Author Topic: Bridgeport and clone users with rpm display  (Read 84 times)

Carpenter84

Bridgeport and clone users with rpm display
« on: June 24, 2019, 10:56:35 PM »
 The guys with BP's and clones who have an rpm display. Where did you put the sensor?
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

Carpenter84

Re: Bridgeport and clone users with rpm display
« Reply #1 on: June 26, 2019, 06:04:48 AM »
None of our regulars have this setup, I presume?
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

4GSR

Re: Bridgeport and clone users with rpm display
« Reply #2 on: June 26, 2019, 08:27:52 AM »
I rely on the VFD readout.

Hz= RPM.  What I did was take my RPM tach and checked the RPM's at various Hz levels such as 10, 20, all the way up to 70 Hz, which is max on my VFD without changing parameters.  From this I wrote on the belt guard the RPM's vs Hz readings.  It works good for my needs.

At 70Hz, RPM is approx. 1200 RPM.  For other Hz, RPM's, I'd have to go look at the mill.  But I found this range to work good for most of my needs.  I can change the belt speeds to slower or to much higher RPM's if needed.

I know it's not the answer you want there.

Ken
Ken

Carpenter84

Re: Bridgeport and clone users with rpm display
« Reply #3 on: June 26, 2019, 09:10:12 AM »


I know it's not the answer you want there.

Ken

Not necessarily, but that's actually a rather good idea. I could just take some readings with my handheld tach and make a legend in Hz increments.

There's limited info on Google from guys posting the work. Mainly people putting encoders on the gear in the back gear housing. The one that actually drives the spline.
I could probably use one of the cheap Chinese hall prox sensors to do the same. Put the magnet on the top of that gear and maybe have the sensor pointing down through the housing in the center of all the spinning belts. Not ideal, but might work.
But from what I'm seeing, there's no simple location, it's a tear down type operation. And God help you if the magnet comes loose inside the gear housing....
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

chips and more

Re: Bridgeport and clone users with rpm display
« Reply #4 on: June 26, 2019, 09:23:54 AM »
My BP has a RPM dial. But I also use a VFD to power the BP and seldom have it set at 60Hz. More like 10Hz to 30Hz. So the RPM dial reading is invalid. After many years of use, I have learned to just use the position of the RPM dial and not its speed reading. Also my gut and Hobby Shop time has given me the guessing wisdom to find the proper cutting speed LOL! An accurate speed indicator would nice, I would not take if off if it had one, but I would also not take the time to make one and put it on a machine…Dave