SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Nov 27, 2009, 12:11 PM
Registered User
Dave Barrow's Avatar
Ky
Joined Feb 2003
1,498 Posts
If an esc gets too hot, it will shut down the motor, but the Rx still gets power. This is not usually a big problem on a normal plane as the control surfaces still operate and you can still glide it in for a landing. Bob's Tri design only uses motor control for all altitude and directional controls, loss of even a single motor means you are about to witness a crash. Using more than 2 mini servos with the internal bec of an esc can cause more heat to accumulate in the esc than it can normally dissipate. Bob is using a normal size servo, which draws more amps than a mini, thus the safety factor of an external bec.
Dave (Anxiously awaiting my HC order)

I see Bob answered while I was typing.
Dave Barrow is offline Find More Posts by Dave Barrow
Reply With Quote
Sign up now
to remove ads between posts
Old Nov 27, 2009, 12:35 PM
FPV addict
Giske, Norway
Joined Aug 2009
521 Posts
Hi guys,

I'm looking at HobbyKing's webshop and I see that the UBEC is not in stock.
So I'm wondering if I can use this one instead:
http://www.hobbycity.com/hobbycity/s...BEC_for_Lipoly

And this engine:
http://www.hobbycity.com/hobbycity/s...idproduct=7707

Thanks

Kristian
KristianS is offline Find More Posts by KristianS
Reply With Quote
Old Nov 27, 2009, 12:44 PM
Droner
SebastianJ's Avatar
Denmark, Capital Region of Denmark, CPH
Joined Mar 2006
2,410 Posts
AP2000i and the Tricopter.

OK, I promised to share the trick to make the AP2K work for tricopters, here we go:

The AP2K is made for servos, not ESC's, by connecting multiple ESC's and trying to arm them all at the same time the AP2K gets confused and as a result one of the ESC's doesn't arm, sometimes they all arm at once, but this is unusual.


I have tried it with these gyros:

-GWS PG03, too much temperature drift.

-Imax G192, these works fine, but not as good as the 'bees.

-Telebee, these are the best I've tried.


I'm pretty sure that I still have bald spots in my scalp from scratching my head trying to figure this out back in the days.


Here's how it goes:

Assuming that everything is connected according to the manual: http://www.spartan-rc.com/products/a...user_guide.pdf except I have throttle instead of pitch connected from the RX to the AP.

-First locate the ESC that doesn't arm, it's always the same in a setup, mine is the front left.

-Power up and let the ESC's arm.

-"Toggle" the inactive ESC by disconnecting and connecting it two times in all.

-The ESC will now arm.

-Fly your AP2000i controlled tricopter with a big grin on your face while everyone at the flying field goes: Whoaaah!


That was the trick, these are my DX7 settings to control gyro gain and IR sensor on/off and calibration:


Gyro gain:

-I have gyro gains connected to the AUX, this normally controls the pitch with the TX in heli mode.

-Pitch curve: 88 for all five points (this is what works for my setup with 100% TA), flat line, try 100% and adjust gyro gain using travel adjust to move the endpoints.

-Make sure to program the curve in all flight modes so that the gyros won't go beserk if you flip the switch.


IR stab on/off and calibration:


-Connect to the GEAR channel, travel adjust: +105, -100.

-Do a program mix that looks like this:

AUX2>GEAR ON
RATE: 0% -25%

SW:ON
OFFSET: 0

The gear switch is on/off for the IR stabilization and the AUX2 activates the calibration process.

-Take off without IR stab.

-Trim to a perfect hover.

-Activate IR stab calibration, AUX2 switch for a 2 seconds.

-Activate IR stab, trim if needed.

-Fly your AP2000i stabilized tricopter with a big grin on your face while everyone at the flying field goes: Whoaaah!


That's about it, If anyone want's any additional info just let me know and I'll add it to this post.




Sebastian.
SebastianJ is offline Find More Posts by SebastianJ
Last edited by SebastianJ; Jan 12, 2010 at 02:38 PM.
Reply With Quote
Old Nov 27, 2009, 12:58 PM
Worn-out the seat of my pants
Lomcevac's Avatar
Dorset UK
Joined Dec 2006
922 Posts
Quote:
Originally Posted by signguy View Post
The tailplane thing maybe, but wasn't it a brit by the name, I think, Walter Whittle that made the first jet engine? Maybe I missed some sarcasm ?
Also it was a rocket that first officially broke the sound barrier.
just bustin' you!

Bob D
Frank Whittle
Yup you missed the sarcasm! Both things invented by Brits of course but we were jolly decent about having them pinched.
Lomcevac is offline Find More Posts by Lomcevac
Last edited by Lomcevac; Nov 27, 2009 at 01:00 PM. Reason: Stiff upper lip
Reply With Quote
Old Nov 27, 2009, 01:22 PM
Registered User
signguy's Avatar
Swansea, Massachusetts
Joined Dec 2004
2,088 Posts
Quote:
Originally Posted by APdude07 View Post
Ok so load sharing is the issue and could cause a premature burnup of one or more ESC's. So, couldn't I still just use one of the ESC's BEC and cut out buying the extra UBEC? There's got to be a reason why Signguy went with the UBEC and I'm trying to figure it out.
you can do that. I had a problem at one time with one speed control losing power before the others. At that time, I switched to a 7805 voltage regulator to try and solve the problem. At the same time I switched back to lipolys from A123's. The problem went away. Weather it was the VR or the battery, I don't know. The 7805 VR is about $2. To me this is VERY cheap insurance.
Will you have the same problem? Maybe, maybe not, but if you break more than one prop because of it, you've already lost money.

