Michael
Go here:
http://www.hippocketaeronautics.com/hpa_forum/index.php?board=33.0
All your questions will be answered if you read everything in the topics
about Wright Stuff.
For this one:
*Would the best time potentially be derived from the propeller which
requires the least amount of torque for cruise flight,*
The answer is maybe but probably not.
ArmorAll is what I use for a lubricant. Silicone oil for model race cars is
also good.
On Tue, Jan 26, 2016 at 9:14 PM, thepoopgod_at_yahoo.com [Indoor_Construction]
<Indoor_Construction_at_yahoogroups.com> wrote:
>
>
> Hey all,
>
> My name is Michael Mu, I'm a senior in high school and I do the event
> Wright Stuff in Science Olympiad, which involves the building and testing
> of a rubber-powered, balsa (usually) monoplane. I was wondering if any of
> you could help answer some questions that have plagued me for quite a while
> now, after a year already of doing this event. I've already read through
> quite a number of the discussions in this group, so I have to say my
> knowledge level probably isn't very high comparatively, so forgive me if
> that's how it comes across!
>
> First and foremost, I've been looking for a consistent and reliable
> winding approach. My brother, who did this event when he was in high
> school, taught me a technique called "stretch-winding," which consists of
> alternately winding turns while moving slowly inward and then stopping and
> stretching back out, and that this would help pack the most number of turns
> in. However, I've had trouble with this technique as it's gotten me quite a
> bit of variation each time I wind. So my question is, is there a better and
> more consistent way to wind? I've read about a common strategy which goes
> something like stretching out to 4x relaxed rubber length, winding about
> 55% of the max turns while stationary, and then winding the rest while
> moving in. However, how would I go about determining the max number of
> turns? If it is of any significance, primarily I'll be flying in
> low-ceiling areas (about 20' to 25').
>
> I've also heard that as you break in a motor, you can put more winds into
> it and therefore get a higher time. With each successive wind, however, how
> would I change my winding to account for this? Would I still aim for 55%?
> If so, how does max turns increase, if it does, for each wind? Or is this
> whole process kind of just guess-and-check?
>
> A second question that I've discussed with my brother goes like this: with
> each propeller + plane setup, there is a certain required torque for cruise
> flight. I have several propellers each set at different pitches. Would the
> best time potentially be derived from the propeller which requires the
> least amount of torque for cruise flight, provided that you have a good
> rubber match? Does that line of logic sound right?
>
> Finally, (least important), what kind of rubber lube is most effective
> (while still being relatively cheap)? Or does this selection not matter too
> much?
>
> Thanks so much for anyone's time,
> -Michael Mu
>
>
>
>
Received on Tue Jan 26 2016 - 21:22:20 CET