my new motion control rig

[Jason Miller]

here is my new motion control rig, no welding, took all of my spring break to build, it can be controlled by the computer of by joy stik function, has 3 axis of motion will eventtually have 4, as the stands are crank up stands and can use motors to left and lower them. however now it only has pan tilt and dolly, it can be inclined, to roll up hill or down, and the camera can be as much as 13.5 feet in the air, or 1 inch off the ground. There are no operating parts off the dolly except the computer chips, so storage is pretty easy, as its easy to take apart and put together, the hardest part to transport is the 16ft ladder base. will post video from it within the next couple weeks.

http://www.isarapix.com/pix71/sm/1206332917.jpg (http://www.isarapix.com/my.php?isara=pix71/pre/1206332917.jpg)

http://www.youtube.com/watch?v=Xt6RL3BiCLg

http://www.youtube.com/watch?v=mgIv1q7zqlA

hope you like it.

[Postmaster]

Wow! I am impressed.
Ab bit noisy thou. Can you "programm" it with the computer? Speed ramps? Ease in/out?

Frank

[Jason Miller]

yes yes yes, and yes, but its actually quiter than the "pro" moco rigs out there, those suckers are loud. lot of adr.


this one still has a few bugs to work out, the motor I used for the dolly has a ton of power, but no real speed, so I need to find a better one. and I need to make a few adjustments to the gear rack, and in these videos the ladder is not bolted down to the stands, its just sitting on them, its much more stable when its bolted down. I have a really nice test without it bolted down, but there are a few imperfections in it, I'll try again when its bolted down propper.

[hoarp001]

Looks cool, but in the videos it seems quite erratic... Can you actually program in reliably and accurately repeatable moves with this system?

[Erik Olson]

Keep us updated on this? I love motion control stuff and would like to see how your system progresses as you add functionality. How are you controlling it - is it an off the shelf motion-control program or one you wrote?

As a total side note, I had the pleasure of putting my hands on the orginal Dykstraflex system at Apogee in the early 1990s, which was the one they used in Star Wars. Having Dykstra and Jon Erland explain that beast in person was one of those incredible high points in my early filmmaking career.

Good luck!

e

[Jason Miller]

hoarp, yea I made it look erratic so people would look at it and say oh wow man thats awesome, I've noticed that when things rund smoth and steady people are like um yea so what, they dont get slow and steady are very hard to get, and erattic while exciting is much easier,

but to answer your question, yes I can program it for repeatable motion.

this next two weeks will be hell on wheels for me as I have to catch up in my renderman and fluids classes, so I will only be working with this off and on, now its basicly fine toning and desiding which program I like best.

as well while the motor has 55 tourque inch pounds, its some what slow, so I'm going to be looking for an alternative dolly motor. and sugestions on something cheap fast and strong what runs on 12 to 18 volts?

Jason

[Jason Miller]

Erik thats very cool, Ive seen video footage of that system working, Id love to see it in person. I'm sure at some point I will as I now live in the bay area. working on my MFA in VFX, if theree is an episode 7-9 I'm sure I'll work on them.

[SimonB]

Wow, impressive!

[hoarp001]

When i biult my PT head i decided against using thin materials to make it stronger... you should consider bulking it out a bit, but it looks pretty cool... Slow and gentle would have impressed me more :-D

http://uk.youtube.com/watch?v=Azt6YHi0ASM
photo (http://www.whogivesatoss.com/crane4.jpg)

[Jason Miller]

here is a test shot I took last night, its a simle one axis shot, it isn't perfect, the ladder/track isnt bolted down, its just sitting on the t-bars. but I think its working pretty well. its coming along at least.

http://www.youtube.com/watch?v=41V-zq-1i7A

[Thomas J. O'Hara]

dude this is pretty awesome!
I wish you lived down in SD, I'd want to help you with this thing. I don't know much about it, but it would be fun to test out and perfect.

[bilgami]

nice job!! how much did it cost to make this?

