Magne

Hi.
I have nothing to contribute here other than some questions.

What is the verdict so far on the A60 for F3A applications?

Dave Lockhart is quoting: A60-20S w/ 18x11 glow prop, 68 amps, 36 volts, 7800 RPM.
Any others?
What about the A60-22S? Any test results yet?

Magne

wk9000

When I figured it, I like the A60M
because I want the bigger prop and safety margin, but I am
a sport flyer so I don't need to meet the weight constraint.

Is the A60S really the right motor for f3A, or should we be looking
at the A60M ?

Thanks

Adamg-RCU

You are considering running a 24oz motor for a 2M pattern plane?

OhD

The AXI 5330/FAI is 23 oz and some folks are pretty happy with it. The A60 with a lower Kv sounds like a better match for big props.

Jim O

DaveL322

A60-M w/ 20x12W is about 28 oz, A60-S w/ 18x12 is about 23 oz. Considering we no longer need to carry 8 amps worth of lipos uphill and dynamic braking is now available from from the ESC to kill airspeed downhill, I see little use for the huge diameter prop - unless there is some benefit to stork landing gear and increased gyroscopics that I am missing.

Regards,

Dave Lockhart

Adamg-RCU

Prop efficiency, useless pitch speed...

DaveL322

Well.....

Increased prop efficiency is always good, the question is the balance of diameter for efficiency pitch (and/or RPM for speed). The majority of electric pattern setups (thus far) have focused on diameter/efficiency at the expense of pitchspeed.

If your priority is to go uphill at 1/2 throttle at a snails pace, the big efficient prop will do that, and the pitch speed (lack of) on that setup forces a change in flying style, and lacks reserve speed to penetrate heavy wind. The best glow setups generate plenty of thrust 400+ oz), and far more pitch speed (+20%), leaving far more options in a variety of wind conditions. The various ecalc/mcalc stuff shows this, and radar gun info in the field show it as well. You can guess which setup I am trying to duplicate with my electric tinkering.

Dave

OhD

Dave,

Tell me about the dynamic braking. Does the controller try to maintain the idle rpm in a vertical downline for instance? Has anyone got in-flight data to see how well this works? Sounds neat.

Jim O

DaveL322

Jim,

I am aware of 3 brands with a "dynamic" brake - Castle, Hacker Master, and Schulze - and they all work differently. I've been using the Castle brake function since fall 2005 CC10, 25, 80, 45HV, and 85HV on a variety of motors - mostly small outrunners, but also a B50-11S 6.7:1 and a couple big guys - Pletty 30-10, Cyclon 160, and Hacker A60-20S. The software for the braking function is still beta and available free on the Castle site (you do need the Castle Link tho).

In laymans terms (I'm not an EE), the Castle brake applies a variable amount of brake based on available amount of braking power - ie, when the prop is spinning faster, the ESC will apply the brake harder. It does not govern to a particular RPM (I don't believe any of the brands do that), but that is effectively what happens in a pattern routine (save the stall turns and spin entries). The brake engages on the bottom throttle "click". There are several parameters that can be set to tailor the braking characteristics -
- % of brake, ie brake strength (0-100%, between 15-25% is good for pretty much all the outrunners).
- delay, how long before the brake engages after getting the throttle stick to full idle.
- "ramp", how long the ESC takes to ramp up the brake.

Cool thing about the setup is that the same brake setting seems to be just right for both vertical downlines and 45 downlines, which I attribute to the variable amount brake the ESC applies. It does not need much fine tuning when different props are used. Getting a data logger is one of the things on my list of stuff to do.

The HM I believe is a "drag" brake - where a fixed amount of resistance (adjustable) is applied by the ESC on the bottom click of throttle.

The Schulze is based on the car software, and from what I understand, the amount of brake power can be adjusted (from the TX as well), and the engage point of brake can be set to be the bottom click, or two or three, etc on the throttle and the amount of brake in the "braking" zone is progressive.

Flying the Castle setup it is very evident when the "right" amount of brake is in the system - I start out on the light side, and increase the brake strength and watch the downlines get slower, and then at some point, the prop occasionally stops (or spins very slowly) and downline speed increases again.

Regards,

Dave Lockhart
Team JR, Team Castle Creations

can773

My Feedback: (1)

The break on the Schulze (available only on two controllers commercially now...32.55KA and 32.80KA) is set according to the signal pulse output of the TX (forgive me if my terminology is incorrect)....

