Wizcrafts

Tackgirl; You may or may not be getting a good deal on the used machines. As I have often written, just because a sewing machine is an industrial machine, it may not necessarily be good at sewing leather, such as we use on this forum. Our leather projects are not usually seat covers, although we may make some now and then. Most of the leather crafters haunting Leatherworker.net are making a wide variety of items, including many that are constructed from dense and often thick leather. We like to use heavy bonded nylon thread that is capable of holding these items together against strong external forces. When we go a-lookin' for a leather sewin machine, we have a whole nuther kind a machine in mind. Let me explain. The machines you posted the pictures of are upholstery grade machines. They are great for sewing drapes, seat covers, couch covers, boat covers, sails, awnings, even jeans. Yes, they will sew leather. But, how fast are they setup to sew? What type of tension springs are they equipped with? How high do the feet lift and alternate? What needle system do they use? How big are the bobbins? How tight is the mechanism? how thick is the take-up lever and its crank shaft? How heavy is the flywheel? Is the wheel and machine balanced? Any good, modern walking foot machine, with strong, good steel take-up and moving parts, can be modified to become an efficient leather sewing machine. You want one that is already in good condition and is able to clear at least 7/16 to 8/16 inch under the fully raised presser feet. If equipped with a system 135x16 or 135x17 needle, they can effectively sew through 3/8 inch of material. If everything is tight and the take-up lever is not worn with a thread groove, and the springs are replaced with heavier tension springs, it can be made to sew 3/8 inch of leather. If equipped with system 190 needles, they can sew to almost 1/2 inch! Here's what else you need to do to accomplish this goal: First, the speed is important. Leather cannot be sewn at high speeds like garment machines run at. It will smoke from friction and melt the thread, and burn the leather. Upholsters like their machines to run at 2000 rpm. As one upholsterer put it to me, when I asked why his machines ran so fast: "time is money." A machine spinning at 2000 rpm is great is you're sewing fabric, canvas, or sometimes vinyl, but not leather. Even 1000 rpm is way too fast for leather. I see smoke from the needle at 600 rpm! If you want your machine to sew mostly leather, the top speed should be under 600 rpm. Most crafters have theirs set to 320, 160, or less. I had an Alder 204 that had a clutch motor and a speed reducer. It's full speed, pedal down, was 2 stitches per second! That's only 120 rpm. If the motor is a clutch motor running at 3450 RPM, lose the motor. Sell it off. If it is a 1st generation high speed, low torque servo motor, sell it off. If it is a 1725 rpm clutch motor with less than 1/2 horsepower, get rid of it. If it is 1/2 HP and has a pulley larger than 2.25 inches, replace the pulley with the smallest one you can buy. 2 inches is perfect, in my opinion. Your goal is to equip it with a motor that has a lot of punching power at all speeds, but can easily be made to sew slowly, by foot. For clutch motors, that means learning to feather the clutch. For servos, they have a knob or up/down speed limiter buttons, to set the top speed. Some have more actual range of foot control that others. If you have to replace the motor, I recommend the one I bought to replace my clutch motor. This is the .SewPro500GR, sold by Toledo Industrial Sewing Machines (866-362-7397). It has a built in 3:1 gear reducer and a 2 inch pulley. While it bolts into the same holes as the original clutch motor, it sits closer to the table. So, when buying a new belt, you need to choose one that is not only an equal amount shorter than the original pulley to new pulley diameter, but you must subtract one inch more for the closer body profile. With a walking foot machine slowed down to a controllable speed, your next concern is the size of the bobbin. If you only want to sew thin leather, using #69 bonded nylon thread, a standard industrial class 15 bobbin will do fine. But, load that bobbin up with #138 thread, and you cut your sewing distance in half, per bobbin load. So, most leather sewing machines are equipped with a large bobbin. Most of them use the M size, which holds 50% more than the standard bobbin. Juki LU machine large bobbins hold double the standard size! All of these facts relate to industrial flat bed machines, like those you asked for opinions on. If you want to buy a used, or new upholstery grade machine, be prepared to pay to modify it to sew leather. You can probably save a lot of expense and aggravation by contacting our dealers and asking what they can sell you at a price you are willing to pay. Let them know what you intend to sew and you will get a machine that fits your needs. Additionally, you get dealer support. You probably won't get that if you buy a used machine from a warehouse, or Chinese import off the boat.

