Mesa 5i20 daughter cards

Okay we have decided on the a 7I47S for step motor drive, spindle encoder in and spindle analog out and a 7I37TA for 24V limit switch in and 24V coolant etc out. We are adding a differential encoder with index to the spindle to be able to do rigid tapping in the future. We may use US Digital H5 with index and differential output www.usdigital.com/products/encoders/incr...tal/rotary/shaft/h5/
Any thoughts on that and what resolution I should use?

Thanks again,
Rick G

John,

I was unaware of that supplier I'll take a look today after I place my Mesa order.

Thanks,

Rick G

Hello all,

I am now bench testing the 5i20 with a 7i47S and a 7i37TA. The computer is a 1.3GHz with EMC 2.4.1 and the current Hostmot2. With the 5i20 doing all the heavy lifting of the step generation I do not feel I need any more computer than that. With a full tower case I should be able to mount all the cards inside the one computer

I got off to a bumpy start with my first setup that resulted in ferrors and with the ferror set high my steppers did not move particularly smooth. ( a bit of an understatement there) I researched this and found a thread that suggested setting the stepgen acceleration somewhat higher than max acceleration might help. On my setup I found that with max velocity set at 1 and max acceleration set at 8 if I set stepgen velocity at 1.012 and stepgen acceleration at 16 I could get great movement and set my ferror down to .001 inch. This problem and solution may be unique to my set up. The normal set up has stepgen max acceleration at 0 and stepgen max velocity at 0 when set accordingly emc controls the stepgen acceleration and velocity.

Going back to basics I started with the sample hm2-stepper set up and found the problem did not exist there, it worked great.

I then studied my set up to find a difference that could cause the problem. After many changes without success I went back and removed the BASE THREAD from both my hal and ini files. I probably do not need a BASE THREAD with hardware step generation. I then reset stepgen max acceleration to 0 and stepgen max velocity to 0. On my machine this did the trick, the stepper moves smooth as silk, can be run faster, no more ferror, life is good.

Now on to the spindle VFD section...

Rick G

And the beat goes on. On the test bench things are looking good. The 7i47S spindle speed (analog signal) does it job just as advertised.
When supplied with a 5 volt source it put out a 0-5 volt signal out based on the requested spindle rpm and generated with a pwm generator.

After setting a spindle speed and using the MDI commands m03 m04 and m05 everything works great.

One curious thing about my setup is that even after setting a spindle speed (S2000) when I return to the manual mode in AXIS hitting the spindle stop button works fine but hitting the spindle start button sets the speed at 1 not 2000 rpm.
I will have to study my hal file some.

Rick G

Don't bother looking for a HAL problem, that is just what it does.

Thanks Andy that will save the time of looking for problems that do not exist. I was thinking that might be the case.

In theory you could link a pyvcp button to be "restart at current speed" by using an MDI_COMMAND with M3 in it.

Good point on the pyvcp, I will have to try that.

I can also turn the spindle on and off plus increase and decrease the spindle speed from my usb pendant, I normally use the pendant to the turn the spindle on and off anyway.

I have to admit the hal tools such as "watch" are great for troubleshooting.

Rick G