Where is the center of gravity on an XL2? at DVinfo.net

Go Back   DV Info Net > The Tools of DV and HD Production > Support Your Local Camera > Jibs / Cranes / Booms


Reply
 
Thread Tools Search this Thread
Old October 18th, 2005, 10:27 PM   #1
Major Player
 
Join Date: Aug 2005
Posts: 119
Where is the center of gravity on an XL2?

I recently built a small crane for my xl2. It's a fairly simple model using pulleys and an underhung sled. I want to modify it so that I have tilt control. If I can figure out the center of gravity I can have a sled fabricated that will put the camera's centerline on that of the pulley's and keep the apparatus balanced which seems to be the key in any jib/crane contraption. If anyone out there knows where the magic spot is I'd appreciate the help. Thanks, Jason.
Jason Varner is offline   Reply With Quote
Old October 18th, 2005, 10:34 PM   #2
Wrangler
 
Join Date: Oct 2003
Location: DFW area, TX
Posts: 6,108
Images: 1
As you probably know, the stock XL2 is a bit nose heavy. Your best bet is to put some weight on the rear accessory bracket that will put the CG right at the tripod connector screw. This will simplify the design of the support sled.

-gb-
Greg Boston is offline   Reply With Quote
Old October 19th, 2005, 02:06 AM   #3
Regular Crew
 
Join Date: Aug 2002
Location: Atlanta, Georgia
Posts: 1,892
Another way to find CG is to simply place a pen under the base on a flat, level table and adjust the pen back and forth until it balances on the pen. That point will be the CG.
James Emory is offline   Reply With Quote
Old November 4th, 2005, 03:37 PM   #4
Major Player
 
Join Date: Feb 2005
Location: Indianapolis, Indiana
Posts: 218
Jason,

I know it's been a couple of weeks since you posted, but I'm just stumbing across your question.

I built a crane a few months ago for use with my XL2. Like Greg said, I used extra weight on the rear - an ankle weight, like you use to exercise attached to the accessory bracket. I even use is when the camera is on my shoulder, because it helps to balance it in that situation as well.

The only problem with this, as you may have already discovered, is that one of the keys to a small home-made crane is the effect of even a few extra ounces out on the business end of the thing. It requires a great deal of extra counterweight at the rear to then balance the crane, and depending on how light you built it, the total weight can overwhelm the design very quickly. You are much better off finding the "sweet-spot" and rigging a way to place the center of gravity on your pivot point, rather than just adding weight to the rear of the camera. I learned from experience.
__________________
Sony PMW-EX1R, Canon XL H1, XHG1, Panasonic GH2, Mac Pro 3.2 Quad running FCPS 3, FCPX, & Adobe Creative Cloud CC www.creativejuicesvideo.com
Vence Vida is offline   Reply With Quote
Old November 7th, 2005, 01:38 AM   #5
Regular Crew
 
Join Date: Aug 2002
Location: Atlanta, Georgia
Posts: 1,892
Jason, you really need to make a cut out and centered X (fore & aft, left & right) on the mounting plate where the bolt that attaches the camera plate will slide in for adjustment. This way you can slide the camera fore and aft to achieve the correct balance. That's how my jib's mounting plate is made and most others are as well.
James Emory is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > The Tools of DV and HD Production > Support Your Local Camera > Jibs / Cranes / Booms

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 05:44 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network