Messages

21

General Mach Discussion / Re: Height Following

« on: October 17, 2008, 04:03:02 AM »

Hi.

For laser cutting you need to use ring sensor around your nozzle and the position can be measured with linear potentiometer or LVDT sensor. The measurement can be translated to a analog voltage which can control servo drive directly - or if possible - through Mach.

The better way for metallic materials is capacitive height sensing where you have oscillator that gives frequency (in range of 200 kHz - 1 MHz) to your insulated nozzle. By monitoring the amplitude or phase locked loop comparison you can get out signal that depends of the nozzle distance ie. capacitance between nozzle and plate. This signal can then control your analog servo drive or given to control.

I have some data of capacitive sensors but no time to produce devices at the moment. If someone with electronics skills is willing to continue - I'm willing to co-operate.


BTW. I'm still waiting for faster M03 M05 handling to Mach as this is slowing my applications significantly!! Any news??

BR. Arto

22

General Mach Discussion / Re: Omron drives and motors?

« on: October 17, 2008, 03:27:58 AM »

Hi.

Maybe you have already solved out your problem and I'm late with my reply but anyhow...

In Omron the inputs have optocouplers with 220 ohm resistor in series. So your positive pulse goes to pin 1 if pin 2 is grounded and your positive direction pulse goes to pin 3 if 4 is grounded. If you use negative pulses - this can be reversed.
Minimum pulse width is 2,5 us and between pulses there must be 5 us. Ie. the max is 200 kHz. It's not needed to slow down pulsing in Mach.

Parameters CN-01 bit F must be 0 and CN-02 bits 3,4,5 must be 0,0,0

After major setup changes with Omron driver you need to trip power to make changes effective.

With Mach I have controlled Omron only through DSPmc/IP (Vital Systems) controller but I have used Omrons much in positioning with pulse position inputs. It's very reliable device!

Hope you are progressing fine!

Terveisin!
Arto

23

General Mach Discussion / Re: Omron drives and motors?

« on: August 19, 2008, 04:22:55 AM »

Hello.

UA type of Omron/Yaskawa AC servodrives can take in only analog signal for speed or torque. Another type of this Sigma I series has a step/direction input too and all Sigma II servodives can do it.
I have used DSPmc to control Omron servo's and this combination works fine. The machine has been in production several hudred hours without problems.
With AC servo's and DSPmc you can get very good dynamics in your movements. The main limitation you'll have is the Y-movement made without slave servo on the right side.
Your application does not need pulleys with AC servo's.

If you however decide to sell those servo's/drives/cables - I can offer you 100 per each.

BR. Arto

24

General Mach Discussion / Re: M3 / M5 execution delay

« on: August 14, 2008, 05:03:44 PM »

OK. Great! Thank you for your help! I will test new version right away when available as it will save a lot of production hours to me!

BR. Arto
 

25

General Mach Discussion / Re: M3 / M5 execution delay

« on: August 14, 2008, 04:13:26 PM »

Hi All!

Some comments.

1. The delay with M8/M9 is the same as with M3/M4 when I change those to command a output - not saying 'DoSpinCW' etc. That seems to do other things too (spending time). Looks like the IO-handling takes time and the delay is varying from command to command.

2. Using direction line would be instant but I'm using DSPmc which controls AC servo's with analog +-10V signal. Mach pulsing engine is not running. This is also a bit unsecure way to use a 300W cutting laser.

3. About brain output speed I don't have experience.

I could also use a optoswitch in Z-axis to switch laser on and off but I'm not so willing to use such workaround yet. (The machine has 4 axises, X, Y+slave A, Z).
The next thing on my wish list would be a programmable output to give pulsing with frequency f and with ontime t which can be set as a parameter (beam modulation).

Sorry about my rude reply earlier - was written too early in the night (2-3 AM)..   

So. Still wishing miracles with this delay problem

***

A bit easier question - is there a good way to limit speed in small radiuses - except acceleration which I´d like to raise?

BR. Arto

26

General Mach Discussion / Re: refitting AC SERVO SYSTEM TO MACH

« on: August 14, 2008, 05:49:35 AM »

Hi Bostjan,

Both plugin and DSPmc firmware was adjusted during our run-up. Our problems were mainly speed and  dynamic behaviour related issues. If I used it with mill I never found those problems.

Servo control itself did not need anything special. Speed loop PID setting was done normally in servo driver and the position loop PID setting in DSPmc. The setup program is also much more easier to use now.

BR. Arto

27

General Mach Discussion / Re: M3 / M5 execution delay

« on: August 14, 2008, 04:45:29 AM »

So you saw my short video and some hole cutting in there. There are no piercing or end delays in the G-code. Just the M3/M5 delays.

They are not important in lathes or mills. You might think this is not important but please compare these two videos:

This is still not the fastest machine:
http://www.youtube.com/watch?v=80-ZIWDNfIE

And this is what I have now
http://www.youtube.com/watch?v=36wVkDoE9AQ

Can you see my point?

Br. Arto

28

General Mach Discussion / Re: M3 / M5 execution delay

« on: August 13, 2008, 08:15:25 PM »

No.

29

General Mach Discussion / M3 / M5 execution delay

« on: August 13, 2008, 07:33:25 PM »

I have noted the command pair
M3
M5
takes ca. 600 ms to execute if it controls 'DoSpin CW' 'DoSpin Stop'
and ca. 300 ms if is says 'ActivateSignal (7)' 'DeActivateSignal(7)'
I tested this with printer port mode and with DSPmc and the delay seems to be equal ie. the delay comes from Mach3.

Is there any possibility to make this delay smaller or some other way to give out faster commands from Mach3 R2.63 /XP 1.6G ?

Br. Arto

30

General Mach Discussion / Re: refitting AC SERVO SYSTEM TO MACH

« on: August 13, 2008, 07:25:22 PM »

Thanks!
Starting with DSPmc took some effort as the firmware was not complete but it has now all I need with this laser application. Naturally there are new needs in future..
We're planning EU type breakout boards too as most peripherals here need source type outputs and positive high inputs (valve blocks, inductive switches etc.).

After those are ready, I'm going to keep a small stock here.