Sep 16, 2010, 08:03 AM
Aerial Images of Texas
The Texas Gulf Coast where hurricanes come to play
Joined Aug 2003
1,960 Posts
Quote:
 Originally Posted by SkyEyes Booooo! lol. Surely your not admitting defeat? I actually believe that we are over complicating the equation. Forget frames, motors, electronics, etc etc. Just draw a standard T shape (with the Bottom arm longer or the same as the horizontal arm) and with a bit of (mathematics/angles) calculation, on that shape alone, we can come up with a centre, where all the "triangles meet". I'll look into it further (although we are assuming that all 3 Motors are identical - but there is the extra weight of a Yaw Servo at the back too... DOH!)...
Balance is balance. Build your T with whatever equipment/gear you choose and If you make all arms the same length put a mark 20% back from the front of the T and move gear around till you achieve center of gravity nirvana. If you choose to make your tail arm longer for whatever reason you will need to move the cg rearward as the kaptein did on his T design.
Sep 16, 2010, 08:06 AM
United States, GA, Carrollton
Joined Apr 2006
1,806 Posts
Quote:
 Originally Posted by tashley Under debate at present. Yes, throttle channel for lift motors and gear channel for yaw. Select your escs first and then follow their instructions. *Tip* Pick programmable escs and buy a program card. Turn delays off. Counter clockwise. Yes Small and light is better for aerobatics. Around 12" arms. Read.

I'll be using CCPM. So I don't think the throttle channel needs to be tied to the ESCs. As I advance the throttle stick, the "pitch" channel should advance from 0% through the curve to 100%. I plan on flattening the curve around mid stick for a stable hover.

If that isn't the case, please let me know.

I'm hoping my 11X will allow for multiple gyro gains in heli mode. I hope to be able to tie the two front gyros to one gain channel, the tail motor gyro to another, and the tail servo gyro to a third gain channel.

The reasoning is that I can balance the "twitch" or "hunting" on each gyro separately.
Sep 16, 2010, 08:07 AM
Multi Rotors Rule ! ;-)
United Kingdom
Joined Jul 2010
880 Posts
Quote:
 Originally Posted by tashley Balance is balance. Build your T with whatever equipment/gear you choose and If you make all arms the same length put a mark 20% back from the front of the T and move gear around till you achieve center of gravity nirvana. If you choose to make your tail arm longer for whatever reason you will need to move the cg rearward as the kaptein did on his T design.
I do understand what you are saying, and appreciate your feedback.
Do you think that having a longer rear arm on a "T", will make for a generally more stable Tri, as the 'triangle' between the 3 motors is that much bigger?
 Sep 16, 2010, 08:09 AM Registered User United States, AL, Foley Joined Nov 2005 544 Posts [QUOTE=Reflex1;16062760]Stage Two. Propeller Balancing Good info Paul. You are peaking my interest in dusting off my Tri and making it fly better. Thanks
Sep 16, 2010, 08:15 AM
Aerial Images of Texas
The Texas Gulf Coast where hurricanes come to play
Joined Aug 2003
1,960 Posts
Quote:
 Originally Posted by SkyEyes I do understand what you are saying, and appreciate your feedback. Do you think that having a longer rear arm on a "T", will make for a generally more stable Tri, as the 'triangle' between the 3 motors is that much bigger?
Yes I do, if I were building a T Tri I would make the rear arm longer than 50% of the front arm for reasons of stability. That would also make it easier balance wise to fit equipment. In other words you could hang ap gear out front and still achieve balance.
 Sep 16, 2010, 08:19 AM Aerial Images of Texas The Texas Gulf Coast where hurricanes come to play Joined Aug 2003 1,960 Posts "I'll be using CCPM. So I don't think the throttle channel needs to be tied to the ESCs. As I advance the throttle stick, the "pitch" channel should advance from 0% through the curve to 100%. I plan on flattening the curve around mid stick for a stable hover." You asked where the gyro gain wires should be on the rx and I posted the throttle channel.
Sep 16, 2010, 08:35 AM
Videopilot
United States, NC, Charlotte
Joined May 2009
2,862 Posts
Quote:
 Originally Posted by Xptical I am slowly making my way through the 600-odd-pages of this thread. As of now, if the guidance isn't in the first (original) build documents, I haven't really seen it.
Also read 'backwards' from the end and you will see some of the recent developments of this thread, as well as alternatives or (minor) improvements to the original setup design. This helped me a lot to catch-up without reading every post.

