Wizcrafts

Only furriers, advanced tailors and dry cleaners use fur machines. If you know of any such shops in your area, take the machine head to them and see if any of them are willing to take it off your hands. Then deliver the motor and table. You'll be lucky to get a couple hundred bucks if it is in really good condition. I admit that there were times when I wish I had one for repairing seams that come apart on customers' fur coats. But, a few minutes of whip stitching by hand, with a curved needle, gets the job done just as good. The only hassle is opening up the lining, then whip or top stitching it closed. It seems that you are going to buy that ULS machine. My advice to you, as a newbie to them, is leave it set up exactly as is and use the same thread they were using. Don't try experimenting with the stitch length right away. Learn to sew with it and thread it first. Learn to wind the bobbins, adjust tensions and to change the needle and awl and align them properly. Memorize the oiling regime. Once you are confident in your ability to operate the machine, then change the stitch length setting slightly. See if it still sews without missing stitches or missing the awl holes. If so, change it all the way down, to the maximum length. Hand wheel the machine until the needle is just under the leather. If the machine is adjusted tightly and optimized, the needle should come up through the hole. If not, it will miss the awl hole and try to push the leather up. If you don't stop it immediately, the needle will bend and become useless. Part of the hassles you will encounter may be repositioning the needle mechanism when you change stitch length. There are adjustments for forward/backward and for left/right and they are made in different places. You will need the 4 sided T-wrenches and a large flat blade screwdriver and an open end or socket wrench to make these adjustments. You may also have to change the hook timing by adjusting the timing gear under the machine when you change stitch length. Your best hope is that somebody has already optimized the settings before you get the machine.

If you are good with and well equipped with wood working tools, you might be able to mount a speed reducer. But, if the machine is the old style, like mine, the motor is on the top rear of the table, making it virtually impossible to ad a reducer. The new style, form the 1960s on, have the motor under the table, making it much easier to add a reducer, or even a 3/4 HP servo. Note, if you change to a non-continuous run motor, you'll have to lock the clutch into the flywheel asbestos. Normally, there is a very long heavy steel lever that runs under the table, with a hinge on the right side. A steel rod gets locked through a hole in that lever and goes straight up to a lever on the back of the machine. That lever is connected to the back of the machine and when lowered, pushes a rotating steel cup against a cone shaped clutch on the flywheel.

You can purchase an actual printed manual and parts list from Campbell Randall, in Yoakum, Texas. That's where I got my manual. It helps to have the parts list when you start ordering replacement screws and such. You should ask if there are spare parts, accessories, needles and awls and a threading wire with the machine. If not, prepare for some serious sticker shock. Here are some prices you need to be aware of before you buy the machine: Needles and awls go for about $33 for a pack of 10 Bobbins are about $20 each various presser feet sell for about $105 each and up Various throat plates sell for $100 and up Roller edge guides are over $100 Barbour's Linen thread is close to $50 a pound. Bonded polyester is about $20 to $25 a pound. They are the maker of liquid Lax Wax, needed to sew with linen thread. It's about $15 a quart +/- Replacement screws run from a few dollars, up to almost $10 each. Replacement springs cost from $5 to $25 depending on which spring it is. The 4 sided internal cut adjusting wrenches range from about $20 to $30 each. Add shipping and Customs costs, GST, etc to these prices, and conversion of CDN into USD. Try to run the machine, with or without thread. Make sure it runs smoothly at all speeds. The clutch is on the flywheel. With your foot off the (right) speed pedal, the wheel should not turn easily by hand. A slight toe down should release the brake from the asbestos clutch and allow you to hand-wheel the machine. Under full power, the machine will sound like a piece of farm equipment, like a thrasher or harvester. If possible, oil the machine before running it at full speed, which is 800 stitches per minute. The presser foot is lifted by the left floor pedal. You may need to push it all the way to toe to the floor to get the foot to lift to clear 3/4 inch of leather. Make sure that the bobbin winder is included and actually works.

Buy new feet and keep the originals for Naugahyde and Sunbrella jobs.

