t20sl Report post Posted July 22, 2023 Can this be done? I can machine / fabricate so that is not an issue. What I need to know more about is speeds etc. I read where most servo motors run at a min speed of 300 rpm which seems way too fast. What am I missing? Quote Share this post Link to post Share on other sites
shoepatcher Report post Posted July 23, 2023 You can gear the servo down. Make sure it has a 45-50mm pulley on the motor. There is a way to make the balance wheel on the treadle stand into a speed reducer. I can walk you thru it. The lobes on your bellcrank are worn. That is why the stitches are so small glenn Quote Share this post Link to post Share on other sites
AlZilla Report post Posted July 23, 2023 On 7/22/2023 at 9:10 AM, t20sl said: most servo motors run at a min speed of 300 rpm I'm hoping someone more knowledgeable than I will chime in here. i have a couple of Eagle EA-550s and they start at 200 rpms. No ramp up, no slow start - BAM, instantly 200 rpms. I've read things that lead me to think the "other" style of servo, with a knob and it looks more like a clutch motor, will go much slower but at the expense of losing torque. One of my EA-550s is on a machine with a 3:1 speed reducer so my "instant on" speed at the needle is only about 52 stitches per minute. Actual, counted speed. Quote Share this post Link to post Share on other sites
kgg Report post Posted July 23, 2023 On 7/22/2023 at 1:10 PM, t20sl said: Can this be done? The answer is yes. Some of the 29k's came with a domestic small foot pedal operated motor which cost about $30- 40 CAD but the mounting hole is in the casing on some models. I owned a 29K-71 which came from Landis and they had installed a geared domestic motor on it before being sold to the original owner. Speed can be an issue with the 29K's and clones as they are not really rated for anything over 500 rpm. You can see the motor on the rear side of the Singer 29K-71 in video https://odysee.com/@SingerSewing:0/singer:a The main purpose of that video is to demonstrate how effortless they should be able to be turned over by hand without anything under the presser foot. Another video with just a straight domestic motor installed on a 29k https://www.youtube.com/watch?v=qICJV7j56Gs Also here is another one be it of poor quality with a servo motor installed. https://www.youtube.com/watch?v=vMfzIcJ-spY The main question is are you trying to get torque for punching poor or just convenience of being able to use both hands? 31 minutes ago, AlZilla said: No ramp up, no slow start - BAM, instantly 200 rpms. If I'm not mistaken the Eagle 550 is a 6 or 9 coil brushless motor. I think the motor has 6 coils but the sudden jump in my opinion is do to the motor having less coils. The 9 and 12 coil brushless don't seem to have this problem or not as noticeable. More internal motor coils means higher low speed torque with smoother speed control. Adding a speed reduce can really help mask the problem. kgg Quote Share this post Link to post Share on other sites
t20sl Report post Posted August 5, 2023 (edited) Where do I find the 9 or12 coil motors? Would like to know how to gear slower or find a gear head servo motor if available. Edited August 5, 2023 by t20sl Quote Share this post Link to post Share on other sites
