Wizcrafts

@Sblof Your Nakajima 280L machine has been discussed on these forums, before. Here, here and here. It is a compound feed walking foot machine. It uses the common System 135x16 and 135x17 needles. It takes all manner of Singer 111 style feet. Most are smooth. It was a forerunner of the current Juki 1541.

Some Puritan machines have been in service for a century, or longer. Parts wear out over decades of use. Finding replacement parts may be difficult. I believe that Redwing repairs their Puritan machines on-site and probably manufacturers all needed replacement parts, or out-sources them to local machine shops. Here are some references and videos of Puritan Machines in action. https://www.youtube.com/watch?v=RMWAPPEucMI https://www.youtube.com/watch?v=DOVaDCN-BEI Here's one (currently) for sale on eBay, in Pennsylvania.

Redwing boots are sewn on Puritan chainstitch machines. Some have 4 or more needles to sew parallel lines at critical seams on the boots. I guess it wouldn't hurt to contact them and ask if they have any Puritans they want to sell off.

I try to keep my minimum sewing speed to about 1 stitch per second, except on intricate turns and patches. I slow down to get the best needle placement, then speed up on straight-aways.

Despite all of the improvements made in electronic motors over the last almost 20 years, I can still feather a clutch motor so it barely turns over the machine, and hold it at a slow and steady speed. Yes, they are noisy and generate a bit of heat. But, they are like the Ever Ready Bunny: they just keep on going! If anybody reads this and is having trouble controlling a clutch motor, try backing off the big screw on the clutch housing. This adds a certain amount of slack movement before the disks engage. You can also tighten the coil spring that holds back the clutch lever. That keeps the lever up and away from engaging accidentally. Finally, you can smear a little grease on the internal cork disk that mashes into the main disks. The final adjustment is to replace a large motor pulley with a 2 inch pulley, or to add a 2:1 speed reducer.

I didn't find that. I sewed with the optically modified motor on my cb4500 and a couple of walking foot machines. They worked very well. The Cowboy had a 3:1 reducer. My long arm Singer machine fed directly from the motor's 45mm pulley. They had no hesitance to start turning over.

I'm not an engineer; just a knowledgeable user. Optical speed control is not new technology. I've had volume pedals for my pedal steel guitars from decades ago that used a small light bulb or LED to emit a focused beam against a photo-resistor. The sensor/resistor controlled the signal transfer between the input and output jacks. When backed off, heel down, a small phenolic board blocks the light beam, so there is no output at all, yielding full resistance. As one moves the pedal with his toe down, the phenolic board is brought out of the line of light, gradually increasing the amount hitting the sensor, decreasing its resistance. This results in an extremely smooth transition from zero to the maximum volume that the volume pedal is able to transfer to the amplifier (~95%). My current electronic volume pedal is still optically controlled, but uses a variable density filter instead of a solid piece of board. It has a small amount of amplification so that it doesn't lose any signal at full volume. Fast forward out of the world of pedal steel guitars and into the world of digital servo motors on sewing machines. In 2011 through 2013, our main 441 machine suppliers sold them with a digital motor that had a 45mm pulley. Some started with a jolt at 200 rpm. Others started with a similar jerk at 100 rpm. So. somebody took their motor apart and saw that it was optically controlled, just like my old volume pedals. That person had a good printer and some transparent "paper." He went and printed out some strips that had a varying density of gray ink, smoothly ranging from 100% black to 100% transparent. By playing with the spread of the printed filter, he came up with a simple optical filter that anybody could install inside their motor. He sold them through the forum for a modest fee. I installed one in my Cowboy cb4500, in my buddy's Cobra Class 4, and on a Techsew I acquired a little later. This modification worked 100% as designed. The only thing that caused a variation was if the machine hit a bump in the floor when I moved it to sew a log project (webbing strapping or a long rifle case). It was a simple matter to reposition the filter, which I later glued in place. So, is this new KineDyne motor optically controlled? If so, have you considered using an optical variable density light filter to control the speed? I think I still might have a spare filter in an envelope. Bob Kovar might still have a couple left. We could probably get one to you to experiment with. I'm pretty sure there is a variable density filter in my original digital servo from my cb4500, which is on the floor in a closet. If you try the variable density filter control system and perfect it, then secure it to survive shipping and man-handling, you will be able to offer a motor that smoothly transitions from absolute zero through the top speed as set on the control panel, with good low speed torque from the numerous coils. A side benefit of having a digital servo motor running this slowly is that there seemed to be much less heat being generated. Originally, we felt the heat as we sewed at 5 to 9 stitches per second. It was even running hot at slower speeds due to it starting at 200 rpm. I also disliked the non-linear speed change which ramped up after I pressed down on the pedal. It wasn't an instantaneous change that I preferred. I grew up using clutch motors on sewing machines, and still do on a few of them. I have since moved away from touchy digital servos to the analog motors sold by my Cowboy dealer. They contain brushes and replaceable carbon signal transfer blocks on springs. They reliably start at zero and speed up linearly as I press my toe down; just like my volume pedal on my steel guitar.

