35 replies to this topic

[momentsky]

Mat Wellington, on 31 January 2012 - 04:27 AM, said:

I think I alluded to the answer to this earlier in a post

Keep the STD tail rotor, get a standard sevo, pull out the control board, disconnect the wires to to servo motor, and solder them to the tail rotor motor. Disconnect the feedback pot on the servo and solder in two 2.2 k resistors, to simulater center position.

Now all we have to do is send a 1500 us signal to make the motor stop. Go above that and the motor will spin on way, below it will spin the other

Mix

Ch1
Type =motor
Throttle = 127
Yaw= 65

Ch2
Type = motor
Throttle  = 127
Yaw = -65


Set ch1-3 4000 Hz

Ch4
Type = servo
Pitch = 127

In the output screen, make ch4 minimum = 1000, midpoint about 1500( or wherever motor stops spinning) and Max 2000

That's the good way out! Should try this one.

Tail motor is extreamly weak. So I have to change it to something more powerfull.

Is there any way to control the main rotor motors thru servo ESC? I have another idea to leave the standart kit motors for the main rotor. Because If I should change to brushless outrunners (2x70g) + ESCs + 3S LiPo 3300 (280g) It seemes to me to be overweighted   And the kit motors work on light 2s LiPo. The aircraft in kit config is 500g so it is within 400 class helis. With Bruhless Outrunners it should be close to 1000g Main rotor D is 420 mm. Should it takeoff with the new weight? Any ideas?

[Mat Wellington]

I would, if I were you, buy two brushed esc's for the two main motors - they are cheap as

I would not increase the weight if ya can help it

[momentsky]

Mat Wellington, on 31 January 2012 - 09:30 PM, said:

I would, if I were you, buy two brushed esc's for the two main motors - they are cheap as

I would not increase the weight if ya can help it

Ok! I should search for the brushed ESC to start assembling. May be it should take some time.

[Adverse Effects]

CR23L Contra Rotating BL System 1100kv

Contra Rotating BL System 375W

CR23S Contra Rotating BL System 1700kv

CR23M Contra Rotating BL System1550kv

any of thes help?

Edited by Adverse Effects, 31 January 2012 - 10:25 PM.

[momentsky]

Adverse Effects, on 31 January 2012 - 10:23 PM, said:

CR23L Contra Rotating BL System 1100kv

Contra Rotating BL System 375W

CR23S Contra Rotating BL System 1700kv

CR23M Contra Rotating BL System1550kv

any of thes help?

That's a great info for future planing. Really I didn't know that HK sell such stuff. I'am projecting more advanced coaxial, made from scratch. The first way is to make the swash system. It should be more compicated of course. Now I see another cool way to do it.

Thanks a lot!!!

[momentsky]

Since there is no brushed ESCs availible locally decided to assemble it for my own. Here is the scheme I should use for the ESC.
It's 15 A capable. And that should be enough for my application.

[Mat Wellington]

Nice simple circuit, good find

[Adverse Effects]

is this what your looking for?

2 ESC's in 1 for brushed motors

Sabertooth dual 12A motor driver for R/C

Edited by Adverse Effects, 01 February 2012 - 03:40 AM.

[momentsky]

Mat Wellington, on 01 February 2012 - 01:30 AM, said:

Nice simple circuit, good find

Yeah! I like it too no rare parts at all. And extreamly lightweight 8g.
Here it is http://www.math.niu..../speed-ctl.html

Adverse Effects, on 01 February 2012 - 03:33 AM, said:

is this what your looking for?

2 ESC's in 1 for brushed motors

I should try to assemble it for my own. No problemm at all!
And too long waiting from the e-store.
This aircraft should be for testing purposes only. To test CC in coaxial application.

[Mat Wellington]

cant wait untill some one decides to CC an airswimmer



and ......NO...... im not going to ! (did think about putting a propeller from a parkzone ember on my boys one he got for xmas)

[momentsky]

Mat Wellington, on 01 February 2012 - 10:30 AM, said:

cant wait untill some one decides to CC an airswimmer

Yeah thats cool app
Is there any way to deal with constant yaw changng in movement. ~~~~~>>>

[bobrcnut]

Just for the record, you CAN reverse the rotation of a brushless motor, but it requires using an RC Car/truck type ESC which gives you forward/reverse capability.  Castle makes a number of them, but they're bulky, and designed to handle fairly high current draw.

[momentsky]

bobrcnut, on 04 February 2012 - 09:40 PM, said:

Just for the record, you CAN reverse the rotation of a brushless motor, but it requires using an RC Car/truck type ESC which gives you forward/reverse capability.  Castle makes a number of them, but they're bulky, and designed to handle fairly high current draw.

Thanks, not bad to know more!

[Adverse Effects]

but the airswimmers can only carry a few grams so you would not be able to use normal equipment

[Mat Wellington]

yea, control gear from a parkzone ember would be ok, all up they only weigh 17 grams

[lebrett]

momentsky, on 01 February 2012 - 10:43 AM, said:

Yeah thats cool app
Is there any way to deal with constant yaw changng in movement. ~~~~~>>>

Hi all,

My two cents (correct me if I'm wrong), this config (the picture on first page) is basicly a tricopter, the two front rotors being two big coaxial heli rotors.

Balance it with the CG  closer to the tail,and you only need a fixed pitch rear rotor.

You could add some yaw authority with a tilting servo on the tail rotor.