Lack of torque. Is it the motor or battery?

[Zeks05]

ya, ok i understand that... but any good motor/ or hand-wound motor require more amp draw.. ask the gents with the 7t puller motors... so if he has a nice 35t hand-wound he is drawing some amps there.. more then a normal integy 35t

 

[hoghead5150]

i think the concept your failing to understand is the esc gets it's power from the battery. the motor (whatever you run) draws power from the battery thru the esc. without an external bec the esc also has to supply the servo with power. this is where brown outs can occur. when you install a bec the servo draws it's power from the battery thru the bec and reciever. the esc no longer supplies any power to the servo. it's only job is to power the motor. the bec voltage has no bearing on how much amperage or voltage goes to the motor.

to the OP, when you installed the bec, how did you wire it up? if you wired it per castle instructions, you did remember to pull the RED wire out of the esc plug didn't ya!

 

[crawler_noob]

Yea i wired it like the instructions told me to, yeah i pulled the red wire. I turned the steering dual/rate down some and it feels alot better ALMOST perfect but it did give out on me a couple of times. Mainly because I was pushing it trying to see what it was capable of, it seems like the warmer the motor gets the worse it gets. Just hate to sacrifce turning radius for what I thought the bec was going fix to begin with.

 

[Charlie-III]

Yea i wired it like the instructions told me to, yeah i pulled the red wire. I turned the steering dual/rate down some and it feels alot better ALMOST perfect but it did give out on me a couple of times. Mainly because I was pushing it trying to see what it was capable of, it seems like the warmer the motor gets the worse it gets. Just hate to sacrifce turning radius for what I thought the bec was going fix to begin with.

Did you change the dual rate, or the steering EPA's??

With the power off in the rig, move the steering through it's whole range from side to side noting where it binds.
Then power the rig up and set the steering EPA's just short of where the steering binds.

 

[hoghead5150]

problem is charlie is he is running the stock axial radio. it doesn't have epa settings on it. just steering trim, throttle trim, and steering dual rate. the bec should have fixed any overcurrent amp draw from the servo causing your problems. like i said before if you stall a motor it doesn't take long at all to do damage. without getting to technical when the motor stalls it's drawing MAX current. this current has to go somewhere it just doesn't disappear, and will cause damage to the motor. we can get all techy and tell ya what exactly is getting damaged, but you really don't care about that unless your gonna get into motor rebuilding and such. just know that every time you stall the motor it's not good, and will cause the motor to either get weaker each time, or if its bad enough or long enough will cause the magic smoke to come out.

if you have a place to test things, take the truck out and get it to where it usually stalls the motor. now pull the servo plug out of the reciever and see if the truck still stalls in the same spot. if so then it's the motor, if not then you may have a servo current draw issue. did you check the motor for timing??

 

[Charlie-III]

problem is Charlie is he is running the stock axial radio. it doesn't have epa settings on it. just steering trim, throttle trim, and steering dual rate.

OK, I looked and didn't see a reference to the radio he was using.

OP, you could also try using a shorter distance from servo center to drag link mount distance. This will drop the servo throw a bit (at the knuckle).

 

[schiesz]

Just hate to sacrifce turning radius for what I thought the bec was going fix to begin with.

We aren't saying to just turn it down farther. You shouldn't be sacrificing much at all by turning it down. You just need to turn it down to stop JUST BARELY before it gets to a mechanical lock. You don't want your servo to try to fight against the point where it can no longer physically move. Even without specific EPA adjustments, you should be able to get pretty close to the stops with the dual rate (on one side, anyway).

 

[SMR 510RR]

The AE-2 is rated to run on 3S with the use of an external BEC.

I would drop your gearing a little bit and move up to 3S packs, you will like the difference!