@X24 A few years ago, I was friends with a guy and lady who were producing bespoke shoes and boots. After a couple of years, she left the partnership and went on her own. She decided to make moccasin style footwear. She enlisted me to help find some suitable sewing machines. To my amazement, I discovered a specialized shoe sewing machine that is called a "sole sidewall stitcher." This type of machine combines the vertical sides attached to the soles to the uppers, all around their sides. I did a quick Google search and discovered that some of our own advertisers sell these sidewall stitchers. Brand names that come to mind include Cobra, Cowboy and Techsew. Although not an advertiser, yet, Campbell-Randall in Texas also carries these machines. You can see them in action in the videos in a 2017 topic linked to in the topic below. Here is a previous discussion about sidewall stitchers on Leatherworker.net:

It's probably not going to fit on the needle bar of the 45k. I recommend contacting industrial sewing machine dealers who sell the GA5-1 machines and ask if they carry the roller foot assembly for it.

I'm not familiar with either machine. But, I googled both and found that the main difference is that the Seiko is a compound feed walking foot machine, while the Consew is merely a needle feed machine. The walking foot would have an advantage if you have to sew over new layers and tall seams. Its compound feed will simply walk up and down over these changes in layers. The needle feed machine will stop against a new layer unless it is very thin. Both machines are double neelde machines. You'll need to learn how to turn corners properly and balance the knots with two tensioners and bobbin tension springs. Both use large bobbins. In some instances, time is money. If your sewing is based on an hourly charge, the needle feed machine will probably spin faster and run smoother. There was a discussion about the Seiko in 2016, here:

When you come to any sharp corner, bury the needle, then feather the speed pedal, or hand wheel the machine until it rises a little so that the hook is inside the thread loop on the right side of the needle. Raise the presser foot enough to clear the leather, then rotate the leather, lower the foot and continue sewing. Doing these steps insures that you don't break the needle or lose the thread loop, which will cause a skipped stitch.

@thobgood In case you didn't know, Juki machines are top shelf for many applications. Yours is a top notch garment material sewing machine with a fixed foot and bottom/drop feed. Once you get the timing right, it will be a money maker. Many leather crafters on this forum sew heavy and thick leather projects on specialized machines we often refer to as harness or holster stitchers. Way back around 1986, or so, Juki came out with a heavy duty harness stitcher that they assigned the model name/number: TSC-441. I saw one that was still in a wooden carton in a sewing machine warehouse. At that time, the dealer told me that I could take it home form only just under $6.000. I didn't have that kind of money and they didn't do financing to individual buyers. Fast forward to around 2011 and a Chinese sewing machine company obtained a Juki 441 and disassembled it. Then they made molds and began casing new versions of that Juki. They gave them new model names and sold them to dealers who assigned their own brand names. I bought one in 2012 that I still use every time I need to sew a thick project. It is a Cowboy cb4500. My best friend has an equivalent brand, called a Cobra Class 4. Both have the same capabilities. Techsew offers their own model as a Techsew 5100. You can now buy one of these machines for between $3500 and $4400, with all manner of accessories! In contrast, I just found a new Juki TSC-441 for sale from a dealer for $9400 plus shipping. Enjoy your Juki!

Some hooks have a deflector shield that will prevent the needle from touching the needle. They are thin steel and bendable. Yours may or may not have one. If not, just move the hook away from the needle slightly. This may alter the timing, so recheck it afterward and advance or retard the hook as necessary.

No, that isn't the opener. On some machines there is a lever with a bent arm that pulls back on the bobbin case to let the thread slip through without getting hung up. If your machine has a latch opener, it is quite abrupt in comparison to those found on our typical walking foot machines. Without the opener lever, the only thing making room for the thread to the hook is the thread itself. That works if the top thread is taut, but can fail if it has too much slack.

The bottom travel stopper is set by the bottom screw inside the open channel in the bracket. The slack adjustment is the little screw in the curved slot that's above the main shaft and nut.