So say the break activates at x pulse width and is maximum at full pulse width (1 ms I guess?)....so its a simple matter of varying basically the throttle trim, or curve or ATV's to adjust and set the break as you wish (activation point and strength). Again as its the signal that is affecting the break its fully adjustable during flight. Typically I use a single setting for all manuvers but things like vertical 8's where you dont want breaking through the crossover point to retain some energy you just bump up a click (or however you have it set) to remove breaking without actually adding power. Or say after a 45 down snap after you have lost your momentum in the snap you can take off the break for the rest of the 45....just opens up some options.

Dave, I am curious to see your logger files when you get one....after looking closely at mine I notice that the break is drawing power from the batteries and is increasing the power draw during a downline...so I am not so certain that the breaking effect is a fixed quantity. I am wondering if the CC controller give the same signature.

OhD

Thanks for the rundown Dave. I've got the Hacker and I initiate the ESC with the throttle and the throttle trim pulled all the way down. I then set the idle at about 500 rpm and leave it there throughout the flight. Reading the Hacker instructions, it sounds like the brake would engage only if I pulled the stick and the trim down to the initiation point and then the motor would stop either slowly or fast depending on the setting. There doesn't appear to be a means to set the brake trigger point independent of the motor off point. Does the CC work the same way? Do you fly with the throttle low end set to stop the motor? It is not clear how to make it engage on the last click of the throttle unless the trim is pulled back. Am I missing something?

Jim O

can773

My Feedback: (1)

Its my understanding that Hacker only sells their breaking controller with their C50 Comp motors as a package and not as a standalone unit....so unless you have a C50 Comp motor its unlikely you have the right controller.

The break you describe is a conventional break...you can't have an idle setpoint on an aerobatic break as there is no airflow to keep the prop spinning.

DaveL322

Jim,

Following on Chad's input -

For the Castle, the bottom click of throttle shuts off the motor and engages the brake. I believe the Hacker is the same way. Tailoring of the brake for the Hacker is (I believe) limited to brake strength (using the program box) and some of the other parameters are matched in advanced (ie the Opto 90 is matched for the 12,13,14XL stuff).

Dave

OhD

After thinking about it, this capability might be another advantage of the direct drive. With the gearbox we want to minimize the starts and stops to save the gears so you never want it to stop in the air. You don't have this problem with the outrunner. Now the question is, do I want the higher rpm/smaller prop like you guys are using? I'd like to see one perform or hear from a diehard C50 fan that he is changing, before I decide.
I guess you have flown both and have decided.

Jim O

Magne

Jim.
There is a very big difference between how my Cyclon F3A motor and my Hacker C50 12XL starts. The Cyclon just ticks away, while when starting the Hacker on the ground (by pushing the trim forward) the whole model shakes and the motor starts at a fairly high speed. Then I have to pull the trim back 2-3 clicks to reduce the idle speed.

However, the way I see it, (and I have no experience with regulators with brake function, as I use the normal H77 and H90 regulators) is that you don't really want to set up your brake to stop the propeller in flight. (A slowly rotating prop brakes much better than a stopped propeller.)
I therefore have these questions regarding the various regulators:
I have considered the Schulze regulators. With this regulator, is there a risk of stopping the propeller at entries to spins and stall turns? (by pulling the stick too far back?)
Is it the same with the Castle Creations regulators, or will these regulators actually "back off" on the brake power as the air speed decreases?
(Dave Lockhart wrote: "the Castle brake applies a variable amount of brake based on available amount of braking power - ie, when the prop is spinning faster, the ESC will apply the brake harder."
Does this mean that the CC regulators will switch off the brake automatically as the air speed approaches zero??

Magne

can773

My Feedback: (1)

Magne

Even with high break settings on the Schulze which are usually way too much, I have not notice the prop stopping at any point in the flight. It gets very slow where you can actually see it turning though

Remember low throttle stick does not have to be high break....you could have idle be no break or idle be full break....just depends on what you end up liking when you fly. Thats the one nice thing about the Schulze...if you have too much or too little its just a simple matter of moving a slider or knob while flying. Although I have found once set you dont play with it much.

Barye

My Feedback: (27)

Brake

darkvader

Hi
What is the most adequate ESC for the A20M ?

can773

My Feedback: (1)

Doh....I type faster than I think

OhD

Magne,

I would guess the outrunners would not stop in a normal flight even with the throttle all the way back unless the brake was set to stop it. It sounds like the Schulze can be set up to turn the brake off as the stick gets down to the last click and that might be very desirable. It is not clear the CC can do this and we know the Hacker can not as this is when the brake is applied. If the CC actually brakes as a function of rpm and stick position it might be the best. Who is the expert at Castle? Maybe we can get a clear answer.

