Review - HK 450 PRO TT - Torque tube version

Started by anwar, April 23, 2010, 04:52:46 AM

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vinay

Dont bother to take any snaps. found a way to mount it.  ;)

anwar

Quote from: anwar on December 18, 2010, 06:53:20 PM
Optimize for (or take into consideration) all 3 above factors, and that is what you want !

And one more thing... any given motor/pinion/ESC setup will have a sweet spot in terms of head-speed.  If you try to go over (trying larger and larger pinions), you actually end up with LESS performance (ie head speed) than what is the best possible with that motor.  That is probably why you are seeing better performance with a smaller pinion.
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vinay

No anwar bhai. as i said, iam dealing with the second most powerfull motor if run on 3s (first being scorpian) and its probably the most powefull motor at 4s for a 450 heli.

People are running 13 T on it. crazy headspeads! but what i noted was at the edges (+/- 12 degrees) the HS was more on the smaller pinion.

So I would like to summarize the following:

1)As you said there should be a balance of motor power to pinion.
2)So if one has to do a lot of 3D, the a crazy HS is required as the blades gain more momentum at 0 degrees and supply the power to the 3D manuvers for a short burst, but the heli cant sustain the HS at the extreme pitches.
3)If the pinion is small(so that it generates more HS at the extreme compared to its bigger pinions) then the heli moves fast but not good for 3D/fast Tic tocs etc. But more flight times.

Iam going to 11T pinion. and try it out. since I have another heli with the same motor and bigger pinion. I will compare to it. And stick to the one that suits my flying style/capability.

BTW guys, dont keep the heli near the table edge when building it. I was lucky this time and nothing broke  ;)

sujju

pls use Mr. Mel's head speed calculator.. gives a great idea on the required HS, close to perfect
http://heli.dacsa.net/CalculatorV2/
CEO
RcBazaar

anwar

Quote from: vinay on December 19, 2010, 11:41:24 AM
People are running 13 T on it. crazy headspeads! but what i noted was at the edges (+/- 12 degrees) the HS was more on the smaller pinion.

Got it ! It was the edges that you were focusing on... I had missed that part. And as you said, the smaller pinion would help the motor drive the head faster at the high pitch ranges (if one were to keep the head running at those ranges, instead of just popping in and out).
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vinay


anwar

One word of caution.  I was doing some rebuild on it, and two screws broke without applying much pressure at all.  Sort of scary of a 3D heli like this.  I would suggest that anyone doing any pitch pumping on this to upgrade the screws, especially the long slender ones (the ones of the main shaft and the ones holding the tail case on to the boom).
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vinay

Correct, one of the other member of this forum, broke the tail boom screw. A screw from the align frame hardware bag is what i use. Breaking a jesus bolt is like ruining the heli. Ask me how i know  ;)

anwar

Quote from: vinay on April 30, 2011, 10:35:29 PM
Ask me how i know  ;)

How do you know ?  :P

In my case, the last few threads are lodged inside the tail case, and it would be really hard to get it out unless I find some really small drill bit.  The hole is like less than 2mm.  Might as well get another tail case !
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vinay

Well once the main gear jesus bolt broke and I had to melt, YES , melt the main tail gear to remove it.

And second time the upper jesus bolt broke as i didnt know how much anabond to use. I had to literally hammer out the screw. In most cases considering the price of the parts, its better not waste time on drilling them  ;) and loosing patience.

But considering that broken jesus bolt means the whole heli is struck unlike the tail screw. So getting the frame hardware bag for 10 $ is worth it.