 

[hoghead5150]

according to what axial sent me the ae-2 esc is only rated to 2s lipo. they even made the comment that it's written on the esc itself! they also told me that they would NOT warrantee the ae-2 esc if it was ran on 3s lipo.

that being said i ran my wraith on 3s, and am running my ax10 on 3s both with a stock ae-2 esc without any problems so far. i am running the CC bec also.

just want to get the correct information out there straight from axial customer service. mine tho runs well on 3s lipo and the power difference is great!

 

[Olle P]

... the esc gets it's power from the battery. the motor (whatever you run) draws power from the battery thru the esc. without an external bec the esc also has to supply the servo with power. this is where brown outs can occur... the [external] bec voltage has no bearing on how much amperage or voltage goes to the motor.

The internal BEC and the motor feed are two separate circuits. They operate almost independently of each other. (See more below.)

The AE-2 is rated to run on 3S with the use of an external BEC.

according to what axial sent me the ae-2 esc is only rated to 2s lipo. ... they would NOT warrantee the ae-2 esc if it was ran on 3s lipo.

These statements are both correct! The manufacturer pulls all warranties if it's run on 3S, but the ESC should cope with it.

It all boils down to the internal BEC.
A BEC does produce heat, and has some maximum input voltage rating. The heat produced will add to the heat generated by the ESC parts. With high voltage feed and power drawn both parts will cause a heat build-up, that might cause problems.

As for "brownouts", since both the ESC and BEC (internal or external) are fed from the same battery any drop in battery voltage will affect both parts. (The motor will be affected more directly though, since it's often fed the full voltage. The BEC is there to reduce the battery voltage and will just draw more current from the battery if the voltage goes down.)

 

[crawler_noob]

OP, you could also try using a shorter distance from servo center to drag link mount distance. This will drop the servo throw a bit (at the knuckle).

If i make it any shorter the wheels will start to toe in. But i guess thats better than "browning out"

if you have a place to test things, take the truck out and get it to where it usually stalls the motor. now pull the servo plug out of the reciever and see if the truck still stalls in the same spot. if so then it's the motor, if not then you may have a servo current draw issue. did you check the motor for timing??

Yeah it will only stall when im trying to turn and apply throttle at the same time. When it hit thats binding point and i let go of the steering it won't stall.

Yeah i checked the timing, its at 0

I'm thinking a higher torque servo might do it along whith a higher voltage battery

It seems like its some sort of voltage issue.

 

[SMR 510RR]

according to what axial sent me the ae-2 esc is only rated to 2s lipo. they even made the comment that it's written on the esc itself! they also told me that they would NOT warrantee the ae-2 esc if it was ran on 3s lipo.

that being said i ran my wraith on 3s, and am running my ax10 on 3s both with a stock ae-2 esc without any problems so far. i am running the CC bec also.

just want to get the correct information out there straight from axial customer service. mine tho runs well on 3s lipo and the power difference is great!

Well then Axial has conflicting information internally.

From their web site: (Axial AE-2 ESC Set-up and Programming)

Input Voltage - 6 cell NiCad/NiMH or 2cell lipo**

**You can run higher voltage batteries such as a 7 cell NiCad/NiMH or 3 cell lipo with the installation of a “Castle BEC”

Maybe you should point that out to their customer service next time you speak with them about this issue. Not saying it is "right" but there is technically no way (that I know of) for them to tell what voltage you were running so I can't see how they could deny warranty based upon you running 3s...Obviously if you ran something crazy like 6s they would probably be able to tell.

Anyone who has issues with them not honoring warranty repair/replacement based on running 3s on the AE-2 please direct them to the link I posted above. I didn't see any mention of voiding the warranty by using 3s in that link. I would bet that the warning is just a "Cover Our Butt" warning intended for people with little/no RC experience picking up a RTR version including the AE-2.

Note:I personally don't have a AE-2 so I am going by information posed in that link, I can't comment on information contained in the user manual or any other source.

If i make it any shorter the wheels will start to toe in. But i guess thats better than "browning out"



Yeah it will only stall when im trying to turn and apply throttle at the same time. When it hit thats binding point and i let go of the steering it won't stall.

