Wizcrafts

Welcome back, Andrew! We missed you!

Is this motor optically controlled? If so, there were people printing variable density optical filters that users could install inside their digital motors. These filters smoothed out to speed variations so the motor started at zero rpm and steadily increased as the operator pushed down on the speed pedal. Stopping the foot motion left the motor at that speed until one backed it off or pushed down further. I had this modification on a motor that came with my Cowboy cb4500, in 2011 or 2012. I would compare the action to the analog motors that replaced it.

My first Juki was an LU-563. The reverse stitches were always smaller then the forward stitches Eventually, I discovered the adjustment to get the distances closer. However, as you found out, the faster I sewed, the greater the difference became. This was in the mid 1980s. Since then, I've had various machines with reverse levers, some of which matched at any speed and some of which were flakey, like my old Juki. A Consew 206RB-5 was pretty reliable in both directions. Many of my current crop of sewing machines don't even have a reverse lever. I either sew all around to sew over the starting threads, or spin the work around 180 degrees and perform what I call, "poor man's reverse." In both cases, the stitch length is constant. I sometimes do it on a machine that has reverse simply out of habit.

One problem I have had with digital servo motors vs analog servo motors is the jerky start up. I can understand that lowering the startup speed to 50 rpm will be less jerky than a 100 or 200 rpm startup, it will still engage with a hit. Analog servo motors I have start at zero and smoothly increase in speed as the pedal is pressed. There is no jerk at startup on those motors. I have helped convert several Cowboy and Cobra 441 clones and one Union Lockstitch machine from digital to analog servos for this very reason. Once the change was made, the owners never complained about being able to control the machine or position the needle as needed. I would be happy to have a digital servo motor that started at zero and increased in speed only as I pressed down more on the speed pedal. I don't like motors that start fairly slow, then speed up on their own ("ramp up"). The motor speed should be pegged to your foot position on the speed pedal. If one needs an external speed knob, the same should apply. As the knob is rotated, the speed should increase. Because many servos lack high torque at lower speeds. I can see that the ones having more coils will have more low end torque. I would gladly pay more for an analog servo motor that eliminated to need for a speed reducer. However, when sewing thick veg-tan leather, the faster one sews, the greater the heat that is generated on the needle. I found that when I sewed at 15 stitches per second, smoke came from the needle! This also began melting the bonding agent on the nylon thread. The result was a weakened stitch line. I doubt that I am the only person who prefers to sew slowly to maintain control of the stitch line and needle placement, as well as to keep down the heat on the needle. I typically sew within a range of 1 (for detailed designs) to 6 or 7 (on straight edges) stitches per second. When I sew at higher speeds, I use an edge guide. When the leather is thinner, I can sew faster than when it is very thick. It can be dangerous to sew 3/4 inch at 5 or more stitches per second. If a fast moving needle is deflected by thick layers and breaks, it could embed itself in one's skin! Ask how I know this!

I got my first ULS in 1986 or 87. I bought it off Tandy Leather. It was sitting in the middle of their parts warehouse, unused for years. There was nothing with it except the needle and awl in the head. No accessories or thread. Once I got a manual and learned how to thread it correctly, I used the large sizes of thread I already had from a Singer 132k6, which was my previous heavy duty machine. All my thread was bonded nylon. So, I used nylon thread in various sizes. I adjusted the pull up positioner, the looper, etc, until I got perfect stitches. I did this for most of the time I owned that machine. I tried running Barbour's Irish Linen thread, but it kept hanging in the barbed needle, or on the looper. I just couldn't figure out how to run linen thread through liquid wax without it sticking to the needle or looper. Arrg! So, I kept going back to bonded nylon. If I get another ULS, I will buy bonded polyester thread just to keep it happy! ;-)

MB, when the ULS was main primary stitcher, I bought every size needle and awl available. First, I got them from New York. Later, from CR. If memory serves half right, I had needles from .5 through 6 or 7 and awls from 1 through 7 or 8. My most used combos were a #2.5 needle and a #3 or 4 awl. Some of the awls had slanted leather points. These made tighter holes for edge stitching. I was able to sew with thread sizes 69 through 554. You're right about the reason for the tool tray. I kept the round wrenches in it, as well as packs of needles and awls. Did you ever do business with Freedman (or Freidman) Harness in Toronto? That's where I learned about Campbell and Randall machines and how to operate them. They helped my with setting up my first ULS machine (from 1968). I brought that machine with me when I moved back to Michigan. I wish I had kept it. The then wife said why don't you sell that big ugly thing that's taking up space in "my" dining room. She's long gone, but so is that machine!

