WILL MARK VEG-TAN AND BRIDLE LEATHER
5. Snap feed: The feed dog pulls from the bottom while the outer foot pivots on a spring loaded hinge. When the feed dog drops, the outer foot lifts and snaps forward. GOOD FOR BUFFING WHEELS, CAR WASH CLOTHS

Of these types of machine I find #1 to be the best overall machine for a variety of leather and vinyl sewing. The triple feed mechanism ensures that there is no slippage of the layers of material (the needle moves the work with the feed dog), the alternating feet will walk over seams and back down, you can apply as much top pressure as needed to keep the material from lifting and it still feeds properly and you can hold the material fairly tight and it will still feed and give the desired stitch length (unless there is too much slack in the drive system).

The double feed system, #2, is typically used in portable walking foot machines that are designed for and sold to the marine vinyl repair industry. The teeth on the bottom of the outer foot move in time with the feed dogs and provide great traction on otherwise slippery and large vinyl boat and seat covers. However, these teeth will mark veg-tan and bridle leather pretty badly.

Type 3, the jump foot, is the harness makers choice. These machines may or may not have a smooth feed dog underneath, but always have a moving needle and slotted single pressor foot. When the needle penetrates the leather the pressor foot lifts up, then the needle moves the work back according to the preset stitch length. As the needle begins to lift, the foot comes down to secure the work against unwanted movement, or lifting, from a hot needle and thick thread. A sub-category of these machines includes needle and awl machines (more on that later on).

The pressor foot drive in the shoe patchers is meant for patching shoes, boots, zippers, holes in garments and handles on bags. The teeth under the foot are fairly aggressive and will create deep marks in veg-tan and bridle leather. Despite this, a lot of leathercrafters use shoe patchers for a lot of their projects. The real problem with patchers is the typically tiny bobbin they have, although certain models have a larger, double capacity bobbin.

Finally, the snap feed system is not much use when sewing any slick or waxy leather surface. This feed system was stock on the Singer 132K6 machines. I had one early in my sewing history and thought it was the cat's meow. That is, until I tried to sew the edges of a hand stamped and carnauba creamed veg-tan belt. The snapping top foot let the belt slide forward between stitches as it slipped forward prematurely, causing the stitches to vary in length all over the place. It did a good job feeding soft or roughed up leather and buffing wheels, but had a hard time feeding smooth grain leather. I don't recommend these machines for sewing most leather projects.

Interestingly, the snap feed system in the Singer 132k6 is the same principle used in the even feed attachments for the so-called "industrial strength" home sewing machines.

Aside from the snap foot system, which has trouble feeding slick top grain leather, all of the other walking foot systems provide a solid feeding system, with adequate top pressure to allow the operator to control the work as it enters the needle area. If you are stitching a large leather seat cover, a walking foot, compound feed machine will provide the best control and drive to pull the material through the work area, even if it is long and folded over the front of the table, or hangs around nose of a cylinder arm machine. All you need to do is make sure the material feeds the correct distance in from the edge and doesn't fall off the left side of the arm, or needle area. An edge guide really helps to stitch a defined distance in from the edge. You just need to hold or clamp the layers together and press them against the right side edge guide. The walking feet and moving needle do the rest!

If you intend to sew harness, halters, bridles, sheathes and holsters, a narrow slotted jump foot machine is the best for these jobs. Some machines offer optional feet that only have one left or right "toe" - rather than the slotted double toe. With a right toe jump foot you can sew right up to the raised edge of a molded case, or holster, from the top side. Also, since these machines either have no feed dog, or a totally smooth bottom feeder, they do no create tooth marks on the back side of the leather. This is especially important if you want to produce show harness and commercial holsters and Police gear.

In my next installment I will provide some pictures of these different types of walking foot machines.

Note, that I have not addressed the amount of clearance under the pressor feet yet. This is because that figure varies with various brands and the way they have been equipped by the seller. Most walking foot flat table machines will sew up to 3/8" of leather. Some machines are capable of sewing 1/2" and others, 3/4" and more.

Time to go to work. Lee Ya Sater folks!