Charlie Cat, my trumpeting friend from N'orleans, that Landis 12K is only good for sewing new soles onto shoes and boots. It is of no other use. The thread it uses is 6 or 7 cord right twist Barbour's Irish Linen Thread, run through a wax pot. This "thread" is thicker than the string used to bundle most meat packages or fly a kite. There is very little depth inside the curved needle area. It is designed to sew along the outside perimeter of shoes. It can also sew knife sheathes and holsters, certainly up to 1/2 inch thick. But, no reverse, and no turning the work around to backtack. Another thing you should know: a Landis 12K weighs in at around 500 or 600 pounds, in 3 square feet and usually ships with a 3 phase 220 volt motor. Are you sure you want a machine like that for your first sewing machine? This not so good news is played to the tune of Basin Street Blues

See if you can get close up photos of the remaining machines. The area of particular interest are the head, showing the presser foot/feet and throat cover plate and the right side, showing the model number. In lieu of photos, see if you can get and post the exact model numbers. You need to be made aware of the fact that just because a sewing machine is industrial, it is not necessarily any good for sewing leather, such as is made by crafters. There are industrial sewing machines that are made to do only one particular task. Some are made to only apply an edge binding cloth. Some are high speed. low lift, small thread machines, used to produce garments. Some only sew a preset pattern, as in bar tackers and X tackers. Here are some features that set leather sewing machines apart from garment or specialty machines: Leather sewing machines usually have walking feet; typically triple feed, where the feed dog, inner foot and needle all pull the material in sync. Beefed up tensioners, to properly position the lockstitch knots, when sewing with #138 or larger bonded thread. beefed up take-up lever, to withstand the highly increased strain caused by heavy thread being pulled into hard materials. large or very large bobbins. Larger threads need bigger bobbins to do a reasonable amount of sewing, per load. extra heavy top pressure springs (it takes a lot of pressure to hold down 2 or 3 layers of veg-tan belt leather as it is being stitched) interchangeable presser feet and throat cover plates. Different feet are made to do various special tasks. Leather sewing machines frequently use a set with a single left toe outer foot. threaded holes inline with the needle, to attach an edge guide (to keep your stitches along the edge in perfect alignment). larger pulleys and hand wheels on the rear. With a large pulley and heavy hand wheel, the machine will run slower and smoother at slow speeds. slow speed (1725 RPM) 1/2 HP clutch motor, with a 2" to 2.25" pulley, or a servo motor capable of sewing under 1 stitch per second, with lots of torque. There are servo motors, then there are servo motors. Not all are as good for slow speed, high torque sewing. You need one built to power a leather sewing machine. some have an additional speed reducer between the motor and machine. a v-belt of the proper length so the motor positioner is in the middle of its up/down range, with about 1/2 to 3/4 inch displacement, with light finger pressure, in the middle of the belt. plenty of oil holes leading to critical moving parts. Only use sewing machine oil, not 3 in 1. All industrial machines should have: a solid wood table top mounted onto steel k-legs frame, with a floor speed pedal an oil drip pan mounted in the machine cutout of the table (does not apply to cylinder arm machine tables) a knee or foot lifter assembly for the presser feet. a solid thread stand, for at least two 1 pound spools of industrial thread. a bobbin winder on the table, unless one is built into the machine. a long flex light, so you can see what you are sewing. a sliding drawer to hold spare accessories, needles and bobbins