Having owned and sewn on ULS machines, I can confirm that they are unlike modern single needle machines. I've owned several heavy duty lockstitch machines, but none can come close to the tightness of a properly adjusted Union Lockstitch machine. Admittedly, they take some time to learn how to operate and adjust them. But, it is worth the effort. I even taught myself how to sew thinner leather projects on mine. I was able to sew single leather 10-12 ounce bridle leather belts on my ULS machines. In some cases, that included sewing fishtail stitching patterns; aka: gunfighter stitching. I still use the knowledge gained on old ULS machines when sewing fishtail patterns on belts using my current big Cowboy cb4500. For anybody reading this topic and having a ULS or Randall lockstitch machine, I will share a tip I learned from experimentation to avoid ratting a previous stitch when sewing over it in a design, or to end a row by sewing over the starting stitches. As you approach a previous stitch, if you carefully rotate the work, or reposition the angle of the barbed needle, you can sew right next to an existing stitch without ratting it with a forward facing barb in the needle. I taught myself to just angle the stitch line to one side as the needle came up and the looper threaded it. As the barb comes down, I made sure the previous stitch was at an angle to the barb. If one masters this, you can sew inline over the starting threads without ratting them on the way down. Feel free to test this free tip! It was also important to choose the smallest needle that still held the top thread in place without dividing the thread strands. A filled needle is less likely to catch a previous stitch! Last time I checked, Campbell-Randall stocked needles and awls in a wide range of sizes. I always used an awl that was one number larger than the needle. If the finished project holes look too big, tap the surface with a steel harness makers' hammer.

That machine sounds like the bobbin drops in vertically and a securing latch snaps down on top of the bobbin. If that bobbin thread slides out of the edge of the bobbin, it wil either wind around under over over the bobbin and wrap around the post or the snap down retainer. Maybe this bobbin thread is wound too loosle and is unwinding outside the edges of that particular bobbin. Try winding another bobbin and see if it has closer toerances inside the basket. Also, feed the bobbin thread against the rotation of the shuttle.

During the mid-1980s, I was trained to sew harness straps and reins on a Randall Lockstitch machine from the early 20th Century. The straps and reins tapered from about 1/4 or 3/8 inch at the folded ends to a solid 3/4 inch along the length. That machine laid down the most perfect stitches using yellow 4 cord Barbour's Irish linen thread. It chugged along at 300 rpm, which translated to a about 3 stitches per second. The thread ran through a waxpot filled with Super Ceroxylon clear thread lube/wax, which is still available from Campbell-Randall Co. When straps were much longer, or time was of essence, I switched to running a Union Lockstitch Machine, built around 1940. It ran at 15 stitches per second when I floored it! Campbell-Randall is still the rebuilder and seller of the ULS machines. They stock parts, needles and awls for it, as well as the Campbell and Randall Lockstitch macines. I've owned two Union Lockstitch machines, so far. I have a friend in Roseville Michigan who owns and uses one Union Lockstitch and three Campbell-Randall Lockstitch machines. I can honestly say that unless one never oils or maintains them, these machines will keep working as designed for over a century. This information was totally unsolicited. I am simply sharing my personal experience running their machinery. It was and continues to be targeted at the harness making and repairing industries.

I sometimes sew denim with walking foot machines. I only tweak the check spring position and balance the tensions so the knots don't show on the outside. I find that as long as there is sufficient pressure on both feet to hold the material all the way down against the feed dog, I don't get odd knots or skipped sititches. So, try adding more foot pressure. Adjust the inside foot to press down just before the needle hits the material. Match the check spring throw to stop just as the needle penetrates the material, and not before.

The black body Cowboy machines were a special custom color made for or by a Texas based dealer, who has been out of business for several years now.

Lily white oil is a special clear, thin oil meant for sewing machines. Being clear, it doesn't discolor most fabrics if it drips out as you sew. You can buy it in 4 ounce containers that have a pull out thin brass tube, and in quart bottles to refill the 4 oz containers. It is very light weight oil. I recommend buying and using it in all your sewing machines.

First of all, what in the Sam Hill is that thing sticking out the top of the head? I've never seen any pin like that. Somebody added it to the machine. Second, it appears that you haven't passed the thread through the check spring. You must pull the thread around the tension disks, then feed it through that spring, then up to the take-up lever.

There are five possible explanations for the birdsnest on the bottom. The bobbin tension is too tight, or becomes tight as you sew due to improper winding, or the alignment of the bobbin in the shuttle. The top thread is not getting pinched by the top tensioners, or is simply too weak to pull the thread up. The top thread is coming out of the tensioners as you sew. The top thread is not feeding through the take-up arm/lever on the upstroke. It must be pulled up to form a stitch. The awl is too small. The hole must be large enough to make room for the lockstitch knots to pull up inside the hole in the leather. Check your parts manual to ensure that nothing is missing in the take-up and tensioning system. And, put the cover back on the shuttle compartment! It's also remotely possible that the machine was previously set up for waxed linen thread. You may be dealing with was residue on the rollers, guides and tensioners.

We have three main industrial sewing machine dealers supporting the forum. They are: Leather Machine Company (Cobra) in California Techsew in Montreal Toledo Industrial Sewing Machines in Ohio Additionally, Weaver Leather advertises here and sells leather sewing machines. They carry Adler and a house brand. Tippmann is an advertiser here and makes the manual Boss stitchers.