Dana Dolly Motion Control

[Robino_J]

Wanted to share the V1 of my Dana Dolly motion control rig.

I custom molded brackets for the belt. It works really great. This week I'm upgrading it to a digital controller and motor plus a focus motor for repeatable moves via DragonFrame.

V2 will have repeatable moves and V3 will add pan and tilt.

 

[Adrien oneiga]

i was just wondering about that the other day.. are these custom servos or are they a part of the dragon frame system?

 

[David Battistella]

I love the moviolas!

Want much more info on the motors! Looking to build similar thing with Mark Roberts flair.

 

[Robino_J]

The current motor and controller are from Servo city.

It's a 20RMP DC Precision gear motor. https://www.servocity.com/html/20_rpm_precision_gear_motor.html#.VWxmElxViko

I got this one to test the belt system, now that it works I ordered a 19:1 stepper motor from Dynamic perception and a focus motor from Berkey system. http://store.berkeysystem.com/focus-motor/

I will use the bluetooth motor controller from Dynamic Perception as well.

The motor part was not too difficult since you can swap them with different kind and speed all the time, the brackets on the other hand gave me a hard time. They are completely tool-less you just snap them on the dana dolly end track and you're done.

 

[David Battistella]

Need a few close ups of this rig.

or or maybe pm me if you can.

 

[Keith B Plummer]

Would like to see a close up too.

 

[Robino_J]

Here are closeups.

 

[Adrien oneiga]

nice work! do you know what the load capacity is for those motors?
and as far as control goes, are you using a potentiometer / joystick?
looks like a really nice solution, i'm on cinedrive so i'm either waiting until their shuttle dolly, or customizing a dana to rig the slider motor...

 

[Robino_J]

nice work! do you know what the load capacity is for those motors?
and as far as control goes, are you using a potentiometer / joystick?
looks like a really nice solution, i'm on cinedrive so i'm either waiting until their shuttle dolly, or customizing a dana to rig the slider motor...

For the current DC motor i'm using, i don't know but it doesn't burp at all pulling the dana dolly + 504 Head + built Epic and 150wh battery.

The Dynamic Perception Steppers i'm upgrading to are rated at 20 pounds.

Currently i'm using the servocity digital manual motor controller which has a potentiometer. Once I get the Dynamic Perception NMX controller it will be controlled using iPhone with their app or Dragonframe.

I will have all my parts by Thursday so I will update with progress.

 

[Glen David Miller]

I'm curious - why did you mount the belt to the side of the dolly vs mounting it in the middle? Seems pulling from the middle would make things a little smoother. Also, when your motor is running, do you feel any vibration in the dolly plate?

I've wanted to try this on a Dana Dolly, but their site mentions not to place more than 100 pounds on the system because of the soft wheels they use. I have a similar system with a jib attached and I'm working to get it all up and working - and I'm finding why all of those moco systems we used in the past weighed 10 thousand pounds - the more mass - the smoother and the less jiggle and play in the systems.

I love seeing others doing this.

-Glen

 

[Robino_J]

I'm curious - why did you mount the belt to the side of the dolly vs mounting it in the middle? Seems pulling from the middle would make things a little smoother. Also, when your motor is running, do you feel any vibration in the dolly plate?

I've wanted to try this on a Dana Dolly, but their site mentions not to place more than 100 pounds on the system because of the soft wheels they use. I have a similar system with a jib attached and I'm working to get it all up and working - and I'm finding why all of those moco systems we used in the past weighed 10 thousand pounds - the more mass - the smoother and the less jiggle and play in the systems.

I love seeing others doing this.

-Glen

Mounting the brackets in the middle would be difficult since the camera sits in the center and the ball head stick is protruding underneath. The side was my better option.

There is zero vibration on anything. It's incredibly smooth with zero bumps whatsoever. Give me 30min - I'll upload a little clip to show you.

 

[Robino_J]

Here's a quick shot at 1fps 1/2th exposure. The dolly was moving at approx. 2.20sec per inches.

Forgive the jacked up colors as my black shade was off for 1/2th shutter and the crude compositing. It was done very quickly to show you the smoothness.

password: danamoco

https://vimeo.com/129515209

 

[Nick Morrison]

WOW...that looked amazing....

 

[Marcus Friedlander]

Wow! Very impressive!

 

[Robino_J]

Thanks -

Sometimes Vimeo playback is not smooth and makes it look likes it's jerking. Download the video file to see the actual motion.

 

[Keith B Plummer]

Thanks for the demo. Looks good.

 

[Robino_J]

I'm done with V2 of my Dana Dolly moco. Upgraded motors to digital and added focus and pan. I just did 6 passes and they are frame accurate - 100% repeatable motion.

Next version will have an improved pulley design and machined brackets for the belt, then i'll work on adding tilt. Very happy with performance so far.

 

[Björn Benckert]

Looks good.

A little tip. When building moco rigs, most people use 4 sets of wheels, why I dont know. But alot of times I see the 4 "contact points" as a problem compared to running on 3 contact points. In your case it´s not much of a problem but 3 is much more sturdy than 4 for things like this. See it like a chair with 4 legs... if the chair is placed on even the smalest uneven floor the chair would rock, if it was on 3 legs it would not.

So with the above theory you would be better of with a wide wheel base on the side where the pulling belt is and then only one set of wheels on the battery side... in other words having a triangular base.

Next tip would be to flip the motor so you have it... more on board. and try to make tilt as low as possible with an optional riser, as the more close to the track you got your camera weight and especially the lens the less vibrations.

 

[Robino_J]

Looks good.

A little tip. When building moco rigs, most people use 4 sets of wheels, why I dont know. But alot of times I see the 4 "contact points" as a problem compared to running on 3 contact points. In your case it´s not much of a problem but 3 is much more sturdy than 4 for things like this. See it like a chair with 4 legs... if the chair is placed on even the smalest uneven floor the chair would rock, if it was on 3 legs it would not.

So with the above theory you would be better of with a wide wheel base on the side where the pulling belt is and then only one set of wheels on the battery side... in other words having a triangular base.

Next tip would be to flip the motor so you have it... more on board. and try to make tilt as low as possible with an optional riser, as the more close to the track you got your camera weight and especially the lens the less vibrations.

Thanks Björn for the great tips. Yes the motor will go on the board when i update the pulley module - i'm not liking it hanging like this but after bolting the cheese plate on the dana dolly, there was no place for the motor. I'm fixing that.

Makes sense for more contact points - I have seen other dolly manufacturers with options like this at Cinegear and might try one of their option. The ball head is temporary until i get the tilt going. I will have an L bracket for that and the camera should be lower. I'm also thinking of mounting the pan rotation unit under the dolly and that would make it even lower.

Thanks for your help and i'll update with pics as I go.

 

[David Battistella]

Hey Robino,

Glad to see the updates in this thread and thanks for the photos. Can I ask about the mounting cheesepalte you attached to the Danadolly. I'm all set for motors and such, but I was curious about the housing you have there. That is the part I'd like to figure out.

Thanks again for sharing.

David