Differential throttle on a twin electric

Are you wanting the rudder to counter the torque when you advance the throttle for take off? If so, the flight pack should be set-up normaly. The programing will be done in the Tx. I'm sleepy, I may be misunderstanding. :/ mk

| > TIA, | >

| > Geoff the electronics idiot | | Are you wanting the rudder to counter the torque when you advance the | throttle for take off? | If so, the flight pack should be set-up normaly. The programing will be | done in the Tx. | I'm sleepy, I may be misunderstanding.

Well, the title is `twin electric', so I think you're misunderstanding.

There will be two throttles and if they're going to be seperate, they'll each be on separate channels. You could use an elevon/flaperon on-board mixer to give you one channel for throttle and one channel for a delta between the two throttles, or you could just give each ESC it's own channel and do the programming in the TX, if it can handle it.

I wouldn't expect it to be different between an electric or an IC powered plane. Except that you could make a hardware mixer in the plane for the IC version, where your main throttle servo moved another servo that let you adjust the throttle to each engine -- this would just be a hardware mixer built into the plane. People sometimes do elevons and flaperons in the same way.

But using a small electronic elevon/flaperon mixer would let you do the same thing with an electric model.

I do this with my Dueces Wild. Works great! You should see the sucker spin! My transmitter is a Futaba 9CAPS and the ESC's are e- flight 60's. It should make no difference between I-C and Electric. I haven't disconnected anything either. One ESC connects to the throttle channel, the other to Ch7 IIRC. The e-flight ESC's allow you to parallel connect them to the receiver with no problems. Not sure about others though. Check the Futaba FAQ page for the setups.

-Rob-

Why two throttles? My "Sick Stick" is a twin electric and I just "Y'd" the rx leads for the ESCs together into channel 3. Then you would just mix the rudder/throttle the same as you would for any single engine/motor plane.

Dan

Perhaps he wants to have some additional turning capacity to work with rudder and aileron.

-- Ray

If you are using BEC equipped ESC's then you will need to disconnect one of the two positive (red usually) power wires from one of the ESC's where it plugs into the Receiver. If using an external RX battery then disconnect BOTH of the positive wires from the ESC's where they go into the RX.

The important thing is that the Black (ground or negative depending on your terminology) and the signal wire (White on Futaba wires) must be connected from both ESC's to the RX.

The red leads are only used to SUPPLY power to the RX and the rest of the servo's, you cannot have both ESC's feeding the same RX (without wiring in some diodes) without causing problems.

Pop the connector out of the plug and then just bend them back against the ESC's servo lead; then wrap some tape around them to secure them and insulate them.

If using one ESC and its built in BEC circuit to power the radio gear make sure it can handle the current demands, or it could overheat and shutdown with 'interesting' results :-)

Chris, you've got the answer I was seeking. Thanks. I am indeed planning to use differential throttle for on-water steering since the plane has no water rudder. I was pretty sure I needed to disconnect one ESC positive wire, and you've confirmed it. The mixes in the radio will handle the coupled rudder/throttle differential - I just couldn't remember how the rest of it went.

Thanks to all for your input!

Geoff

| The important thing is that the Black (ground or negative depending on | your terminology) and the signal wire (White on Futaba wires) must be | connected from both ESC's to the RX. | | The red leads are only used to SUPPLY power to the RX and the rest of the | servo's, you cannot have both ESC's feeding the same RX (without wiring | in some diodes) without causing problems.

It won't cause problems if you don't do this.

If one ESC provides slightly higher voltage than the other, then it'll end up providing most of the power to the RX and servos. If they both provide exactly the same voltage (which isn't likely), then they'll each share 50% of the load.

They're just voltage regulators in most cases. You can put them into parallel just fine -- it doesn't break anything -- but in general you'll find that the load isn't evenly distributed among them because they'll have slightly different output voltages. But if one ESC can handle all the load (and usually this is about heat more than anything else), then there's no problem.

| If using one ESC and its built in BEC circuit to power the radio gear | make sure it can handle the current demands, or it could overheat and | shutdown with 'interesting' results :-)

Well, that's always what you should do with any plane that has has at least one BEC.

Neat differential thrust video :D :D

Cool! If you didn't know about the VPPs you would wonder how the heck he did that.

Danka Ron, mk