Furitek Brushless Scx24 Conversion ... Odd Stutter issue

[da_jokker]

Hi all, I'm new to RC and picked up a deadbolt SCX-24 about a year ago. Long story short it keeps burning up 030 and 050 motors. Someone suggested I replace the ESC And while looking at possibilities, I stumbled upon the Furitek brushless conversion kit and decided to give it a try. So sick of buying motors, I figured pay now or pay later (burnt out my 5th motor already).

Anyway, I just got everything installed. Managed to fit everything inside of my deadbolt with just some minor tweaks. But I've run across a strange issue... Hopefully I can explain it well enough.

Basically if I go from 0 to full throttle the motor acts like it's confused and just sits there and pulsates back and forth, like a stutter/shake. It only does it when I go from no throttle to 100%.

If I give it a little bit of throttle, just enough to get going and then go full throttle (talking like 1 second or less between just off 0 before going all the way to 100) it runs fine.

When I first put it together, I thought the teeth were slipping, but I actually took the motor out and held it in my hand and it did the exact same thing so I know it has nothing to do with the running gear or any binding, etc.

If I use the app to limit the max throttle to about 70%, I can go from 0 to full throttle with no issue... But 70% is way to slow.

I just emailed Furitek support see what they say. I know very little about the settings but I did lower the punch all the way to 1 with no effect.

Anyone know if it's just some setting? Or did I end up with a bad motor or bad ESC? Oh, its the Tegu esc and not the lizard And I have done a throttle calibration.

I'm running the latest firmware, v 2.3 on a 2S lipo.

 

[vinceherman]

I hope that you can get it working.
Just to check and this may not be what you are describing, but what mode do you have the ESC set to?
If you have it to Forward-Reverse With Brake, it is easy to confuse the brake with a stutter.
Set it to Forward-Reverse instead.

 

[da_jokker]

I hope that you can get it working.
Just to check and this may not be what you are describing, but what mode do you have the ESC set to?
If you have it to Forward-Reverse With Brake, it is easy to confuse the brake with a stutter.
Set it to Forward-Reverse instead.

Hey I'll take all ideas.... But unfortunately I am set to the default forward-reverse (without brake)

Maybe I'll play with those different settings to see if any of them make a difference.

 

[HumboldtEF]

I know exactly what your talking about, mine does the same thing but only when going from zero to full throttle. Honestly I have a feeling there isnt a fix for this. I think this may be a limitation of the ESC and motor combo being that is sensorless and pretty small. Even my Holmes Hobbies Revolver does this 'stepping' at very low throttle where the motor is basically being told the rotate x degrees and stop, repeatedly. I think maybe thats whats happening.

Good thing is the bandaid fix is easy, dont mash the throttle and just ease into it.

 

[da_jokker]

I know exactly what your talking about, mine does the same thing but only when going from zero to full throttle. Honestly I have a feeling there isnt a fix for this. I think this may be a limitation of the ESC and motor combo being that is sensorless and pretty small. Even my Holmes Hobbies Revolver does this 'stepping' at very low throttle where the motor is basically being told the rotate x degrees and stop, repeatedly. I think maybe thats whats happening.

Good thing is the bandaid fix is easy, dont mash the throttle and just ease into it.

Yes that is exactly it. If i mash..it just sits there spazzing out. If I give it a little bit of throttle momentarily and then mash it's fine.

There are a ton of firmware choices, but updating makes me nervous so I didn't want to start going backwards to see if the issue is related to a bug.

I did find one post on google where a guy seems have had a similar issue and replaced the motor and it fixed it.
https://www.reddit.com/r/SCX24/comments/ms3sgu/is_this_surpass_motor_a_dud_is_this_normal_can_i/

Which Esc are you running? Firnware version? How long have you had the issue?

 

[da_jokker]

Okay so I don't want to count my chickens just yet. But I was in there messing with that Forward and reverse setting. None of them actually made a difference, and it's clear that the only setting that should be selected is the forward-reverse

However on that same page I noticed two other settings. One was max brake And it was set to 100%. I lowered that down to 50%. Also there was an FOC setting that could go between 10% and 30% and it was set at 30. I split the difference and put it at 20%.