[Techsew Ron]

Great job so far, Wiz!

Ron

[Wizcrafts]

Great job so far, Wiz!

Ron

Thanks Ron! May I link to some of your videos in this article?

[Cobra Steve]

Thanks Ron! May I link to some of your videos in this article?

Great job, Wiz. Steve

[Johanna]

Click on Ronnie's (Techsew) or Steve's (Cobra) banners on the top of the page- they have both made their videos available to anyone interested. Anyone that wants to make more videos is welcome to post them here on LW. We've got plenty of bandwidth, and lots of interested people.

Whiz, Thank you for this. All the sewing machine guys are cheering you, and that tells me all I need to know about the accuracy of the info. You are helping people now and in the future by explaining in plain English the mysteries of leather sewing machines, and we appreciate the time and effort you're putting into the series.

Johanna

[Techsew Ron]

Thanks Ron! May I link to some of your videos in this article?

No problem! All demo and instructional videos are located on our YouTube channel: http://www.youtube.com/user/raphaelsewingVIDEO

Ron

[Wizcrafts]

I have finally managed to take a series of photos and reduce them enough to be able to post several in one reply. The following photos are from my National 300N heavy duty walking foot machine. Similar to a Consew 206RB, it is capable of sewing a little over 3/8", depending on the density of the leather and needle and thread sizes. It handles a range of thread from #69, up to #207 - bonded nylon or polyester. It takes series 135x needles from #14 (smaller available, but not recommended), up to #25, max. These photos show it with a #22 leather point needle and #138 Weaver nylon thread (messy), which was used to sew suede lined guitar straps and rifle slings.

This is a serious leather and vinyl sewing machine! I have replaced the clutch motor with a servo motor I bought from Bob Kovar, at Toledo Industrial Sewing Machines. It is geared down internally and has a 2" pulley. It produces the equivalent power of a 1/2 to 3/4 hp clutch motor and has a top speed of 1500 rpm. The motor draws no power until you apply the floor pedal to it.

One more thing, the bobbins on this type of walking foot machine are known as M style bobbins and are 1 inch in diameter. They have a higher thread carrying capacity than standard industrial machine bobbins.

Walking Foot sewing machine, with compound, triple feed.

More pressor feet (inner and outer sets) for a compound feed walking foot machine. These are known as 111 series feet, named after the famous Singer 111 walking foot machines, of antiquity (but still in service!). If there is a job to be done that needs a special foot, you can find one for any industrial machine that uses series 111 pressor feet.

Last, but not least, here is a close-up, left side view, of my Union Lockstitch needle and awl stitcher sewing about 50 ounces of hard belt leather. The top of the needle is barbed. The thread is fed into the barb through a thread guide and looper arm, that revolves around the lifted needle. The needle then goes down, where a revolving pickup point grabs the loop off the barb, under the throat plate, and carries it around the bobbin shuttle. This machine is capable of some very serious sewing! The photo shows it threaded with #277 bonded nylon, top and bottom, which is in the low range of the weights it can manage. I have sewn with #550 thread on a Union Lockstitch machine!

Edited July 16, 2010 by Wizcrafts

[Wizcrafts]

For those of you who are just getting into sewing leather, or are about to move up from a home sewing machine, here is a comparison of the bobbins used in various types of sewing machines.

From left to right, front row, we have:

1. Small bobbin shoe patcher (Singer 29-4 and most K series)
2. Large bobbin shoe patcher (Singer 29k172, etc)
3. Class 66 home sewing machine bobbin
4. Class 15 and standard industrial or Kenmore bobbin
5. Large M bobbin

Finally, in the back, is a bobbin for a Union Lockstitch Machine.

Here is a comparison of a spool of #207 vs #69 nylon thread (1 pound vs 1/4 pound). The #69 thread works in most home and straight stitch, static pressor foot, drop feed industrial sewing machines, with a #16 or #18 needle. To use #207 requires a very heavy duty machine, with a BIG motor, and a #25 needle.

When you are choosing a sewing machine, don't just select it because of its price, or local availability, check out its needle, thread and bobbin size capacities.