[NSRCA-discussion] Plettenberg Advance 30-10 ESC - Questions

Mon Jun 8 07:23:17 AKDT 2020

Earl,   Good analogy with servo loops.  I suppose if the regulation were written about control surfaces, we'd all by flying control line.  The rule as written however seems to explicitly restrict ESC's from self-regulating power output.  With this device, when the plane changes attitude, the ESC adjusts power.  Self regulating speed controllers had to be the targeted restriction; what else is there in an ESC?
FYI - I asked the AMA about it and have two different perspectives so far. Some of those folks may be on this list as well, but I'll share their feedback when it's determined.   

-----Original Message-----
From: EARL HAURY <ejhaury at comcast.net>
To: Chad Northeast <chadnortheast at gmail.com>; General pattern discussion <nsrca-discussion at lists.nsrca.org>; Tjpritchett <tjpritchett at aol.com>
Sent: Mon, Jun 8, 2020 9:50 am
Subject: Re: [NSRCA-discussion] Plettenberg Advance 30-10 ESC - Questions

  I suppose an Electronic Speed Controller might be expected to actually control motor speed, however most don't. They simply control the amount of power applied to the motor. Great to see some ESC's that now actually control motor speed! F3A rules don't address power management systems, while the AMA rule would appear to address aircraft performance rather than motor speed control. Possibly the latter needs some wordsmithing.    
   Certainly the new ESC systems involve an on board feedback loop. However, with the exception of retract servos, all of our servos use an internal feedback loop to ensure that they move and hold where we command. So we've been flying with feedback loops in our airplanes since the exit of escapements and ESC's are just catching up.   
   As has been pointed out, as long as the pilot must select the control input (be it surface position or motor rpm) these systems are well within the rules. Systems that automatically maintain aircraft attitude (gyros) or speed (pitot data to ESC for example) aren't.    
   Earl  
 On June 7, 2020 at 2:08 PM Chad Northeast via NSRCA-discussion <nsrca-discussion at lists.nsrca.org> wrote: 

 So many of us (myself included) flew these at the WC in 2019, and there were many events in Europe that allowed their use.  As well the Hacker Sensitrol (similar function, however it uses direct rpm measurement I believe) was also in use at the WC in 2019, so there is some good precedent for legal use at least internationally.  They were known to the event organizers/jury/judges etc. that they were being used, and no one was disqualified or asked to remove them that I am aware of.  Personally I did bring along a full batch of other esc’s in case this happened as there was definitely “chatter” about them being illegal, however it turned out that was not an issue.   
   My understanding is it would become illegal if you say used it to maintain airspeed, which would then in turn auto adjust the throttle input from the rx, essentially taking the pilot out of the “control loop”.  What I understand in simple terms is that as long as the pilot is part of the control loop then its most likely legal.   
   Maybe Mark or Derek, or someone more in the loop on the inner workings of the rules with the FAI can give more info.   
   It would be a great shame to make these sorts of innovations illegal as ultimately it will stifle creativity and has zero bearing on the results.  Everyone has access to them, so its a level playing field, the best pilot will rise to the top as usual.   
   Chad   
  Sent from my iPad   

 On Jun 7, 2020, at 12:34 PM, Tjpritchett <tjpritchett at aol.com> wrote: 

  As I was reading this thread, I was wondering how a self regulating speed control might fit within the current competition regulations. We’ve considered the gyro/ stabilization debate before, and that issue is pretty clear, since the relevant rule was written after gyro control was already available.   This capability, prop rpm, was not really around until now, and may need to be evaluated more carefully against existing rules. The most relevant I could find is copied and posted below, from the 2020-2021 AMA Competition Regulations, 4.4.2.  Point number 3 seems particularly relevant.    What do you think?    
    Examples of control functions not allowed:   1. Preprogramming that will automatically perform a series of commands based on a timeline.   2. Automatic leveling or electronic stabilization in any axis.   3. Power plant management systems that adjust power with regards to model performance, position or attitude.   4. Positioning systems utilizing any sensors such as air data, GPS, distance, etc.   5. Learning functions involving maneuver-to-maneuver or flight-to-flight analysis.  
Sent from my iPhone  
On Jun 7, 2020, at 1:11 PM, flyintexanmark via NSRCA-discussion < nsrca-discussion at lists.nsrca.org> wrote: 

