Edge finder probe assembly

Assembly of the edge finding probe and test part 3
With all the parts made we can now assemble and test the probe

[@ActiveAtom]

Hi Alan, nice to be here. we like the build as it shares like a how it is made and how it works as you build this machine probe. Thank you for the share, Lance & Patrick.

[@MattysWorkshop]

You have done a fantastic job making this prob Allan, quite a lot of fiddling around to get the led situated correctly with out the connection touching together in such to small area, a lot of thought would of went into designing and making the components for this, a credit to you mate, a bloody top job, thanks for sharing this, I truely enjoyed following along Cheers Matty

[@adaml52]

Good job, Alan. You may want to put a 1\8 watt resistor of 5.6 to 6.8 kilo ohm in series with the LED. This will drop the voltage and limit the current, so the LED only draws about 20 micro amp's This will make the batteries last longer, also protects the LED Adam

[@jrkorman]

With the 3V batteries Alan is using, 5.6KOhm will give a current of just over 500 microamp. To get good enough brightness, around 5 milliamp, so using standard resistor values of 680 or 1000 ohms at 1/8 watt would do well.

[@adaml52]

@@jrkorman The typical forward voltage of a red LED is 1.7v (3v - 1.7v) \ 1000 ohms = 1.3mA (3v - 1.7v) \ 680 ohms = 1.9mA Most red LEDs will give a good brightness at less than 1mA or even less Most button cell batteries of this size, expect a load of less than 1mA to give good battery life

[@gospelman7222]

Very good! Works well. Did you ever determine why the chuck was running out? I had a similar problem with the chuck on my Chinese drill press, inspection revealed that the taper bore had been wrongly machined and I had to scrap the chuck. Replaced it with a Jacobs which gave a run-out of 0,001"

[@حمزةحمزة-م4ف4ض]

Cool work 👍

[@RRINTHESHOP]

Nice works great.

[@Blackcountrysteam]

Not long purchased one but I think I'll also make one it's an interesting project !

[@colmone5592]

Good job.

[@navaho5430]

Great work just bought one off ebay $ 16.00 delivered the ball is spring loaded, it beeps and lights, the exact same thing in the Hare & Forbes machine book $93.50 + delivery accuracy 0.005mm check out there web site. But nothing beats making your own stuff cheers from OZ.