Togalosh":1fpz1r6c said:
Hiya Rhyolith,
That looks very smart in British racing green ..& very good photography too.
I see that you have a different belt & pulley set-up. Mine has 1 belt with an adjustable pulley in-between machine & motor to adjust the belt tension. Are your pulleys on the plummer block the same size as on the machine ? (that question most likely shows up my engineering ineptitude). How do you adjust the belt tension ? What size is that big pulley ?.. I don't know what the rotating speeds I need to work it out (& don't have enough fingers & toes to work it out even if I knew).
Also the copper tube on the lead screw ? Is that for protection against something? Are there any other modifications ?
Togs
The speeds are worked out with simple ratios. The motor runs (in theory) at 1440 rpm. The motor pulley is 2" diameter, driving the large 8" pulley. This gives an 8:2 ratio, therefore the large pulley (and the countershaft it connects to) runs at 360 rpm.
The stepped pulleys on the countershaft and lathe spindle give three different ratios... 1:2, 1:1 and 2:1. With the countershaft running at 360 rpm, the the three lathe spindle speeds will be 720 rpm, 360 rpm and 180 rpm.
The lathe also has a backgear that can be switched in, giving a further 6:1 ratio. That's another three spindle speeds of 120 rpm, 60 rpm and 30 rpm.
I hope some of that waffle makes sense....
Edit: can't remember if the motor speed is 1440 or 1420, but the principle is the same