Optimark
7th May 2018, 05:26 PM
Today a friend came over with his new toy, we had a bit of a play; his toy is a portable digital tachometer.
We attached a small piece of the reflective material onto the hand wheel of my Nova 16-24-44 8 speed lathe, then fired it up. The lathe belt was on the 300 rpm pulley, the digital readout was substantially higher, hovering around 344 rpm.
This lathe has two speed ranges dependent upon whether you are running 50Hz or 60Hz. As Australia is 50 Hz we are on the lower speed and the selected belt should give close to 300 rpm. If in the USA at 60Hz then according to the chart on the Nova it would be running at 360 rpm.
If the error is in the pulley ratios, then in the USA this machine would be running at 412 rpm, instead of 360 rpm, which for the second of eight speeds, is getting up there for off balance heavy stuff.
As the lathe had a big blank on, I wasn't about to change speeds to see how different from stated speeds the other 7 pulley set-ups were.
I am not worried about this, just thought it was interesting.
Mick.
434961
We attached a small piece of the reflective material onto the hand wheel of my Nova 16-24-44 8 speed lathe, then fired it up. The lathe belt was on the 300 rpm pulley, the digital readout was substantially higher, hovering around 344 rpm.
This lathe has two speed ranges dependent upon whether you are running 50Hz or 60Hz. As Australia is 50 Hz we are on the lower speed and the selected belt should give close to 300 rpm. If in the USA at 60Hz then according to the chart on the Nova it would be running at 360 rpm.
If the error is in the pulley ratios, then in the USA this machine would be running at 412 rpm, instead of 360 rpm, which for the second of eight speeds, is getting up there for off balance heavy stuff.
As the lathe had a big blank on, I wasn't about to change speeds to see how different from stated speeds the other 7 pulley set-ups were.
I am not worried about this, just thought it was interesting.
Mick.
434961