ESC settings

[mikef]

F5J newcomer here.  I bought a 'used' model on the forum for a very nice price and l got it into the air last September.  I had 4 sessions with it then and I'm pleased with the way it flys.

My first session since then  was yesterday and I tried some serious F5J practice - great weather to flatter my flying.  Got away From 17m to a good height after a struggle over about a minute below 30 meters.

Anyway, I was having trouble timing the switch-on at the start of the slot.  I found the motor was taking what seemed like a second or more to get going if I waited for the 'hooter' to switch on.  If I tried to anticipate, sometimes it seemed to respond to the switch more quickly and start before the hooter.  (100 point penalty!).   It didn't seem consistent.

I have now discovered that the ESC is set for a slow start.  Can I just set it to fast start to get an instant response  without causing other problems?

Here's the set-up.

YGE 60 v4 esc bec 7.4

3s 850mAh Tattu Lipo

Tenshock Viper CC 102012T + Reisenauer micro edition gearbox

13 x 7 Vitaprop (13x8 GM to try next)

The full ESC set up is below.  I would welcome confirmation that I haven't accidentally set anything incorrectly.

[SteveH]

Mike - which TX are you using? Some TX's such as the Frsky range offer the ability to alter the startup and slowdown of the motor control. If the ESC is also programmed for slow start and slow stop the two can give some strange interactions.

It is beneficial to have a slow startup and slowdown on the motor control as it gives the gearbox an easier life.

 

[mikef]

Thanks Steve - Multiplex Royal Evo 9 with HFMX 2.4 gHz module.

For safety,  I have the throttle on a slider which I move to full with the throttle cut applied in the last few seconds before launch.  I've just watched the monitor screen as I turned the throttle cut off.  The throttle channel goes to full instantly.

[PeteMitchell]

Your YGE settup looks Ok Mike. 

Changing throttle setting to 'plane middle' will give a quicker ramp up at the start and should not cause any excess wear on the gears.

Your motor will most likely be pulling around 45/50Amp which is really as much as these lipos can deliver reliably.  Your erratic or delayed motor starts could be because your lipos are not able to deliver the current to meet the sudden demand. 

It could be that the lipo pack has one cell failing , this cell will have a raised internal resistance. which will reduce the current the pack can deliver.

I have found that the smaller Tattu lipos often suffer with this problem.

Mind you, starting at17mtrs is far too good 

[mikef]

Thanks Peter,

Sadly I didn't start at 17 m!

I climbed to 104 m and couldn't find lift.  After 2 minutes I was working out a landing pattern but 'you're not down ‘til you're down.’  After well over a minute below 30 m, I got well away until the end of the slot.  Then I messed up the spot landing - didn’t come down soon enough and fell short burning height to stay inside the slot time - too much flap too early.
 

[mikef]

I decided to compare the ‘plane slow‘ start with the ‘plane middle' start on the bench.  'Slow' first, prop-off (indoors)  and it starts instantly.  No point trying  'middle' on the bench, it couldn't be any quicker.  Does this tell me anything?

(I didn't mention before, there's an AMRT in the esc to Rx line but it wasn't there when I first flew the model and the start delay was always there.)

What I'm getting with the prop on is a delay (possibly a variable delay?) rather than a slow wind-up.  Does anyone else get a delay, (of about a second) after slamming to full throttle, before the motor starts?  I have the throttle set to full and then switch the throttle cut off to start.

Can anyone explain the difference between the effects of startup speed and startup power please?

Could the ESC be faulty - has anyone else got a similar ESC - if so, please, what are your settings?

I'll try a change to the settings and test it  prop-on when the wind drops a bit.

[PeteMitchell]

Problem most likely is not related to the  AMRT.

As I understand it, startup speed refers to the voltage increasing, either as programmed by the esc or as applied by tx throttle (or both together) to make the motor rotate faster

Startup power is Amp draw at the motor to provide power to overcome the resistance caused by the prop as the voltage tries to make the motor rotate faster.

Hope some one will correct me if this is wrong.

Without a prop on, the motor start pretty much instantly and will run very fast even at low voltage and most manufacturers warn against running fast without a prop.

One possible cause of erratic starting worth checking on is the solder joints in the wires and plugs between the motor and the esc.

All my models have YGE esc. and they are very reliable. I have burnt one out, it was my fault, I sent it back to YGE who repaired it. Total cost of postage to and from Germany and the repair was about £55 which was a lot cheaper than buying another 65LVT.

[mikef]

Thanks Peter.  Neil Jones kindly remade the soldered joints for me, direct to the motor, no connectors.  I have a watt meter I can video the startup to see current draw.   I will experiment when I can safely run outside on a test stand - bit breezy at the moment.

