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-   -   Air Filled Tires for a dolly? (https://www.dvinfo.net/forum/dolly-track-cable/486725-air-filled-tires-dolly.html)

Dale Workman October 27th, 2010 09:09 PM

Air Filled Tires for a dolly?
 
Hello everyone,

I am looking into building my own camera dolly. Good caster wheels seem plentiful, and reasonably priced - but I was just wondering if there would be any advantage at all to building a dolly using air filled tires. I have not been able to find very much information on the internet about people doing this - and I have not yet looked to see how small of tires I can find at local stores. I am hoping to find something like kids wagon tires.

I just figured it may provide smoother movement - however I am guessing I would have to add weights to the base and remove some air from the tires.

Any thoughts on this? Has it been done - and is it even worth it?

Don Bloom October 27th, 2010 09:19 PM

I have searched high and low for these as well. Pneumatic tires come with tubes and the absolute smallest size I found was an 8 inch wheel/tire combo. The most popular size is 12 inch and larger at least based on my web search. They are not easily found in home improvement stores or even stores that sell or repair things like lawn mowers o snow blowers but if you search the internet for pneumatic tires I think you'll find some places to compare product and prices.

Dale Workman October 27th, 2010 09:29 PM

Yeah I suspect these will be difficult to find. But I would even buy a kids wagon or tricycle for the pneumatic wheels if I thought it might work. I just think there would be alot of advantages, and would operate way more smoothly than any caster wheels.

Bob Hart October 27th, 2010 10:28 PM

How you might want to use the dolly will dictate what wheels you want. I assume it is to roll on surfaces not on rails. If it is indoors on smooth hard floors or carpets, I don't think you can go much past rollerblade wheels similar to those used on the P+S Technik Skater.

1970 - 1988 or so vintage vee-belt ( wedgerope) GM airconditioner tensioner pulleys with the alloy tensioner arm are handy if you make light rails out of bediron or right-angle steel stock.

The tensioner arms are already drilled and threaded and you can bolt to them through a frame made of right-angled stock through simple drillholes. If you can still get small rubber pipe rings to roll onto them these work reaonably well as tyres for hard floors.

This is all a bit iffy now as it is 30year old obsolete tech but I made a great rail dolly out of them, some bediron off the landfill and some automotive tailshafts for upright tube columns.


-------------------------
WARNING: (DANGER WILL ROBINSON) - If you use automotive tailshafts, don't touch any that have been in a landfill fire. The cardboard inner dampener becomes charred and high pressure gas is driven off and remain in the steel tube. Likewise, don't hit them with a blowtorch.

Before cutting them with any sort of saw, drill a small hole in the tube to let any gas pressure out. Even better, drill a hole at either end and purge any gases out with compressed air. There is a risk that contained gas may be flammable or even explosive.

I know this from frightening personal experience when yoke cutting. At the final cut with the hacksaw I smelled a slight acetylene odour. I had cut close to the yoke weld as it is easier and the saw does not rip through the thin wall of the tube and jam. When I tapped the yoke to loosen it, there was an almighty deafening explosion of compressed gas.

The yoke flew, destroyed the cover of an outboard motor, dented the flywheel, went up and cracked the ceiling. If I had stood in front of it, I would been killed for sure. There's things out there in the world just waiting to lay a Darwin Awards audition on you.
--------------------------


Kmart over here have economically priced sets of rollerblade wheels. Buy from a sports store and you may pay gold-plated prices. You may find you can actually buy the wheels cheaper by buying complete kids roller-blade boots at Coles, Target etc..


You may discover that the fit of the bearing balls in the swivels and wheels of industrial castors is too loose and you get rocking and other unwanted movements which the jolt the column at camera height.

With air-filled tyres, you will need to ballast the dolly pretty heavily to force the tyres to cushion over small objects if you roll it directly on paths or roadways. The tyres themselves may sway. You could do what tractor owners used to do and partially fill the tubes with water to stiffen them up a bit. I'm not sure what that would do to the lifetime of the the inner tubes though.

If you want to go au-natural along footpaths, roadways and across lawns, you might need to consider 8 wheels in two parallel rows of four like an 8 wheeler truck or wheeled military cross-country vehicle. It still won't be silk smooth like steadycam.

I am no expert in this game, so please listen to the advice of more qualified others who respond here.

Kevin Spahr October 29th, 2010 10:24 AM

I've been thinking about making a dolly too. Dale, are you making a "ride on" dolly or a camera support dolly?

If you're close to a Harbor Freight store, they have a good selection of wheels, some air filled, they have really low prices. You will have to determine quality level for yourself. But 8" is the smallest air filled tires I've seen. Grainger's might be another place to look for wheels...

Anybody ever see the dollys that use bungie cords to support the camera platform? The operator sits on the dolly and controls the camera to help with sway and bounce - supposedly.

Bob Hart October 30th, 2010 02:22 AM

That's what Jeep Wranglers with double roll bars in the back are for, to hang the camera from when being followed by riders on horseback, used on Dan Parry's jeep for the indie project "Congoro".

Dale Workman November 1st, 2010 10:43 PM

I was thinking just a camera support dolly. I am starting to think I will just make one using caster type wheels - and put the air filled wheels on hold. I am just thinking that casters will store a bit better, and I am a bit worried that I will have to put a lot of additional weight on the air filled wheels for them to work properly. Not sure - still going to do some research.

I was just thinking that air filled wheels would give a bit more smoothness to dolly movements than caster wheels - without the time involved in setting up a dolly track.

Buba Kastorski November 29th, 2010 03:58 PM

a bit pricy, but you can find 8" air filled caster wheels on ebay,
even without additional weight, and at 'normal' pressure they still be softer on the floor bumps than solid rubber casters, but for the smoothness additional weight is needed;
I will probably get those for my manfrotto 114.

Aaron Holmes November 29th, 2010 06:20 PM

Ever seen those fancy baby "jogging strollers" with 12" inflatable tires? You could always just get one of those off craigslist and add a camera support arm to the frame. Then you have something that already folds up, has a nice handle to push it around with, and the front wheel can be locked or unlocked to let you lock it to a straight path or push it anywhere. Plus you've got a basket underneath and a seat to throw all sorts of stuff in. :)

Best,
Aaron

Scott Elkins November 29th, 2010 11:25 PM

3 Attachment(s)
I made a dolly using rollerblade wheels I found at Harbor Freight Tools. The wheels caster and
have brakes, makes it a little more stable if you want to stay in the same position. The
rollerblade wheels work fine on hard surfaces including driveways but they don't work very
well off road.


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