I bought my first Union Lockstitch directly off the floor of a Tandy regional headquarters in Canada. It was sitting idle for several years after the only person who understood the machine had retired. I bought it with virtually no accessories or manual. I couldn't even thread the machine correctly and it refused to sew a stitch. My lucky day came after I called several old-time leather crafters and one put me on to Freedman Harness, in Toronto. I called and the owner, Sam Freedman (deceased) invited me to his shop, where is graciously photo-copied his Union Lockstitch manual. He was nice enough to also sell me thousands of dollars worth of spare parts, needles, awls, bobbins, feet, throat plates and wrenches, plus a threading wire, from his long-unused, turn of the Century ULS machine. I paid as much for those accessories and spare parts as I paid for my machine. When I sold that machine in the year 2002, I spent a solid hour demonstrating to the buyer how to thread, time, tension, adjust and change stitch length on the machine. I'm sure that, even with the manual, he would have had to spent at least a day learning those things on his own if I hadn't stepped up to the plate. Anybody contemplating buying a Union Lockstitch machine for the first time should make sure that they go somewhere and learn how to adjust and maintain their machine. Failure to do so can result in heartbreak and even physical damage to one's self. A properly set up and adjusted ULS machine can sew everything from Wilson Footballs to commercial gun belts and holsters. They are thread agnostic and have true square drive. One only needs to match the best fitting needle and awl to the needle and awl bars, change thread and maybe twist a tensioner, to sew from #138 thread to #346 thread, into from 6 ounces up to 20 ounces of leather. If one wishes to sew beyond 3/4 inch, they must alter the top of the pressor foot to clear the looper and thread guide. Or, get a special thin foot made at a machine shop. I use machine shops a lot for my ULS machine.

I have a Singer 31-15 that I believe was built around 1915, It sews perfectly. I replaced several worn screws and the needle bar. It does NOT use 135 system needles; they are too big around and hit the side of the hole in the throat pate.. It uses DBx1 - 16x257 needles and interestingly, my leftover 134 needles from a Pfaff I used to own.

I have owned two Union Lockstitch machines. The current one is up for sale in our used sewing machines section of the Market Place. There is no other sewing machine like a properly set-up ULS. Therein lies the problem. Very few owners of these machines really understand them well enough to set them up for one size of thread and stitch length, then change over to an entirely different combination. If you are contemplating purchasing a Union Lockstitch machine, make sure that the previous owner will give you plenty of instructions on threading it, timing it, changing needles and awls and changing the stitch length. A threading manual with parts list is very helpful. There are about 20 oil holes that must be oiled regularly during, or before using the machine. The bobbin winder needs oiling. The machine has a clutch built onto the huge flywheel. The take-up lever system is so powerful it can filigree softer leather. The position of the knots is controllable by moving the take-up lever assembly, as well as by changing the upper and bobbin tensioners. It is possible to set the machine to sew from a very loose stitch, to one that is pulled right into the grain and flesh sides. Union Lockstitch Specs: Maximum stitching speed = 800 spm or 15 per second. Max clearance under the lifted foot = 3/4 inch Max thickness it sews = 3/4 inch Feed system = needle feed and jumping foot Minimum thread size = #138 bonded nylon/polyester or 3 cord left twist glace linen Maximum thread size - 554 bonded nylon/polyester, or 10 cord linen Stitch length range = from 12 to 4 to the inch Bobbins are about 3/4 inch tapering to 3/8 inch inside x 2.5 inches outside diameter and hold at least 300 feet of #277 or 4 cord thread. Needles have barbed ends and are available in sizes 1 through 7. Awls are available in sizes 1.5 through 8. The smallest and largest sizes of needle and awl are getting hard to find. The head alone weighs about 250 pounds. The motorized 3" thick table, thick steel frame and pedal assemblies weight another 150 pounds. My setup: I typically use a 2 needle and a #2.5 awl, to sew with #277 bonded nylon thread. If the thread is really well bonded, I can use a half size smaller needle and awl. I am able to feather the foot pedal speed control linkage to get about 2 stitches per second. I can single stitch by just feathering the clutch enough to move the machine to the beginning of a stitch then halt. I use hand pressure on the flywheel to move it over the "hump" for exactly one stitch. On straight-aways, I floor it and get 15 stitches per second. If you do buy the machine, there are certain tools you must have to thread it, time it or adjust the foot lift and hook position. There are three sizes of T-handle wrenches with four sides milled into the inside of the mouth of the wrenches. The two smaller sizes are must-haves. There is a long threading wire with a barbed end. You'll need a fairly thin 5/8" open end wrench to change the timing. The 3 primary shafts are set into position and clearanced with a large flat blade screwdriver, then locked down with a 13/16" socket. A new ULS is worth about $7,000. A factory rebuilt-to-specs model is worth about $4500. A privately rebuilt machine, like mine, is worth about $3000 to $3500. If your ULS is not rebuilt and is over 50 years old, or has had a lot of use and abuse, it may need to have a lot of parts replaced. This was what I had to do. I invested about $1,000 in replacement parts and accessories, not to mention more in needles, awls and bobbins. Needles and awls sell for about $3.25 each and are sold in packs of ten. Bobbins are about $20 each, plus or minus. These are the pertinent facts about the Union Lockstitch machines. They have been produced entirely in the USA, since 1905. Campbell Randall is the current owner of the ULS machines and has parts and accessories for them, as well as linen thread and liquid wax. More: You asked how much you could expect to sell it for it you don't want to keep it. That depends on its condition, what extra parts and accessories go with it and what a buyer is willing to pay. A lot of these beat up machines move between unhappy owners for about $1500. They usually need another $1,000 to $1500 put into them to bring them up to snuff (as I found out).

