Messages

1031

General Mach Discussion / Re: Strange CV behaviour

« on: February 04, 2012, 06:16:21 AM »

Just ran your samples and I see similar results here except that the number of exact stop moves I see at the front is different. That might be down to our different lookahead settings/steps per/motor tuning etc. However when I take the F off from every line (just stick it in once at the beginning) on my system they BOTH run in CV just as they should. I'm guessing it's more of a case that the F on every line is killing the interpreter on small moves.

Looks to me like your CAM/POST could do with a slap  

Ian

1032

General Mach Discussion / Re: Unstable analog inputs

« on: February 03, 2012, 11:17:43 AM »

 

1033

General Mach Discussion / Re: Unstable analog inputs

« on: February 03, 2012, 04:47:20 AM »

Hi Tony - just for the fun of it...

a = getinput(64)
if ((a mod 6) > 0) then
  setDRO(21, INT(a / 6) + 45)
end if

This will map your 10bit ADC input to give you FROs in the range 45% to 215% with the input value having to change by a factor of 6 to change the output. There's a deadzone between each set to suppress jitter.

I understand why you chose 6.827 to give you EXACTLY 150% range but it doesn't really bring anything to the party and integer values allow the modulus to give you the deadzones. You can widen the deadzones by increasing the >0 to >1 or 2 but of course anything more than 4 and you'll have nothing but deadzone!

Ian

1034

General Mach Discussion / Re: Unstable analog inputs

« on: February 02, 2012, 04:25:35 PM »

Nope... You're thinking INT(Y/Z*Z) but what we're doing is INT(Y/Z) * Z two vaaary difrant sings - simples!

(10/5)*5=10 ....... INT(10/5)*5=10 ............ INT(10/5) = 2 ........ 2*5 = 10
(11/5)*5=11 ....... INT(11/5)*5=10 ............ INT(11/5) = 2 ........ 2*5 = 10 etc.
(12/5)*5=12 ....... INT(12/5)*5=10
(13/5)*5=13 ....... INT(13/5)*5=10
(14/5)*5=14 ....... INT(14/5)*5=10
(15/5)*5=15 ....... INT(15/5)*5=15
(16/5)*5=15 ....... INT(15/5)*5=15

Ian

1035

General Mach Discussion / Re: Unstable analog inputs

« on: February 02, 2012, 01:16:00 PM »

I see what your saying - I'll have a think...

But meanwhile...

now that I look at it again doesn't (Y/Z)*Z = Y?

Yes indeed it does BUT... INT(Y/Z)*Z does not ALLWAYS = Y and that's why it bands

Ian

1036

General Mach Discussion / Re: corners getting radiused at higher speed on plasma table

« on: February 02, 2012, 10:20:22 AM »

I've built tables with 3Nm (424 oz/in) that get 2500mm/s/s (~100 in/s/s) no problem - in fact that's backed off so I don't jerk the hell out of the things. That gantry looks really light - you MUST be able to get a LOT more accel out of that puppy. What's your power supply, drivers, motors specs, drive ratio?

Ian

1037

SmoothStepper USB / Re: How It Works ???

« on: February 02, 2012, 10:04:59 AM »

Thanks Jeff - not planning on writing one anytime soon - just interested.

Ian

1038

General Mach Discussion / Re: Unstable analog inputs

« on: February 02, 2012, 09:51:46 AM »

Hi Tony - if I've understood your requirement properly you want to "band" your input?

x = int(y / z) * z

x will be y banded into divisions of z with an automatic dead zone at the top. Season to taste.

Ian

1039

General Mach Discussion / Re: New computer = weird problems

« on: February 02, 2012, 07:04:56 AM »

The problem is that the LEDs on the diagnostics screen are showing my home switches going off and on sporadically which is causing limits to trigger when I home it.  My BOB is showing a constant signal, but the diagnostics screen is definitely not showing that.  I have made a video to show what is happening (I disabled limits for this).

You probably wouldn't see your BOB LED flashing because it'll be too quick. The "LEDs" on the screen are only updated 10 times/sec so you're kind of seeing a slow motion version of reality. Trust Mach - if they're flashing (which they are) then the signal IS intermittent. In fact if you look at your vid when you look at the BOB LED you CAN actually see it flash once when you jog onto your switch which if all was well it wouldn't do. I reckon your on the bounce point of your switch. Debounce of any value is not going to help if your switch is constantly bouncing. What happens if you jog up just a tad more onto the switch? does your screen LED settle? I'm gessing it's NOT noise otherwise your on screen LEDs would flash even when you were miles away from the switch.

1040

SmoothStepper USB / Re: How It Works ???

« on: February 01, 2012, 10:48:41 AM »

The SmoothStepper plug-in takes the same moves that Mach has pre-planned and converts them into a format that is easy for the SmoothStepper to work with and feeds them out to the SS board.

Jeff, do you know where the protocol that Mach and the plugin communicate via is documented? (Not the protocol between the plugin and the SS which I assume is proprietary).


Thanks

Ian