The bottom line is that if you have to choose between two machines, which you will be trading for, the 31-15 is more customizable-alterable than any 29 type. Neither machine is built for heavy duty usage. Neither was made with heavy thread in mind. But, the patcher machines are not nearly as strong as they look. These machines are easily damaged and wear out quickly, if used to sew hard leather, with heavy thread. Finally, the bobbins on the patchers are either tiny, or minute. What is sold as a large bobbin for the big bobbin models is about 2/3 the capacity of a "standard" industrial bobbin. That bobbin is the same as the one used in the ancient Singer 15- class home machines. So, you can sew farther with any size thread with a 31 type machine, than a 29 type. The only reason for having a 29 patcher machine is to do patching of torn shoes and garments, to install zippers in bags, to fix cylindrical pouches, or to sew patches onto vest and jackets. They are perfect for sewing inside of round goods, up the arm and back.

Okay Charlie Cat. Did you know that everyday is Caturday? Especially in N'orleans Since you are going to have to trade for a machine and you only have two to chose from, let's whittle it down, shall we? Your projects don't seem like they will require a lot of thickness, but could exceed 1/4 inch. That leaves out the patcher. So, by the process of deduction, you just bought a Singer 31-15. Finding it too fast to control, you'll buy a smaller motor pulley and shorter v-belt. You can purchase some different presser feet, in time. You may even convert it into a roller foot machine, someday. Being an experimenter and new note finder, you shall manage to make the machine sew consistently good stitches with #138 thread, top and bottom. Being inquisitive, you will find an alternate needle type that is a little longer, but still fits into the needlebar. You will learn to retime your machine for the longer needle. Then, you will realize that you can raise the presser foot a bit higher, until it just clears the descended needlebar. That will allow you to sew about 3/8 of an inch; maybe more. Someday you will remember where you dreamed all this up and thank me. to the tune of Limehouse Blues

We have dealers who are members of this forum (Their ads appear on top of every page, and rotate with every page refresh). Why don't you contact each of them, reveal your budget, state your sewing requirements, and see if anybody can fit a used machine to your wallet?

The Juki DU-1181 is a very quiet "walking foot" - dual feed machine. It is fed by the bottom feed dog and outside presser foot. The needle and inside foot are fixed position parts. The specs say it can sew with thread sizes 33 through 92, nylon thread, using system 135x17 needles. The maximum lift of the presser feet is stated as 15 mm, which is over a half inch. However, the actual stitching capacity will be no more than 3/8" to 7/16" maximum. It is common these days to find new machines with huge amounts of foot lift, but using standard industrial needles the limit the thickness than can actually be sewn. The extra lift is to get over piping, corners, spots and studs, buckles, etc. The feet on this machine will most definitely mark veg-tan leather. It is not designated as a leather sewing machine, by Juki. They intended it for use in the vinyl sewing trades. I just realized that the motor and pulley system that ships with these Juki's makes the machine sew at 2000 RPM! The clutch motor rotates at 3450 RPM, double that of the clutch motors fitted to leather sewing machines. If you buy the machine with that motor, you are going to need to replace it with a servo motor, or a standard, 1725 RPM clutch motor; either fitted with a 2 or 2.25 inch pulley. You are not going to sew leather at 2000 RPM! 600 RPM is about the most I use, after considering the pulley ratios Even then, the needle smokes..

The Singer 29 machines will only sew 1/4 inch maximum. The 31-15 can probably sew 5/16". Note: there is a difference between how much material can be stuffed under the raised presser foot and how thick it can actually feed and stitch. The 29 types have a foot that both pulls the work back and lifts off it to move forward for the next stitch. So, you can technically shove 5/16" of leather under the foot, but it won't feed it properly. The 31-15 is a bottom feed machine. It feeds all the material under the foot. However, it uses garment series needles, which are a little on the short side of the industrial systems. The machines using those needles are made to sew garments that don't normally exceed 1/4 inch thickness. The needlebars have a shorter stroke than walking foot machines. I have read about people who raise the pressor foot on a 31-15, to get them to sew 3/8 inch. I don't know if they also changed the needle system and/or needlebar. The 31-15, although made as a tailoring machine, is also used by many shoe repair shops for sewing flat upper leather. One guy I knew had a Fortuna Skiver, which he bought from me, a Singer 31-15 and a Singer 29k something, for making custom shoes and boots and repairs to same. This was in addition to the sole stitcher and other shoe repair machines. Of course, he only used #69 thread in the Singer machines.