Back off the presser bar pressure spring (or springs if you have one for each foot bar). Use #69 bonded nylon thread with either a #16 or 18 leather point needle. Make sure the feet are smooth on the bottom. If necessary, lower the lift of the feed dog.

Always try to use smooth presser feet on a walking foot machine, when sewing any leather that remembers impressions. The triple (compound) feed walking foot machines are the best for sewing multiple layers up to 3/8 inch. Virtually every industrial walking foot machine is capable of tensioning #138 thread, top and bottom. Most of today's walking foot machines use the same presser feet as the original Singer 111w155. There are literally dozens of different foot sets available for these machines. Most use system 135x16 leather point, or 135x17 round point needles. These needles are available from about #12 up to #25. Roller foot machines leave a roller track, the depth of which is related to the top spring pressure. The pressure exerted on the roller has to hold down the leather as the needle ascends to form each stitch. The roller is able to ride very close to the left side of the needle. In fact, you can adjust the distance from direct contact, to 1/16 inch or farther away. Small rollers are able to sew more intricate designs onto boot uppers. Most of these machines are used on shoe and boot upper leather, with a typical thickness of 2 to 4 ounces. Most of the fancy stitching on Cowboy boots is done on a roller foot machine, using #33 or #46 bonded nylon thread and a #9 or #10 needle. The stitch density is usually 20 to the inch. A Singer 31-15 is a garment machine. It can be used to sew leather garments if one uses either a Teflon or roller foot. The springs are made with light thread in mind. You will have to swap out the main tension spring to use #138 thread. A heavier presser bar spring may also be needed, to hold down leather and big thread, sewn with a #22 or 23 needle. This combination places a lot of stress on the take-up mechanism of the machine. The feed dog and plate also needs to be replaced with a heavy tooth set, to properly feed leather. I use this machine to sew hems onto cloth goods and pants. I use a National walking foot machine for guitar straps, flat belts, denim cuffs, leather zipper replacement, vinyl sewing and most jobs that benefit from the triple feed system. It is similar to an older Consew 206 series machine. It has a large M style bobbin, a large push down reverse lever, a round dial for stitch length. I have equipped it with a SewPro 500 GR servo motor, which gives total speed control from 0 to 1500 RPM. I use thread sizes 69, 92 and 138 with that machine.

I forgot to list the US measurements. It occupies a floor and wall space of about 26.5 x 41 inches. The rotating locking casters could extend out, adding a few more inches to the floor space. The pedestal floor base itself is 20 x 27 inches.

I don't know about the Tuff-Sew portable walking foot machine, but I did briefly have an Alphasew portable, which is basically the same machine. There was nothing tuff about it and it did not sew. The machine appeared to have taken a shock on the bottom from the box being dropped during shipping. That shock caused the main shaft to jam, bending the soft metal cranks that turn the machine hopelessly beyond normal repair. The metal used in most of these machines is soft and easily bent. However, had it arrived intact, the most thickness it was meant to sew was 1/4 inch. Some members have modified their portable walkers to sew up to 3/8 inch, but I don't remember which brands, nor do I know if the machines held up to the increased stress. Further, they have top and bottom feed with teeth on both feet. They are meant for sewing denim, awning, vinyl and sail material, not leather. Sailrite is advertising that their new machines have beefed up steel rods and cranks and better polished and flattened mating surfaces. You might have a better chance of sewing 1/4 inch belts with a Sailrite, equipped with the "Monster Wheel" conversion, than a clone from eBay.. These machines do use system 135x16 and 135x17 needles and have a standard class 15 bobbin.

My new Cowboy CB4500 occupies 68 x 104 CM of floor space. It is a stand-up to operate machine. Total weight is about 350 pounds. The machine base is on casters that can be locked or left movable.

