• Welcome to RCCrawler Forums.

    It looks like you're enjoying RCCrawler's Forums but haven't created an account yet. Why not take a minute to register for your own free account now? As a member you get free access to all of our forums and posts plus the ability to post your own messages, communicate directly with other members, and much more. Register now!

    Already a member? Login at the top of this page to stop seeing this message.

Have tech questions? Will answer.

Hi John, I have a question for you and a thank you, I read I believe on another forum where you discussed throttle curves and why they should always be done in the ESC not the TX, very good information, thank you. Now for my question, I have been noticing allot of HW, Tekin, HH (Yours), etc... ESC's allow for frequency switching adjustments in their respective programming menu's could you briefly explain how changing these values affects torque, power, heat, rpm, noise etc...., and offer some guidelines to follow when changing the frequency? Also I notice on all of my CC ESC's they do not allow this parameter to be changed, do they have a specific reason for that (if you know). Thank you very much, Ed
 
Last edited:
edjo69 said:
Hi Robert, I have a question for you and a thank you, I read I believe on another forum where you discussed throttle curves and why they should always be done in the ESC not the TX, very good information, thank you. Now for my question, I have been noticing allot of HW, Tekin, HH, etc... ESC's allow for frequency switching adjustments in their respective programming menu's could you briefly explain how changing these values affects torque, power, heat, rpm, noise etc...., and offer some guidelines to follow when changing the frequency? Also I notice on all of my CC ESC's they do not allow this parameter to be changed, do they have a specific reason for that (if you know). Thank you very much, Ed
Click to expand...

We don't have a set PWM frequency. We used to use a fixed 6khz frequency but on our newer products we use a dynamic pwm based on the rpm and load of the motor. We found that at the expense of motor noise we could increase the efficiency and torque output of the motor. Different motors react to different frequencies slightly differently based on the inductance of the motor. Being dynamic, we can run any motor at any RPM and in any situation with no extra input or tuning from the user.
 
Hi Robert, Thank you for your answer,it makes perfect sense, why not use the switch freq. to the motors advantage under the appropriate situation. On another note when your motor become ava again will there be any changes made, specifically to the 1512 1Y 2650kV? Just wondering as I have been waiting on this motor for the better part of a year now and I hear maybe Nov??
 
Last edited:
To expand on Robert's response, lower frequencies allow cooler ESC temps, while higher frequencies tend to allow a motor to run more efficiently. As an ESC manufacturer, keeping a certain fixed frequency or unchangeable dynamic frequency is best to ensure optimal and predictable operation. Going from 8k to 13k can be the difference between a warm ESC and cooked ESC in high speed/ bashing/ racing environments. We tend to have a low enough load in crawlers to get away with it.

As a motor manufacturer, I want to have the freedom to design my motor without worrying about acoustic harmonics , or in non crawler applications having too low of inductance for the ESC to clamp at the stock frequency. This is where frequencies 13k and above come into play, as they become more silent and will clamp amperage rise fast enough to deal with behemoth motors.


The problem with higher switching frequencies is the cost of turning a mosfet on and off. The ESC WILL run hotter. A mosfet gate will only charge and uncharge so fast, and our drivers can only push so much power into them. So as we increase frequency, the time spent driving gates on/off becomes a larger and larger portion of total time. Switching losses start becoming an issue. It becomes a balance of having mosfets with low enough IR, but also low enough gate charge, with a stout enough driver to push the device through the miller plateau quickly, and a low enough frequency to allow this to happen. It is testament to any power engineer who can make a motor controller! Just getting it to function at all is a big deal! Also getting it to operate at inaudible frequencies is generally not most efficient operation, but a concession in performance that must be made.
 
Ok, I have an 1/8 RC4WD moa crawler with the super bully axles that has been sitting on the back burner for about a decade. I want to get it going. I have 2 new(old) HH Torquemaster esc's and 2 new CC 10a bec's. I still need to get servos,motors and batteries. I was thinking Protek's new 4s 4100mAh battery and Protek 370 servos. For motors I want HH brushed motors. So, my question is will this set up work? If so, what HH brushed motors will work with the 4s battery? If this set up will not work then could you point me in the right direction.?
TIA
 
reddogg517 said:
Ok, I have an 1/8 RC4WD moa crawler with the super bully axles that has been sitting on the back burner for about a decade. I want to get it going. I have 2 new(old) HH Torquemaster esc's and 2 new CC 10a bec's. I still need to get servos,motors and batteries. I was thinking Protek's new 4s 4100mAh battery and Protek 370 servos. For motors I want HH brushed motors. So, my question is will this set up work? If so, what HH brushed motors will work with the 4s battery? If this set up will not work then could you point me in the right direction.?
TIA
Click to expand...

You can make work with those components. MoA is more how you implement it that what you use IMO. You can run any brushed motor on 4s it just how long is it going to last, and how fast do you want it to go. The Higher voltage makes the brushes wear out faster. Lower turn motors are faster but may run hotter. I don't know about the super bully axles but my bully 2 axles don't like motors bigger than 540. The longer 550 motors get in the way of links and turning.

I'm not entirely sure where your concern lies. If 4s is ok? yes. Holmes motors are quality and they can handle it for a while within reason, just monitor temps, if they get hot you should look into a smaller pinion, higher turn motors, or less voltage.

