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Old Nov 07, 2012, 10:39 PM
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Left Coast DJ's Avatar
United States, CA, Los Angeles
Joined Jan 2012
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Anyone know how to program differential thrust for a twin engine plane on the 8FG (and/or 14SG)?
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Old Nov 08, 2012, 03:29 AM
Registered User
Brighton UK
Joined Dec 2010
353 Posts
Quote:
Originally Posted by Left Coast DJ View Post
Anyone know how to program differential thrust for a twin engine plane on the 8FG (and/or 14SG)?
Assuming that each engine is controlled by a different function (e.g. Throttle and AUX1) you can do this with a program mix. Setting rudder as the master and throttle as the slave will cause one engine to increase or decrease in speed relative to the other.

Setting a second mix working in the opposite direction on the second engine (AUX1) will cause one engine to increase in speed while the other decreases.

The complication comes from the need to prevent the engines cutting at low throttle settings and servo stalling/linkage damage at high throttle. To prevent the latter you should make sure that the upper limit point is set to the same as the end point on each of the throttle channels. You can do the same with the lower limit/end points to prevent cutting but this will disable any throttle cut and idle down you may have set. One way around this is to set the mixes so that they only increase engine speed and not lower it. Another option is to use the throttle stick to switch the mixes off at low throttle.

Hopefully that gives you some food for thought. If you need more detailed help we need more information about your setup and exactly what you are trying to achieve. e.g. I/C or electric? Functions to which each engine is assigned? How do you want to control the differential? Permanent on or switchable?
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Old Nov 08, 2012, 03:32 AM
Registered User
Brighton UK
Joined Dec 2010
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Just a thought following my previous post. I have never operated a twin since buying this radio. Do people use VPP to control the second engine on a twin? It seems the obvious choice as it is set up by default and its ready-made 5-point curves allow easy synchronisation of the engines throughout the range. The switchable curves easily emulate idle down and throttle cut. Are there any problems?
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Old Nov 08, 2012, 03:39 AM
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DeeCee 57's Avatar
Zurich, Switzerland
Joined Nov 2009
550 Posts
Steve and Andy, thanx for your answers... It works

Managed as well to assign RD as a ground steering tiller for tight corners whilst taxiing, really
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Old Nov 16, 2012, 04:23 AM
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Malaysia
Joined Jun 2001
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Quote:
Originally Posted by dbar101219 View Post
COOL i have some of that but did know to use it that way i allways use it to build battary packs

I call futaba and this is the switches they said to use

SA FUTM3677 - 3 position short ML-1BFSP
SB FUTM3680 - 3 position long ML-BFLP
SC FUTM3680 - 3 position long ML-BFLP
SD FUTM3677 - 3 position short ML-1BFSP
SE FUTM3677 - 3 position short ML-1BFSP
SF FUTM3680 - 2 position long ML-BFLP
SG FUTM3677 - 3 position short ML-1BFSP
SH FUTM3680 - trainer ML-1FLP

thanks for all the help
Would anyone know?

Is the above suitable for 12FGH? My Switch SC ie 3 position long is busted.

WIth me located 10thousand miles away, and with only one or two tiny items which dealer would willing to entertain my request. Sad....
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Old Nov 16, 2012, 04:36 AM
Oxford Panic
AndyOne's Avatar
United Kingdom, Oxford
Joined Feb 2003
3,637 Posts
Does anyone know the Futaba part number for the trainer type switch which is fitted to some of the lower end radios, the one that has 3 positions and is latching one way and sprung to centre the other way.

A.
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Old Nov 24, 2012, 08:26 PM
Fly Low-Crash-Rebuild-Repeat !
RotorJockey's Avatar
Jackson, MO
Joined May 2009
3,184 Posts
Running my 8fg super on a lipo.

What happens if I accidentally reverse the polarity and plug the battery in backwards?

Fred
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Old Nov 24, 2012, 08:29 PM
Sippin the Koolaid!
losifanatic's Avatar
United States, NC, Hertford
Joined Oct 2007
16,394 Posts
Quote:
Originally Posted by RotorJockey View Post
Running my 8fg super on a lipo.

What happens if I accidentally reverse the polarity and plug the battery in backwards?

Fred
Being its a 3 prong plug on our battery nothing will happen as the negative terminal will connect to nothing and the positive which is in the middle will still be there. So your ok if it happens
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Old Nov 24, 2012, 08:41 PM
Fly Low-Crash-Rebuild-Repeat !
RotorJockey's Avatar
Jackson, MO
Joined May 2009
3,184 Posts
Quote:
Originally Posted by losifanatic View Post
Being its a 3 prong plug on our battery nothing will happen as the negative terminal will connect to nothing and the positive which is in the middle will still be there. So your ok if it happens
Nah... I'm not.

been using a 2 prong mini jr plug and plug it into the -+.

Got in a hurry this evening to finish programming my plane.

It'll turn on, then kick off. Just don't know if it can be fixed or if it is totally fried...

Feel like a dum@$$...
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Old Nov 24, 2012, 08:46 PM
Sippin the Koolaid!
losifanatic's Avatar
United States, NC, Hertford
Joined Oct 2007
16,394 Posts
Ouch sorry to hear about that. Sorry l can't offer any help to your situation. That sucks
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Old Nov 24, 2012, 09:01 PM
Fly Low-Crash-Rebuild-Repeat !
RotorJockey's Avatar
Jackson, MO
Joined May 2009
3,184 Posts
Ok,

I just fixed it!

I ordered another one...
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Old Nov 24, 2012, 10:37 PM
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Alex Schauer's Avatar
United States, MN, North Mankato
Joined Feb 2011
4,500 Posts
Ouch
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Old Nov 24, 2012, 10:42 PM
Fly Low-Crash-Rebuild-Repeat !
RotorJockey's Avatar
Jackson, MO
Joined May 2009
3,184 Posts
Yeah...

Definitely gonna make an adapter lead to keep that from happening again.

I'll send this one back to futaba and sell it after they fix it.

I'll be out a few bucks, but that's the fastest way to get back in the air!

Question...

I've got an SD card in my 8FG. Will my models and settings be on it or in the Tx memory?

Fred
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Old Nov 25, 2012, 12:02 AM
3d Kiwi
uptime4downtime's Avatar
New Zealand
Joined Dec 2007
2,999 Posts
I believe u have to manually copy or backup the models onto the card. Someone will chip in if I'm incorrect, but I did that to a few of my models recently. Rick
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Old Nov 25, 2012, 12:28 AM
Registered User
South Africa, WC, Cape Town
Joined Dec 2009
1,389 Posts
you need to manually copy the model files...
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