Members BDAZ Posted June 8, 2014 Author Members Report Posted June 8, 2014 Yup, Mod is for the FS-550. No specs on the pot other than log taper, carbon and counter clockwise. It's a drop in replacement for the supplied pot. I have ordered a 50K and 20K pot and will try both. I may even extend the jumpers and have the pot mounted on the table for easier access, The magnet mod is described earlier in this thread. Cya! Bob Quote
Members BDAZ Posted June 8, 2014 Author Members Report Posted June 8, 2014 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. I was wondering what the threshold was set for. A 10K resistor in series with the pot should do the trick! Any issues with the magnet mod? Cya! Bob Quote
Moderator Wizcrafts Posted June 8, 2014 Moderator Report Posted June 8, 2014 My FS-550s has a rotary switch, not a pot. The slowest setting is full clockwise. It speeds up the wrong way, CCW. On the pot mod, is the slowest speed at the lowest resistance (~10 - 12k)? Quote Posted IMHO, by Wiz My current crop of sewing machines: Cowboy CB4500, Singer 107w3, Singer 139w109, Singer 168G101, Singer 29k71, Singer 31-15, Singer 111w103, Singer 211G156, Adler 30-7 on power stand, Techsew 2700, Fortuna power skiver and a Pfaff 4 thread 2 needle serger.
Members JoMama Posted June 9, 2014 Members Report Posted June 9, 2014 I did the magnet mod above on a Family 550 servo, but the motor is the same as this Cowboy motor with a slightly different electronics box. Running a 2" pulley on the motor, a 3:1 speed reducer and setting the rotary speed limit switch to around 3000 rpm. I get easy control from 15 spm to around 400 spm. I also put an extension on the control arm coming off the motor (not shown in the pictures posted earlier) and moved the bottom control rod attachment point from the piece that bolts to the top edge of the pedal, down to the side of the pedal, after drilling a hole in the side of the pedal. You don't need the arm extension if you drill the hole in the side of the pedal closer to the pedal pivot. Now, there is no reason to set the speed limit lower, because the foot pedal has much more range, for better control. It uses the full range of the foot pedal now. Quote
Members Random Posted June 9, 2014 Members Report Posted June 9, 2014 (edited) My FS-550s has a rotary switch, not a pot. The slowest setting is full clockwise. It speeds up the wrong way, CCW. On the pot mod, is the slowest speed at the lowest resistance (~10 - 12k)? 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. I was wondering what the threshold was set for. A 10K resistor in series with the pot should do the trick! Any issues with the magnet mod? Cya! Bob 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 :-) --------------------------------- ---- ---- ---- ---- ---- --------------------------------- Edited June 9, 2014 by Random Quote
Members catskin Posted June 10, 2014 Members Report Posted June 10, 2014 I was thinking of ordering a servo motor from Toledo but after reading all of this thread I am wondering if it is possible to get a servo that works without all this pot and mod and ohm crap done. The cowboy 4500 I bought a couple years ago has a servo that with the nob turned to the slowest speed will go so slow you can almost have coffee between stiches, are these good ones no longer available? I notice the Bob,s have not said anything on this thread I wonder why if they sell these motors? Quote
Members BDAZ Posted June 10, 2014 Author Members Report Posted June 10, 2014 I assume that they buy standard industrial sewing machine motors and I would guess for every leather machine sold, there are dozens of industrial machines sold for the garment industry and similar high speed stitching. As to ordering the motor, this IS the motor from the 4500. I had no problem getting the machine to stitch slowly but I wanted to be able to get more of a range in the slow end but the option to gradually increase the speed when I have less complicated items to stitch. With the existing potentiometer, that was not possible, Just a touch and it was slow then another touch and it was fast. The two mods go a long way in optimizing the machine for slow stitching. While the magnet mod is a bit more work and a bit finicky, the pot mod is plug and play. When I finalize the values I'd be happy to make a plug and play mod available for a few bucks. The pot mod should take less than ten minutes. Cya! Bob Quote
Moderator Wizcrafts Posted June 10, 2014 Moderator Report Posted June 10, 2014 To your knowledge, will your pot mod substitute for the rotary switch currently installed in my FS-550s? I already have great slow speed control, especially with the 3:1 reducer in the chain. Quote Posted IMHO, by Wiz My current crop of sewing machines: Cowboy CB4500, Singer 107w3, Singer 139w109, Singer 168G101, Singer 29k71, Singer 31-15, Singer 111w103, Singer 211G156, Adler 30-7 on power stand, Techsew 2700, Fortuna power skiver and a Pfaff 4 thread 2 needle serger.
Members BDAZ Posted June 10, 2014 Author Members Report Posted June 10, 2014 I assume your switch is like this one with a number of resistors switched instead of a carbon /wiper or wound /wiper system? There should be some marking on the pot giving it's value. The stock pot on my 3200 was 200K. I think we have determined that the ideal pot would have an initial resistance of 10 ohms and then max out at around 50-100 ohms.for typical leather stitching. This should give you the full (around 340 degrees) range of the pot to control the maximum speed. The switched resistors that you have is a much more expensive potentiometer because each detente will give you a very accurate resistance and should be easily repeatable and could be calibrated. BUT if the behavior of the switch is too abrupt, going from slow to maximum, then a lower value pot would be called for. I just ordered a 50 ohm and a 20 ohm pot and will jumper a 10 ohm resistor so there wound be any significant dead space on pot and it will be in the best part of the curve. Cya! Bob Quote
CowboyBob Posted June 10, 2014 Report Posted June 10, 2014 Catskin, Yes,you have the same motor.We have always felt they worked pretty good esp when connected to a speed reducer,but I guess it's like anything you buy some people need it to be different.Look what they do to a new car or truck,jack it up big tires,loud exhausts.paint,sunroofs & etc. It has been some very interesting reading & way over my head since I'm not into electronics to understand it all. This motor is 1000x better than the one we used to sell that you had to program for the speed,it went from 0-wide open in 1/2" of foot pedal push. Quote Bob Kovar Toledo Industrial Sewing Machine Sales Ltd. 3631 Marine Rd Toledo,Ohio 43609 1-866-362-7397
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