Laser Head Height Sensor – Looking for a Beta Tester

Awesome to see more folks doing Linuxcnc fiber lasers. I also just ordered a 6kw laser source from raycus together with the chiller and laser head. I am debating if i will use a raytools controller as those are quite inexpensive or linuxcnc.

What is the current state of the art in linuxcnc fiber lasers? any pointers?

So, has there been any progress on getting this sensor to market? 

I'm trying to get a laser machine built, but, this is one of the toughest issues I'm facing.  I have a MESA 7i76EU that I have been trying to interface a BCL-AMP output to.  I have the BCL-AMP connected to a Raytools BT210S002A cutting head sitting on the bench with a chunk of steel in front of it and grounded to the case of the Raytools cutting head.  Between the BCL-AMP and the 7i76EU, I have a TI SN74HCS74DR dual Schmidt Trigger Flip Flop that I'm using to divide the BCL-AMP output frequency by 2 and "clean it up" at the same time.  However, it's just not very stable.  The velocity measured by the 7i76EU jumps around about 600-700 hz.  The velocity range only seems to be around 6500 hz from 0-10mm (3/8") sensing distance, so, my positional sensitivity sucks at around 0.1 inches.  Just for giggles, I ran the signal through 4 Flip Flops to see if the 'jumping around' would decrease.  It didn't.  Which leads me to believe the instability is introduced somewhere in my circuitry or wiring.  I even tried connecting Q and Q not outputs into the MESA card as differential signals and twisted the wires.  No help.

Anyhow, This CV2 height sensing device sounds very promising.  

  The velocity range only seems to be around 6500 hz from 0-10mm (3/8")

That does seem quite small, maybe too much stray capacitance on the sensor?

The BCL-AMPs ~2.5 MHz /2 frequency of ~1.25 MHz only gives you about 1250
counts per 1 ms servo period which will end up adding quite a bit of noise.
 This may be improved if you set the hires-timestamp of the encoder true but
a better solution may to use the periodm's frequency output as it does frequency
estimation by 1/period_average:

forum.linuxcnc.org/plasma-laser/51568-in...e-sensor-to-linuxcnc

Thanks for the info. From what I gather, reading previous posts, the periodm function requires linuxcnc 2.10. I'll have to make up another test unit for that. Also, I'm running a 2msec servo thread. Is that going to be an issue?

It does make the resolution of the encoder frequency  a bit better than at 1 ms
but the periodm does not care as you specify the number of period averages.

I agree with you. The topic is not easy.

I had to put the project on hold for a while because the sensor had problems with some heads (precitec) that contain electronic components inside nozzle holder. This effectively prevented my sensor from working.

Now I have dealt with it and it seems to work correctly, so I want to put the device into production.

If you have time and want, I will prepare a test device for you.

I want the device to work at the highest level, so any feedback is valuable to me.

The tests were very promising.

Interesting product. Any idea if your sensor works with PLLA (plastic/polymer)?

Can't test at the moment as the intended laser systems aren't ready yet, but might be interested in testing and/or purchasing units soon.

the device was designed for metal materials. It was tested with other materials and although it works, the precision of the measurement is not satisfactory for me to sign under it as a manufacturer. It works quite well with wood, but a change in structure (a knot in a board) can significantly change the capacitance.

so the answer is: No, the device is designed only for metals.

A test device would be great. What information do you need to get it to me?