Team 3alarm Carnival Productions: 3alarm

Published May 30, 2017 © GPL3+

The Cam Wow 2000

Everyone can make a slider, but the Cam Wow 2000 adds a 2nd axis with a pan head. Programmable and very accurate using steppers and MegaPi.

AdvancedFull instructions providedOver 1 day1,253

Things used in this project

Hardware components

Makeblock MegaPi

MegaPi is a microcontroller board based on ATmega2560.

OpenBuilds NEMA 17 Stepper Motor

24 in. Full Extension Ball Bearing Side Mount Drawer Slide (1-Pair)

OpenBuilds GT3 Timing Belt - By the Foot

belt that drives the slider

Makeblock timing-belt-motion-robot-pack-blue

Lumber, MIsc. 1x4 and 2x6 peices cut to custom lengths

Plated Steel Slotted Angle

Software apps and online services

Makeblock mBlock

Arduino IDE

Hand tools and fabrication machines

Woodsaw

Story

Overview

I am a professional camera operator. I'm always looking to create an interesting shot.

A year ago, I didn't know anything about Arduino, and liked to poke fun at the whole "maker" thing, I was always like "what the hell are you making?" One day I checked out a Sparkfun Arduino Starter kit from my library, and I was hooked!

I finally got it, and I immediately set out to make a camera slider that would be very smooth, heavy enough to handle a really camera, and also programmable, to run either motion control moves, or very slow moves for use in time lapse.

Step 1

this was an early version, using a threaded rod to articulate the camera "sled"

Using some erector set parts, a geared motor and a screw drive sort of worked, but only for time lapses. (see above and below) Shot with a Canon 5D Mark II.

Step 2

So the 24 inch drawer slides worked well for the mechanism to put the camera on, as you see above. But there was still more to be done!

the move is simple, but to get the camera to stay pointed at an object of interest is requiring some math

A tracking shot looks cool, but I wanted to have the camera lock on an target in the frame and keep that object centered.

Step 3

I wanted to use this in real time applications as well, and that's when I discovered the power and flexibility of the stepper motor.

and early version with a bigger pulley on the slide axis (too fast), and the pan axis, too "steppy"

the mechanism in action looks like this. I have to admit, the tripod head that I "found" for this project works perfect for this, but honestly, I dont think there is another one out there... I just happened to have a round base that I could glue some timing belt onto, in order to engage the drive belt that you see above.

Step 4

At very slow speeds, and at the beginning and ends of the moves (ease-in and ease-out, for animators) the pan movement was too jerky (as the stepper motor clicked between coils), with the single belt that you see above, so I added a reduction gear that really slowed it down, and smoothed it out.

Getting the two motors to start and stop their moves would have been impossible for me to figure out without the help of Mike McCauley and the AccelStepper library that ramps the motors up and down with a lot of flexibility and finesse.

recent test shot, 30 seconds per move

Thanks for looking! I am new to this site, so if there is some interest in seeing more of this project, let me know and I will keep improving the story!

Code

30 second travel out and back on the cam wow

// MultiStepper.pde
// 
// This version used on the wine glass shoot  1:00 total 

#include <AccelStepper.h>
#include "MeMegaPi.h"
#include <SoftwareSerial.h>

// Define some steppers and the pins the will use

MeStepperOnBoard stepper1(SLOT_1); 
MeStepperOnBoard stepper2(SLOT_2); 
//MeStepperOnBoard stepper3(SLOT_3); 


void setup()
{  
  // slider motor  01Minute :20 second loop  <good timing>
    stepper1.setMaxSpeed(3000.0);   //2000 and 3000 no change
    stepper1.setAcceleration(400.0);
    stepper1.moveTo(52000);  // 18 inches?
   // Pan head
    stepper2.setMaxSpeed(840.0);
    stepper2.setAcceleration(220.0);
    stepper2.moveTo(-20000);  // 45 Degrees  a little earlier than slider
    // spare motor for future use 
 //   stepper3.setMaxSpeed(600.0);
 //   stepper3.setAcceleration(50.0);
 //  stepper3.moveTo(1333); 
}
void loop()
{
     // Change direction at the limits
  if (stepper1.distanceToGo() == 0)
  stepper1.moveTo(0);
  if (stepper2.distanceToGo() == 0)
  stepper2.moveTo(0);
// if (stepper3.distanceToGo() == 0)
// stepper3.moveTo(-stepper3.currentPosition());
 //   delay (5);
    stepper1.run(); 
    stepper2.run();
    //delay (5);  //delay of 20 lasts about 34 minutes but pan returns too soon
}

Credits

3alarm

0 projects • 0 followers

Camera Operator, RN, TInker, Builder

Thanks to Mike McCauley at AccelStepper.

The Cam Wow 2000