panzertank

What is the neutral point on a Torque tube

panzertank

Anyone?

badazzbusa

My Feedback: (1)

I would assume center but you know what they say about assuming.

syclic

Sorry, in 20 plus years of flying these airbeaters, I have never heard that term. What is it supposed to describe or relate too?

paulaballa

hahha im asuming nuetral for gyro?same thing belt/shaft 0 pitch is I think

panzertank

To put the bearing on the tork tube in the right spot the manual says to glue the bearing 5-7 cm foward of the so called "neutral"point. If you download the manual go to the torque tube point and you will see what i mean.

tippy

Can't download it without a link ... got one?

Bugzilla

A link to the manual please, or at least tell us what heli you are building. Just a stab at it, but maybe the "neutral point" is the natural balance point, like if you held the tube in the middle on one finger to get it to balance? Maybe? Just a guess but can't really be sure without more info.

flash2

They mean from the center of the torque tube or "neutral point"

Bugzilla

Your sure? Well, I was close.

badazzbusa

My Feedback: (1)

Yeah, thats what I was saying, center of the torque tube.

flash2

You DO NOT want the bearing exactly in the center!!!

panzertank

I am building the algin 600n pro. Here is a link

http://www.heliproz.com/prodinfo.asp?number=370000

if you scroll down the page you will find a link for the manual
from here go to the torque tube part and you will see what i mean

Bugzilla

Looking at the manual, I see you are right.[8D] My question is, why don't you want the bearing in the center? I'll have to think about this one.[sm=50_50.gif]

veralee

Imagine a string stretched out between two nails. If you pluck that string you get a certain musical note, pitch, or frequency. Now suppose you place another nail (or support of some kind) exactly at the center of that string such that it cannot vibrate at that point. Now since the string is half as long the pitch of the note will be twice what it was. This is true for both halves of the string. Both halves want to vibrate at the same rate. Now another thought... you may have seen the demonstration of a singer singing a certain note which breaks a glass. That's because the glass wants to vibrate at that note anyway, which is called its "natural frequency", and if it's subjected to that note it will vibrate with the maximum intensity... it takes the least amount of singing energy to break the glass at that frequency or note. When the glass vibrates in response to the singer, this is called "sympathetic vibration". Now back to the starting thought, if one half of the string is vibrating at its natural frequency then the other half will have a sympathetic vibration of that same frequency. It takes the least amount of energy to get this vibration going.

So, by establishing a support on the torque tube somewhere other than the center, the two unsupported parts of the tube will want to vibrate at different frequencies; they will have different "natural frequencies". This thwarts the tendency of a particular frequency ganging up on both unsupported parts of the tube and resulting in a maximized vibration. In other words, to minimize the vibration you want the support to be off-center by some amount.

Bugzilla

[sm=idea.gif]Yeah! Now I get it! I play guitar and drums, and I saw the Mythbusters episode on breaking the glass with the human voice, so what you said makes perfect sense. Kinda want to kick myself for not thinking of that. I knew it, it just never came to me in so many words. Thanks! What part of TN you from veralee? I'm from McKenzie, which is about halfway between Nashville and Memphis, and about 40 minutes off the Kentucky border.

veralee

Hey Bugzilla... I'm near the little village of Hilham. That's between Nashville and Knoxville, and around 40 min from the Ky border. Guitar and drums... WOW... I have an old Strat, which I bought back in the 70's, but I never learned to play the thing. I may have to take it with me and learn to play it in my next life.

Bugzilla

A vintage 70's strat? Cool! Wish I had one. At this moment I have only an old guitar made by a company called Fame. Gonna get some new instruments when I get back to the states. Goin to Colorado, Pikes Peak Rally here I come!!!