I bought mine a month ago for $120, for everything (machine, motor and table, needles, thread, bobbins).

Investigate all available options when it comes to buying a sewing machine that really sews the kind of leather most leathercrafters want to assemble. I too was looking for a portable solution, but soon realized that is wasn't going to happen. I have had and still have a Singer 29 Patcher. It is a fine machine that sews with up to #138 thread, but only into a little over 6 mm (about 5/16 inch). Typical walking foot machines will sew through 3/8 inch (10 mm), but again, are not good at tensioning thread thicker than #207 (T 210). The real problem with these and all flat feed industrial and so-called "industrial strength" home and sail makers' machines is the metal in the pressure, take-up and tensioning system is too light weight to handle the stress of penetrating, holding down and pulling thick thread up through thick or dense leather. I have had all metal industrial machines that will not hold down 1/4 inch of veg-tan leather, even with the top tension adjuster all the way down. The metal parts on portable walking foot machines are a joke. Trying to sew a holster will probably cause the critical moving levers to bend. They are not designed to take the stress of sewing hard leather. A real leather sewing machine will have very thick hardened steel parts in the take-up, needle bar and presser bar parts. Its springs for tensioning the presser foot, top thread tension disks and bobbin case tension will be about twice the thickness and strength of standard industrial springs, which are already twice that of home sewing machines. The available needle sizes for various machines plays a part in choosing a leather sewing machine. A typical walking foot machine uses a system 135x16 or 135x17 needle, in sizes up to 200 (Singer size 25). These needles are only able to sew through a little more than 10 to 11 mm of anything. The alternating outside foot may only be able to lift up high enough to clear 10 mm of work, before the needle bar hits it on the down stroke. Real leather sewing machines use a much longer needle system, like types 328 (long) or 794 (longer). A machine that uses a 794 (also 7x3) needle type can sew over 3/4 inch (20 mm+), depending on how the machine is set up. The machines using these needles have extremely thick moving parts and springs. The cases are massive as are the flywheels. Sewing with #415 thread is not uncommon with these machines. Their needles are available in sizes up to #28 or #30; the size of the nails used to hold wooden porches together. Just some thoughts for you to keep in mind before you invest in a sewing machine based upon the seller's hype.

You mean a swing-away roller edge guide like this? I combined a swing-away flat guide set with an individual roller edge guide. The screw post needed to be brazed on the bottom of the plate, to keep it from turning when I use pliers to tighten down the roller guide. Bob Kovar sells them already customized like this. 866-362-7397

Keep looking for a place where you can adjust the sideways position of the needle bar. You can't use the machine with the needle hitting the foot or throat plate hole. Try rotating the needle bar and see if it moves the needle's position at all. The bar might be warped, or the bearing on the bottom worn, or an adjuster screw set improperly. Are you using the proper needle type? is it a loose fit or tight fit inside the bar? If it is loose and able to wiggle, the needle is the wrong "system" for that machine. The proper needle system should just slide into the bottom of the needle bar and line up directly with the holes.

KND; Please get some other thread and see if it fixes the problems. Thread can vary, spool to spool, batch to batch, color to color.

A standard industrial sewing machine table has a 7" x 19" cutout. The knee lever mounts in a common general area. The oil pans have a cutout for the knee lever to operate. If your machine will drop into a 7" x 19" cutout, with hinges lining up with the pins on the table and the rubber stoppers in the corners catch the edges of the machine, you're good to go. If not, you'll need to either brace the hole in the table with solid wooden supports, or route out a larger space, to match the base of the machine.

It sounds like the same problem another member just had: a loose flywheel. Tighten up the two screws that secure the wheel to its shaft. Then tighten the pulley and motor belts a little more. It is possible that the bison skin is stressing the mechanism somewhat. But, if the wheel it fully tightened and the belts don't slip, the motor should force the needle to penetrate all layers. Just yesterday, I sewed through1/8 inch of plastic taped to 12 ounces of Latigo with a Cobra 4, using a #25 needle. Had to tighten the upper belt by lowering the pulley all the way.

