Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: ostie01 on July 23, 2008, 10:59:44 AM

Title: Tool height input and probe input together
Post by: ostie01 on July 23, 2008, 10:59:44 AM
Hi, just finish my (X-Y-Z) probe and tool height offset probe to measure tools. I have setup pin input for the probe which work fine but how do I hook up the tool measuring device. I've seen in this forum that  they are both connected to probe input.

I did not want to use a plate to measure tool height, I wanted to have a fixed place on my router where I could measure the tool height.

Can I set up another input pin for  (except probe input) the tool probe
( (   (X-Y Probe)

( (   (tool probe)

I would like to input G code to place the tool over the tool height probe, measure it and be ready to machine my stock.

With my X-Y probe, I can probe on Z axe too, So I could do all my measurements at once.

Title: Re: Tool height input and probe input together
Post by: jimpinder on July 23, 2008, 03:06:17 PM
All the probe, or your tool height plate do is send a signal to the computer - so you can set them up anywhere you like. The thing that makes the difference is what happens next.

If you are using the same program to measure your tool height as you are for your probe then there could be a clash if both use the same input. If the probe is just a switch, and the tool height fixture is just a switch, then there will be no problem - since both are open then one closes when it touches, then there is no feedback to the other.

If there are some electronics in the probe or the tool height fixture, there might be some feedback and in that case,I, personally, would use a Nand or an Or CMOS chip to combine the two signals - the cost is a few pence. The chips have numerous inputs, but only one output, and all you do is lead the inputs to the chip, and the output to the breakout board. The chip isolates the inputs, but as it's name implies if one input OR the other signals then it passes the signal to the computer. (The Namd chip is the same, but inverts the signal)

If you are using a seperate program for your two sensors, then use seperate pins as inputs and configure accordingly.