Quote:
Originally Posted by Fusion_power
A couple of formulas would work, but a lookup chart would probably be more helpful.
C = 2 times PI times Radius
5280 / circumference gives Revolutions required to equal a mile.
For a piece of stock 6 inches diameter, radius is 3 inches, pi is 3.14 (close enough for this work), so 2 * 3 * 3.14 gives 18.84 inches. 5280 divided by 18.84 gives about 280 Revolutions to equal 1 mile. Your lathe spinning stock 6 inches in diameter at 3250 RPM is doing nearly 12 miles a minute. That's not bad for a cantankerous geriatric junkyard reject.  |
The spindle runs at top speed at 1400 rpm so it is a reduction from the motor by way of the transmission and the big an little pulley on the motor and lathe.
The slowest speed is 70 rpm.
If you look at the old South Bend lathes they dont run for squat and aren't really set up to run carbide tooling they go too slow and the motors are too small and under powered.
Some of the lathes only have like 3/4 hp motors even for the 10 inch and they run at I think 1700 rpm or somewhere around there.
For a calculation of 600 rpm for a high speed tools you double that speed rpm and feed speed to some degree for carbide.
After looking at the older South Bend lathes I am so glad I didn't buy one of the old out dated things, new condition or not.
Even the new South Bend 10 K lathes have that stupid change belt pulley setup on the spindle to change speeds.
If and when something happens to that belt you will have to pull both shafts to fix it or buy a link belt you can take apart.
That isn't going to happen either because they aren't v belts.
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