Re: Steering rig, VP hinge stiffness

From: John Kagan <john_kagan_at_hotmail.com>
Date: Tue, 17 Aug 2010 22:46:31 -0000

--- In Indoor_Construction_at_yahoogroups.com, Tapio Linkosalo <tapio.linkosalo@...> wrote:
>
> Two questions raised:
> - what sort of line would be good for the steering balloon? ...
> should it be elastic (like dacron), or as stout as possible (dyneema)?
> Is it getter to have a tight contact with the balloon, or line that can
> dampen some impulses?

I like having a solid feel with the balloon. I'm using a braided line called "line backer", or something like that - from the fishing supply store. It comes in bright neon colors, too.

> Further: I had glued some thin dyneema within the
> foam rod to take the load, but my thinned contact glue did hot hold the
> line in the slot, any suggestions for a good glue for this application.

My caulk backing is 3/8" closed cell foam (i.e. it has a water proof skin on the outside. It works fine w/o any reinforcement.

> ...mr. Tregers model actually started
> climbing after the steer. A common explanation for both these event
> could be, if the prop hinges were "holding" a little...
> pitch? Does this happen in F1D, or does the rubber unknotting give
> enough "tapping" to make the hinges move freely?

It probably varies per VP design, but mine has enough static friction to cause a jump in RPM when the prop is touched. The pitch will change in response to the changing torque of the motor, but will get an extra boost when bumped. I think it is due to the sliding parts (actuator arm, etc.) more than the hinges.

As a result, you have to take that into account when choosing to steer. If your model is lower than you want, you might choose to steer as soon as the opportunity is available - i.e. as soon as you approach the building structure or get into risk of a midair with another model.

On the other hand, if additional climb will put you in the ceiling, you may want to wait until the last possible moment to touch the model.

As another result, you have to decide how to set your VP up. Do you set the preload lower and count on having to steer - running the risk of not drifting enough to get the opportunity? Or do you set the preload higher and plan to not steer - running the risk of being forced to touch the prop and then climb too high?

Just a few of the things to consider when setting up a flight :)
Received on Tue Aug 17 2010 - 15:50:22 CEST