Jim O

DaveL322

Magne,

Assume any motor/ESC/prop/plane combo and assume zero brake. When the throttle is shut down, and the plane lands, the prop will freewheel and stop at some point (might be before touchdown, or after).

The CC brake engages at the same point that the current to run the motor stops. The brake becomes very weak when the prop is slow and the prop will continue to slowly freewheel, stopping just before or just after landing. If the brake is set to a much higher percentage, it will stop the prop on landing approach, and may stop the prop on stall turns and spin entries (which I've not had a problem with, as I typically carry a couple clicks of throttle on stall turns and spins and the brake never engages until I go to full idle in the downline). Sitting on the ground, with the throttle off, the brake is engaged, and if you spin the motor by hand, the brake will engage to slow the motor.

Make sense?

Regards,

Dave Lockhart
Team JR, Team Castle Creations

DaveL322

Jim,

The CC brake only engages when the throttle stick is at (or below) the set point (bottom click of throttle with idle trim centered, I adjust the low throttle ATV to accomplish this). I don't know for sure that the amount of brake applied is a function of RPM specifically, but it acts that way - this is particuarly noticeable on some motors as they "hum" (windings of the motor - feedback of sorts I guess) when the brake engages, and the humming gets quieter as the RPM drops, and is silent as the prop stops. I'll check with one of the engineers at CC and see if a more detailed explanation is available.

Regards,

Dave Lockhart
Team JR, Team Castle

[quote]ORIGINAL: OhD

If the CC actually brakes as a function of rpm and stick position it might be the best. Who is the expert at Castle? Maybe we can get a clear answer.

Jim O

[quote]ORIGINAL: Magne

Magne

Yes, that makes sense, David.

What I do with my "normal" (no brake) Hacker regulator is to push the trim forward until the motor starts (at about mid position), adjust the idle if necessary, and fly, leaving the trim in this position.
Then on landing approach, I pull the trim fully back just before touchdown. (The propeller is still rotating until well after touchdown.)

Therefore, with the CC regulator, am I correct in assuming that you can set it up this way:
Adjust things with the ATV such that you get "an appropriate" amount of braking power with the throttle trim in mid-position. Pushing the trim forward/back a couple of clicks will reduce/increase braking power. With the trim in this position, the motor may, or may not, stop on final approach, (but it WILL stop when the model stops) but if I actually wanted it to stop in the air, I could do this by pulling the trim fully back. (??)

Chad. With the Schulze regulator, do you mean that you have to use a separate slider/knob to adjust the braking power, or could this equally well just be the throttle trim? (i.e. as described above, set up for normal braking power with the stick fully back and the throttle trim in mid-position, and adjusting the braking power by pushing the trim forward/back.

In both cases, on takeoff, the motor is not turning until you actually move the stick, right?
(As opposed to what I do, where I start the motor with the throttle trim, adjust the idle speed, and then push the stick forward to fly.)

Magne

DaveL322

Magne,

Not quite. The actual strength of the CC brake is not affected by the throttle stick, throttle trim, or ATV. The brake is on or off. The strength of the brake is adjusted by the settings in the ESC (brake strength percentage).

I use the ATV to shift the on/off point of the motor (which is also the on/off point of the brake). With the throttle stick at idle and the throttle trim centered, the motor is off and the brake is on. Adding 1 click of throttle trim or throttle stick will turn the motor on and the brake off. Reducing the throttle trim below center does not increase the amount of brake, nor does it disengage the brake. So with the CC brake set for what seems to be optimal for F3A, the prop can not be stopped in air, which is not something we would want for F3A anyway.

Yes, on takeoff the motor is not turning until the throttle stick is advanced.

Regards,

Dave

can773

My Feedback: (1)

The Schulze is fully proportional, the brake can be adjusted as you want...via throttle stick, trim, dial, slider....just depends on how you set it up in the transmitter. How I have it setup is like this...

idle - as much brake as I want normally in flight
3 clicks above idle - brake is not active - motor not active so the prop is freewheeling
4 clicks above idle - motor activated

This can all be setup in a throttle curve, and ATV....then with your idle trim be it on a slider/dial/trim lever you can adjust the strength at idle in flight if you wish.

This allows me to manipulate the brake as points in the flight where maybe you dont want any brake and dont want any power....say a short duration horizontal flight through a figure 8 or something. Or maybe after a snap on a 45 down.

On landing I typically run no braking action as I find it slows the plane down far too quickly.

With the Schulze there is no programming of the controller...all the brake setup is done in your transmitter with ATV's, throttle curves etc.

Have a glance through the Schulze instructions and it might make it more clear than I can...

http://www.schulze-elektronik-gmbh.c.../gfutu_a-e.pdf