Quote from: OTmachine on June 05, 2021, 05:07:36 PMQuote from: Rob M on June 05, 2021, 04:33:58 PMJames is spot on , otherwise , youd have variable pitch on a manual machine which until now has only been accompllished on cncI still am having trouble understanding.1.5mm = .0590625 inchWith Transposing Gears for 1.5mm = .060576 inch10 x .0590625 = .59062510 x .060576 = .60576.60576 - .590625 = .015135 difference from startyes i get that.. what im describing is thread crest to thread crest should never change.. yes, it may be a longer section ( or shorter ) to hit 20 crests, but the threads should be uniform to each other as the leadscrew is always spinning the same rpm as when the threads started.
Quote from: Rob M on June 05, 2021, 04:33:58 PMJames is spot on , otherwise , youd have variable pitch on a manual machine which until now has only been accompllished on cncI still am having trouble understanding.1.5mm = .0590625 inchWith Transposing Gears for 1.5mm = .060576 inch10 x .0590625 = .59062510 x .060576 = .60576.60576 - .590625 = .015135 difference from start
James is spot on , otherwise , youd have variable pitch on a manual machine which until now has only been accompllished on cnc
If you have room and can find one; a 127 tooth gear will give you a true metric thread; since it is the lowest even multiple of the 2.54 cm/in or 25.4 mm/in conversion.... Here's a link to where someone else explained it rather well; and I stole my info from https://bbs.homeshopmachinist.net/forum/general/38898-metric-threading-with-120t-127t-gearsJesse