Turned off and on the ESC and now the issue is a ton better. I can actually go from still to 100% throttle instantaneously, it does it stutter like one or two times and then takes off.

Could be completely coincidental so I don't know. Do these motors have to be broken in at all? Could it literally just be that I haven't used it enough to kind of loosen everything up?

 

[HumboldtEF]

I just tested mine again and the stutter seems to be almost gone, not sure why but I can hardly notice it. When it was happening it would only stutter for a second and then it would spin up just fine.

The motor is a Komodo 1400kv, ESC is the Lizard. I think I'm still on the firmware that it shipped with, I read that someone bricked theirs when updating it so I haven't wanted to mess with it.
Brushless motors do not need breaking in.

I guess the other thing to consider is the drivetrain of the SCX24, the worm gears do create a fair bit of friction so I dont know if that may be playing into it or not.

 

[da_jokker]

I guess both yours and mine got the memo

You have the lizard, I have the tegu And both were doing strange things and magically seem to have almost fixed themselves.

I've been working with support but it's been painful. I emailed them a ton of information, and they come back with a four word sentence like "try factory reset" or "calibrate the throttle"

Of course none of it helpful at all, not to mention I told them I calibrated my throttle and the original email.

I'll play with it a little bit longer, cuz I think I have like 30 days for a warranty at least and I'll go from there.

 

[MattTheGenus]

Mine also has an odd stutter at very low throttle input, and when I first start reversing. I like the esc a lot but I don't think its the miracle that some of the early reviews would lead us to believe.

 

[da_jokker]

Just an update. Furitek support has been little help. But I finally made a video, sent it to them and basically said how to I get a replacement motor under warranty?

Just taking a guess that is the motor but we'll see what happens.

video here

 

[da_jokker]

For anyone like me that runs into this issue, it is called "cogging"

Drove up to the hobby store I bought it from (about 80 miles away) and talked to the folks there. They said it can be normal due to the setup being sensorless and it is called cogging.

Now that I know the term...time to research.

 

[vinceherman]

I would push to try the latest firmware. I have updated firmware on about 60 Furitek ESCs (20 Tegu and 40+ Lizards) and have not bricked any.

 

[2471:24]

I read here that somebody had the pin loose on the left or right drive shaft. That’s a lot of burnt motors. Have u tested to spin the universal joints with your finger, do they roll easy?

 

[da_jokker]

So my final follow-up, just in case anyone ever runs across this thread.

What I discovered was that on a full charged lipo battery (8.4v) The Cogging was pretty bad. But as the battery drained the cogging would go away (~7.6). Kind of made sense since slowly getting on the throttle had no issue, but quickly getting on the throttle causes the problem.

Convinced it was either the ESC or the motor, I returned them and got a new set. (And FYI, the cogging occurs with the motor completely detached and just holding it in my hand, So the idea of binding or pinion gearing is moot)

Guess what, problem is still there. After installing (or more accurately reinstalling) both, I started playing with the settings. Notice that if I adjust some of the settings, it got much better, but didn't entirely go away.

I have no idea which one made the most difference... Results WILL vary but....

Startup power : low
Foc: 30
Punch: 10
Low speed: 20 ***

** I found the low speed would actually completely eliminate cogging the higher I set the number. But then of course the rig gets more and more slower. So finding something in there that worked for you might be the key.

Good luck. Kind of sucks, but if I stop burning up motors it'll be worth it.

 

[vinceherman]

Which ESC do you have now?
What version of the firmware?

 

[da_jokker]

Which ESC do you have now?
What version of the firmware?

the Tegu, firmware 2.3. i selected the Tegu over the Lizard because it had a higher amperage rating but now I'm wondering if I should have gone with Lizard since that is what most people seem to go with.

 

[zork]

just adding in my resolution for any future searchers-


i found that in the bluetooth app settings the motor type was set to "godzilla..." something instead of "komodo micro/mini".

i was getting stuttering/cogging above 80% throttle on a komodo mini/lizard pro/3s combo.

once i changed the above setting, it worked fine. i didn't think to check something like that since i had ordered them together as a pair direct from furitek.