Yes, the Rex 26-188 is well suited to sewing vinyl and textured chrome tan leather seat covers. The presser feet have teeth on the bottom, as does the feed dog. The feed is accomplished by the outside foot and feed dog, and the aggressive teeth don't allow the material to slide out of alignment. You can really hold back the layers, taut, and the feet keep it in place. The pull of the feed mechanism is really intense. I work part time at a leather shop that sold the same machine for the same price. They are solid machines from what I can remember, what few times I sewed with it. While it's great for cloth or vinyl, you wouldn't want to use the Rex to sew any kind of leather that would retain the tooth marks.

First, you're welcome! Second; I wouldn't go there (Tacsew brand) if I were you. Do not confuse the Tacsew junk machines with Techsew, which is a good brand, distributed, setup, adjusted and modified if necessary, by Raphael Sewing in Montreal. This is just my opinion. Opinions are like a__holes: everybody's got one!

When the time comes for you to buy an upholstery style machine, try to purchase one that is complete with motor and table and normal accessories. Best success with you hunt for a proper leather capable sewing machine!

Buyer beware. This looks like a drop-shipped Chinese portable walking foot machine. Pray that the box doesn't get dropped literally. A shock along the front or back can hopelessly jam these machines. Unless it is an improved model, many of the moving parts can be bent by hand pressure alone. As the seller about the quality of the metal parts and the casing. Make sure there is a 100% money back guarantee if it doesn't work, out of the box. If the machine arrives in one piece and actually sews, here is what you can expect from it. These machines sew up to 1/4 inch thickness without any modifications to the feet. With modifications on a grinder and buffer, they can manage up to 3/8 inch. They use the standard 135x16 and 135x17 industrial needle system. The tensioning components only allow you to sew with #138 thread. However, some people have been able to replace the tensioner springs to sew with #207 on top. The bobbins are standard industrial bobbins, thus, you can't sew too far with #138 thread, on one bobbin load. The portable walking foot machines are best suited to sewing marine or home vinyl, canvas, or light weight leather, like chap leather. The walking feet both have teeth on the bottom. These teeth secure the work between stitches (inside foot) and pull the work during stitches (outside foot). The needle and inside foot are static. The feed is accomplished by the outside foot and the feed dog. While useful for apartment dwellers and flea marketeers, portable walking foot machines are neither built, nor meant to sew hard leather. The pounding caused by the increased pressure required to hold down dense leather, as the stitches are formed, will wear these machines out in a short time and may void their warranties.

You are going to have to buy a motor, v-belt, bobbin winder, thread stand, flex lamp, k-legs frame w/pedal/knee lifter, oil drip pan and cutout industrial table to use the Consew head. When you add the cost of these items to the cost of the head only, will you still be getting the bargain you think you are getting? Maybe, maybe not. As 50 Years Leather told you, this machine is capable of sewing up to 3/8" of leather, but is really best suited to using size 138 and under in thread. Most holsters are sewn using #277 thread and if they have filler welts, can exceed 1/2 inch thickness. You will need an entirely different kind of machine to do that kind of sewing. Our dealers sell leather stitchers that are capable of sewing over 3/4 inch with very heavy thread. They can also be used to sew bags and put in zippers by using a smaller needle and thread (~#92 thread with a #19 needle). It's a stretch downward, but I do it. It's easier to downgrade a big machine than to upgrade a lesser type. The Consew 206RB series are upholstery machines and are also used to sew denim garments, marine and automotive seats, etc.

