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Old 09-15-2010, 12:09 PM   #1
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Default sensorless timing advance

do you know if a brand increase timing more than 30 degre in sensorless mode


i made my own firmware and i can increase timing to 50 degre and if i check signal with my scope i see only 15 degre with more rpm than KV

and the motor run same noise than normal timing with only twice current no load

this thing can be very good for stock racing
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Old 09-15-2010, 12:26 PM   #2
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It's hard to advance timing on a motor when you don't know the rotor's position relative to the poles of the motor.
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Old 09-15-2010, 01:06 PM   #3
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how to know where is rotor with only 60 degre sensor only approximate with calcul

if i can i think big brand can also

in sensorless with little imagination you can make to much with good ADC and comparator

this type of advance can be ROAR legal for stock racing you can't proof you have more than 15 degre
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Old 09-15-2010, 01:34 PM   #4
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This has been discussed by one of the Castle guys, and was agreed to by one of the Tekin guys I think it was. As you increase timing past a certain point the EMF feedback that a sensorless relies on becomes blurry and it becomes very difficult to decipher the needed timing information, as I understood it.

I’m not completely following everything you wrote, but you seem to be saying the same thing:

Quote:
Originally Posted by dgaumond View Post
do you know if a brand increase timing more than 30 degre in sensorless mode


i made my own firmware and i can increase timing to 50 degre and if i check signal with my scope i see only 15 degre with more rpm than KV

and the motor run same noise than normal timing with only twice current no load

this thing can be very good for stock racing
Possible perhaps, but it’s apparently quite challenging.
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Old 09-15-2010, 01:53 PM   #5
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i not tested more than 51 deg now at 37000 rpm with 13.5T 7.5Volt

before to know how to advance timing i made firmware with 12 step by turn

same final RPM with more torque and less heat and 15 deg fix timing
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Last edited by dgaumond; 09-15-2010 at 02:11 PM.
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Old 09-15-2010, 02:05 PM   #6
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"ESC advances are out of control, stock needs to be slower, etc"

And now it's begun again, guys trying to figure out an advantage in spec/stock.

I have a couple things for sale, which are guaranteed to improve lap times in the stock class.

2oz bottles of "Practice" - $59.99 shipped
4oz bottles of "Skill" - $89.99 shipped
1 gallon of "Car Setup" - call for pricing, must be used with "Practice" and "Skill"
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Old 09-16-2010, 09:49 PM   #7
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Quote:
Originally Posted by HarryLeach View Post


"ESC advances are out of control, stock needs to be slower, etc"

And now it's begun again, guys trying to figure out an advantage in spec/stock.

I have a couple things for sale, which are guaranteed to improve lap times in the stock class.

2oz bottles of "Practice" - $59.99 shipped
4oz bottles of "Skill" - $89.99 shipped
1 gallon of "Car Setup" - call for pricing, must be used with "Practice" and "Skill"
thats it if you wanna go faster use a bigger motor.. simple.
I cant understand ppl trying to dial the shit out of the motor for what??? a fast car for less than 2 secs a lap. The rest is up to the driver and if you cant drive you might as well have the fastest car you can and still get flogged. lol
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Old 09-24-2010, 06:38 AM   #8
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This is not to run faster in stock class but for research in electrical and motor

after today i did can increase rpm but with very low torque

but now i found how to reach 90 degre timing sensorless and have more torque than zero timing 4000kv with 3000kv motor

and motor turn like a charm less noise than zero or 30 degre timing

i like my 15$ towardpro 13.5T motor to run it was very solid and need more rpm for onroad or offroad
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Old 09-24-2010, 07:27 AM   #9
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Est-ce que tu pourrais expliquer brièvement en français ce que tu cherches à faire ? J'avoue que je comprends mal ton anglais- no offence, of course. Un peu de ponctuation serait sympa, aussi ;-)

Quel matériel de mesure ? quel ESC, quel moteur, etc... the more details the better !
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Old 09-24-2010, 08:29 AM   #10
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même en francais, j'écris mal

Mon Histoire:
Je suis technicien depuis 10ans
Sa fais deux ans que je reprogramme des esc mystery atmega8.

