OT: DIY Track Dolly - redesign help

richard-courtney wrote on 6/2/2008, 6:05 AM
I am thinking of reworking the platform dolly http://www.sonycreativesoftware.com/forums/ShowMessage.asp?ForumID=4&MessageID=540040I made[/link] awhile back.
The wood panel makes it hard to transport so my neighbor welded a steel
bar connecting the two V bars forming an "H".

The rails have 24.5" spacing between in case I want to rent a pro track
and passes through doorways.

My question:

By shortening one V bar and moving the wheels closer forming more of a
"T" shaped base will make it even lighter. Will it be less stable than the "H" pattern?

EDIT: Changed "Y" to "T" for clarity

Comments

Cheno wrote on 6/2/2008, 6:27 AM
The V bars your referring to is the angle iron you used to connect to the platform and connect your wheels too, correct?

I guess visually I'm not seeing a Y pattern unless you're shortening one of the angled pieces like in this example

http://www.guygraphics.com/GGPROD-797.html

...but you end up with more of a "T" shape for the dolly.

There are economical ways to save weight and size on the dollies but I'm having a hard time grasping a Y frame underneath your deck unless you're considering only one set of wheels on one side of the dolly.

Remember though that one of the benefit of the dollies in Hollywood films is weight. They weigh a ton. Good reason for that as they're very, very stable and smooth because of that. Something that you don't have in many of the portable, lightweight tracking dollies. Again, each tool has specific needs.

richard-courtney wrote on 6/2/2008, 6:39 AM
The angle iron is the V bars
Yes I meant "T" (T & Y keys too close on keyboard).

Your example does look "cheap" in the "T" pattern.
As far as weight I guess I loose nothing keeping the H pattern
as I can bolt the wood panel back on.

Thanks for responding.
Rory Cooper wrote on 6/2/2008, 6:58 AM
When you apply pressure on your dolly to move it and its an H shape you will have an initial jerk movement whereas a Y shape distributes the pressure more evenly that’s if you are not using tracks but direct on floor
So make sure your angles are exact and your lengths are even and long enough otherwise the pressure will be forward toppling and not down moving
farss wrote on 6/2/2008, 7:15 AM
If you want a simple, lightweight dolly the Wally Dolly is the way to go. Easy enough to duplicate the design.
http://www.wallydolly.com.au/

At a pinch you can transport this on a motorcycle.

We have three of them and they get a lot of work.
Replace the screw together tube with PVC pipe.
To hold the tripod to the dolly use a bungy cord.
No, you cannot stand on it and you don't need to.

Bob.
richard-courtney wrote on 6/2/2008, 12:41 PM
I had no reservations using the DIY system with the heavy board. With a rented
XDCAM and the H config did not feel it was unsafe other than the fact I almost trip
on the leg extensions. There is very small amount of drag so it moves with a pinky's
pressure, actually an issue on sloped ground moving unattended.

farss: It looks like a "T" config used in the Wally Dolly does not appear to be an issue
with the larger pro cameras.

I am almost a couple band saw cuts away from trying.....
farss wrote on 6/2/2008, 2:31 PM
Indeed the "T" section is no problem. The "T" does come apart which makes it very easy to transport. Each leg of the tripod sits at the end of the "T" so the load is transferred pretty much directly to the wheels.

Bob.
richard-courtney wrote on 7/9/2008, 2:16 PM
I redesigned it for 3 legs and added http://thebroadcastshop.com/sales/show.asp?key=b-7001-080&x=19&y=10Sachtler straps[/link] to secure the
legs. (TheBroadcastShop.com)