[Jason Miller]

heres another test shot, still not bolted down.

http://www.youtube.com/watch?v=PT0DcYN9Tf0

and you thought 1 on me was bad, try three, if you look closely I'm arguing with myself, its a common thing, but not normally on video lol

Jason

[Erik Olson]

I spent a good deal of time at Kerner Optical back in the day. Hopefully, they still get call to do some analog work over there!

e

[Jason Miller]

here is another video clip of the rig in action, this time is slow and steady and going up a preddy good incline. I hope to get it to go up a much steaper one soon.

http://www.youtube.com/watch?v=Q9kImnvMs_k

there are a few other videos posted but just check out the videos under my name, more small tests 3 axis slower smoother motion than the first ones I posted.

Jason

[DCERVENKA]

Jason - nice work! Is that the servocity pan/tilt system?

[NOMADIC]

what kind of stepper motors you got in that? my old roommate runs gecko drives, which are pretty nice steppers ... in fact, i think they are in the space station.

[wynnefraser]

What controlled do you use to control it from the computer with? Also what software is it linked to?

Wish I had broadband to watch those video's

[Jason Miller]

Nomadic, they're not steppers, they are just now starting to make 12v steppers, two of them are servos, and one is a 12 2.3 amp motor with 55 inch pounds, controlled by a motor controller hooked into a servo controller which is also hooked to the other servos, and my computer. I'm really shocked at how few motion control rigs are out there considering they are not that hard to build. with the servos so cheap, and the servo controllers working so well, I mean the scott edwards servo controller has been around for over 10 years now.

and it works, everyone keeps asking me how accurate my system, and I'm here to tell you that with motion control you do not need accurate motion, you need repeatable motion,

what i mean is, say you want you motor to stop at point c, and you can only get it to stop at point c + 3 degrees, that isn't very accurate but it is fine as long as everytime you run that motion it stops at point c+3 degrees. then you have the same motion repeating over and over again, you can do all sorts of things.


_______________________

I'm wondering what you all think its rental value might be, it currently has 3 axis of moco movement, dolly, pan and tilt, and it can shoot from anywhere form 1 inch off the ground to around 13 to 14 feet of the ground.

I am wondering what you all think its worth to have a 3 axis moco and operator on set?

[Jason Miller]

Just replaced the 2in sprocket with an 8.5 in sprocket, the thing has some speed now, will post videos of it when I get the sprocket installed properly rather than with c clamps.

[Erik Olson]

Nomadic, they're not steppers, they are just now starting to make 12v steppers, two of them are servos, and one is a 12 2.3 amp motor with 55 inch pounds, controlled by a motor controller hooked into a servo controller which is also hooked to the other servos, and my computer. I'm really shocked at how few motion control rigs are out there considering they are not that hard to build. with the servos so cheap, and the servo controllers working so well...

Back in the 80s, several entrepreneurial SFX people tried using servos in place of steppers for motion-control work and the things were very susceptible to radio interference. Okay and "acceptable" when your rig is fifty pounds - not so funny when you have five-hundred or a couple thousand.

Beware placing too much trust in a servo operated motion-control rig.

e

[Jason Miller]

the dolly motor isn't a servo the two servos are for the pan tilt,

I never thought of something interference, as everything is wired and nothing is wireless, if it happenes whats the best way to counter it.

[shred444]

Are the servo motors for pan/tilt continuous?

If not, how do you know their position....or you dont.

Also did you build the pan/tilt piece, or was it prebuilt and you purchased it?

[dory_breaux]

is that on a ladder??? thats really cool!

[Jason Miller]

Are the servo motors for pan/tilt continuous?

If not, how do you know their position....or you dont.

Also did you build the pan/tilt piece, or was it prebuilt and you purchased it?

the head is a servocity head and they work via degree, so I set a certain degree in and the servo knows where to go.

the dolly on the other hand is a motor hooked to a motor controller, hooked to the servo controller. it turns both ways at about 35 rpm, with 55 in pounds. with the 8.5 in sprocket, thats 4.25 inch from center, it cuts it down to about 12in pounds, of power, but ups the speed, with the bearings I have it isn't a problem to move it, however I'm still unsure how its going to handle the incline feature I incuded in the rig. I may get a 4 and 6 inch sprocket as well and make them swapable, less speed more power in predictable steps.