I had a hand operated machine like your Gritzner. I used it for new attaching outsoles to boots

I had one also. It was very quiet in operation and sewed a reasonably wide stitch, but not as wide as the Singer 20U zig-zag machine. Do not attempt to sew anything like belt leather with that machine! You will break needles. It sews okay with #69 bonded nylon thread. I used it for freehand embroidery on denim and nylon vests, and for hemming cloth garments.

I still dream about creating my own customized leather stitcher; combining the best features of the best machines into one. Ferdinand Bull machines were created by a man with such a dream. He also had capital to back his venture. I am good friends with the owner of a top-notch manufacturing plant in Lapeer, Michigan. I made their website. This company can cast, mill, drill, or turn any material, to incredibly close tolerances. With some funding and after a successful prototype was created, that machine could be produced here, in the USA. I have no idea how much it would cost to machine the parts, but this topic is about "If money was no object." Some of the items I would design into my dream machine would include: My dream machine would be a cross between an Adler 205, a Juki 441 and a Luberto Classic. The parts would all be made in the USA (remember: money is no object)! Closed eye needle machine, using system 794 needles. Needle and awl system is very finicky, especially when reversing to lock stitches, or when sewing webbing. Why be aggravated by trying to avoid ratted bottom thread or webbing? Square drive needlebar system: The needle fully penetrates all layers of the leather, straight down, before it moves to form the stitch length. Then, it gets pulled straight backward or forward, rather than pivoting from the top (eliminating the "pendulum effect"). Jumping pressor foot remains down until the needle has penetrated the leather. Then it lifts completely off the leather until the needle has pulled the material back (or forward when in reverse). The foot lowers to secure the leather just before the needle begins to ascend. The needle withdraws, then moves to its starting position (fwd or rev). Heavy, long and wide coil spring for presser foot pressure (similar to Union Lockstitch), with easy to spin thumb wheel on top. Full range from almost zero to lots of pressure. Bobbin and hook same as 441 types. Some type of compensator designed to account for different timing when needle is in reverse, vs forward motion. Timing in reverse is sometimes tricky now, especially when using long stitches. Presser foot hand lift lever on top-left front of head, not inside. I hate that the lift levers are on the inside on 441 clones. I find it awkward to reach in, behind the head. I prefer the Adler 205 lifter system. Adler style drop down roller edge guide. The swing away guides are problematic for me. 18 inch arm, but not tapered toward back as on most machines. It would have the same diameter, from left to right Heavy flywheel for smoother operation at very slow speeds Narrow feed dogs (smooth and with teeth), only 1/4 inch wide and a standard throat plate to match. This set would cover needle sizes 18 through 23 Wide feed dog and matching narrow slotted plate, for heavier work and bigger needles (#24 to #27). This set would be the same ginormous set that ships on all of the current 441 clones. Either Teflon coated, or highly polished chrome plated throat plates, to reduce drag. A wide array of raised throat plates (holster & stirrup), plus long and short flat plates (long = more support on left for wide items : narrow = cut off close on left side to sew right up to the edge of shaped cases. Presser foot array: left toe, right toe, double open toe, narrow (1/4") closed double toe with slot, 1/2" wide closed toe with slot, trailing toe for shoe soles or shaped cases with narrow stitching flanges. A compensating in-out shuttle system that optimizes the distance of the needles to the pick-up point, from #18 through #27. No skipped stitches from too much side space when changing from large to smaller needles for one job. No need to change spacer shims like on Adler 205. Lift adjuster for the height of the jump foot, to fine tune for thin or thick leather and large or small stitches. Lower lift would be quieter operation. Central oil distribution system, with oil wicks emanating from a reservoir on top of the machine. Second set of oil wick ports on cylinder arm, for shuttle shaft and feed dog shafts and connectors Micro switch or optical sensor to halt motor drive if bobbin case is open!. I don't know why, but sometimes I start to wind a bobbin reload and forget to close the bobbin case! A sensor that prevents the machine from turning by the motor would save me from an expensive bobbin case replacement. A needle positioning servo motor that actually allows a full range of speeds, without a speed reducer, capable of sewing very slowly or fast, but without dropping out below 1 stitch per second, or less. Sometimes, I have to sew into existing holes, which may not be perfectly spaced. The current breed of standard servo motors tend to shudder and drop out as I slow down below 1 per second or every other second. I consider slow speed to be as little as 1 stitch in 3 to 5 seconds! I'm not kidding! This motor would also be designed and built in the USA, with discreet components, soldered by hand. It would probably be an SCR controlled motor. The case would be cast in a mold that does not leave rough porous edges or blocked/ragged internal channels. The bearing channels would be a proper fit and the oil holes would line up the the holes in the bearings. All shafts, bearings and gears would be machined from known good quality bronze and steel. Threads would be cleaned before the parts were delivered to me for assembly. I figure that a machine built like this one would easily out live me and could continue doing good work for a century. I have a 101 year old Union Lockstitch machine that sews like it was brand new. It was produced entirely in the USA, with US iron and steel. It is a complicated machine that sounds like a thrashing machine when run fast.