With the hand wheel properly tightened, is everything now moving in sync? Check the other screws on moving parts you can see. Make sure screws are not loose. But, make sure moving parts are not binding. Let's work on the top thread problems. Grab a kitchen funnel, or go to an auto parts store and buy an oil funnel, which is just slightly bigger on the bottom than the spool of thread is on top. Make the spool into Tin Man,with the thread feeding out the long narrow spout of the funnel. Feed it up, through the thread guide hole and pull the thread. See if it unwinds from the spool, feeding through the tornado of the funnel spout. If so, let's continue wit the Tin Man concept. If not, remove the cap and we'll try something else. Whether the funnel trick helps or not, feed the top thread from the hole in the top guide bar through the top hole in the post on top of your machine. twist the thread against the direction of any coils, to loosen it as much as possible. Now, thread the rest of the way as shown in the instructions. Choose the correct needle and thread combination for the leather thickness and hardness you want to sew. That might be a #25 or #26 needle for #277 thread, top and bottom, depending on the hardness of the leather. Don't try sewing thick nylon thread into thin leather. This requires a different, softer type of thick thread that you are using. Using a larger needle than required sometimes makes it harder to balance the position of the knots than if a smaller needle is used. Too small of a needle may cause the knots to stay on or near the bottom no matter how hard the top pulls. Try different size needles with your thread and stick with the ones giving the best, repeatable results. Make sure that the bobbin spring presents smooth friction for the bobbin thread and make sure the bobbin is loaded to feed backwards to the slot in the case. Remember what I told you last night about checking the bobbin for any starting thread that may be looped out of the little hole and around the top of the bobbin disk. These leftover threads are grabbed by the spring inside the bobbin case and cause tension variations. Make sure the top thread is not twisting around anything it should be passing through. Set the tension adjustment around the middle of the top disk adjuster. Sew a few inches and see what you get. Adjust the top adjuster for the best consistent result. Hints: If both top and bottom stitches are loose, tighten both top and bottom spring tensions. If both are dug into the leather too far, loosen both tensions. If the knots are all on the bottom, tighten the top tension. If the knots are all on top, loosen the top tension. If the knots are all over the place, tighten the bobbin case spring and try again to balance the thread. Finally, change to a different brand of thread and try again. If you can't do that, spray the spool with silicon, or place it into a can of pure mineral or sewing machine oil for a few minutes. Dry off the excess lube and try using your lubed thread. If this helps, consider buying only pre-lubricated thread (e.g.: http://www.tolindsew...com/thread.html). Another thing that just came to me: Make sure your thread doesn't say RT, or right twist! Our single needle sewing machines require left twist, also known as LT, or Z twist.

Cajun; Why don't you start a new topic requesting help from other Cobra owners? Somebody may have experienced the same problem and knows how to fix it. I sew with a Cobra Class 4 at work and am responsible for adjusting and maintaining it. I may be able to help you get yours working right.

Pull the thread out of the machine, including the bobbin thread. Close the empty bobbin case. Place the same thickness of leather under the feet and try hand or slow machine sewing without thread. Does the machine hang as the take-up lever is rising? Does the needle stop while the hand wheel turns? If so, try tightening the screws that secure the wheel to its shaft! It could be that simple.

I'm starting to dwell on the idea of somehow mounting a funnel over a spool of thread and feeding the thread through it to the loop or hole in the stand.

I think you are going to want to move down to #92 or 138 thread for those thin projects. Here's what you need to bet and the changes to make. 2 spools of each color bonded nylon thread you want to use in sizes 92 and 138. Eight ounce spools will do. A pack of leather point needles (system 794-LL) in sizes 19 and 22, or 20 and 23. another half dozen or more bobbins. Tightly wind bobbins with the #92 and #138 thread, in various colors, and label them or hang them on size-labeled hooks. After inserting a bobbin with #92 or 138 thread, tighten the bobbin spring to maintain some tension on the thread. The setting for #277 will be totally loose with #92, and almost totally loose with #138. Back off the top tension disk setting It might be necessary to lighten up the action on the check spring, on the bottom tensioner. Run some test strips and fine tune the tensions on the bobbin case and the top tensioner. It might be necessary to feed the top thread straight through the top hole in the machine mounted thread guide post, without wrapping it around and out a second hole. Two wrapped holes may present too much resistance and override the tensioner disks. I use these tips myself when sewing everything from garments to saddle bags, to belts to rifle slings. Using a #22 needle with #138 thread produces a tighter knot in thin leathers. Using a #23 needle makes it easier to position the knots higher in thick leather, with #138 thread. Also, for thin leather projects, back off the presser foot pressure adjustment. It may need to go almost all the way out for very soft or thin work.

