Wizcrafts

That's what I do on ALL of my sewing machines. Does that mean I am a Seamster?

In item #5, where I mentioned the tension on the spring on the second adjuster, I meant the beehive spring on the lower rolling disk on the faceplate. The check spring is a separate, but connected item that can be adjusted separately. What size thread are you using, on top and on the bottom? What size and point is the needle?

Some beginners are known to mark the adjuster nuts on the two upper tensions with white paint. One can even put a white dot on one side of the bobbin tensioner screw. Then, count half turns as you make delicate adjustments. This assumes that you are starting from a good reference point. Apparently, you have lost that happy place. Let's try to regain the upper hand... If you have not changed the bobbin tension, nor the bobbin thread, nor inverted the bobbin itself, adjust the top tension as follows: Examine the bobbin thread to see if it has slipped out from under the bobbin tension spring, causing a total loss of bottom tension. Check top thread path for twist-overs or knots. These cause unexpected increases in top tension. If there is no thread binding problem, if the knots are near the top, loosen the top tension adjuster counterclockwise, a turn at a time, until they drop into the leather. If the knots are at the bottom, turn top adjuster clockwise to increase top tension until they are balanced in the leather. If the top adjuster nut doesn't bring the knots to the best position, check the tension of the lower adjuster spring and its connected check spring. The check spring is factory set for heavy action, as needed to control thick thread. It may totally override the tension disk settings unless you loosen its lock nut and turn the split threaded post counter-clockwise, to relieve some spring tension. Leave enough spring tension to allow it to move all the way up and back down to the stop motion block under it. If you have changed needles, size matters. A larger than required needle allows the knots to rise to the top, where they may have been previously centered vertically.

Eric works in a magic place; a sewing Wonderland that most mortals can never see.

LU-563, as long as it is tight (but not binding) and sews a proper stitch. Also, make sure that the stitch length lever doesn't raise up when you speed up, shortening the stitches. That is caused by weak springs in the reverse mechanism.

I used one of those until I got a walking foot machine. The OP also uses a walking foot machine and won't need the jig.

Technically speaking, your Class 4 will sew under 6 ounces, but only with very light thread, a small needle and tensions rolled almost all the way off. I actually sewed a burlap bag closed on a Cobra Class 4. I also used it to sew zippers onto vinyl jackets, some of which were 4 or 5 ounces thickness. The machine needed a lot of adjustment to do this and this takes time. Here is a checklist to use for sewing under 6 ounces of material. #69 bonded nylon or polyester thread, on top and bobbin. #18 needles (not usually available with a leather point in this size). Back off the top tension entirely. Reduce the tension on the check spring for the lightest pull that still moves it all the way up and down during the take-up cycle. You may or may not need to unscrew the bottom tension spring to reduce top tension. Adjust the bobbin tension spring down for a modicum of pull; smooth, but not tight. Don't let the screw head extend so far that the top thread gets caught on it as it feeds around the bobbin case Back off the pressure on the feet using the big threaded adjuster on top. You won't need as much force to hold the leather down. Some people do the opposite and crank up the pressure. This just pushes soft leather deeper into the feed dog hole and slot. Make sure that the presser foot go all the way down, to secure the leather between stitches If you got the blanket foot set with your machine, it may work better than the harness feet. The blanket feet are large and have teeth. The outer blanket foot also has steel all the way across the back, giving more holding power behind the needle and inner foot. This gets around the issue of soft leather lifting with the needle when using harness feet, which are wide open on the back. The blanket foot set includes a different feed dog, which has teeth. It may or may not prove more efficient than the smooth dog. Also, the blanket feed dogs tend to have a smaller needle hole than the smooth dogs have. Hold the threads back and test on some scraps of the same thickness, adjusting the top or bobbin tension springs to balance the knots. If the blanket foot is too wide, take it to a grinder and cut down the right (and/or left) toe

My advice is to ask the seller about the slow speed controllability. Have him make a short phone video of the machine in motion, from the slowest possible, to highest possible speed. If you like what you see, buy it. If you think a different motor is needed down the line, buy it. At least get some time on the machine with the motor already on it.

