most of you know i have a turn of the century Barnes 6' lathe. when me and dad got it, it was set up for overhead shaft drive as most machine tools of that time were. As most of what we did with it out at teh farm was low speed trimming and truing, we built a motor bracket, and set it up with a very slow belt drive. once i started doing gunsmith work with it, i needed more speed. i could get by on most jobs but i had to sublet out a couple cause my drive wasnt fast enough. also the belt did cause slippage on some hard cut jobs, and every time it slips you burn off a 19$ belt. well after a few of those i decided to upgrade to a faster chain drive. the advantages here are absolutely no slippage, plus with the addition of a bigger drive sprocket and a coupel whole and haf links i can adjust speed however i want for about 20$ per speed change sprocket. I was able to get everything i needed at work (with my employee discount ) and today i got time to put it together.
the old system
old pulleys and belt stripped off
now comes the fun part. i have to cut a 3/16 keyway in a hardened steel driveshaft. the local machine shop quoted me a minimum of 198$ plus hourly rate to bring out a portable mill and cut the keyway. taking it apart to sublet out would have taken around 4 hours and i would have had to completely take apart the drive gearbox (not something im inclined to do with a 125 year machine tool). So i got out hte dremel, bought a 10 pack of 1" grinding wheels, and spent nearly an hour grinding a key way in.
(pic taken at mid-cut)
With that done i ground a taper in the key stock, installed the driven sprocket and tapped it home.
the drive motor sprocket was much easier as the motor has a stock 5/8" keyed driveshaft.
installed 60 pitches of #40 chain, a half link and a connector link and away we go.
total cost for the project was about 100$, but i doubled the available useful drive speeds, plus for 20$ i can step up the drive sprocket and add three MORE speeds.
SW
Bookmarks