BallisticTip Report post Posted January 9, 2014 I'm thinking of building a jackshaft reducer system for my machine. I see most reducer pulleys are 3:1. Would there be any problem going with 4:1 or even higher? Would there be useful benefit to this ratio? Quote Share this post Link to post Share on other sites
Northmount Report post Posted January 10, 2014 4:1 will give you even slower speed, more torque, easier to punch through hard temper or thick leather. Will of course reduce your top speed too assuming you have a servo, or are good at feathering your clutch. For new sewers, lower speed is nice, easier to control, etc. I have one that is about 6:1 with a servo. At the highest speed setting, I can crawl real slow, or go about 200 stitches per minute. That's on the slow side for many, but fast enough for me. (Slow for winding bobbins, but I'm going to set up a variable speed drill with my bobbin winder on of these days.) You can figure out the speed your machine will run at, so you will have a goo idea if that is right for you. Tom Quote Share this post Link to post Share on other sites
Anne Bonnys Locker Report post Posted January 10, 2014 Have had a number f disagreements with mechanics over this. Mechanically oiled machines will be starve at such low speeds BUT bearing wear is based on load and speed so when you reduce the speed you proportionally reduce the wear. On most older machines the bearings are very high quality and massively overdesigned so simply manually oiling on a reguar basis will give you decades of use. Quote Share this post Link to post Share on other sites
CowboyBob Report post Posted January 10, 2014 I'm thinking of building a jackshaft reducer system for my machine. I see most reducer pulleys are 3:1. Would there be any problem going with 4:1 or even higher? Would there be useful benefit to this ratio? What machine do you have?If it has a 3" pulley on the handwheel it wouldn't hurt to use the 4-1 but if it's a larger wheel6-8" they already run real slow w/a DC Servo & the 3-1 so I doubt if you need to go any slower than that. Quote Share this post Link to post Share on other sites
BallisticTip Report post Posted January 10, 2014 (edited) What machine do you have?If it has a 3" pulley on the handwheel it wouldn't hurt to use the 4-1 but if it's a larger wheel6-8" they already run real slow w/a DC Servo & the 3-1 so I doubt if you need to go any slower than that. It's a Pfaff 145. Edited January 10, 2014 by BallisticTip Quote Share this post Link to post Share on other sites
