2Sunny

So last year flying my Inspire in Sportsman I never gave a thought to "setting an idle". Then young Joseph Sczur flew my plane after the competition one day and suggested "setting an idle" plus I noticed several other "pros" doing it at the last competition I attended. So I started "setting an idle" as well. Then recently someone mentioned that you want to set enough idle to keep some airflow over the rudder during a stall turn, and now with the help of my new "fancy-shmancy" Castle HV80 I'm getting prop data for every flight and I see that my idle is roughly 800RPM.

So whats the science behind what you set? Are there pros and cons? Can I set to high of an idle? What about to little, does it do anything positive?

Anyways, just wondering what the "big boys" do


Thanks as always,



Joe

JAS

My Feedback: (2)

Starting procedure:

Tx on, throttle to low, idle trim to bottom/lowest setting, idle-down 'cut'. (on Futaba the throttle cut function stops the throttle from working, so I use the Idel-down function)
Plug 10S pack to controller, put canopy on and turn radio on (ALWAYS staying away from prop and airplane supported from moving).
Wait for my controller arming beeps to stop, click up to 7 on the throttle trim, flip the idle-down switch and the motor turns 500-600 rpm.
Take-off, fly, land, smile and hope it was worth it

Jetdesign

My Feedback: (8)

How does setting an idle affect the break function of the ESC? Can you actually have both?

can773

My Feedback: (1)

Yep usually you have to set a switch with a lower setpoint on the throttle to activate the brake.

I just set the idle as low as possible, I think its around 800rpm with the schulze/pletty. Then a switch to give me a lot of brake power that I only use on long downlines.

Jason Arnold

G'day Chad,

I'm using a Spin 99 and if I have any idle at all the brake function will not work. Took me ages to figure this one out as I misunderstood how the brake function worked. A mate put me straight though... Duh!

Does the Schulze brake work differently in this regard?

Cheers
Jason.

can773

My Feedback: (1)

Hi Jason,

I have never used a Spin, but based on your description then the Schulze must work different. Basically with the Schulze its all based on signal from the Rx, so at output of 1ms you are at full brake, at 1.5ms you change from brake to power, and 2ms is full throttle.

You just need to adjust your radio settings to get those points figured out, I usually just do it by a bit of trial and error. Once its setup, you can have a switch for the brake, so when you are at idle on your stick and the brake switch is off, you will have an idle that you can adjust with a trim like a glow motor, when you flip the switch you move to brake, the strength of which can be set by playing with the endpoint when that switch is on.

DaveL322

With the Castle, to engage the brake, you need to have the throttle low enough. If the motor is idling, the brake is not active.

I have my low throttle endpoints set such that I have the minimum idle with the throttle trim in the middle, and brake engages at anything less than mid throttle trim.

I have a three position switch (thr>thr mix, with offset to only affect low throttle) that does nothing in the center position, adds several hundred RPM in the high position, and engages the brake in the low position. I normally fly with the brake engaged, except on very windy days when I want to keep speed a little higher. The idle up is nice for spins and stall turns....keeps the tail from "going dead".

The exact lowest idle RPM will depend on the motor......some outrunners will be as low as 300 RPM, while the geared NEU F3A motor is about 700 RPM. When the brake is engaged, the ICE logging will show the idle as zero, and an Eagletree with electrical RPM tap will show the idle as zero. This is because the brake when actively is essentially shorting the windings of the motor.

Regards,

Dave Lockhart
Team Horizon / JR / Spektrum, Team Castle Creations, Aero Tech

serious power

Hi,
This thread might develop into something interesting.
I use 3 flight modes to suit particular maneuvers.I do not use throttle trim at all.
1 ; My normal ; low t stick = brake (I use 30% max on a shulze), one click up = 15% brake, 2clicks = free spinning.
2 ; Stall turns ; In this mode I get high rate rudder + high tick over ~ 1200 to 1500 rpm (have not measured it - shhulze min = 800rpm).
3 ; Spins ; High rate elevator and rudder ,same high tick over but now an elevator to throttle mix to reduce the motor speed as elevator is applied. This is a little tricky to set up but once got it works extremely well. I have it so the motor is stopped completely by ~ 25% elevator. It gives me great spin entry control.

Brian

SanJoseDale

I also just recently learned that the brake has no effect with an idle set. (don't know why I didn't figure this out before) Why would an idle be desired, except for some prop wash in a stall turn, which I now just add a few clicks of throttle to achieve?

Dale

woodie

If you are running an ESC with proportional brake, then idle probably won't help. However, if you don't have a propotional/programmable brake, then a motor idling provides more drag on downlines than one that is stopped.

