Why is my post binding?
Posted 28 February 2004 - 04:53 PM
What am I missing?
Posted 28 February 2004 - 05:53 PM
If so, it's most likely that the post is not perfect. It's diameter may change EVER so slightly from the top to the bottom, hence the binding.
My telescoping post lowers and raises with ease, but if the monitor bracket and the docking rings are TOO tight it is a bit tougher.
However, if I raise and lower my gimbal on the outside post, it is a bit stiffer on the lower end than it is on the upper side. I only noticed it when I was cleaning and lowered the gimbal to the bottom. It was VERY minor, but did notice it didn't move up and down quite as easy on the lower half of the top post. Since I basically never lower my gimbal that far, it's NO issue for me.
Again, my guess is, if it's been that way the whole time, you got a bit of a "lemon" when they cut and milled your post!
If it's an issue, talk with GPI
Posted 04 March 2004 - 11:29 PM
I own a PRO Sled. Only 4 years old. When I begin to extend the post for balancing it binds. I mean really binds. I've tried loosening the monitor bracket and that helps. Yet it continues to bind. I do have 2 docking rings, for low and regular mode on the post. I've backed way off of the tension on the rings and the grip wrap.
What am I missing?
I'm guessing that that problem started recently? Which would indicate that either the outer or the inner tube got bend. I would guess the inner as it takes up most of the stress if extended, also due to the design with the sliced inner post, it's easier to deform that tube.
If it was present from the get go, 1999, it is due to the fact that it would be still one made by Bob DeRose. If the plating is dull that would be a sign, his Center Posts where always very tight. I used to own one that I could only extend if I would loose the Monitor Bracket.
What you could try is:
- Take the post apart and clean everything with "goof off" or similar. If it still binds than...
- Try to determine where it binds the most, if its the whole way, it's most likely the outer post. If it's only partial it would be the inner. Try to squeeze the inner post with your hand and see if it improves.
- Or skip that altogether and give GPI a call.
Posted 05 March 2004 - 09:35 PM
Thanks for the insight.
Posted 06 March 2004 - 10:14 PM
So it was the internal sleeve that binds the inner post via the tension knob. I used a little silicon spray from both ends of the tube and I'm back in action. So nice to have everything back in perfect shape. I appreciate the advice guys. I've been meaning to address this issue for a while.
By the way, I've been using Gregg Bubbs ergo handle for over a year now and it is splendid. It gives you a little more distance between the sled and arm so dutching into your body is easier. The curvature of the handle is amazingly comfortable. Just thought I'd mention it.
Posted 07 March 2004 - 08:38 AM
Your post will bind for several reasons:
1. Out of round. Even by one or two thousandths will make telescoping a chore. All, I repeat, all aluminum posts will be out of round of they are not centerless ground when manufactured. Carbon fiber posts, by the very nature of their manufacture are centerless ground to make their outer diameter round. Many out of round conditions are caused by over torqueing externally clamped devices which range from docking rings to gimbals and monitor brackets.
2. Dents. Enough said.
3. Debris. Maintenance is critical for all moving Steadicam parts. If it is a rental rig, look out!
Remember that the tolerances we must utilize for our work have closed up significantly since the Good Old Days.
Happy Dynamic balancing!
Brant Fagan, SOC