2-Axis Motorised Timelapse Head

[Ross]

Hello everyone,

First off its been  while since I've posted I hope everyone is well I've been keeping busy but too busy to write anything up!

I started drating a new little project a while back throwing some ideas about and I've got carried away and I've started making it. I'm building a motorised tripod head for panorama and time-lapse photography this is one of my other hobbies. These are available at ranging prices in the hundreds and only really feasible if you are a professional freelancer not a mear apprentice like me.

this is the sort of thing I'm replicating in my own way.


The results are incredible, see the video below which features a motion control head:



Now to the nitty Gritty, I've already got 2 stepper motors and a programable Arduino circuit board coupled with a stepper motor driving unit. have a few avenues for software but I'm going to experiment once I'm up and running as I'm not sure what requirements I'll need.

I am using a worm gear and a 57 tooth gear as my drive method with a 200 step motor 1.8 degree per step . Individual steps and micro steps can all be controlled. all holes will have ball bearings.

I am currently looking into a laser cutting service for some 10mm perspex, I am awaiting a quote form a company that say they can do it but I am told that the  laser will cut at a 'slight' angle. Though this shouldn't be too crucial as I can add a allowance to mill off the sides  flat for parts that fit together.

here is a screen shot of the parts I am seeking to cut, I have left a few spare just in case..



If anyone has any Laser cutting experiences or companies to recommend I'd be grateful a lot of places have a minimum order value which isn't feasible.

I aim to have this finished in the coming months as it really isn't complex mechanically it is the electronics that is the biggest of all learning curves for me.

[S. Heslop]

How accurate do those things need to be if you're going to mill them flat? You could probably cut them out freehand with an jigsaw (or any saw that'll cut plastic clean), and stick em together with double sided tape for drilling the holes through and milling the edges.

[Ross]

How accurate do those things need to be if you're going to mill them flat? You could probably cut them out freehand with an jigsaw (or any saw that'll cut plastic clean), and stick em together with double sided tape for drilling the holes through and milling the edges.

I want to keep the milling to a minimum because I have no mill! I should be able to get the sides of the base (one with the circle in the middle) squared up locally if needed. 

[S. Heslop]

I want to keep the milling to a minimum because I have no mill! I should be able to get the sides of the base (one with the circle in the middle) squared up locally if needed.

Ah I didn't realise you didn't have a mill. What's stopping you from just cutting them out free hand and sanding/filing up to scribed lines though? You can acheive pretty fair accuracy doing it that way.

You could maybe even print out the pieces from an inkjet printer and glue that onto the plexiglass sheet. Then score through the lines with a razor blade and a straight edge. Those printers tend to be pretty accurate, and might even count as CNC.

[ddmckee54]

Do you know anybody in your area with a CNC router?  10mm perspex is realatively easy to cut and compared to some of the stuff I've cut on my CNC router, those pieces look dead simple.

I'm on the wrong side of the pond or I'd offer to cut them for you.

Don

[Ross]

Ah I didn't realise you didn't have a mill. What's stopping you from just cutting them out free hand and sanding/filing up to scribed lines though? You can acheive pretty fair accuracy doing it that way.

You could maybe even print out the pieces from an inkjet printer and glue that onto the plexiglass sheet. Then score through the lines with a razor blade and a straight edge. Those printers tend to be pretty accurate, and might even count as CNC.
[/quote]

My hand filing leaves alot to be desired! I need a 30mm hole for two bearings on each side (of the angled pieces) that would be an issue..  I'm getting there with the laser cutting and should have something soon.

Do you know anybody in your area with a CNC router?  10mm perspex is realatively easy to cut and compared to some of the stuff I've cut on my CNC router, those pieces look dead simple.

I'm on the wrong side of the pond or I'd offer to cut them for you.

Don

That was what I was thinking too, sadly I don't know anyone with one, even if a company had one they'd want a minimum order of 50+ parts.

[Ross]

An update on this,

I'm getting the structure laser cut out of aluminium after drawing it up on cad.



