View Full Version : Why a mechanical throttle trim on X9303?
th3tick
11-28-2007, 12:30 AM
The title says it all. Why is this a good idea?
Coolice
11-28-2007, 04:44 AM
Hey,
I always think this is for saftey really as well as quickness.
In an emergency to kill the engine a mechanical trim is better than a digital one. Also when it comes to starting as well I find it easier to put the trim into the the starting position with a mechanical trim than a digi one, unless you remember the number it was at.
I have a 10X with mechanical throttle trim and a 9XII with all digi trims and prefer the 10X's throttle trim over the 9X.
However it is just personal preference I suppose, but in case of things going bad it is quicker to fully close a mechanical trim than the digi one.
.
BarracudaHockey
11-28-2007, 09:29 AM
I dont know about JR but the Futaba radios with digital trims let you program a switch to cut the throttle. Its really 6 of one, half dozen of the others.
sbmon
11-28-2007, 07:31 PM
On the x9303 you can program throttle cut to a switch but you have to be in normal mode for it to work. So if you are in idleup during a start you would have to throw 2 swithches. You can't even get throttle cut to work if you are in throttle hold, atleast this is how mine is working. I wish throttle cut would overide all other flight modes and switches it just makes safety sence to me.
tailStrike
11-28-2007, 07:41 PM
Mechanical throttle trim isn't gonna help ya if you start her in idle up :P.
BarracudaHockey
11-29-2007, 04:18 PM
On the x9303 you can program throttle cut to a switch but you have to be in normal mode for it to work. So if you are in idleup during a start you would have to throw 2 swithches. You can't even get throttle cut to work if you are in throttle hold, atleast this is how mine is working. I wish throttle cut would overide all other flight modes and switches it just makes safety sence to me.
The reason you HAVE to be in normal, and probably below a predetermined throttle position (i know Futaba is that way) is so you dont shut your engine off by accident. You can hit throttle hold which will over ride all other modes incase you are going to crash, that should suffice till you can calm down, switch to normal and kill the engine.
Imagine bumping a throttle cut switch when you were 6" off the deck inverted!
sbmon
11-29-2007, 09:12 PM
My gripe is that you can not activate throttle cut while in throttle hold. Say you end your flight with an auto, from idle up you throw throttle hold and land, now you want throttle cut so you must stay in throttle hold throw flight mode switch to normal, turn throttle hold off and now finally you can throttle cut. Don't get me wrong I am really liking this x9303 radio it is just taking time getting use to some of its idiosyncrasies. The really nice thing about this radio is the ease of access to most all of the menus from 1 screen.
BarracudaHockey
11-30-2007, 01:33 PM
The really nice thing about this radio is the ease of access to most all of the menus from 1 screen.
Thats funny because thats what annoys me about the 9303. You have to power it up with one of the buttons held down to get to some functions that are model specific. With Futaba you can get to all the model specific settings from within the same programing area, the only things in that service menu effect all models like stick mode and some other things.
tailStrike
11-30-2007, 07:44 PM
Can you switch models on Futaba w/o powering down the Tx? That's one thing that annoys me on the Spektrum/JR's (not to mention the infernal warning when you power up with throttle hold on).
sbmon
11-30-2007, 09:44 PM
tailstrike
I can only speak for the futaba 9chp/cap . It depends if the two different models are using the same modulation mode ppm or pcm. If switching models that have the same mode pcm to pcm or ppm to ppm then no you don't have to power off the radio. If switching models that use different modes then yes you must cycle power.
BarracudaHockey
11-30-2007, 10:01 PM
If you are talking the 2.4 stuff then yes, you have to cycle power.
DebianDog
12-01-2007, 10:25 AM
I DO like all the options on one screen
I HATE having to cut the power to change models.
I understand why the throttle id not digital now. If you set up your radio "old school" you would have no way to quickly cut any and all throttle.
sbmon
12-02-2007, 06:57 PM
If it were a digital trim you could just make the throttle trim extremely course and it would cut throttle quickly.
DebianDog
12-02-2007, 08:41 PM
If it were a digital trim you could just make the throttle trim extremely course and it would cut throttle quickly.
Then all the other trims would be course and defeat the whole purpose.
sbmon
12-02-2007, 10:51 PM
I don't follow?
On the x9303 you can select how course the trims are for each channel independently.
DebianDog
12-03-2007, 01:26 AM
I don't follow?
On the x9303 you can select how course the trims are for each channel independently.
OK even so, given that do you really think even at the max (course) setting you could cut the thottle faster than I could move the manual one to the bottom?
On my 12Z you can have two switches that can instantly cut your throttle. Mine is set up so the two switches are on the right side. One is a spring loaded throttle cut and the other is the auto switch which takes it to an idle.
I like the idea of set it and forget it idle trim.
DebianDog
12-03-2007, 08:11 AM
On my 12Z you can have two switches that can instantly cut your throttle.
I set my helis up like that too. Throttle hold is never an option. I would bet what it really boils down to is:
There is some "old guy" on the development team at JR that wanted that way ;)
sbmon
12-03-2007, 09:38 AM
I'm with you on the "old guy" theory. :)
Whirly-Girl
12-04-2007, 12:56 PM
Even back on the XP9303, it was an option...you could order a TX with dig trim or mech trim. My husband and I chose mechanical.
Why: It is easy to know where that trim is at. I can memorize a physical location. We both fly airplanes and helis off the same TX. I guess the mech trim is a bigger benefit to the airplane side of our inventory as we can adjust our idle by feel quickly rather than trying to beep a digi trim to the the needed setting. We fly alot of different high performance models and keeping it simple (KISS) is safer for us. If I don't have to assign a switch to flip and memorize, that's better for me. Some airplane guys have switches for flight idle, taxi idle and a kill switch...that's just too much to add IMO to flight mode switches or dual rates, and oh yeah, heli flying too.
Trim Step - Remember, if you make that trim step on the throttle too course, 1 beep "UP" is going to be a huge increase as well. For helis, that's bad. I set my courseness base on what gives me a good start idle at mid-trim and what kills my engine at 0 trim.
Jeanette
DebianDog
12-04-2007, 01:32 PM
You honestly find it easier to take your hand off the stick and pull that trim down as opposed to hitting the throttle switch in the back???:confused::shock:
Whirly-Girl
12-04-2007, 04:27 PM
Yeah, I do...
Because I have certain habit patterns and procedures that I do identical in each flight...
Kinda like the 4-step procedure on downwind, abeam the touchdown point:
1) Power reduced to 1700 rpm
2) Apply back pressure, airspeed in the white arc
3) First notch of flaps, trim
4) Clear the area, turn to base
When there is a set procedure of flow to something, I can do it w/o thinking. I guess it doesn't bother me to leave the stick because of when/where I do it everytime during the flight.
Does that help at all?
DebianDog
12-04-2007, 10:16 PM
Sounds "planky" for a Heli Radio :P
1. Set throttle hold
2. Plug In
3. Idle up 1
4. Release
BRING IT!!!! :banana :Bang
RTDillon
12-06-2007, 10:26 AM
The throttle trim will not let you kill the motor when your throttle stick is not at full negative. IF I need to the engine in the air, this is a real problem. The trim is not effective in throttle hold.
If I am in the air and need to kill the motor I am out of luck.