I am looking at building a relatively low cost mo-co rig....probably four
channels. Skateboard dolly with toothed track-one channel. Geared head
conversion - two channels. Focus - one channel. I am looking for a little
advice on the use of steppers over servos or vsv. I am particularly interested
in how to ascertain ratings of torque and required speed etc.
Has anyone fabricated such a device out of relatively cheap process control
I am really looking at cobbling together a system for an upcoming doco
and beyond. I will eventually have on board a robotics guy and several
electrical engineering friends but at present they all have little idea
of the particulars of film requirements.
>will eventually have on board
a robotics guy and several electrical >engineering friends
but at present they all have little idea of the >particulars
of film requirements.
My advice is, Don't. There have been many who have thought they could
build a motion control and ended up wasting a lot of time and money. As
near twenty year veteran of the industry, I have seen it again and again.
Having said that, here is a moko building primer.
There are three main components to a system. First is the mechanical part.
The physical machine that moves objects like cameras via motors attached
to gears and belts. Many a grip or mechanic has looked at a motion control
rig and said "I could make one of those". I now just inwardly
chuckle. The trick is to make a repeatable machine that can do MANY differently
things rather than just one expensive rig that can only do one type of
shot. As it is, the most flexible of the rigs that are manufactured for
use by the film industry cannot do it all. There is not any one repeatable
machine that sets up quickly, goes super fast, is ultra quiet, has a long
reach, fits through a standard doorway and also shoots time-lapse and
stop motion miniatures.
The Second component is the driver electronics. This unit translates the
incremental and directional signals from the computer into power units
to move the motors. This technology has been made quite easy in the last
ten years. There are now many companies selling modules that make building
this component a near plug-and-play operation.
Third is the development of programming software. Here is where I say
don't! As a systems consultant on a few "in-house" systems,
I would say the number one problem software designers have is that they
are not camera people. The control of the camera is so separate in it's
needs that programmers need to end up making TWO motion control programs
within one seamless interface.
Unless you want the ultra simplest of operations, you should buy a Kuper
system. Industrial Light and Magic had a team of software designers working
over a year trying to develop their own Apple based program. After a reputed
1 million dollars was spent on the own in-house motion control system
they pulled the plug and bought a Kuper system for (then) $3,500.00 US.
Beside buying a Kuper system for the card and software, I would recommend
looking at what your primary shooting is going to be (remember, NO RIG
WILL DO IT ALL) and look at buying a used rig. They come up for sale often
from closing effects houses. Unless you have a very special need like
shooting underwater, your money is best spent adapting a rig that someone
else has spent years debugging.
Last month Disney closed their Visual Effects division called The Secret
Lab. They sold all of the Moko gear they had. It was all the equipment
that had been developed and refined at Dream Quest. The mouse had bought
out the two decade old company and dumped it after only a year or two
Lastly, if you are still going to scratch build your own system, talk
to the film industry Motion Control suppliers about what wiring standards
are already in place. There are thousand of connectors and wiring schemes
possible and if you want to rent a device like a simple rotator for a
two day shoot, it's as easy as making a phone call and sending it back
with a check.
Believe me, you do not want to be cutting wires, making adapters and totally
rewiring both ends of the system while on-set. The same goes for mounting
plates and hole patterns. Standards are great, let's just not have so
many of 'em.
Disclaimer: I do not work for Kuper Controls nor am I paid any money by
them for my recommendations. In fact, I don't think I have paid THEM enough
for the help I have gotten from over the years.
>I'm doing some
research before committing. There seems to be systems out there and I
am only looking at a field portable unit with pan, tilt, focus and dolly
action. This is to be backed up with laptop or dedicated controller...preference
for a system that allows movement capture so that we can work a shot then
scale the movement on replay. Ring any bells...who makes a cheapish version?
Film & Digital Cinematography
Nick Paton wrote :
>Thanks, Eric. I'm doing some
research before committing. There seems >to be systems
out there and I am only looking at a field portable unit >with
pan, tilt, focus and dolly action
For the pan, tilt, and focus part you might want to look at Hot Gears.
Miran Salamati developed that system and is a good guy to deal with.
IATSE Local 600
When I first saw this post, my reaction was the same as Eric said about
hearing a grip or machinist say "I could build one of those..."
I inwardly chuckled.
As another with 20+ years experience with all aspects of motion control,
I recommend you read and re-read Eric's post. I have nothing to add, I
simply post this for emphasis.
I was particularly drawn to comment by Eric's disclaimer about how he
doesn't feel he's paid enough for the help he's gotten from Kuper. I agree
totally with this statement, as I would wager every motion control operator
in the world would...even those who don't regularly use Kuper.
An interesting development in Motion Control is Arri's new "ArriMotion"
equipment (I'm not sure whether it really exists yet). It will be interesting
to see if they can get it right where so many others have failed, including,
as Eric pointed out, the grand-daddy of visual effects, ILM.
Arri's system is totally new hardware and software system, apparently
build from the ground up to work with some new, some existing hardware.
Time will tell if it will work, if it will be cost effective, and if it
will be accepted.
If so, it might be just the thing for Nick's project...if it ever becomes
more than vapourware.
Get in touch with Maxim Ford who has a couple of simple rigs using steppers,
including a tracking system with toothed track. It is(or was) controlled
with the little Psion computers and is an ideal field rig, although perhaps
more of a time-lapse/repeat move rig rather than accurate moko.
I don't have his details to hand but a web search should find his site.
Thanks all for your information on motion control.
I've been put onto a few
companies stateside by the kins readers here and will most probably use
existing technology with the addition of some customisation. There seems
to exist a few people around the place who are very knowledgeable and
prepared to do custom rigs with small dollars.