The esc's are rated to 6s, so youre good there,

The servos have a 6.4 amp stall and the esc is rated for 5amp so a bec is not a bad idea but possibly not necessary. Since you don't run your servo at stall all the time.

No idea how the battery fits on the rig so ?
 
Voodoobrew said:
You can make work with those components. MoA is more how you implement it that what you use IMO. You can run any brushed motor on 4s it just how long is it going to last, and how fast do you want it to go. The Higher voltage makes the brushes wear out faster. Lower turn motors are faster but may run hotter. I don't know about the super bully axles but my bully 2 axles don't like motors bigger than 540. The longer 550 motors get in the way of links and turning.

I'm not entirely sure where your concern lies. If 4s is ok? yes. Holmes motors are quality and they can handle it for a while within reason, just monitor temps, if they get hot you should look into a smaller pinion, higher turn motors, or less voltage.

The esc's are rated to 6s, so youre good there,

The servos have a 6.4 amp stall and the esc is rated for 5amp so a bec is not a bad idea but possibly not necessary. Since you don't run your servo at stall all the time.

No idea how the battery fits on the rig so ?
Click to expand...

The only reason for the 4s is the mAh in the allotted space. I think I will go with the 3s and less run time and less maintenance, than with the 4s battery.The 550 can fits no problems. Thank you for your advice.
 
Hello all. I've got a bit of an issue with the system in my Enduro. When I start up the ESC, the servo jerks violently in coordination with the beeps of the ESC. Then seems solid. But then when the throttle is applied, I start to see twitching again.

My setup:

Sidewinder 4
Holmes Revolver v2 1800kv
Castle BEC powering servo
Servo is irrelevant as it did on an ECO 124T, a Hitec HS7954SH and a Savox 1231SG.

It was worse at first with the radio being my Turnigy GT5. I could actually jiggle the servo signal wire and get servo jitters. I then replaced the Turnigy with my Hitec system (Axion 4 Rx) and this cleaned it up to the point where I could at least wiggle the wire. But the other issues still existed. I've added a 1000uf cap to a spare receiver port and that didn't seem to do anything.

Is it possible that I have a bad BEC? Other than that, I'm lost. Any help appreciated. TIA
 
Which wires from the reciever are being used for the servo.
Does the bec power the reciever?
A wiring diagram would be helpful.

Sent from my SM-N950U using Tapatalk
 
Voodoobrew said:
Which wires from the reciever are being used for the servo.
Does the bec power the reciever?
A wiring diagram would be helpful.

Sent from my SM-N950U using Tapatalk
Click to expand...

ESC powers the receiver, Castle BEC powers the servo and the servo signal wire is the only connection between receiver and servo. I'll see if I can make a diagram later today.
 
JohnRobHolmes said:
Add ground between servo and RX
Click to expand...

And leave the ground between the BEC and servo? Thanks John.


Untitled-1.png
 
There is a post where JohnRobHolmes talks about this if you do an advanced search. I don't remember it all that well.

I have mine same as yours with no issue, but the post talked about some electronics being finicky and wanting the ground a certain way. Wife over The shoulder making sure I'm on the honeydew list so I can look it up at the moment.

Sent from my SM-N950U using Tapatalk
 
My MMP gave up the ghost, so I pulled my hobbywing V 3.1 out of another truck. It has a dedicated crawler profile in it. I'm running a Tekin sensored 4600 KV motor in my Wraith. With the MMP, slow startup throttle was very smooth, but with the hobbywing it stutters and cogs a bit before the throttle will kick in. I'm guessing it's something in the ESC that isn't set right, or maybe a bad sensor wire. I have the crawler default settings set in the ESC. Take a look at the crawler settings and let me know if you think if anything needs to be adjusted. Thanks

https://www.manualslib.com/manual/1259434/Hobbywing-Technology-Xerun-120a-V3-1.html?page=9#manual

Sent from my LM-G710VM using Tapatalk
 
MaX-D said:
My MMP gave up the ghost, so I pulled my hobbywing V 3.1 out of another truck. It has a dedicated crawler profile in it. I'm running a Tekin sensored 4600 KV motor in my Wraith. With the MMP, slow startup throttle was very smooth, but with the hobbywing it stutters and cogs a bit before the throttle will kick in. I'm guessing it's something in the ESC that isn't set right, or maybe a bad sensor wire. I have the crawler default settings set in the ESC. Take a look at the crawler settings and let me know if you think if anything needs to be adjusted. Thanks

https://www.manualslib.com/manual/1259434/Hobbywing-Technology-Xerun-120a-V3-1.html?page=9#manual

Sent from my LM-G710VM using Tapatalk
Click to expand...

Unfortunately, that's just the startup of most hobbywing products. The only smooth thing they have is the AXE, and the system is proprietary so you can't swap out motors to another brand.
 
You must log in or register to reply here.

Similar threads

R
Choosing a platform for my first RECON G6
2
Replies
23
Views
3K
Reezo
R
T
WE RC ROCK Rules 2024
Replies
1
Views
2K
cooper_xl
cooper_xl
I
Best option for 1st time competetive Rock Crawler on a budget
Replies
18
Views
2K
IronArcher
I
D
Motor overheating problems in SCX10III
Replies
1
Views
1K
Druxus
D
A
Few different issues. Not sure what to do
Replies
15
Views
2K
Afterbang
A
Back
Top