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Showing posts from October, 2017

photo interrupter , lichtsluisje HBM BF30 toerenteller

I got a second hand (but barely used) BF30 clone milling machine.
The rpm meter was not working correctly (not showing high RPM, nonsense numbers)
I investigated and found the photo interrupter on the spindle axle.
It was covered in grease (sticky brown Chinese transport grease).
After taking it apart I noticed all holes were over-sized (and slotted).
Mounting the thing back and getting the perfect alignment would be a gamble (I like more precise work, but it appears all holes in this machine are too large or slotted, every edge is sharp and needs deburring).

I made a little tool to check the workings, it is impossible to adjust once the motor is mounted so it has to be correct before I put the motor back on the machine.

Here is the setup :



The ring has 16 holes, so the rpm is more accurately (or quickly) determined.
How this works : the system counts number of pulses in one second and from that displays the number of rpm ( NL: toerental in omwentelingen per minuut)  (rounds per minut…