Woodie

Jason Arnold

I was under the impression that the ESC brake function stopped the RPM increasing on a downline at any throttle setting. How wrong I was!

This was only discovered when I started flying my Spark and you could hear the motor spool up on downlines. Then a mate helped the penny drop...

Cheers
Jason.

Jason Arnold

Thanks Chad,

I have heard that the Schulze brake operates differently to the Jeti Spin.

Cheers
Jason.

JAS

My Feedback: (2)

To activate the brake I flip the idle-down into the 'off' position (zero rpm) and the Jeti brake activates. When done, I flip it back to low idle (about 500 rpm)

2Sunny

Huhhhhh . . . darn good thing I started this thread 'cuz for sure I was under the same impression. Now I just gotta go figure out which switch to put the throttle-throttle mix on, and then try it out next week.

Thanks for all the awesome insight from the pros!


Joe

nofuss

Hey guys, would any of the clever people on this thread be able to share a typical THR -> THR mixing setup with me? This for a JR 9303 TX, MASTERSPIN 99 Opto and a Pletty? Things like offset values, ESC acceleration and endpoints settings comes to mind, but I know very little as yet as I am only starting off with E-Pattern flying. Converted my 2-stroker to E very recently...

Any feedback will be hugely appreciated
Danie

OhD

Here is how an "old guy' does it. Set the ESC up with fixed endpoints. I used 1.0 and 2.0 milliseconds when running Spins. I'm now using 1.1 and 2.0 for the YGE. I use both throttle cut and idle down functions. With both switches off and the throttle stick down, the AFR and throttle trim is set to yield an output a little over 1.1 msec to get the desired idle rpm. The ESC will not arm with this starting condition so the motor doesn't start when you turn the receiver on. I throw the throttle cut switch and the PW drops to about .95 milliseconds and the ESC arms. I push my plane to the taxiway and throw the throttle cut to off and the motor starts in idle. ( With the Spins I had to jog the throttle stick to start the motor and get it to idle.) I taxi out and take off. Once in the air I switch to idle down so that when the stick is pulled all the way down the PW goes below 1.1 and the brake is activated.

One could do all of this with one switch, the idle down as JAS suggested but I like the safety of the throttle cut when I am on the ground. I once accidentally hit the throttle stick when I was pushing my DA 50 powered model to the taxiway. With the throttle cut activated the stick has no control and the motor cannot start or speed up.

byoung466

My Feedback: (16)

Jims way works great.

(BTW: Dont forget to set your failsafe to kill the throttle on electric. If you have failsafe at an idle setting and kill the transmitter first it can be a problem. I was going through my shake down and forgot that on my latest plane, good thin I had ahold of the right part of the plane.)

le_petit_suisse

Hi uncle Jas,

Please can you tell us when are you using / not using brake in P11 (or F11) ?

Thanks in advance.
Sylvain

rc_heli_flier

My Feedback: (12)

I understand a lot of about electrics now that I've mostly converted to them, however, I don't understand the reasoning behind setting an idle on an elcetric. I'm sure there's an advantage to it, but not sure what it is. Can someone explain the theory behind this?

woodie

Since my current controller does not have a proportional brake setup, I use an idle to create more drag on downlines. I think a windmilling prop creates more drag than a stopped prop.

Woodie

Magne

Yes, but on a downline the propeller would not stop if you just turned the motor "off", unless you used a fixed brake. It would still windmill as long as the plane has a reasonable forward speed.

Magne

woodie

True, but in my case, I do not want the prop to stop in maneuvers like stall turns, final approach, etc. So, I set an idle to maintain some minimal rpm. My response was more in line with wanting a spinning prop vs a stopped prop (ie using brake). I suppose it makes little difference whether the motor is 'idling' or not in a long downline, the prop will probably reach the same windmilling rpm.

Just a personal preference for me.

Woodie
Team Acme LG

SanJoseDale

I'll add to the confusion here, since I have been trying to understand this, and asking endless questions of Don (Woodie). I do have a proportional brake, CC HV85 and run an outrunner (Pletty). I also don't understand why one would set an idle with an electric and a set up such as this. With my brake function set to 70%, the prop only stops completely at the entry to a stall before a spin and only on the ground at landing. I do need to add throttle for a stall turn, but the brake makes really nice slow downlines now, compared to when I had no brake.

That's my story and I'm stickin to it

Dale

SanJoseDale

OK, I stand corrected, was just told the brake in a CC in not proportional....but it works as i described.

woodie

Actually, I should have said 'programmable brake', not 'proportional brake' in my previous posts. The brake is not proportional at all, just goes to a preset value over a programmable amount of time which is not proportional at all.

Woodie
Team Acme LG