springs for new arm

[AqueousmagiK]

hello i just recieved both of ur books cody and WOW their excellent cant wait to get one made for a short film im gonna shoot later in the year

but

i had one question about the plans for the new arm

how do i work out what springs i need for this one?

ill be using a jvc DV500 (just like the cameras they use on the news) which is around 4-5 kilos (bout 10 pounds) ill be buying an lcd monitor, and is it nessary to have the battery on the sled?

the battery packs that we have can go around the waist which can bring down the weight of the sled a bit

do u think that this camera is too heavy?

i dunno i need help 

thanks in advance

[Brett A. Noe]

Don't use the batteries on a belt pack. Cables running from the sled to elsewhere can very easily throw the sled off balance.



The battery on the sled is also part of the counterweight for the camera. You need a weight that is equal to, or slightly greater than the camera weight on the bottom of the sled. Minor adjustments are made by sliding the gimbal up or down the post.



That's my $.02.  

Brett

[Jake Danilchik]

I am trying to determine which springs to use for a 13 pound sled ( Cody's phase II 3A arm ).  Unfortunately I don't have have MS Excel so I cannot use Cosmin's formula ( imagine that  ! ).    Would Cody, or someone who has closely adhered to Cody's " building a stabilizer Arm " plans, run the numbers using one of the spring formulas here:   Thanks in advance !!!

http://homebuiltstabilizers.com/greytipsformulas.htm

Also..given that info does anyone have the part number for the corresponding spring from Centuryspring.com ?

p.s.  I determined the total sled weight by adding up the weight of the camera ~ 3.5 pounds + 3.5 pounds (counter weight at 1:1 ratio) + sled 6 pounds = 13 Total pounds.

thanks,

Jake