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-   -   Gear up on trottle (https://www.rcuniverse.com/forum/rc-jets-120/11620057-gear-up-trottle.html)

rcpete347 07-27-2015 08:58 AM

Gear up on trottle
 
HI all, have you accidently hit the gear switch in the pits and dropped your jet, I guess everyone has done it at one time, so with my DX-18, I need info to set up the gear with throttle over 70 percent, in other words, I will use 2 switches to raise the gear only, gear switch and throttle .
Any info would help.
Rcpete

raptureboy 07-27-2015 10:33 AM

Try looking under switch assignment in the manual. In my airtronics radio they call it Boolean condition; or/and. Using Boolean Conditions OR/ANDSwitches can be made to operate interdependently using the Boolean conditions OR/AND. You can assign a function to two different switches and make them dependent on one another. For example, the SnapRoll function can be assigned to switch position 21 AND to switch position 24 (Gear). Doing this will allow the Snap Rollfunction to work ONLY when the landing gear is retracted. This makes the operation of the Snap Roll function dependent onthe landing gear being retracted. This would prevent a crash if you accidently hit the Snap Roll switch instead of the landinggear switch after takeoff.

megafly 07-27-2015 11:07 AM

I've done this this weekend :mad: now I have to change the hinges on the front gear door...
Can I do this in the JR 12x?

Couch Potato 07-27-2015 11:28 AM

I've put a 2-3 second delay on gear up.
Gives you a chance to put the switch back if you bump it by accident, and your jet won't belly flop.

megafly 07-27-2015 11:52 AM


Originally Posted by Couch Potato (Post 12075999)
I've put a 2-3 second delay on gear up.
Gives you a chance to put the switch back if you bump it by accident, and your jet won't belly flop.

Nice one! I will do that, thanks .

Henke Torphammar 07-27-2015 11:58 AM

With other brand of Tx it's possible to use a speed sensor to trigger stuff. Ie, no speed gear out. Also a physical switch can be used just as the real jets have, so that the gear must be flexed out to retract.Don't know if Spektrum does that.

alasdair 07-27-2015 12:44 PM

I have made that mistake a few times too often.
Now I have started to use the Mode switch on my DX18 to set 3 modes.

mode 1 is Ground, and the gear will not retract
Mode 2 is TOGAL (take off, go-around, land) and everything works
Mode 3 is cruise, and the flap will not come down.

I start up and taxi out in Mode 1, stop before entering runway, perform pre-takoff check (including gear selected down)
switch to Mode 2, enter runway and takeoff
after climb and cleanup I switch to Mode 3 for fast passes and aerobatics.
When it is time to land, back to mode 2
after clearing runway, back to mode 1

the throttle interlock could be a good idea too. I have not thought it all the way through yet.

raron455 07-27-2015 03:01 PM

I have the 18 as well, the throttle toggle switch is quite long, i bumped mine putting the transmitter down in a chair in the pitts, my gear came up on my old elan, pissed me off, i immediately grabbed my dikes, and cut 1/2 the swich lever off,, probably one of the best mods ever for a radio. I have beeen flying with it like that for a while, no issue activating my gear, and no more bumping that long sumbtch just my 2 cents.

Dblex 07-27-2015 04:13 PM

Lmao!


I did did it on take off roll out...went to lower flaps one more notch and boom!!!! Had to replace hinges on flaps!!!!!!!


I heard pilot has a new electronic gear actuator and it alarms for 4 second before gear move.....hmmmmmmmm

basimpsn 07-28-2015 03:59 AM


Originally Posted by raptureboy (Post 12075971)
In my airtronics radio they call it Boolean condition; or/and. Using Boolean Conditions OR/ANDSwitches can be made to operate interdependently using the Boolean conditions OR/AND..

Or using a cheap arduino mini to recognize full throttle to arming the gear switch using (boolean in a loop) then sell the unit lol.

https://www.youtube.com/watch?v=ehQ5g52-g_c

rgburrill 07-28-2015 06:01 AM

OOPS:) Amazing he did not bend the props.

That 4 second alarm sounds like the best idea. If I ever spent the kind of money you guys do on jets or even giant scale gas I would look into thos. Hope it's loud enough to hear in the air when the gear goes down.

