Homemade Motion Control

[Petros Nousias]

A year ago, during prep for a feature film I was shooting, I decided to build a motion control rig. The idea had come long before, but the actual planning, construction and software was made in 3 months while I was prepping the film(acting as co-producer, DP and VFX supervisor, so I was quite busy!). It's a 3-axis rig(pan, tilt, track) with focus capabilities that were'nt implemented completely as there was plenty of DoF in the shots it was used. I'm extremely happy and proud with the outcome since I'm not an engineer, just a DP-evn though I enjoy building stuff as a hobby. In the film(called Evil in the time of heroes-check out the trailer in youtube) we had one 9-pass and one 17-pass shot among others that lined up perfectly in post. Now that the film is finished I'll be doing improvements, both mechanical and in software(which was written by a friend of mine, Im not capable of writing a single line in any programming language).
The photos are a bit shitty, but they are the only ones I got that are on location.

 

[Christian Edwards]

looks pretty mean dude ,
iv been looking into doing the same thing... when i say looking into I'm mean its just a random thought. I was kinda under the impression that the cost in materials would outweigh the cost of buying a functional one as the gearing systems need to pretty accurate with expensive parts but maybe im thinking of something a bit more eloborate, did you have parts machined specifically for this? ... how much did you end up spending on this?

 

[Petros Nousias]

Everything was either laser-cut, CNC'd or done in my house(with normal tools-nothing fancy) depending the accuracy needed. So far it cost me around 4000-4500 euros.

 

[Tim Hole]

Me too!!

I think you will find that there is a lot of interest out there for DIY-Moco...especially when it comes to Scar/Epic being such perfect effects cameras.

I am shooting a feature next year that will need Moco to pull off some of the effects effectively. I have engineering skills but no code skills and I don't really have the time or the inclination to learn. Thankfully there is enough around the internet to be able to jump on someone elses ship.

 

[Tim Hole]

Everything was either laser-cut, CNC'd or done in my house(with normal tools-nothing fancy) depending the accuracy needed. So far it cost me around 4000-4500 euros.

is that by partly getting bits CNC'd professionally or have you actually spent 4000-4500 euros on components and materials?

 

[Christian Edwards]

(which was written by a friend of mine, Im not capable of writing a single line in any programming language).

Haha everyone has a friend thats a programmer join the club "Goodbye world"

Me too!!

I think you will find that there is a lot of interest out there for DIY-Moco...especially when it comes to Scar/Epic being such perfect effects cameras.

.

Yup :thumbsup:

 

[Tom Lowe]

Awesome, dude. I love to see people doing things like this, and then posting BTS pics. Were you using servo motors? How much did the whole thing cost to make?

 

[Barry Gregg]

What did you use for the drive cable?

 

[Kwan Khan]

Pretty Nice..

 

[Petros Nousias]

It was around 4500 alltogether, materials being the most expensive. I expect to pay another 1000 in the modifications, so in total around 5500, a bit less.

I used steppers because they are easier to communicate with, they dont need feedback(as long as you stay within torque limits and dont lose a step) and I was allready familiar with the technology since not long before I had made a timelapse head for documentary work, again with steppers.

what do you mean by drive cable?

 

[Tom Lowe]

don't the steppers present a problem for smooth, fast real-time moves? are they noisy?

 

[Petros Nousias]

Micro-stepping and gear-reduction will get you smoothness, and stepper motors can get pretty damn fast if they are driven correctly and have enough torque.

...but they are noisy. It never concerned me because most fx shots are MOS and if not a guide track with subsequent dubbing is a small price to pay!

 

[Petros Nousias]

Me too!!

I think you will find that there is a lot of interest out there for DIY-Moco...especially when it comes to Scar/Epic being such perfect effects cameras.

I am shooting a feature next year that will need Moco to pull off some of the effects effectively. I have engineering skills but no code skills and I don't really have the time or the inclination to learn. Thankfully there is enough around the internet to be able to jump on someone elses ship.

You will find plenty of stuff in the net about motors and the mechanical part in general, but I dont think you'll find anything that useful software-wise(at least I didnt) unless you're looking for a simple parallel port interface. If you're looking for accuracy its worth investing in a moco card(I got one from advantech) which of course will need coding in order to be suitable for film use.

 

[Barry Gregg]

It was around 4500 alltogether, materials being the most expensive. I expect to pay another 1000 in the modifications, so in total around 5500, a bit less.

I used steppers because they are easier to communicate with, they dont need feedback(as long as you stay within torque limits and dont lose a step) and I was allready familiar with the technology since not long before I had made a timelapse head for documentary work, again with steppers.

what do you mean by drive cable?

I mean the grey plastic stripe down the middle of the track with the cogs that the motor attaches to.

 

[Petros Nousias]

I mean the grey plastic stripe down the middle of the track with the cogs that the motor attaches to.

It's a T10 belt, easily found in automation stores. It's extremelly strong and wont stretch when high force is applied(It will eventually but Im well below the limits), making it suitable for this type of use.

 

[Constantine Tyrintzis]

Very nice Petros.Maybe I can help you with mechanics and stuff next time, Ive done a lot of robotic stuff past projects.
Well done man.

 

[Petros Nousias]

Very nice Petros.Maybe I can help you with mechanics and stuff next time, Ive done a lot of robotic stuff past projects.
Well done man.

Thanks.We should meet, miltos told me all about your rig, I would like to see it.