[AJ993]

Hi Mike,

I'm certainly no expert but maybe try changing the Timing to 12 from the 6 you've got it set to now. I believe that the motor specification gives 8 degrees but the programming card only allows 6 or 12 to be selected. I have mine set to Auto-Timing but my motor is a Tenshock 1515T.

Regards, Alex

[mikef]

Well, it's OK now but I don't know why!  Before I checked the settings shown above, the delay problem was there.  I sought help on the Facebook F5J group and here - so I thought I would try something from the suggestions received.  I plugged the programming card in again to check and the settings were as above, as expected!  I changed nothing.
To get a datum, I set up a camera to film the wattmeter and ran the model in the test stand.
NO DELAY!!?!
This was the first prop-on run since the first time the programming card had ever been used to read the ESC.
It's as if the act of using the card to read the ESC fixed whatever was wrong.
Happy but no wiser, I can now worry about the smoke that comes off the motor.  It doesn't smell electrical perhaps it's hot paint.  It's pulling about30 amps.
I then changed to smooth brake from middle so I'm on the gentle start and the gentle stop.  Still delayless hurrah.
Thanks for your time!

[mikef]

On 05/06/2020 at 17:19, mikef said:

I decided to compare the ‘plane slow‘ start with the ‘plane middle' start on the bench.  'Slow' first, prop-off (indoors)  and it starts instantly.  No point trying  'middle' on the bench, it couldn't be any quicker.  Does this tell me anything?.

Well maybe it was telling me that the problem was fixed......

[PaulR]

You didn’t mention the state of one of the variables in your later test -  the battery. 
I imagine that you charged it at least before the final test. If it was a different battery or a different state of charge then that could be a cause of the different behaviour observed.
Hopefully fine now but worth checking if you observe the issue again...

[mikef]

I tried two different fully charged batteries and one partially charged - no delay seen......

[PeteMitchell]

Glad you got a good result Mike.

It reminds me that I have found YGE esc’s are a bit prone to need resetting after some simple miss use which may be what happened to your one.

For instance, if motor power is connected to the esc before the tx is switched on, or if the prop should suddenly get stopped whilst the motor is running (like when it hits your fingers), these can cause the esc to go into a ‘fault’ mode. Maybe yours had a setting corrupted by something similar? The only way to recover this is to connect the esc  to the card reader with power on. No need to press any buttons, just let the card read your settings and re confirm them.

I carry my card reader in my flight box just incase.

[mikef]

Thanks Peter.  Your findings reassure me that I've not just imagined it all!

[Feefo]

8 hours ago, mikef said:

Well, it's OK now but I don't know why!  Before I checked the settings shown above, the delay problem was there.  I sought help on the Facebook F5J group and here - so I thought I would try something from the suggestions received.  I plugged the programming card in again to check and the settings were as above, as expected!  I changed nothing.
To get a datum, I set up a camera to film the wattmeter and ran the model in the test stand.
NO DELAY!!?!
This was the first prop-on run since the first time the programming card had ever been used to read the ESC.
It's as if the act of using the card to read the ESC fixed whatever was wrong.
Happy but no wiser, I can now worry about the smoke that comes off the motor.  It doesn't smell electrical perhaps it's hot paint.  It's pulling about30 amps.
I then changed to smooth brake from middle so I'm on the gentle start and the gentle stop.  Still delayless hurrah.
Thanks for your time!

Are you running 2s or 3s? Your OP said 3s 850mah but low 30a is low for 3s.  The GM 13x 8 on 2s is quoted as pulling 31a and a 13x AE 5 is 41a on 3s.  https://www.reisenauer.de/artikeldetails.php5?aid=2076&sprache=2  Hope it was tongue in cheek about the smoke from the motor, but if there's a burnt smell then somethings not right. 

 

[mikef]

The 850 mAh battery is 3s.  Here's a run on a 13x7 Vitaprop.  'Plane slow' start.  Pre-start 12.67v minimum at 24 secs 10.47v recovery to 10.58v later in run and 11.69v 5 sec after motor stop.

Current peaks at 35.1A when motor gets to max after about 3 sec.  Average is about 31 'by eye'.  Power is about 315 watts mid run.

I hadn't run canopy-open on a sunny day with no battery in the 'cockpit' before so it may have smoked before but this was the first time I've noticed it.  I haven't had the motor out to inspect It yet.

[Feefo]

With Pete saying he finds the YGE esc needs resetting due to misuse, and you saying there's a 'smell', I'm wondering if the motor got damaged and caused the esc malfunction. Hopefully that's not the case and the odour is from something else. 

[PeteMitchell]

Thats a cool graph Mike.

What did you use to produce it?

[mikef]

I set up a digital camera and shot a video.  I then stepped through the video and wrote down the numbers.  There's a couple of stills from the video attached.  You can see a wisp of 'smoke' if you compare the shots.

Once you have the data, any spreadsheet programme will plot graphs.  I used the one on my iPad.