Ignorance – Not Always Bliss

At this point, it’s been over a year since I bought my Juki DNU-1541 sewing machine. This is the upholstery machine on steroids that will effectively stitch through flesh and bone if you aren’t careful. I’m stitching all of my holsters on it at this point, and have had many a stern conversation with ‘Priscilla’ (pronounced ‘Pear-ish-oola’ as pronounced in the Japanese version of Gun X Sword). This machine has a 1/2-horsepower clutch motor with the pull of a mule and about 1,800 stitches per minute when the clutch is engaged. When I set the stitch length to an attractive 5mm stitch, it will pull a piece of material through very quickly. The machine head is capable of higher speed, but my supplier saw fit to limit its speed with a smaller motor pulley. (The machine in the following video is not the very machine that I took home with me, nor did I get my machine from that supplier.)

Because of how fast this machine stitches and how hard it pulls, I often run it manually by the hand wheel around tight curves and corners. This has led to many blistered fingers, sore arms, and general pain. On Friday after doing extensive stitching on several shoulder holsters, I was trying to ignore my two new blisters and general stiffness in my right hand, but I realized that I could no longer continue on the way I have been. I know that clutch motor has a brake in it, and the brake applies every time I let off the throttle. As an experiment, I pressed on the clutch pedal with the power off and turned the wheel by hand. It stitched through a piece of heavy horsehide with very little effort that way. It didn’t even make my blisters hurt! Yeah. I have to do something differently.

So, I started looking on the interwebtron for servo motors, whose speed is adjustable either by pedal pressure or by manually turning a knob setting on the motor control. I found this entry which only provided a small bit of clarity for my issue. In looking at the motors online, I found that I could expect to pay about $200.00 for a good servo motor. *Sigh.* If that was what I needed to do, I’d save up the money and do it. But, I decided that it was time to give a call to the sewing machine shop first. I got on the phone with Darren at the sewing machine shop and told him I thought I needed a servo motor. He said that he had one in stock that he’d sell for $150.00 if I wanted it. He also explained that the servo motors wear out a lot faster than the clutch motors. I recalled in the link above how the woman testified to having one go bad with only a few hours use. Yuck.

So, I described my problem with the detail work and fighting the brake and asked if he had any suggestions for me. “Wait,” he said, “That brake shouldn’t even engage unless you heel down on your foot pedal.”

“What?” I asked for clarification, “The sucker is engaging hard every time I release the throttle.”

“…” he said, “There’s a little spring on the control arm with a wing nut at the end of it.”

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“Why don’t you loosen that thing up and see what happens. If you go too far, the machine will spin under power when you don’t have your foot on the pedal. If it’s too tight, the brake will lock up on you when you let off throttle pressure.”

I gave the wing nut in question several left-hand twists, unthreaded the needle and fired up the motor. The needle and feet stayed at rest as the motor whirred to life. I placed a piece of leather under the foot and applied throttle pressure. The machine laid down twenty stitches in the fraction of a second it took for me to heel down, where the brake engaged. When I removed all pressure from the pedal and let it go neutral, I turned the hand wheel. Effortlessly. *Face palm.* For A WHOLE YEAR the motor control was adjusted wrong and I have been KILLING myself trying to use it. This was all because that’s how it had always run and I didn’t know any better. The guys at the sewing machine shop are good. I’m sure they had it adjusted properly and it probably settled out on its trip to my home. I felt so stupid. I have to remember that I didn’t know any better. This is not stupidity, this is ignorance. We are allowed a little of that every now and then. One way or another, I’m smarter now, and this should make my job easier.

7 thoughts on “Ignorance – Not Always Bliss

  1. Ouch. My wife, who sews some, face palmed right along with you when I told her about it. Don’t feel bad. I grew up in a commercial sewing shop and I wouldn’t have known either.

    At least you had the guys at the sewing shop tell you. My mom and dad would have figured it out and harassed me at every Christmas and Thanksgiving for the rest of their lives.

  2. Well, I’m glad you figured that out just in time to make my Leatherman case, holster and belt 😀

    Oh, and I’m also glad you won’t be tearing your hand up anymore, that’s a nice bonus

  3. I am so thankful I found this post!!!! I bought a used DNU-2541 and the hand wheel has been so hard to turn and I couldn’t find out anything online until now! My dad kept saying that the break must be on when I would whine about it, but I didn’t know it could be adjusted. I just knew carpel tunnel was in my near future haha. Thanks again!

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