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  1. Thats right. the first ~10K ohms is a dead area and my servo does not activate until past that point. As the resistance increases the speed increases. The Pot I used from Frys electronics is labeled as a "16mm Potentiometer 50K Ohm audio taper without switch combo terminal" by Philmore. The Magnetic mod suggested by JoMama in post #12 was spot on and I had no real problems. His directions are great. Just make sure to pay attention to the clocking (1/4" grooves at end of shaft that he mentions in step #10 for easy alignment. Se hi res diagram below :-) --------------------------------- ---- ---- ---- ---- ---- ---------------------------------
  2. I did mine last week with the 100K Pot and a 50K pot. I adjusted the 100K Pot to just below the thresh hold where the motor started (12K ohm) and then used the 50k pot for fine control. Substituting a 10K or so resistor for the 100k pot would do the same thing. I also modified the magnet positioning as was also suggested and I now have fantastic control.
  3. Just noticed this thread or I would have responded a lot sooner. I ordered a Servo from Toledo (Ordering and shipping was fast and flawless.) I discovered that low end speeds were almost impossible to get right. I am a DIY sort and since it was 10pm I didn't expect Toledo to be open. I grabbed an old dead computer gaming headset and ripped the volume control off of it (2K Ohm) and grabbed a pot from a computer Power supply fan (100k ohm). Spliced them in series and was able get the speed adjusted to my liking. For ~60 SPM the reading is 18.3K Ohms and using the 2k Pot will adjust the speed up words to ~120 SPM. Its's no wonder everyone is having trouble getting it zeroed in at the right speed since at the low end a turn of just 3 degrees can result in a doubling of speed. The other advantage with doing this mod is that I now have the speed control mounted near the reverse lever so I can quickly and easily adjust the speed. I didn't even know there was an item called a Log/audio Pot, and apparently neither did the person who designed this Bob seems to be right on the money and if his test works as well as I expect it to I will grab a Log Pot and throw it in series. Thanks for the info Bob. Random
  4. Juki Dnu 241H

    I purchased a used 241 clone (Nakajima 280L) about 3 years ago and have not regretted it. It easily punches through 20+ ozs of Vegtan leather the same as the day I bought it. If I can fit it under the 3/8" inch presser foot it stitches. I bought it used and used WizCrafts check list for examining it. (Thanks again Wiz) http://leatherworker...=1 I found some online manuals that apply to the Juki 241 as well as mine at the following links... http://www.raichert....obe/dnubook.pdf or http://www.raichert....on%20Manual.pdf and used them to find all the oil points and to learn the basics. I did reduce the speed by replacing the small pulley with a smaller one and a new belt from Ace Hardware. Total cost about $10 and an easy DiY job. I also found that adding a wooden block under the back of the foot pedal so that you don't push the pedal all the way down, but only far enough to solidly start it stitching allowed me to control the speed MUCH easier. However a servo motor might suit your needs even better. At the time patience (1 hour for DiY vs 1 week to order and ship the Servo) and money ($10 vs $200) were both in short supply Best of luck. Random
  5. Holding Items Together For Sewing

    Contact cement on this end. I have sewn items after only letting dry for an hour (on top of the 45 minutes initial set time before joining the pieces) and have had no problems after 100+ items. Contact cement has a strong affinity for the contact cement already on the leather and tends to easily peel off metal so my guess is that is why it doesn't stick to the needle.
  6. I have very little experience with anything besides my Nakajima 280L so that is all I will comment on. I purchased my Nakajima 280L about a year and a half ago and I am quite happy with it's performance. It still punches through 20+ ounces of Vegtan and Latigo leather with ease. The only problem I had was that the (feed Dog?) would leave marks on the bottom of the leather. You can buy smooth feed dogs to eliminate this problem, but I was in a hurry so I simply removed the feed dog, filled in the grooves with a small amount (Pea sized) of JB weld then lightly sanding it smooth. I ordered another feed dog in case I needed to switch back but so far have never needed to and the system is running like a champ. From my understanding, the 280 was built like a tank and my experience supports that. I have purchased other feet and accessories for it and they are easy to find. The only quirk is that it does require hand oiling as it does not auto lubricate but that takes less then a minute and I only do it at the start of the day. And even that may be more often then is needed. At the time I purchased it I could find no negative information about it and those reports I did find gave it good to great reviews. My original post on it can be found here as well as a link to a manual. http://leatherworker.net/forum/index.php?showtopic=32863&hl=+nakajima%20+280l#entry204504 As for the Yamata I have never used one so I can not say anything good or bad about it.
  7. Will A Tk-806 Sew 12Oz+Lining.

    Thanks to all of you for your advice.I did NOT get the machine. I had resigned myself to giving up and waiting till I could save up to purchase one of the other machines when I saw a listing 2 hours later on Craigs list for a Nakajima. I remember from reading this forum over the last few months mention of them having made good machines. I went to see it and it was a Nakajima 280L. I followed WizCrafts check list for examining it. http://leatherworker...=1 It passed all the checks and he let it go for $250 with a broken table (the back left slot has broken away) . Ijust finished repairing the table this morning. Oiled it in all the spots using the Juki 241 Manual available for free here. http://www.raichert....obe/dnubook.pdf or http://www.raichert....on%20Manual.pdf I just fired here up to test her. She still has an upholstery needle, Not one of the leather needles I bought last night. She sewed flawlessly through 2 pieces of 8 ounce leather like butter. By feathering the pedal I was able to get it to do 1-2 stitches at a time, and I'm sure with practice and some modifications. I'll be able to do it consistently. I may save up for a ServoMotor, and if my future needs expand beyond what this Nakijima can do then I will go for one of the big brutes from one of you gentlemen who are experts and specialized. Once again a sincere and heart felt THANK YOU to all of those both in this thread and who have posted their past experiences on the Nakajima. .
  8. I have a chance to get a sewing machine and need to know if it will do the job, weather parts are available for it and what it is a clone of, if anything. I currently make cuffs out of 4 to 12 ounce Vegtan or Latigo with a lining of velvet fabric or 2 to 3 ounce suede. I have a chance to get a Chinese machine made by Yuancheng Model Number TK-806. Here is a website with a picture of the machine. http://zblt0402.en.e...72.html?gubun=S I know I would need to get a servo motor to bring the speed down and that it should cost around $150. So will this machine do what I need and how much should I pay? Is there anything I should be aware of? If this machine won't then what would you folks recommend?