  A slight tweak in kv and a d3 should allow use of a ys200 prop. The right throttle curve and it may be possible to get Bryan Hebert to fly electric :)  
   Seriously it seems more possible now than ever to emulate a YS. 

    -------- Original message --------   From: Chad Northeast via NSRCA-discussion < nsrca-discussion at lists.nsrca.org>   Date: 6/7/20 9:27 AM (GMT-06:00)   To: nsrca-discussion at lists.nsrca.org   Subject: Re: [NSRCA-discussion] Plettenberg Advance 30-10 ESC - Questions   
  I will chime in my 2 cents on the Pletty.  I have used the Jeti Spin 99 and the Futaba 9100 (same as OS 1100) and the D3, all of them without issues so I think you are safe with those for sure.  I have not used the CC or the Jeti Mezon, but I imagine the Mezon is like the Spin.  There is no issue taking a Pletty Advance to 90A, and no issues for big props, in fact the bigger the better.  I use a 22-13, which hits around 85A and 6300 RPM on the ground, any prop made you can run on the motor depending on what you like.  
   Braking has always been an issue, even with the Jeti/Futaba ESC braking set I have never been able to get it “perfect” where its good in downlines and in 45’s etc, there always seemed to be a compromise.  Propellor selection had some impact, I found APC’s brake better than a Falcon on their own so that helped to get the balance better at least for my style.   
   This is where the D3 shines (braking/constant speed), I think blows the doors off every other controller made.  It is a total re-learn of how you fly, but once you get it I don't think you would want to go back.  For those that don't know, the D3 is produced just for pattern and is custom to every motor, so you order for the motor you want.  There is no programming, no telemetry, nothing really, you just put it in the model setup your tx and fly.  It is a governor controller so setting up your RPM is absolutely critical, if you get it wrong you will not have great results and likely struggle with it.  However the ability to get constant speed is very good, it really turned the Pletty into a setup that has braking as good as anything else IMO.  It manages power for you in a lot of cases, for instance as you pull vertical and the models starts to slow down and load the prop the esc will apply power to maintain rpm, so you don't need to throttle up much, maybe 2 clicks on the stick.   
   Some of the adjustments you need to get used to, generally you want to start throttling up prior to pulling the exit radius, as the esc is always maintaining rpm of the motor you dont have that freewheel to help carry speed out of an exit.  So if you don't throttle up early you will really lose airspeed.  Mostly in looping elements you actually never need to really come to a full idle, as the esc is essentially braking all the time to maintain the rpm based on your stick position.   
   I have also found it very efficient consumption wise, as good or better than the Futaba/Jeti’s that I have used prior.  Some really nice side benefits, it is light ~70g and inexpensive.   
   Below is a chart of rx output and motor rpm for the Pletty, personally I use 950 rpm for landing, 1950 rpm for normal flight (downline idle), and 5600 rpm at my midstick position.  In case it doesn’t show up properly, one column is % of output, one column is us output of rx (0 - 2000 us) and last is motor rpm.   

| 100.00% | 2000 | 6700 |
| 90.00% | 1800 | 6030 |
| 80.00% | 1600 | 5360 |
| 70.00% | 1400 | 4690 |
| 60.00% | 1200 | 4020 |
| 50.00% | 1000 | 3350 |
| 40.00% | 800 | 2680 |
| 30.00% | 600 | 2010 |
| 20.00% | 400 | 1340 |
| 10.00% | 200 | 670 |
| 0.00% | 0 | 0 |

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