View Full Version : Question for the pro's or engineers out there.


Zac Stein
May 11th, 2003, 09:01 AM
Heya all,

My father just came in here to tell me that some posters i made for a company that does work for him payed off big time and they landed a big client directly related to that poster, and they owe me a favour and would like to repay me.

The compnay does machine metal work and wood work, mostly related to cabinets, shopfittings and so on, but they are capable of machining very intricate work.

There is one piece of camera equipment that has really caught my attention and that is the Spider Dolly.

http://www.porta-jib.com/spider_dolly.htm

http://www.porta-jib.com/flex-trak.htm

Since i don't have 1-3k USD to purchase one of these i was thinking of having one of these made. Now i am no good with diagrams.

I can see from the 3 leg configuration that is seems to have 2 legs on one side that only swivle while the other leg has an extended pointing that can flex in and out as well as swivle.

But do the legs themselves move on the middle circle spreading and compressing closer together/ further appart.

Does anybody here have any insight on how thing thing works so i can advise them on the methods and how this works so their engineers can quickly work it out.

The reason i ask here first is that the people reading here are much more orientated to film apparatus and things geared towards that, i think they are more about designing structual weight bearing stuff that is static.

I guess this one could be directly to charles P. (for Pro :-) ) as he may be able to advise me as he has used dollies on really extended runs which is what i want to do.

Charles, would you advise the use of a single thicker fixed retractable mono pole from the center of the device, that say use a crank or twist method to lock down, maybe ever hydrolics, or a snap and fix on tripod. Which is actually a better setup to use out on the field for extended periods of time?

Charles, is it easier to balance or use a dolly with only the single point of weigh bearing directly in the middle and then spread amongst the bottom.

Am i better off desiging this to have a seat on it and an extra operator or a simple handle and i walk behind and operate it?

And finally, what is the standard size of the footprint of a dolly?, i think i am more concerened about the width vs length (ohh that could almost sound rude). Maybe to fit it through doors or something.

Thanks everyone.
Zac

Charles Papert
May 11th, 2003, 05:22 PM
Zac:

I have evaluated the Portajib dolly at length and actually do plan to buy one in the near future.

The legs do not compress. They all have swivelling skate wheels at the end, one leg has an additional pivot in its length. This gives it the ability to track across the variance in width. In the ridable version, an additional leg is added that has the additional pivot as well.

The operating is always going to be better if you are riding the dolly rather than pushing it yourself. A good compromise is to have someone else push the dolly and you operate the camera while walking alongside.

The advantage of the center pole vs a tripod is that one has the ability to walk around the platform during the move (think about dollying past the subject, and pivoting to keep them in the shot).

I can't remember offhand the width of a Peewee or Fisher 11, but I think they are around 28-30". Ideally, you should be able to pass through a 32" door.

Zac Stein
May 11th, 2003, 10:48 PM
Charles thank you,

The design itself does not actually look that difficult, but the tooling up required to do it ones self prob is where all the money is.



Btw charles in a few months i may be shooting some commercials here... maybe even a short film with a grant, we have secured the use of a arri 16r (i believe it is called) with modified gates for super 16mm, and we are going to need a DP/Operator, if the budget streches you may have a 2 week holiday for yourself lined up. Got to network to be connected i was always told, and i figured since i know you, if the budget allows it would be great to work with an industry professional from that 'other' (american) counterpart.

And we also get to stick a meat pie and real beer into ya'

Zac

Charles Papert
May 11th, 2003, 11:16 PM
Zac:

I arrived at the same conclusion, that getting all the parts built and troubleshooting etc. just wasn't worth it. Also, for me, I respect what Losmandy has done from an R&D standpoint and I didn't feel that great about inspecting the thing closeup and then going and making a knockoff that does the same thing, especially since I think their pricing is fair.

The rubber tubing track is pretty damn cool, and would be difficult to find elsewhere, I'm guessing.

I brought my girlfriend to NAB with me and took her for a ride on a few of these dollies aimed at the DV market; she really took a shine to this system and insisted I buy it!

Speaking of which, she has been clamoring for us to take a trip to Oz...this may just work out! I'm working on a feature until early August, and then may or may not go back to "Scrubs"--if not, let's talk about a trip out in the fall...(that camera would most likely be an Arri SR1 or SR2, from the sounds of it)

Zac Stein
May 11th, 2003, 11:23 PM
Charles for me to buy the kit would cost more than all my equipment all up. I will make one, if it is not perfect, i will make do.

Due to the fact my father has been in the architect trade, as well as furniture AND lighting track design for 30 years i believe his people can work it out, it may not be exactly right, but if i need to find a material if anybody can they can.

You should see the little box we are machining now, i won't give too much away, but it has a canon lens mount, a spinning ground glass plane and seems to be taking shape.

I can't wait to see what happens, who knows if the money is pulled, you could always just come when on holidays and get your name on a truely indi 0$ production just for the fun of it.

Zac :)

Speak to you soon mate.