URGENT MOTION CONTROL PROBLEM; Do techzone gen3 stepper drivers halfstep?

EXTREMELY URGENT

can anyone tell me if the techzone gen3 remix stepper drivers are HALF stepping??

no mention in documentation or website at all means i assume it's full steps .... which if is not the case could have possibly screwed me a bit in non reprap related matters... stop motion animation ... we are doing shots that take 9 hours to achieve 4 seconds of animation, and we have animation software -> arduino - > techzone gen3 ->nema17(200steps) pushing a camera along a dolly 5 steps after every frame the camera takes



Link to some test footage: (best to step through frames in quicktime using arrow keys)

[marklagana.com]

now we have tried to do a close up pan and it looks like every FOUR frames it moves like 7 steps for some reason?

I tried 4.2 steps every frame, and it worked for 3 and every fourth frame it just didn't move at all. So now we are using whole numbers only and that made every forth frame work, but the dolly has done 4 huge shots already just went to do a close up and we can see every forth frame is moving a bit more?! Please look and offer me any advice... i can get the director to email me the arduino script but i don't really think that's the problem... it's pretty simple like "inbyte read yadayada if shoot command stepper step 5 / if delete command step -5 you know that's the whole loop why would it change every forth frame?

Could it be i had it set to 200 steps but the techzone driver is half stepping??

i'm not animating tomorrow but they are with my dolly, i've told the director in the morning to try setting it to 400 steps... will see how that goes... but this is a huge production.. we have volunteers from all over the world... who i consider best in the world, i figure you printer people would be best in the world to ask about this any clues??

apart from that mechanically it's 8 skate bearings positioned 45deg against rails, heavy camera holding it down on the rails, using film as belt but it's tight enough so when the motor is enabled i can't move the camera at all, the gear was recently printed on a commercial printer and cast in resin (very good casting) and feels like a good fit the film doesn't seem to at all slip either way or anything in between the teeth and the idler pully is resting on a compression spring pushing the film away from the motor gear.. pretty much like most 2d printers.

HELP!

ps more info on the short film if you're interested [www.facebook.com]

2am here hopefully it's day time where you people are and can help me before they shoot this closeup shot in 7 hours!! the schedule is reallly tight and we kinda have done all the pulled out shots and urgently need to totally re arrange the set

Edited 2 time(s). Last edit at 04/10/2011 03:08PM by mlagana.

OH and also after some frames i can HEAR the motor making a different sound...

but stepper speed and stepper steps are the same so i should hear the SAME sound EVERY time correct?

Meaning it can't be mechanical..

could it be the script let me find an old copy on my laptop...

i'm pretty sure the script is pretty much like this:

#include 

#define STEPS 200

Stepper stepper(STEPS, 1, 2);
byte inbyte = 0;

void setup()
{
  Serial.begin(57600);
  stepper.setSpeed(30);
}

void loop()
{
inbyte = Serial.read();
if (inbyte == 'S') stepper.step(5);
if (inbyte == 'D') stepper.step(-5);

}

actually i think the test shot script was moving 4 steps every frame not 5. But i think there is something wrong with every forth frame no matter the step size.

Edited 1 time(s). Last edit at 04/10/2011 01:00PM by mlagana.

They should be half-stepping just like the other Gen 3 stepper controllers. At least, I had them set to half-step values for steps per mm when I was still using them in my Mendel and the dimensions came out right.

oh really? i didn't use real maths to calibrate my axes, now over maybe a year of using techzone and makerbot stepper drivers i am finding out it is half stepping... they should have that smack bang on the webshop page it's important..

but thanks brnrd hopefully that's it then...

They need to be half stepping to get 0.1mm resolution with 200 step motors.

---

[www.hydraraptor.blogspot.com]

i see, so full stepping you can't have a decimal place?

i also have just got my first polulu and have it wired up so that the m1 m2 m3 are high, so i have 16X200=3200 steps per rev.. i set my Steps per revolution to 3200? is that possible?? wouldn't 1 step be in the microns..

that's for the quick response guys

ok that did NOT solve the stuttering...

any ideas would be great !! maybe the polulu won't do this stutter every 4 frames thing??

What if instead of using the stepper class... I used low high commands to the stepper pin?

How many miliseconds would one leave the step pin HIGH to push 1 step?

My only other idea is to cut out the software all together, control the canon DSLR camera through arduino with a mosfet... I guess i will just have to try pity it's 2 hours away from my studio

edit: but the arduino is still just sending the same thing over the same wires to the stepper driver, so sending the arduino commands from a computer OR pushbutton wouldn't really make a difference would it? why would it be changing every four frames arghhh i'm going insane here.

Edited 1 time(s). Last edit at 04/11/2011 04:36AM by mlagana.