My shadowgirlproject.com dolly
 

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!

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

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.

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

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

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?

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.

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

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

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...

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

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.

Pleas do, Kevin. Thanks!

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??)

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?

Rob, can you draw me next heheheh


Zac

Sorry, I haven't had the time to check the forum lately, been very busy... but it was a surprise seeing our website mentionned in a discussion title! ;-)

Anyways, I've posted a lot of pictures of the dolly because it served us really well, but it is something (dolly with skateboard wheels) which has existed for quite some time, even in big rental houses. But since they are so easy to build yourself... and the PVC rails are cheap... why rent?

It actually works even better with metal tubes for the rails, although they are of course less practical.

I think the photos are pretty straightforward so that no translation or explanation is really necessary, but if you have specific questions, I'll be happy to answer them.

BTW: For those interested, the film is currently doing the festival circuit and getting good reviews. We even got the Platinum award for best "low budget" feature at the Houston WorldFest, which was the first festival we submitted it to ! :-)

Yup, that picture you linked says it all. Thanks Rob.

PVC sizes
 

If you purchase Schedule 40 1" PVC pipe to use for your track, and 1/2" Schedule 40 1/2" PVC pipe for the connecting "dowels" those you will find have an extrememly tight fit.

I need to upload pics of my dolly that I built. The 4 "trucks" that I built work on a double hinge system.. allowing them to turn 360 (on an axis perpindicular to the ground) and also rotate on a axle that is on a axis parallel to the ground. So essentially you could run a cuved track over the top of a hill, and the 4 corners of the dolly would not ever leave the track.

Lemme know if any are interested in seeing pics of the dolly.. I'll try to get them uploaded.. I need to convert my track to the pipe sizes I mentioned above... I used 3/4" pipes, and connected with a woden dowel (but the connections are loose) definitely not as good as the 1/2" PVC connectors. I also have developed plans on how to make fixed curved track out of PVC and some 2x4 wooden ties.. have all the inner and outer radiuses computed (and tested - as I have curved track as well).

-Brad

I would really really be interested to see (detailed) pictures
of your dolly. I'm currently thinking of constructing my own!

Steven, why would metal pipes be more "difficult". Because
of more weight or something?

Congratulations on your win in Houston, Steven-Marc! What a thrill to pull a Platinum on your first festival submission!

Brad post some pictures. I would be very interested in seeing your dolly.

Rob:D

One thing I did with my dolly set-up was to take my PVC sections (each about 5 feet) and I used some spray insulation, like what you would use to spray around the frame of a window, and sprayed it down into the pipe for each section.

This stuff drys hard and gives the tubes a good solid structure. Doesn't add a lot to the weight but that's what sandbags are for.

To connect the tubes I took a shorter piece (about a foot or so) of the same size PVC and cut one side the entire length so it was sort of a circle with a break in it. I trimmed a bit of the edge so there was a larger gap (so it's more of C ) and basically just squeeze it to shove it in section of PVC and then do the same for the next section.

I've found this works really well and keeps them together and tight.

(hope that made sense)

That are some fabalous suggestions, Kevin. Thanks a bunch!

What a great idea for the connectors Kevin! I'll give that a try!

Next up, a crane/jib. I'll let you guys know how it goes :-)

paulb

Kevin,

That is a great idea, i did something similar once, but i cut the ends on each so they were cut diagnol, kind of like a point came out on each end, then used cork to wedge in there, as it gives a bit, you idea sounds cheaper and easier, but the diagnal cut is worth it because we found it dampens a bump even more.

Zac

Dowels
 

There is an alternative..

You need to get the PVC pipe you plan on using and bring it to a plumbing supply house, a small piece will do. See if they have another grade that will fit snug inside the one you will use for the track. PVC Cement will work on the inside being careful not to get any outside. Be really careful when cutting the sections of track, use a squared true mitre box to make the cuts with a very fine tooth blade. You will get a good straight even cut that you can finish with a light sand paper. Any gap will result in a thump when the wheels roll over it. You can also use steel brackets that will bolt out of the way of your wheels to hold the track sections together. The machining of the inside pieces should be done at a machine shop if you plan on using the original design. Just keep this in mind, wood will swell and wear. I personally would have my inside plugs machined from ACETRON on a lathe, this would make the perfect fit and never wear or swell.

Kevin Nardelle

Small sugestion when operating lightweight tubepipe dollys: Sit down when operating. Since there is no heavy metal base on the dolly you want to keep your weight distributed as low as possible. This way you will be able to move, pan and tilt with better result.

Oh but wait
 

The base of the jib IS very heavy, quarter inch steel plate with three quarter inch thick steel pipes for legs. They are threaded for adjustability should you be wondering. I am appreciative of any advice you have to offer though!

That doesn't sound heavy enough. The only dolly I would feel secure to operate standing would be the SuperPanther or something like it. PVC pipes would get squashed under the weight of it. Otherwise I really like the dolly you built. Seems solid. Good work!

Axel?
 

After reading this very informative thread, I decided to buy the parts to build the dolly...however can someone tell me what type of screw/bolt "axel" I need to connect the wheel bearing to the metal mounting plate? (anything will help...size, model number..etc..I assume I can just use a certain type of nut/bolt combo for this)

Thanks!

Here's what I did:

First, I went over to the local skating rink and offerred to buy 8 used wheels and bearings. They were nice enough to donate all eight wheels and bearings. (Thank you Skatetown).

Then, I went to Home Depot and bought some bolts that fit perfectly into the bearings opening. Then, I bought some standard metal L-Rod, or whatever you want to call it. Basically, it was a 10" long piece of metal that was bent long-wise so that each side was about 2" in wide.

I then cut that into four separate pieces (one for each corner). Then, I drilled holes for the wheels. I needed some spacers for the wheels, because they were too close to the L-bracket. I just used some hollow piping for that.

I don't have any pictures of it, but you can see it an action here:

http://www.toppup.com/treasure/pre/sample_big.wmv

Cheers!
Russell

Thanks Russell...yah I pretty much have everything I need (the L-brackets, etc) I just wanted to see if anyone had exact measurements for the bolts that go into the bearings so that I don't have to hunt for them. No biggie though. That was only thing I'm was even remotely concerned about (the rest is very easy)

Oh, thanks for the video as well - I REALLY liked the dolly shot at the end where you fade to different passes of the couch. Very well done. The only shot that I thought was a little bit weird (if I may be so bold) was the POV shot. It looked like it was on a tripod and not quite in the right position (probably a handheld shot would have been more effective..?)

Thanks for the feedback on the video. You're right. The POV shot didn't work very well. I'm actually pulling it from the production. I'm shooting it a different way.

Hope the dolly works out. I was able to build mine in a couple of hours for about $40. I also bought a tripod base to mount to the dolly for better camera support.

Russell