[Konvas] off-topic -- motorized heads

[H. W. Stone]

 The heads he had all had neat little "free wheeling" switches that left the counter attached but disengaged the gears, so you could track it.

The move I watched him do was a twenty one foot horizontal by eleven foot vertical with two tilt and resets.

And then they did it with components in front of the green screen sixty something times.

Three days, over four hundred components, then a pass to add the actors.



I knew I was obsoleter than obsolete afterwards.




 


 

-----Original Message-----
From: Sean McVeigh <konvas at smallpony.ca>
To: Konvas Discussion List <cinema at konvas.org>
Sent: Thu, 11 Dec 2008 9:58 pm
Subject: Re: [Konvas] off-topic -- motorized heads









Definitely a cool feature. ?I thought about doing this, but I think due to my rather high gearing ratio, there will be no way to free-move the head by hand without somehow disengaging the motor. ?Definitely something I'd like to see in the next (2-axis) iteration :)

As for storing the data, I can appreciate the usefulness of the laptop in that instance, but again, it's only a couple KB worth of data to store a move. ?Easily accommodated in the flash of a small microcontroller (there are some pretty substantial low-cost, low-power system-on-a-chip type parts nowadays), or in an attached piece of compact-flash or similar couple-dollar part :) ?And it'll run off a tiny battery for days :) ?Heck, we're at the point where we can record hours worth of audio on a single tiny flash card. ?Telemetry data is peanuts compared to that ;)




Speaking of CNC mill, that's my project for the spring!




Cheers,

Sean








On 11-Dec-08, at 9:25 PM, H. W. Stone wrote:



 The mechanicals were Off The Shelf geared units that were made for CNC mills.
 
 The 'added feature' of the laptop is that you can "hand move" the camera, recording it on the laptop, then having it reproduce it time after time after time-- and save thousands of moves.
 
 
 
 
 
 
 
 -----Original Message-----
 From: Sean McVeigh <konvas at smallpony.ca>
 To: Konvas Discussion List <cinema at konvas.org>
 Sent: Thu, 11 Dec 2008 4:21 pm
 Subject: Re: [Konvas] off-topic -- motorized heads
 
 
 Thanks H.W. I'm more concerned with the mechanical resolution right now, if you have any insight on that front.?
 The controller has plenty of processing power, and I know he doesn't want to lug a laptop around all the time, so I'm thinking something on the order of 10 pre-programmed moves, plus a manual setting. It'll have a tiny LCD and a keypad or dial or something similar for manual setup. ie. set it to 5 degrees-per-minute speed and just let it go. I should reiterate of course, that he's more interested in very slow moves rather than snappy ones :) Like doing a panning coastal sunset in timelapse, or similar.?
 ?
 Cheers,?
 Sean?
 ?
 H. W. Stone wrote:?
 > The people I have talked to recommend running it via a laptop-- not > directly. They also recommend MAC over PC, and that you use Firewire > to connect it instead of USB2, but USB2 "will normally" work fairly > well. That apparently keeps the problems to a minimum, and allows you > to upgrade joysticks, controllers, and store moves to use in different > locations weeks later, too.?
 >?
 >?
 > -----Original Message-----?
 > From: Sean McVeigh <konvas at smallpony.ca>?
 > To: Konvas Discussion List <cinema at konvas.org>?
 > Sent: Thu, 11 Dec 2008 2:49 pm?
 > Subject: [Konvas] off-topic -- motorized heads?
 >?
 > I'm building a motorized pan head for a friend for xmas... was > wondering if anyone has any experience with such equipment. I'm using > a stepper motor coupled through a worm gear to drive the plate... does > anyone see any problem with a 0.025 degree/step (90as/step) final > resolution on the output plate? He mainly wants to use it for very > slow pans and timelapse type work, so I think it'll probably be fine.?
 > I'm probably needlessly concerned, as I've maybe been paying too much > attention to astrophotography-related websites while trying to spec it > out, where the requirements are more like single-digit arc-seconds per > step.?
 >?
 > Anyone want to recommend some features for such a head? Since it's > going to have a microcontroller brain, I can probably do things like > re-play moves for green-screen matching. Going to make it programmable > off-line so that you could draw curves for it to follow.. heck could > probably even take a dump from a tracker so you could match-move new > shots for compositing.?
 >?
 > I guess next, he'll want a tilt head so he can stick the two together > and plug a joystick into it :) oh.. there's another feature!! DB-15 > connector :)?
 >?
 > Cheers,?
 > Sean?
 >?
 > _______________________________________________? 






?

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