Jason

[Jason Miller]

yes its a 16ft portion of a 32 ft ext ladder.

[Joseph Stunzi]

I once had an idea of taking the Camtram system with a remote head and going to town. This looks a look less expensive!

[Jason Miller]

the camtram is pretty cool, but when all said and done it's just an over priced ladder dolly, there are other cheaper ladder dolly systems out there that cost much less and could be fitted with a motor just as easy, if you're not wanting to start from scratch.

Jason

[wynnefraser]

any chance of finding out what controller you used? did you write your own software?

[Jason Miller]

well Im trying several I leaning toward one, but I really dont want to tell people untill I know for sure its the right one, its worked perfectly for all the tests and In a couple weeks I'll have it on set so I'll hopefully know for sure then.

[Dmitry Yun]

oh wow man thats awesome... :)

[Jason Miller]

quick update, it moves up a 3 ft incline well even with the 8.5 inch sprocket.

Jason

[DVfluffer]

Wow that is pretty awesome piece of kit

[Jason Miller]

used it in its first film yesterday, Will be using it on Friday for the green screen counter shots. all is well so far.

Jason

[Kdawg]

Oh cool, I would like to check that out Jason.

[Jason Miller]

Kdawg I have a few shots from in on my reel
http://www.vimeo.com/1474922

its the two over head shots, one with the baby, and one on the green screen, its a thesis project for a friend, she hasn't done the comp yet, but it matches up.

the other is the very low shot looking up at the woman who is walking, seems to be looking for someone.

all the other :moco" shots on here whre done with floor markers a dolly, and a stopwatch.

Jason miller

[Jason Miller]

welp I just got it put together in my living room so I know all parts will go to set monday, just got all the drivers installed onto my toshiba laptop. seems to be working like new. hope I'll have someone on set Monday to take pics of it and of Gary's hypercam

[Jason Miller]

here is my latest shot with the my moco build,

http://www.youtube.com/watch?v=9L37f0jnBGg

[charles]

Looks great. Got any more pics and would you like your own gallery on HBS?

[Jason Miller]

shoulds cool

[pix2pixels]

What about this USB (http://www.ar.com.au/~softmark/page44.html)controller for the stepper motors?

[Jason Miller]

don't know haven't tried it, I don't have steppers on my rig, I have two servos, and one motor, hooked to a motor controller, that controller and the two servos are hooked to a usb servo controller.

[waefre]

So what kinds of software are you looking at to control this rig. Is it capable of discreet movements and smooth accelerations? I worked on a motion control job a few weeks ago and the software they were using allowed you to set keypoints and would then calculate a smooth curve to make the motion smooth and natural.

[Jason Miller]

my software will do that as well, its actually a cheap $50 serco controlling software, set a start point at 0, and the next point at a speed you want it to reach at that time for the dolly motor, for the sevos you set it for the angle/time and with will determine the acceleration.

[tomk358]

It would be pretty cool if you could 'record' your camera moves in one shot, then have it 'play back' the motion to shoot a clean plate for the second pass.

[Jason Miller]

you could with the proper programs, I think Match movier had a cam export, buju might as well, I'm designing a homemade cnc machine now maybe when I get it together I'll look into using cam to control my moco.

[Postmaster]

Have you ever looked into LEGO Mindstorms?

It comes with several stepper motors, a little computer and a idiot safe drag and drop software.

I stumbled upon it when I researched DIY remote heads.

Frank

[nosys70]

you can add an encoder for cheap (about 50$) to any motor (servo or DC).
you just need to read them to count the distance, calculate velocity etc...
I would go with DC motors so you can cut power on motor but keep reading on encoder. Then you can move the camera by hand and get the system record the moves and reply them again.
you can have some small cpu (gumstick, basic stamp) to get info from encoder at a clocked time and convert it to serial or usb.
Serial is great because you can add a small wireless module at each end and transform wired to wireless with no effort.
the only difficult thing is to build into the system some accurate mechanical references so you can dismount and remount system while keeping the starting position.