First of all, although you haven't said what model your Cobra is, I want to reassure you that the Cobra 441 clones are fully capable of sewing balanced stitches in leather thicknesses from under 6 ounces to over 3/4 inch. I regularly sew with a Cobra Class 4, so I will try to help you with some suggestions. The 441 clones are not light duty sewing machines. They need a certain amount of top and bottom tension and pressure to operate properly. An overly tight bobbin is as counterproductive as one that has no tension at all. Set a modicum of tension on the bobbin spring for the thread you are using. Not too tight, not too loose. It should pull out smoothly, without any hiccups. Hiccups can be caused by leaving a piece of the tied down starting thread looped around the hole it goes through and the top of that side of the bobbin. Cut off any thread that protrudes from the holes in the end disks of the bobbins. Thread the bobbins to feed backwards in the case. With the bobbin case open, rotated backwards so the opening is facing back towards the front, hold the wound bobbin so that the thread feeds off the top towards the back of the machine. Place the bobbin in the case and feed the thread through the slot and snap it securely into the tension spring. Make sure the bobbin thread feeds under its spring and out the mouth end, then snap the bobbin case shut. Pull on the thread that protrudes (4 to 6 inches) and make sure the tension has not changed. Consult the instruction DVD to ensure you are threading the top thread as per Steve's instructions. Before you feed the thread through the needle's eye, pull on it to make sure it is under tension from the top disks. Adjust the spring tension as needed to get a strong amount of resistance, while still being able to pull the thread a bit. Lift the presser foot release lever with the foot pedal and see if the thread pulls easily. Let go of the foot lifter. Now lift the hand presser lifter on the back and see if the top tension has been released at all. I find that the hand lifter only releases a little top tension, whereas the foot lifter lets it go almost completely. The hand or foot lifters, when lifted, should force the top disks apart (with a little lever that moves from the bottom of the disks) to release thread tension. Then, when you release the lifter, the lever that splits the disks must drop down to allow the disks to close and pressure to be applied, as set by the finger adjuster nut. If this lever is sticking in the disks, the tension may not be properly applied to the thread. If the check spring has too much tension, it can cause additional drag on the top thread. The spring has two possible adjustments. Once is the movable stopper plate under it, which sets how long the top thread is kept taut during the down stroke.This is set by the single flat head screw that sits inside the slot in the stopper plate. This is a trial and error adjustment. You don't want it to stop short, nor all the way down, in most cases. set it somewhere in between. If the spring has a LOT of tension, reduce it by loosening the nut on the back of the face plate where the bottom disk shaft is mounted. With the nut loose, insert a small flat bade screw driver into the split shaft and turn it whichever way loosens the spring action. Loosen the spring a little then tighten down the locking nut. Make sure you thread through the needle from left to right, with the cutout scarf facing the dead-right side. If you are using a #25 needle, it works best with #V207 or T210 thread, top and bottom. It will feed #277 on top, but 207 on the bottom is easier to pull up into the leather. If the leather is soft temper, you may be able to get away with a #25 needle and #277 thread, top and bottom. For #138 thread, I use #23 leather point needles. Yes, a 21 or 22 works, but the #23 seems to sew more reliably. Use system 794 Schmetz needles if possible. Set the top pressure spring adjuster so it sticks out the top between 1 and 1.5 inches. Before you start sewing, hold the top and bottom threads back hard. Sew in reverse a couple stitches, then throw the lever to forward and cross over the starting threads. Let go of the threads and sew slowly for a few inches. Lift the foot lifter and remove the leather. Check the position of the knots. If you see the top thread knots on the bottom, increase the top tension adjuster. If the knots are on top, reduce the top tension. If the stitches look decent, sew a longer run of stitches, using your edge guide. As your machine is sewing, look up at the top thread and see if it is winding around anything and causing knots to form. Also, see if it is trying to twist out of the top tension disks. I have actually seen a knot forming as the top thread twists after going through the post on top of the machine. When that happens, try changing how you feed it through that post. Twisted thread causes tension problems. It can even twist right out of the top tension disks! Some thread is just plain shitty. If you have really springy thread, remove it and try another brand, or another spool. Thread can vary from run to run. If the thread is feeding properly, without kinking or knotting, and without popping out of the center of the top tension or bottom tensions disks, and the bobbin thread is feeding evenly, with a bit of resistance, using the proper needle size for the top and bottom thread, your stitches should all fall into the same vertical position in the leather. Failure to do so indicates that there is either a problem with the thread or the machine needs adjusted. Sometimes a screw may shake loose and affect the timing or repeatability of good stitching. Please rule out everything else before you assume that the machine needs to be adjusted beyond the tension settings I mentioned. I will watch for your replies tomorrow morning, or night. I'll be out all afternoon. If you get a chance, photograph how you are threading the top thread, from the spools, all the way to the needle.