Reduce throttle percentage or lowercell count?

[SirCrashALot]

I have a question guys. I hope anyone knows the answer.
When i run a 6S battery and i reduce the throttle percentage on the remote to say 80%, does it mean that the whole throttle curve is reduced to 80%, or do i still get 6S power, with a hard power cut off at 80% ?

 

[King blitz]

I believe your limiting just the throttle and still getting 6s power

 

[MMoelmann]

I believe it depends on your radio. I have a cheap radio and when I lower the throttle percentage in the radio I can tell that the percent of throttle I get is lowered throughout the trigger pull.
Reverse and breaking are also affected. So if you like your forward percentage set at 80% you might want to reprogram your ESC so have slightly higher breaking force.

Another way to put it is that you don't get 100% of your power through your first 80% of the trigger pull and then it cuts you off at 80% because you set it at that. You get 80% across the board.

You would be better off getting a smaller pinion if you don't like how fast it is now. Just my opinion.

 

[Hector_Fisher]

If you're referring to the Arrma radios (i believe all of them act the same way), then yes it just reduces the throttle curve, by basically just scaling back the amount of "pull" you make on the trigger. So if you're set to 50% power, and you pull the trigger 100%, you'll get the equivalent 50% trigger pull. Pull about half way (50%) on the trigger, and you'd get the equivalent of a 25% pull, and so on. That's essentially the easiest and simplest way to implement something like that.

The other way you're describing sounds like an RPM limiter, which would mean the ESC essentially stops the motor from spinning up higher than 50, 70, 80% (etc) RPM. That would be interesting. I'm not aware of anything like that.

 

[LibertyMKiii]

If you were going to pin the throttle and have the radio limit to 80%.....
It would be better to run a lower cell count, modify gearing, or change motors.

An ESC engineer told us the mid-range is hardest on the ESCs. This is related to the FETs switching phases with restricted power. This mid range is where you see the ripple voltage created in data logs. The ESC would be happier running wide-open.
From a perspective of better health/life span of the electronics, this is something to consider.

Another option is to go with a lower KV like a 1700kv (the original BLX 6s motors test around 1915 actual KV despite being called a 2050 kv)

 

[Johnny b]

If you were going to pin the throttle and have the radio limit to 80%.....
It would be better to run a lower cell count, modify gearing, or change motors.

An ESC engineer told us the mid-range is hardest on the ESCs. This is related to the FETs switching phases with restricted power. This mid range is where you see the ripple voltage created in data logs. The ESC would be happier running wide-open.
From a perspective of better health/life span of the electronics, this is something to consider.

Another option is to go with a lower KV like a 1700kv (the original BLX 6s motors test around 1915 actual KV despite being called a 2050 kv)

View attachment 287520

Never knew that! So its best to run wfo so your esc last a lifetime even though all other parts need to be replaced numerous times!

 

[LibertyMKiii]

Never knew that! So its best to run wfo so your esc last a lifetime even though all other parts need to be replaced numerous times!

It is all scenario driven.

If you were going to drive around a parking lot with the throttle pinned at 50% the whole time that would be hard on the ESC.
Bashing we have short bursts of 100% throttle around 2-4 seconds because these rigs go fast!

There are problems with 100% throttle also and that is heat build-up.

This is a log from a MMX8s esc. This one did not have a cap pack and was running 8s.
You can see the ripple voltage highlighted, in the middle throttle range around 50-70% is where it ramps up. As I worked up into the 85 to 100% throttle range the ripple went away. Nothing really changed other than the FETs switching is "happier" in that throttle range.

 

[King blitz]

I keep mine at 100 percent and when I do speed passes I ease into it.i don't gun it right off the bat.i like knowing I have full 100;percent throttle when I need it

 

[Surchaufeur]

Interesting. My 4s motor on the v1 and v2 kraton/outcast gets so hot. My heatshink just melted shrunk away

 

[King blitz]

Interesting. My 4s motor on the v1 and v2 kraton/outcast gets so hot. My heatshink just melted shrunk away

Maybe you need bigger fans

 

[Surchaufeur]

Maybe you need bigger fans

I had a tornado 30mm aluminum fan On it. Running on stock gearing, i believes its one of the worst RtR electronics at this point

 

[King blitz]

I had a tornado aluminum fan

What about different gearing

 

[Surchaufeur]

What about different gearing

Stock gearing on the v2(13t) 13t to 15t on the v1

 

[King blitz]

Are you off roading or on road? Ik that speed running I don't have heat issues at all

 

[Surchaufeur]

I believe the heat generated by the clutch+enclosed module+lack of ventilation inside the truck+ the small motor on a 10lbs rc is what makes the motor and all the wires burning hot

Are you off roading or on road? Ik that speed running I don't have heat issues at all

Off road... the arrma outcast/kraton 4s use 13t stock on their 2400kv combo
The lowest priced motor i could get is a the spektrum 6s motor for 50usd.. the other options go 70-80usd+ at higher kv. The 4s trucks are 1-2 lbs lighter but run a tiny motor on 4s

 

[King blitz]

I believe the heat generated by the clutch+enclosed module+lack of ventilation inside the truck+ the small motor on a 10lbs rc is what makes the motor and all the wires burning hot

Off road... the arrma outcast/kraton 4s use 13t stock on their 2400kv combo

I was going to ask but you answered my question on if you were using stock motor.i say throw a different one on and modify the body cover to get that inside cooler

 

[Surchaufeur]

I was going to ask but you answered my question on if you were using stock motor.i say throw a different one on and modify the body cover to get that inside cooler

Im going to get a longer motor at lower kv. I never ever upgraded a motor on any of my rcs. Never found the need for. But i cant keep going like this if i want to keep my kraton 4s v1 who is now an outcast 4s v2. It tortures my esc and lipo. My concern is it might make my rc uncontrollable. Im not the kind of guy who likes to overpower things im very conservative on that regard

 

[King blitz]

Curiosity..did you check your motor bearing? Actually all bearings? One might be seized and causing the motor to work harder causing excessive heat

 

[Surchaufeur]

Curiosity..did you check your motor bearing? Actually all bearings? One might be seized and causing the motor to work harder causing excessive heat

Yes i have a ceramic sealed bearing on the front. I have the chassis slotted under the spur. I clean and reoil that bearing evey 10-15 packs... the motor module is a hell hole. The dust of death... i oppened my motor module on my v2 after 5 packs its all full of black Powder and metal sparkles everywhere.

I have a question guys. I hope anyone knows the answer.
When i run a 6S battery and i reduce the throttle percentage on the remote to say 80%, does it mean that the whole throttle curve is reduced to 80%, or do i still get 6S power, with a hard power cut off at 80% ?

Back to the question imo it would be best to run lower cell count. Maybe its not the best answer but i have an arrma nero im planning to run on 6s. Im also going to run it on 4s or 3s for crawling or to drift. Lowering the cell count lowers the cogging of the motor and makes going at a lower speed a lot more manageable. Like liberty said going slow increases ripple voltage. Will it be lower at cell count and less hard on the esc? Im pretty sure yes

 

[SirCrashALot]

An ESC engineer told us the mid-range is hardest on the ESCs. This is related to the FETs switching phases with restricted power. This mid range is where you see the ripple voltage created in data logs. The ESC would be happier running wide-open.
From a perspective of better health/life span of the electronics, this is something to consider.

View attachment 287520

I read that somewhere too.
Whatever motor system i put in, these cars are so fast, they will not run full throttle all the time anyway. Knowing that, how much worse can throttling down be?