Also what helps me on long threads is to look only through the picture gallery. There are much less pics than posts (though many pics as well!) but if you run across pics or diagrams that seem interesting/relevant to you just open a new tab and open that particular post to read what is going on.

Hope that helps, above and beyond the obvious 'use search button' methods...
Sep 16, 2010, 08:47 AM
Multi Rotors Rule ! ;-)
United Kingdom
Joined Jul 2010
880 Posts
Quote:
 Originally Posted by tashley Yes I do, if I were building a T Tri I would make the rear arm longer than 50% of the front arm for reasons of stability. That would also make it easier balance wise to fit equipment. In other words you could hang ap gear out front and still achieve balance.
Thanks for that. Well on my Quadrocopter, motor shaft to motor shaft is 20.5". Therefore the front Arm could be similar here on the Tri, for 20.5" motor spacing.
With a 25 - 30 inch rear arm? Greater stability than making all 3 motors 20" apart? Then also as you say, more space to play with/CofG.
Sep 16, 2010, 09:16 AM
Begin with end in mind...
Eagle Lake, Minnesota
Joined Apr 2003
5,624 Posts
Quote:
 Originally Posted by SkyEyes I do understand what you are saying, and appreciate your feedback. Do you think that having a longer rear arm on a "T", will make for a generally more stable Tri, as the 'triangle' between the 3 motors is that much bigger?

My T Kopter has a longer rear boom, I will no doubt be playing with C.G. when I get it ready for flight. If the maiden is successful you can follow along

Mike
 Sep 16, 2010, 10:02 AM Aerial Images of Texas The Texas Gulf Coast where hurricanes come to play Joined Aug 2003 1,960 Posts Very nice work Mike, impeccable as always.
 Sep 16, 2010, 10:02 AM Can you DS it?? Australia, NSW, Berowra Joined Aug 2008 1,420 Posts anybody tried using the Turnigy Sentry 25a ESC's? I've got the Turnigy Plush 30a ESC's on backorder and the sentry's have come into stock. I've got no idea what to do with the balancing plug - I'm guessing you don't have to use it if you don't want to. Oh, the motors are the 2830/14 750kv ones from RCTimer, and I'll be using the recommended props.
Sep 16, 2010, 10:19 AM
United States, GA, Carrollton
Joined Apr 2006
1,806 Posts
Quote:
 Originally Posted by tashley "I'll be using CCPM. So I don't think the throttle channel needs to be tied to the ESCs. As I advance the throttle stick, the "pitch" channel should advance from 0% through the curve to 100%. I plan on flattening the curve around mid stick for a stable hover." You asked where the gyro gain wires should be on the rx and I posted the throttle channel.
So, you use the throttle channel to provide 0~49% for NORM and 51~100% for Heading Hold?

That's pretty clever. Especially since the throttle channel isn't used anyway. Then you can use the GAIN channel for the rudder gyro gain.
 Sep 16, 2010, 10:35 AM Aerial Images of Texas The Texas Gulf Coast where hurricanes come to play Joined Aug 2003 1,960 Posts Set a linear throttle curve at around 30-40%across the board as a starting point. If that's too sensitive go to a bigger number. I have found that 20% makes mine behave like a spaz. Gear channel for yaw gain. Last edited by tashley; Sep 16, 2010 at 10:46 AM.
Sep 16, 2010, 10:51 AM
Videopilot
United States, NC, Charlotte
Joined May 2009
2,862 Posts
Quote:
 Originally Posted by spotterone anybody tried using the Turnigy Sentry 25a ESC's? I've got the Turnigy Plush 30a ESC's on backorder and the sentry's have come into stock. I've got no idea what to do with the balancing plug - I'm guessing you don't have to use it if you don't want to. Oh, the motors are the 2830/14 750kv ones from RCTimer, and I'll be using the recommended props.
No idea on the ESCs (the RCtimer 30A ones are working for me so far) but the balance plug is really only useful if you want to power a secondary system with the main battery. I.e. I use the balance plug to power my pretty LEDs on my tri, and the FPV gear as well. It can also be used to power the low-voltage alarm if you use one, instead of tapping the main wires.
 Sep 16, 2010, 11:03 AM Registered User Ilford,Essex, UK Joined May 2006 2,078 Posts T COPTER Intersting build by MR Gress No rear motor http://www.rcgroups.com/forums/showt...ighlight=gress