What a refreshing display of honesty! Your revelations are much appreciated Greg. Perhaps, first time buyers of machines sold by our member dealers, yourself included, will have a better understanding of what it takes to get one of the clone machines into good working condition, for sewing thick leather with heavy thread. The bottom line I take away from this is that it is not the nameplate on the machine, but, the dealer/mechanic who sets it up, that makes a particular leather sewing machine what it is. The dealers who stand behind their work and offer phone assistance to their buyers is something that cannot be replaced by a cheaper deal from a drop shipper. This doesn't help our original poster though. All I can say about his dilemma is that the choices boil down to these: Buy the best quality level machine direct from China and take your chances. If you have a machine shop you can make replacement parts. Buy a machine that has been setup and modified to work by a leather machine dealer and pay the extra shipping and Customs cost, knowing that the machine will perform as desired for a longer time than might be the case, out of the box. Once a 441 or 205 clone has been gone over and all loose screws tightened and timing set, as long as the box isn't dropped from a truck or loading dock crane, the machine should arrive in the same condition it was in when sent out to you. American and Canadian screw drivers are usually made of very good steel and can apply a lot of torque to screws that arrive loose from China. As to why their heavy sewing machines arrive out of time, with loose screws, rough castings and missing paint, only the Chinese builders know the answer to that question.That's probably where the A-B-C quality differences lie.

This a is job for a Consew 206RB-5 flatbed, or a cylinder arm 227R type machine. Both are medium duty sewing machines, with triple feed and 1/4 inch wide feed dogs. Throw in an edge guide, or use spring edge guide presser feet and you have the best machine for these belts. I would recommend getting a machine with a servo motor, unless you are good at feathering the clutch.

If money was no barrier, I would definitely buy a Campbell High Lift needle and awls stitcher, with all available accessories and lots of linen and polyester thread. My second machine would be an authentic Adler 205-374, with all accessories.

George; What thread is being cut when you back-stitch? Top thread Bobbin thread Stitches already in material Here are some more questions and related mechanical things to check: Are the back-stitches going exactly into the same holes as existing forward stitches? What size stitch length are you using now, where the threads are cutting? Is this a different stitch length than before? Has there been a recent jam in the bobbin case or shuttle? If so, the timing may have changed. Check the timing. Check your timing of the needle in reverse. It the needle is in a much different position in reverse than in forward. With a large stitch length, this can cause the pick-up point to split the top thread loop, instead of going inside it. See if the check spring has sufficient range of motion to keep the top thread slack tight, until the needle fully penetrates the leather, in both forward and reverse mode. Adjust it for more motion if necessary (to reduce slack top thread). Don't go too far down, or the loops won't form in the needle! Is there sufficient top pressure on the presser feet to prevent the material from lifting as the needle begins to ascend? If not, increase the spring pressure. Check the timing of the feed dog, if you are using one. It must move in sync with the needle. After resetting the timing, or not, go over all screws on moving parts to ensure they are as tight as possible. Oil the moving parts again. Try using thread lube, or lubricated thread. Let us know if any of this helps.