Au dédut je programmais en basic et c'étais très puissant mais pas très doux
maintenant je programme en assembleur et c'est devenue beaucoup plus doux

Je course onroad 1/10 avec mon propre speed depuis 1 ans
le record de la track est de 50 tour en 6 minute (TC5R) et je suis capable de faire 48 tour avec mon losi xxx-s 13.5t towardpro (unitedhobbies) et mon speed 40A mystery sbec 5.5V 2-6cell 40A


Ma dernière version (firmware)
timing progressif de 0 a 30 deg avec le rpm
Ajout de temp mort tous les mosfet off
Ajout de 12 step par tour

Si tu mesure le timing avec un scope numérique (ma job) sa donne 15 deg
Le 12 step par tour cache bien le 30 deg timing

Avec sa j'ai baisser la température de 20F du moteur avec plus de punch et un peu plus de top speed avec le même ratio ce qui permet de diminuer le ratio et d'aller plus vite encore



Recherche:

Maintenant que mon speed marche bien et que je touchais plus mon firmware

J'ai commencer à tester pour avoir plus de RPM et torque avec le même moteur en sensorless

J'ai fais plein de test avec les ADC pour aller chercher le moteur avant le zero crossing fonctionne mais pas été capable d'avoir plus de torque seulement plus de rpm 37000 en 7.4V avec un 13.5T (scope numérique)

Quand tu mets sa sur un char au lieu d'aller plus vite sa ralentis


Mais hier j'ai réussit avec les comparateur intégré dans le atmega d'aller checher 90 deg timing et beaucoup + de torque

le moteur tire 6 Amp a vide 32000rpm 10A avec ma roue d'inertie de 2 lbs

au scope sa done une onde carré de 25% OFF et 75% ON

Je sais pas encore comment sa fais pour marcher avec l'onde que sa donne mais le ucontroler a l'air de savoir ce qu'il fais sa tourne vraiment doux moin de bruit ou de vibration que du 30 ou 0 degre timing
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Old 09-24-2010, 08:40 AM   #11
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WOW, you competence exceeds by far my understanding, but it seems to show that you really know your business. Thanks a million for the time you took to write this up. Could you share a pic of your ESC ? I have a hard time understanding if it works with or without a sensor, or in a sort of dual mode.

PS : j'adore le québécois, "char" pour voiture c'est juste trop marrant. J'habite en Suisse et on a pas des expressions aussi rigolottes.
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Old 09-24-2010, 10:38 AM   #12
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This is far to interesting to just write it all in french. Please write it in english
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Old 09-24-2010, 12:00 PM   #13
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My History: I am technician since 10 year

Its make two years that I reprogram esc mystery atmega8.

For starting i programmed it in BASIC and it was very powerful but not very soft

Now I program out of assembler and became much softer

I race onroad 1/10 with my own speed since 1 years the record of the track is of 50 turn in 6 minute (TC5R) and I am able to make 48 turn with my losi xxx-s 13.5t towardpro (unitedhobbies) and my speed 40A mystery sbec 5.5V 2-6cell 40A 7sec by turn very small track 60`x 40`


My last version (firmware)
progressive timing of 0 to 30 deg with the rpm
Dead dand addition of all mosfet off increase batt volt on hard current
12 step per turn and 18 step with dead band

If you measure the timing with a numerical scope (my job) its 15 deg gives

The 12 step by turn hides the 30 deg timing well (normal 6 step by motor turn

With its i have lowered the temperature of 20F engine with more punch and a little more speed with the same ratio what makes it possible to decrease the ratio and to still go faster


research:

Now that my speed goes well and that I don't touch more my firmware
i started to test to increase RPM and torque with the same engine in sensorless


I have make many test with the ADC to go to seek the engine before the zero crossing functions but not able to have more torque only more rpm 37000 in 7.4V with a 13.5T (numerical scope)



But yesterday

I succeeds with the comparator integrated in the atmega
90 deg timing and much torque
the engine draws 6 Amp at idle
Turn at 32000rpm 10A with my flywheel of 2 lbs
to the scope its gives a wave square of 25% OFF and 75% ON

I dont know yet how its make to go but i think the ucontroler know where it go

the motor turns really soft less noise or vibrating than 30 or 0 timing degree

I read that 90 deg timing is the max torque of brushless can have
if it was real the advance timing in sensorless is better i sens exact rotor position not only sensor position

sorry i can't translate it better
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