Bob D
signguy is offline Find More Posts by signguy
Reply With Quote
Old Nov 27, 2009, 02:07 PM
Registered User
Dave Barrow's Avatar
Ky
Joined Feb 2003
1,498 Posts
Quote:
Originally Posted by KristianS View Post
Hi guys,

I'm looking at HobbyKing's webshop and I see that the UBEC is not in stock.
So I'm wondering if I can use this one instead:
http://www.hobbycity.com/hobbycity/s...BEC_for_Lipoly

And this engine:
http://www.hobbycity.com/hobbycity/s...idproduct=7707

Thanks

Kristian
Here is another 3a ubec you could use.
http://www.hobbycity.com/hobbycity/s...idProduct=3735
Dave Barrow is offline Find More Posts by Dave Barrow
Reply With Quote
Old Nov 27, 2009, 02:08 PM
FPV addict
Giske, Norway
Joined Aug 2009
521 Posts
Thanks for the quick reply Dave
KristianS is offline Find More Posts by KristianS
Reply With Quote
Old Nov 27, 2009, 02:13 PM
Brushless
cdi3d's Avatar
Joined Mar 2009
2,065 Posts
It has been a busy Turkey Day - I had a little time to make a new frame - this addiction needs to stop or my wife is gonna kill me - One of those things I guess - It is just so easy to make a new frame with a few mods and transfer everything over - I really like my ziptie method - I even lock the front arms with a small zip tie throught the arm - breaks away really easy in a crash - I added a second level to mine to allow for more room for wires and such - I just find it hard to get everything I want on one level - Top level is for the gyros and I made a universal camera holder so I can use any of my cameras once I get to that level of comfort with my flying - I like the idea of adding a AP2KI to the tricopter - Just wish there was a board with GPS lock that we could get prebuilt for some plug and play - Pictures to come later -
Mike
cdi3d is online now Find More Posts by cdi3d
Reply With Quote
Old Nov 27, 2009, 02:17 PM
Registered User
Dave Barrow's Avatar
Ky
Joined Feb 2003
1,498 Posts
I thought I was experiencing Déjà vu when I read post 350(see post 345). Or a flash back.
Dave Barrow is offline Find More Posts by Dave Barrow
Reply With Quote
Old Nov 27, 2009, 03:58 PM
Registered User
signguy's Avatar
Swansea, Massachusetts
Joined Dec 2004
2,088 Posts
Quote:
Originally Posted by KristianS View Post
Hi guys,

I'm looking at HobbyKing's webshop and I see that the UBEC is not in stock.
So I'm wondering if I can use this one instead:
http://www.hobbycity.com/hobbycity/s...BEC_for_Lipoly

And this engine:
http://www.hobbycity.com/hobbycity/s...idproduct=7707

Thanks

Kristian
That BEC and motor should work fine. You'll have LOTS of power with that motor. You could also use the tower pro 2410-09
Bob D
signguy is offline Find More Posts by signguy
Reply With Quote
Old Nov 27, 2009, 04:11 PM
FPV addict
Giske, Norway
Joined Aug 2009
521 Posts
Thanks Bob
KristianS is offline Find More Posts by KristianS
Reply With Quote
Old Nov 27, 2009, 08:18 PM
Suspended Account
Bilbobaker's Avatar
United States, UT, Salina
Joined Apr 2003
3,117 Posts
Has anyone built a full sized tricopter?
Bilbobaker is offline Find More Posts by Bilbobaker
Reply With Quote
Old Nov 28, 2009, 12:31 AM
Registered User
tigar's Avatar
Athens, Greece
Joined Sep 2001
1,127 Posts
Hi regarding the bec, is it possible to power each gyro from corresponding esc, and disconnect the red wire on the rx side. The rx the yaw gyro, and servo could then be powered from a small bec...
Since the tri have a lot of power consuming extras(4 gyros and a medium servo), maybe this is a way to split the load between 3 esc and a separate bec.
Any thoughts?
tigar is offline Find More Posts by tigar
Reply With Quote
Old Nov 28, 2009, 09:34 AM
Registered User
signguy's Avatar
Swansea, Massachusetts
Joined Dec 2004
2,088 Posts
Quote:
Originally Posted by Bilbobaker View Post
Has anyone built a full sized tricopter?
Maybe Mohler, the flying car quack would try. Everyone else would reason that sense there is no failsafe, or way to recover from even a small electrical/mechanical problem, it should never carry a human.
Mohler reasons that having 5 motors on his "flying car" it is safer. I say, the more motors, the more chances of a failure. His design does not have ANY failsafe. 15 years ago he said we will all be flying his car. His insurance company won't even let him fly it without it being teathered to a crane.

Never going to happen ( I hope)

Bob D
signguy is offline Find More Posts by signguy
Reply With Quote
Old Nov 28, 2009, 09:36 AM
Registered User
techspy's Avatar
USA, NC, Matthews
Joined Aug 2008
3,243 Posts
Well a 6 motor/prop design like the newest dragonflier might be safe enough. Probably way too expensive though.
techspy is offline Find More Posts by techspy
RCG Plus Member
Latest blog entry: My Esprit Saga
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Yet another tricopter build. !!Updated parts list!! SebastianJ Multirotor Talk 2669 Dec 30, 2011 05:48 PM
Discussion What to do? Failed tricopter build! Razor_Racer Coaxial Helicopters 9 Mar 07, 2011 09:20 AM
Discussion Tricopter Build Razor_Racer Coaxial Helicopters 21 Feb 20, 2010 08:24 PM
Build Log Tricopter build SebastianJ VTOLs 1 Dec 22, 2008 04:34 PM
Discussion Trying to build a mechanically actuated tricopter, Help! stefalo Coaxial Helicopters 3 Jan 09, 2008 04:10 PM