Ike; What caused the tension release lever to get stuck between the disks? Others will want to know.

That motor is rated at 2/5 H.P. which is a little on the low side for torque, depending on the material density and motor pulley diameter. If it has a 2" pulley, it will drive a standard walking foot machine, equipped with a #22 leather point needle, through a couple layers of belt leather.

Ah so!

?

The stirrup plate is what you need to sew curved gussets. Once you will get past the thread loop position problems, you'll laugh at this beginner's speed bump. Have you ordered some leather point needles one size larger? This may solve the loops on the bottom problem. Did you know that leather points are available in more than one shape? I use mostly type S, but also have some triangular "diamond" points on hand. They produce a different top and bottom stitch. One more thing: you might try adding some more top pressure to the feet. If the leather is not absolutely pressed down against the stirrup plate it will usually have bad results on the bottom.

Here is a link to the brand new CB3200 web page

Back off the bobbin tension until there is a smooth, even pull, with a little resistance. Sew a text row of stitches on some same thickness scraps, adjusting the top tension as you sew. When the knots are in the middle, you're ready to go to work.

I use my patcher for sewing patches onto vests and jacket sleeves. It is perfect for fixing straps on sandals, ladies pumps and purses, as well as sewing pull tabs onto boots. It can sew in any direction and has a small snout, with an equally small bobbin. I limit my patcher to using #69 bonded nylon in the bobbin, which extends the life span and allows more items to be sewn You need to clean that machine, paint it and oil/grease it.

The spring guide feet tend to be more edge-guidish than the raising feet.

135 is a Canadian/European measurement thang. It is actually size T135 which equals B138. It's like the difference between dynes per cubic kilopasqual vs. inches of Mercury, for barometric pressure.

According to the manual, the feed dog teeth should be about 1 or 1.2 mm above the plane of the throat plate, at their highest point. However.....Some of us set them flush with the top of the throat plate, for mystical reasons, known only to Mr. Peabody and Sherman.

Are you using a leather point needle?

I recall a topic started by a member who purchased a similar machine from an eBay dealer (not a member of LWN) and got it in 3 boxes. She was so frustrated trying to assemble the items (without any viable instructions) that she about gave up after fighting with the parts for well over a week. It is better to order a machine from a dealer who will ship it fully assembled on a pallet and ready to use. At least have the table and its components assembled and maybe the head threaded, in a separate box. Even the step of attaching the head to the table and motor can be too much for a first time owner of an industrial sewing machine.

Back off the bobbin tension spring until the thread flows smoothly with about half the current force.

If by "topstitch foot" you mean the hinged foot with a spring guide that moves vertically in a slotted right or left toe, it is used to either follow a previous stitch line (top stitching a pattern), or for use as an edge guide. A raising foot is used to sew along the top of the right or left edge, to secure a folded hem or cuff. It can also act as a edge guide, as long as the material has a square edge.

Using #138 in the bobbin would confirm or deny the need for a larger needle, depending on the outcome. If #138 bottom thread gets properly pulled into the holes, you needed to move up 1 needle size. Note: this only applies to other leather that has the same density on the bottom. If you change to a softer bottom layer, the existing needle may suffice. FYI: I usually use a #180/24 needle with 207/207, on my CB4500. I sometimes even go down to a #23 if the work is only 7-8 ounces thick and bridle leather soft. I use my stirrup and holster plates on a regular basis and only have to either loosen the bobbin, or tighten the top tension to compensate.

Would you please post a close up photo of the thread on the bottom, with the stirrup plate installed? Additionally, please post a photo showing how you have threaded the top thread. Take it head on, from the left side of the machine, where the disks can be seen. Also, state the thread sizes and needle size.