I have found a wired camera remote for my Sony DSLR. I have worked out that;
    - Red = positive
    - White = focus
    - Yellow = Take photo



I will not need the focus wire as this will be manually set on the camera.  I guess I would only need to utilise the red and the yellow wires by using the analog input on the board?

I would like to incorporate this into the program, and the board. I have not started on the program yet but I am thinking that it will will be processed something like this:
  
   - Move to home/start position (If I can set one)
 
   -Take photo
   - wait ( exposure time )
   -Adjust motor 1
   -Adjust motor 2
   -Wait (interval time)

Hopefully in the coming weeks I may have something built.

  
  

[Ross]

Bit of an update...

I have now got the shutter system working as it should after a little trail and error, thats one of the obstacles out of the way! (I've also got a new camera..  a Canon The connector to the camera is different but the three wires are Identical to the sony's)
I have Fabricated the lower body of the Head, now just waiting for some laser cut metal to arrive!

[Ross]

My laser cut bits were finally finished this week and I have got stuck in a little bit more, I'm now in the process of machining the shafts and assembling, it's getting there now.. slowly!

[Ross]

Another update,

The rig is now 97% finished, Its been tested and both motors work although the bottom section needs another bearing as it gets stuck due to the weight shifting on the top, but these problems are what I was expecting.

the torque of the motors seems ok, I haven't tried it too much with the camera in place but it takes a fair bit to make them stop moving. Battery life seems alright as well but the real test will be the first time-lapse I guess.

Here are some photos:





The time-lapse program I have written has confused me once again, The problem being when I set the motors to go 20 steps per interval of the time-lapse the program seems to only allow 1 step per interval, can I do a loop with a loop that calls up the number of steps the motor has to move? I think this is getting a bit like inception...

here is my Updated (slightly unfinished prototype) code still working on it through trial and error.

Code: [Select]


 


void loop()
{
 
 
  //Timelapse 2-axis Head Program

  #include <AccelStepper.h>
  #include <Wire.h>
  #include <Adafruit_MotorShield.h>
 
 
 
  Adafruit_MotorShield AFMSbot(0x61);
  Adafruit_MotorShield AFMStop(0x60);
 
  Adafruit_StepperMotor *myStepper1 = AFMStop.getStepper(200, 1);
  Adafruit_StepperMotor *myStepper2 = AFMStop.getStepper(200, 2);
 
  void forwardstep1() { 
    myStepper1->onestep(FORWARD, SINGLE);
  }
  void backwardstep1() { 
    myStepper1->onestep(BACKWARD, SINGLE);
  }
  // wrappers for the second motor!
  void forwardstep2() { 
    myStepper2->onestep(FORWARD, SINGLE);
  }
  void backwardstep2() {
    myStepper2->onestep(BACKWARD, SINGLE);
  }
 
  AccelStepper stepper1(forwardstep1, backwardstep1);
  AccelStepper stepper2(forwardstep2, backwardstep2);
 
  const int shoot= 6;
  const int power= 4;
  const int focus= 9;
 
 
  int interval = 1.5; //ALTER
 
  int photos = 20;  //ALTER

  void setup()
  { 
    AFMSbot.begin(); // Start the bottom shield
    AFMStop.begin(); // Start the top shield
     
    stepper1.setMaxSpeed(100.0);
    stepper1.setAcceleration(9999);
    stepper1.moveTo(10);
     
    stepper2.setMaxSpeed(100.0);
    stepper2.setAcceleration(9999);
    stepper2.moveTo(10);
   
 
     pinMode(focus, INPUT);
     pinMode(power, OUTPUT);
     pinMode(shoot, INPUT);

  }

  {while ( photos <0)
 

     
             digitalWrite(power, HIGH);
             digitalWrite(shoot, HIGH);
 
  //CHANGE according to shutter speed
              delay(10 - interval );
     
  //Release shuttter
              digitalWrite(power, LOW);
              digitalWrite(shoot, LOW);
       
     stepper1.run();
     stepper2.run();
       
   
 
    photos--;}}