Gordon W 07-28-2015 08:32 AM

Pete

It sounds as if you want to use your throttle stick as an "Analog Switch" in "System Setup"

Go to this page and ask your question there. http://www.rcgroups.com/forums/showt...pp=100&page=22

I'd love to know how analog switch works too.

Gordon

basimpsn 07-28-2015 08:43 AM

"OOPS:) Amazing he did not bend the props"

He did have a prop strike lol

alasdair 07-28-2015 08:54 AM

Been thinking about the 4 second delay on gear selection.
Not keen, as I did once have a flameout on my CARF Lightning. The deadstick approach went well, I just made it to the strip, but somebody yelled "put the wheels down" at the last second. I flicked the switch and done they came just in time.
Just seems unnatural to have a delay just in case of an inadvertant selection.

On the throttle interlock, again I have misgivings. We select full throttle to commence the autostart. Not a good time for a gear up misadventure.
And when applying full power on takeoff is the worst time for a belly-flop.

Couch Potato 07-28-2015 09:49 AM

Delay on gear up, no delay on gear down.

megafly 07-28-2015 09:57 AM


Originally Posted by Couch Potato (Post 12076544)
Delay on gear up, no delay on gear down.

Fixed my front gear door yesterday and programmed a 5s delay on gear up, It workd very nice

alasdair 07-28-2015 01:33 PM


Originally Posted by Couch Potato (Post 12076544)
Delay on gear up, no delay on gear down.

of course! very sensible. I hadn't thought of that.

I am still not convinced though. In full size flying the gear is selected up as soon as a positive climb is established. To mirror that I hit the gear up switch immediately after the model leaves the ground.

As well as scale fidelity, that ensures that not too much airspeed is gained before gear retraction. I have seen many cases where the gear goes up late, by which time airspeed has risen to such an extent that the gear will not go up, or it fouls on a gear door which has been partially closed by the high speed airflow, often exacerbated by a bit of sideways yaw in a turn, or a bit of rudder waggling.

Countryboy 07-28-2015 02:26 PM

http://www.electrodynam.com/rc/EDR-126/index.shtml.
Works great.

Vincent 07-28-2015 03:11 PM


Originally Posted by Countryboy (Post 12076722)

This unit is for turning on the tx with the retrac switch in the up position. What's happening here is simply just bumping into the retract switch during normal handling of the radio. I like the idea of a beeper going off when the switch is activated.
Vin...

Countryboy 07-30-2015 05:46 PM


Originally Posted by Vincent (Post 12076750)
This unit is for turning on the tx with the retrac switch in the up position. What's happening here is simply just bumping into the retract switch during normal handling of the radio. I like the idea of a beeper going off when the switch is activated.
Vin...

True Vincent. Seems the logical solution would be to have some kind of squat switch if the weight is enough to compress the gear.

alasdair 07-31-2015 03:07 AM

The electronic box is a neat idea, but as Vincent says it offers protection on switch-on only, not subsequent accidental bumps.

The weight-on switch mimics full size protection somewhat, but on a bumpy grass runway the gear could retract after hitting a bump.

What about a climb sensor that inhibits gear up selection until a sensor observes a climb of 3 feet or 5 feet. Are they that sensitive and reliable? I really want the gear up that quickly after takeoff.

Turbotronic 07-31-2015 07:40 AM


Originally Posted by alasdair (Post 12078000)
The electronic box is a neat idea, but as Vincent says it offers protection on switch-on only, not subsequent accidental bumps.

The weight-on switch mimics full size protection somewhat, but on a bumpy grass runway the gear could retract after hitting a bump.

What about a climb sensor that inhibits gear up selection until a sensor observes a climb of 3 feet or 5 feet. Are they that sensitive and reliable? I really want the gear up that quickly after takeoff.


An ultrasonic distance sensor could do the trick. Cheap and simple.

Boomerang1 07-31-2015 02:03 PM


i immediately grabbed my dikes, and cut 1/2 the swich lever off,, probably one of the best mods ever for a radio
I have actually extended my flap & retract switches to make them easier to find without looking at the transmitter.

I don't fly a DX18 but is there another unused toggle switch you can program as an arming switch for the retracts which over rides
the main switch? - John.


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