You are most welcome Warpe!

This is only true when you keep the same size (and sometimes make and model) thread in the bobbin and just change thicknesses of material being sewn. If you change to a noticeably thinner or thicker thread, the bobbin tension can vary a lot. At work, when I change from #138 to #69 thread (for garment leather repairs) I need to increase the bobbin tensioner and loosen the top tensioner. If the previous job used #207 thread, the tension changes are even more pronounced. Otherwise, I set the bobbin tension to allow the thread to feed smoothly, with some exertion, but not too much. A very tight bobbin spring will cause the leather/material to have too much drag against the feed action. On thick leather this means shorter stitches than you might get otherwise. On thin or soft leather, that drag can cause the bottom thread to pinch the leather. Balancing an overly tight bobbin thread with more top tension may cause the thread to perforate the leather. Finally, if the bobbin thread is very tight and you compensate by tightening the top thread, it makes it harder to remove the work when you are done sewing. You lift the pressor feet, with the foot lifter, but need to manually pull the threads backwards, to move the leather out of the machine. Sometimes the top thread will break from too much top tension, as you remove it. If you have need of changing the bobbin spring tension often, make sure you use the proper size screwdriver, to avoid damaging the slot in the screw. Also, stick with one supplier of bobbins (assuming they don't give you any problems from the get-go). Manufacturing differences can throw off your adjustments, bobbin to bobbin. Nicks or bends on the end disks can cause the bobbin to drag at those points of rotation. These are things I have learned while sewing on a 441 clone machine, into everything from 4 ounces of garment layer, up to 5/8" of veg-tan, and through 1/8" of ABS plastic when I'm repairing motorcycle saddlebags.Your milage will vary. We regularly use nylon thread sizes 69, 138, 207 and 277 with this machine. Our needle sizes range from #19 through #25. We mostly use #22 and #23 needles and #138 lubricated thread.

Campbell-Randall Company had some custom screws turned for me, for my 101 year old Union Lockstitch machine. I imagine that if one was to send them a mechanical drawing of a desired screw, they could make it, or have an existing one modified to the required pitch. They already have quite a variety of square head screws and matching t-wrenches. My ULS machine uses three different square head wrench sizes. I own the small and medium wrenches for adjusting timing and the bobbin shuttle position. I just use a suitable 12 pt socket to remove the bigger quad-head screws securing the face plate containing the awl and pressor foot bars. Somebody with a mini-milling machine and lathe should be able to make 4 sided wrenches.

I get my square head screws and T-wrenches from Campbell-Randall, in Yoakum, Texas. These screws are used all over the Campbell-Randall and Union Lockstitch needle and awl harness stitching machines, which they build and sell.

As Trox mentioned, just because the Adler you are thinking about buying weighs 200 pounds and has a 20 inch body clearance, doesn't mean that it will make a good leather sewing machine. I have seen those long body Adlers, with one inch clearance under the feet, and they look like tanks. Nonetheless, these machines were built and setup for sewing sails, awnings, buffing wheels and car wash drying cloths. The buffing wheels and car wash cloths are thick, but made of cloth. They require a specialized high lift machine to sew them, and that's what these Adler 20-somethings are built to do. Adler does make leather sewing machines. They include the model 204 and 205 and various sub-classes. I know of one member of this forum who has an Adler 204-374 for sale at a very good price. It sews up to 3/4 inch of leather, with a #25 system 794 needle, using #277 bonded nylon thread. The take-up and tension parts and the bobbin system are all designed to handle heavy thread, sewn into thick leather. If you intend to sew sails, tents, awnings or buffing wheels, the old Adler 20-20 might be the perfect machine for those jobs.