How would you make this rotate?

[Flyboy101]

This forum has been incredibly helpful so I figured I would throw this out there as well.

I have an atv that I have turned into a camera vehicle. It will hold either a camera crane or a steadicam setup or robotic cameras. I am in the middle of making the robo portion of the rig and am stuck at a certain point.

The atv will have aluminum vertical posts (square 6" x 6" Tube) both front and back. On these posts will hang an arm that slides up and down on this post. The arm holds rental robotic camera heads and cameras.

I need to make these posts rotate at the top and bottom so that we can move camera left and right. The idea I am kicking around is mounting some kind of wheel hub or similar at top and bottom with a disc brake at one end so that it can be held and locked in a position. If not wheel hub, some kind of bearings and a way to lock post. From there posts get tied into cage of atv and trailer hitch of atv.

Eventually I want it to be motorized so that we can rotate and slide arm while we are driving. But that will be next round as budget is limiting to manual for now.

Have included some rough, rough drawings. Thoughts?

 

[Sureshot]

Why not make the slide portion round with a square hole in it if you need 360 motion or simply mount two pillow block bearings and swing the camera and arm on a shaft. If you want to turn the pillar possibly use trailer balls to make pivot points. Easy to assemble and disassemble. If it is more permanent use pillow blocks to hold the 6x6 tubing. Why such large tubing?

I have used hydrauic brakes from motorcycles to do things like this before. Cheap on fleebay and easy to use.

Use a cable crank like a snowblower schute to turn the post if that is how you go. Can be electric or manual.

 

[Flyboy101]

Thanks for reply.

Not sure what you mean by "make the slide portion round with a square hole in it". Sliders are linear motion track that mounts to something with square edge.

As far as the post size, the cameras and robo heads can weigh up to 300lbs with it being cantilevered from post. The mount where the robo head mounts is a 6" industry standard receiver hole mount at the end of arm. Arm and post need to be stable. I think a shaft would not be strong enough or stable enough. Cameras and robo heads can cost hundred of thousands of dollars.

Trailer balls won't work, need better rotation then that.
The pillow blocks where a thought as well, they might work. How would you tie the two pillow blocks to the top and bottom of post? Bottom can lay in there, top not sure how it locks in there.

If I used hydraulics brakes from a bike, I assume I need to use a master cylinder with it? Any recommendations? Sorry haven't worked on a motorcycle. My toys seem to have four wheels.

Thanks

 

[Flyboy101]

To better explain drawings:

There is a central post, the 6 x 6 alum tube.

The round objects top and bottom would be the bearings/spindles/whatever I decide to rotate post

The two vertical kinda rectangular objects are the slide tracks that mount to post. One is grey and the other has a weird line running thru it. Not on purpose, did it quickly in sketch up. Don't know the program well, just imagine two metal tracks at edges on each side.

The arm will either be two plates tied together with a plate at top and the mounting hole plate at bottom. Or, a four link type of setup where the arm flexes up and down. either one bolts to wheels that slide on rails.

Hope that helps.

 

[e-tek]

Can you take pics of the ATV, camera rig or whatever you have up to this point? Will help us better visualize it.

 

[Flyboy101]

Well, these are other peoples versions of what I want to do. I have nothing together right now that would show it any better.

Their posts are fixed. The atv one, the arm clamps to their post and rotates at the clamp. I want to rotate at top and bottom.

The car version is probably closer to what I want to do.

 

[kbs2244]

A rear wheel spindle off a front wheel drive car will give you both the bearing and the brake.
Have you had any stress problems so far?
I would expect you are using some real good mounting plates to take the stress of all that weight when it starts bouncing.
Strong beams still need a foundation so you may need to use the wheel to get the extra dia. To support some diagonal bracing.

 

[Sureshot]

The motorcycle brakes have the master cylinder and handle together. You can generally fab what ever handle/linkage you need from there.

http://www.ebay.com/itm/Atv-Quad-Pa...DefaultDomain_100&hash=item43972b2938&vxp=mtr

Just one of many styles.

U bolts to the pillow blocks or weld a flange on or drill holes or both.

What about using a set of wheel bearings( one top, one bottom) from the likes of an S15 Blazer. You could get a caliper and disk and run about any master cylinder setup you want. Not sure what your budget is but I would think you could get used ones free from someone doing the front end on one of those trucks. The parts are cheap anyway to go new.

http://www.ebay.com/itm/RIVIERA-ELD...Parts_Accessories&hash=item232259676a&vxp=mtr

http://www.ebay.com/itm/79-96-Oldsm...Parts_Accessories&hash=item43a924af1b&vxp=mtr

http://www.ebay.com/itm/68-03-Buick...Parts_Accessories&hash=item5641fe0fe9&vxp=mtr

Or go to a wrecker and get all the parts.

Are you trying to get rid of the swivel the camera is already on in those pics?

 

[Flyboy101]

kbs2244 - Yes will have a good mount both top and bottom. That part I have figured out. Just not how to rotate and lock everything.

Sureshot - thanks for the brake info. The pics are not my rig, just ones I have grabbed off of the internet. Thanks

 

[Sureshot]

If you rotate it with a hydraulic cylinder or servo that will also act as your brake.

What kind of motion are you after? Variable speed, stop start, move only on occasion?

 

[Flyboy101]

Right now it would be a manual setting of arm then lock it, but once I get to the next stage budget wise...unless I can do the animation fairly cheaply... I would need it to be very responsive.

With the cranes I have, the robo heads are controlled by a joystick and servo motors. I would like to achieve the same motion. Input into the joystick or controls moves the arm and post immediately. Smooth, fluid, variable speed, easy of changing direction and fairly fast.

I haven't seen a hydraulic cylinder go that fast. It would I guess have to be servos. Going that way requires power and controls and the budget right now might not allow that. Unless you or others know how to do that cheaply?

As far as the brake, it would not only have to control that weight, but that weight getting thrown all over the place on the atv. Up and down, starting and stopping, plus the rotation of the robo head independently adding force.

 

[Sureshot]

A hydraulic cylinder will move as fast as you put the oil to it. Bigger pump and fittings and it will move faster plus the leverage you could use with all the power. I can't imagine anything going that fast.

What is your idea of small budget and big budget?

 

[NASTYZEN]

Maybe go have a look at how they do it on snowblower chutes. I have seen many with a 12v actuator to operate it remotely. Probably cheap as well.