My shadowgirlproject.com dolly

[Paul Bettner]

Just got a Panasonic DVX100 last week. To celebrate, some of my "crew" and I got together this weekend to build our very own home-built dolly system, recently seen on the dvinfo.net forums courtesy of http://www.shadowgirlproject.com.

I'm very pleased with the end result. The cart rolls incredibly smoothly on the PVC, and the entire assembly can be broken down and fit into a trunk in a matter of seconds. My sincere thanks go out to the shadowgirlproject guys for posting their homebrew solution. Total cost: $80 in parts from home depot, and about 6 hours build time (plenty of beer and breaks in there ;-)

Here's some footage we threw together at 2am last night (right click and choose save target - 30 meg file, sorry):

http://208.193.239.21/~winter/movies/dollytest.avi

--- EDIT --- You will need the latest version of DivX to view. If this is a problem, I can probably encode it in something else if people are having trouble with it. ---

Little caveat on this footage: One piece of required equipment we have not yet been able to find is a set of wooden dowels for fitting the pieces of PVC pipe together. Because of this, we had to rig the four pieces of pipe together using some scrap wood that didn't fit correctly and thus created an uneven gap where the 3' pieces of PVC join together. There are 4 end-to-end segments of track in the footage, and you can see the 8 tiny bumps when the track rolls over these small gaps. When we get the dowels, the PVC pipe will line up flush and these intermittent bumps will go away (for now just concentrate on the smoothness between the bumps, that's what is really indicative of the end result ;-)

The dolly footage is off the DVX100, captured in 24pA mode, F5 scene file with thin detail. I couldn't be happier with the camera itself. I'm getting very film-like footage out of it (with carefully controlled lighting - not exactly what I had at 2am last night ;-)) and it's very exciting to be able to shoot for free ($7, 63 minute tapes) - it allows for so much experimentation!

paulb

p.s. if anyone knows where I might find those wooden dowels (besides lathe-ing them myself) please let me know!

[Russell Pond]

That's just really cool. Thanks for taking the time to share your experience.

I'm starting a project this summer (here in Dallas actually) and I've been contemplating buying a dolly. But your story has goaded me on to Home Depot where I will now build it myself. The only change I think I'll make is that I want to do some stuff around a curved track, so I may pivot the wheels if possible. I'm not sure, though.

Thanks again for sharing your experience. The footage was really nce.

Russell

[K. Forman]

Any lumber store like Lowes, Home Depot, Scotty's will have your would dowels. If you can't find a lumber store, try a craft and hobby shop.

[K. Forman]

Where was the dolly posted? I would like to look at those plans myself...

[Paul Bettner]

Thanks Russell! I also envisioned mounting the wheels to a rotating piece so that it could ride on curved track. It would be tricky to find the right track though (the two parallel rails would need to have different curvatures/radius' to work right.) For now, I'm satisfied with the straight track since it still allows for many different types of shots.

Keith, try this:

Go to http://babelfish.altavista.com, paste in this URL

http://www.shadowgirlproject.com/dolly01.asp#null

and choose "French to English."

BTW, I bought all the pieces for this at Lowe's actually, and although they did have wooden dowels, they didn't have any large enough to fit snug inside the PVC pipe. Ah well, I'll try somewhere else for that last piece...

paulb

[John Locke]

Paul,

With your current wheel configuration, if you used solid rubber tubing for the track...as is used here with the FlexTrak system...do you think it would be able to handle curves?

[Zac Stein]

John,

To handle on a flex track system the wheels would need to be able to swivle, and one side would have to be able to expand and contract from the base slightly to achieve the smooth movement.

[Rob Lohman]

What I keep wondering with these homebuilt systems is how
you get the track to:

- stay where you put it (it doesn't move when you roll down the track)
- lay straight with both tubes (so that you can move the dolly on it), ie, the tubes don't lay closer or father from each other on a certain point than another

[Zac Stein]

Rob,

The ones i have used, you run the dolly up and down the track once or twice quickly and it straightens it out for you.

Zac

[Rob Lohman]

But you don't have any troubles that the track move and don't
hold their place? I can see how the straightenig would go but
not after that. If you roll over it with someone on it etc, aren't
you going to move the track with all that weight?

Perhaps I should just try it out eh...

[Zac Stein]

rob well the smaller ones, are not ride on, just use a handle.

The bigger ones, we sat on, we sand bagged at each end, we encountered very little movement, not enough to be noticable to the shot anyways.

Zac

[Kevin Maistros]

Can someone please translate the instructions on that site?

I was thinking, since the wheels are on top, you could create a few extra track guides for keypoints on the track. Underrings, since the wheels run on top, put on each ends of a metal strip or thin pole would work as track guides.. you could also make the guide pole expand with flat pieces to put sandbags on, or bricks, or something.

___,O,__________,O,___

would be somethin like that.

As far as making it around curve tracks.. Just add a bearing system to the wheel base.. sorta like a shopping cart.... and then add a track to the bottom of the dolly platform running horizontal.. with inner wheels running inside that track piece... the wheels on each end can move a bit left and right. If that's too hard to explain right here, I will be building one on my own soon, and I'll be sure to make a tutorial on it.

[Rob Lohman]

Pleas do, Kevin. Thanks!

[Charles Papert]

The most efficient track wheel (skate wheel) setup is to have two sets of wheels mounted at 45 degrees and opposing each other---this gives maximum stability. Having multiple wheels in each section will help smooth out bumps. (to try to illustrate: imagine looking at the track from the end, in cross section. Given that the track is round, like a clock face, imagine drawing a line from the center point, through 2 o'clock and continuing straight out and away--the part of the line that is outside the clock face represents the angle of the wheel. Same thing at 10 o'clock for the other wheel. Did that make sense to anyone??)

[Rob Lohman]

Let me try to draw what you are saying, Charles:

-\ /------\ /
_O______O_

Ofcourse those lines at the top must be at a 45 degree
angle. That is how you place the wheels.

I think this picture represents as well what you mean?