Yeah i checked the timing, its at 0

I'm thinking a higher torque servo might do it along whith a higher voltage battery

It seems like its some sort of voltage issue.

Charlie wasnt telling you to change the length of the tie rod what he was saying is to shorten the drag link and mount it to the tie rod somewhere rather than running it all the way to the knuckle. My guess is that the theory is that since the drag link is shorter the effective length (looking top down 2D) changes quickly when the end attached to the servo horn moves vertically so that would limit steering travel at the knuckles.


This is the deal with brownouts:
The RX looses power for a finite amount of time when you overpower the BEC (internal or external) and this creates problems for everything that needs input from the RX/TX. Depending on how long the RX looses power this could be just a little hickup or it could be bad enough that the ESC will have to rearm when the RX comes back on line. You may also notice that the servo will center for a moment when power comes back on even if you are steering to one side.

The real problem with internal BEC's is that they aren't rated to handle the required amperage ouput that the servo is pulling. Typically your standard internal BEC is rated to 3-5a @ 2s, as the voltage increases the amperage rating on the BEC decreases...Nothing good there. Of course there is also the issue of extra heat and that should not be overlooked but the limited amperage output is the real killer. A ESC like the Holmes BR-XL has a 10a BEC internally and there is no need to run a external BEC when running that ESC.


OP:
If you arent already running an external BEC you would probably benifit from running one even if that doesnt "solve" your issues. It is $20 well spent. I still suggest reducing you gearing a bit to see if that helps. Of course if there isnt enough power to overcome the bind the the rig will just sit there and try to go, I would volt up and gear down you will gain some power down low and gain some wheelspeed...Best of both worlds!

 

[Charlie-III]

Charlie wasn't telling you to change the length of the tie rod what he was saying is to shorten the drag link and mount it to the tie rod somewhere rather than running it all the way to the knuckle. My guess is that the theory is that since the drag link is shorter the effective length (looking top down 2D) changes quickly when the end attached to the servo horn moves vertically so that would limit steering travel at the knuckles.


OP:
If you aren't already running an external BEC you would probably benefit from running one even if that doesn't "solve" your issues. It is $20 well spent. I still suggest reducing you gearing a bit to see if that helps. Of course if there isn't enough power to overcome the bind the the rig will just sit there and try to go, I would volt up and gear down you will gain some power down low and gain some wheelspeed...Best of both worlds!

Sorry I wasn't clear enough....what I was suggesting was to use a mounting hole (on the servo horn/arm) that is closer to the servo, thus making it a shorter "lever". This will reduce the effective throw to the steering linkage helping prevent mechanical bind. Leave the drag link & tie link alone.
In a way, it's a poor way to do the same as setting a lower value in the TX for steering EPA's.

Make a bit more sense now?8)

 

[SMR 510RR]

Sorry I wasn't clear enough....what I was suggesting was to use a mounting hole (on the servo horn/arm) that is closer to the servo, thus making it a shorter "lever". This will reduce the effective throw to the steering linkage helping prevent mechanical bind. Leave the drag link & tie link alone.
In a way, it's a poor way to do the same as setting a lower value in the TX for steering EPA's.

Make a bit more sense now?8)

Yep that does make more sense...Why didnt you just say that in the first place? :roll:

 

[Charlie-III]

Yep that does make more sense...Why didn't you just say that in the first place? :roll:

Late night???
Really long day????
:roll:
:lmao::lmao:

 

[Olle P]

... it's a poor way to do the same as setting a lower value in the TX for steering EPA's.

It's not a poor way! It's in fact a better way, since it adds steering strength!
The only reason TX EPA can be better is if you want to remove/change the limitation during a run.

 

[SMR 510RR]

It's not a poor way! It's in fact a better way, since it adds steering strength!
The only reason TX EPA can be better is if you want to remove/change the limitation during a run.

Or have different values left and right...I dont know about you but I have never had a servo horn line up just perfectly so that everything is centered out of the box.