Gitzo 2kg spring for G1380 head
 

I just got the very schweet Gitzo G1380 "Fluide" head. It comes with six (6) different "balance springs" of varying load capacities from 1-10kg (2.2 - 22 pounds) to offset the weight of the camera when tilting.

Well, since I have a GL2 with various accessories I am using the 2kg (4.4 pound) spring. Let me tell you, I am 6'2" and weigh 260 pounds. I could handstand on this spring and it wouldn't compress one micron.

What I'm trying to figure out is just how this monstrosity could possibly compensate for such a lightweight camera?! I can't even begin to imagine how hard-sprung the heavier weights are!

What's up with that?!

BTW, here's the B&H URL for the head in the event you don't know what I'm talking about:
http://www.bhphotovideo.com/bh2.sph/...ID=F513EC21BB0

Brendan,
I am really not familiar with this head. It looks like a similar concept to that of the Vinten Vision series which also features an assortment of springs to accommodate various loads.

I'm guessing that the spring operates principally in tension rather than compression. The force of even a light load, such as a GL2, can require a seemingly formidable counter-force when you consider the actual length of the moment arm as well as the drag of the head's tilt bushing.

Ahhhh! That's it!

Tension!

Why didn't I think of that? I have a knack for overlooking the simplest explanations ;-)

Nope. The spring does NOT operate in tension. It is COMPRESSED. That solid metal brick we call the g1380 head has an opposing gear system where a gyro-type thingy (tm) moves in the opposite direction that you tilt the head. As this mechanism moves in the opposite direction the internal spring compresses forcing the head to return to it's previous level state unless you have a weight (such as a heavy lens) to balance out that spring force. If you tilt the head w/o the little plastic door (tm) in place you can look in at an angle and witness the compression of the spring just as it ducks out of view... if you own a g1380 and do this all my gibberish here will suddenly be crystal clear.

I TOO started my g1380 out with the 2kg spring and it is WAY overkill for a normal little cam. It's probably just right for an xl1s w/ accessories... but I'll never know.

I'm going to put in the 1kg spring and see what that does. More then likely it will be about right for cams such as the dvx100 and smaller. We'll see.

If you want to continue using the 2kg spring or better still the 10kg spring I'd recommend that you bring a bag of squirrels on the end of a 6 3/4' pole and attach that to your cam's hot shoe. Or if you don't have access to a bag of squirrels you can probably just mount your 10' boom pole on the hot shoe and the spring will handle everything. The only problem is the squirrels or boom pole will get in your shot.

I've decided to take my Gitzo pod and g1380 head w/ 10kg spring to the annual "Punkin' Chunkin' " contest as seen on the discovery channel. No, I'm not going to get the story. I'm going to enter my tripod under a (hopefully) new category. I'm willing to bet that if you put in the 10kg spring and tilt the pod up to 85degrees verticle and then afix the pan-arm to a stout pumpkin stem that you could fling said vegetable to a new tripod record.

On a serious note Brendan I REALLY want to thank you. I LOVE this head. I'm now understanding how some of the guys from dv.com can sit around just panning and tilting. The action is FIRST RATE... although it perfectly matches my pod, it definitely DWARFS both my pod and camera... I don't see myself "outgrowing" this setup and that's a good feeling. THANK YOU!!!

Also really now, don't discount that spring. Do you ever do whip pans? I love 'em. I'm now going to experiment with whip tilts. With the "too heavy" spring it guarantees an exact speed duplication EVERY time and the spring/head combo creates a smoother motion and speed progression that you could never mimic with your hand. I realise this "trick" will have very limited use because it requires verticle action and editing, but I will use it at times. I guarantee it. The "exactness" of the motion with the pan locked makes it appear like a motion controlled cam...

Well, I gotta' get out and play with this thing some more. Now where's that bag of squirrels?

Brendan, I just got the 1kg spring today and replaced the 2kg spring in the 1380... that's what you should do. The gentle "fall" of the head w/o any spring is reversed with the 1kg spring... you can't feel any force from it but when you let go of the pan arm it gently raises the head rather then lowering it... technically it's your call as to what's better, but having a spring in vs. NO spring in definitely affects the overall smoothness of operation. I like how the 2kg spring feels in the head, but it's clear that for our cams the 1kg spring is the way to go.

When I tighten up on the tilt adjustment I can get it to "dead-stop" with the 2kg spring. But I think I will get the 1kg too and see if that works a little better, which I think you are right about.