Huge throttle/reverse delay with Kinexsis motor/ESC (KXSS0500) and AMP DB

zarthsan

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I'm relatively new to RC cars and have an AMP DB and an AMP MT. Recently, the MT's steering-servo crapped out, and, while I was repairing that, I decided to upgrade the ECS/Motor to one that could naively support LiPO without the need for a Low-voltage-alarm.

$120 later, I had the titanium servo, the KXSS0500 motor/ECS combo, and the ECX13003 receiver.

This is the first ESC install/calibration/pairing I've done, I so googled around and followed the instructions. After I got it working, the results I've had are far less than stellar.

Problem:
When the car is not moving and I pull/push the trigger it's quick to take off, and when I hit the brake it's quick to stop, but that's it. When I want to go change directions I often need to push the trigger from neutral 4 or 5 times - sometimes taking a second or more before the wheels engage in the other direction.

This has made it completely impossible for me to take the truck over any jumps, because I'm totally unable to correct it's rotation in the air. It's also just annoying to drive now since when I run into something and come to a stop, it still takes several frustrated pushes of the trigger to go backwards.

The settings of the ECS are currently all default (settings shown in attached image), and the receiver/transmitter calibration worked (although it was a bit confusing).

Has anyone else experienced something like this? Is this to be expected when shifting from brushless to brushed? Is this a faulty ECS/motor, or just a piece of crap hardware? This was such a disappointing result after switching from the super-responsive motor the AMP came with.

Thank you so much for the help and all the expertise I've learned from while reading this forum.

KXSS0500-defaults.png
 
One thing that it could be, is throttle trim. Maybe the ESC is very picky about the neutral point. Many ESCs will not let you go from throttle to reverse, or the other way around, without coming to neutral first. If your throttle trim is a little bit off, maybe so little that the car is not moving but just slightly tugging against the rolling resistance, maybe the ESC doesn't pick up that you've gone throug neutral. Or maybe it thinks you've gone into reverse, and it delays your throttle application.

I don't know, maybe play with the trim a little, see if it works any better?
 
Oh - what an interesting suggestion. I just went out and spent 15 minutes carefully adjusting the trim to a variety of positions while testing and observing for improvements in the issue.

Sadly, no matter what position the trim was in, the same issue persisted.

I recorded a video of my frustrated throttle controls displaying exactly the issue I'm describing any time the car changes direction. Video is here: https://app.box.com/s/xnt4gteodr3geo0in15382cra31k67tj
 
It's not terribly uncommon for people to have this issue going from an ESC that lets you go directly into reverse to this type of ESC. It's meant to keep you from shredding gears. You kind of have to get a feel for how your ESC requires you to shift to reverse. Sometimes you need a very discernible pause between forward...brake....then reverse. So, you can't just go from forward to reverse. You need to tap reverse then hold reverse for it to be applied.
 
X: If this type of lag is normal, do you have any idea how people are able to correct the spin on their cars when they're in the air from a jump? I'm lucky if I'm able to get the reverse to engage before it's hit the ground, and by that time, it's already far too late (and the truck just landed on it's whatever). And that includes a very careful hitting of the brakes in the air. Release of the trigger. And then pushing into reverse.

Is this safety function something that most ESXs allow to be turned off or tuned? If it is, I'd love to know what the feature is called so I can buy an ESC that specifically allows me to stop this from happening. I've got all-metal gears and drive-train, and I'd rather stress those (or drive less-fast) than have something less-responsive than when I began. I'm guess I'm just surprised that the stock AMP ESC was so responsive and fun to drive, and then a nearly $75 upgrade to a fancy ECX Kinexsis ESC has made the truck miserable to drive, and impossible to control in the air. That's kind of not the evolution I expected when upgrading my first hobby-grade RC.

xlDooM: Great idea. I'll give them a call to see what they think of the video, and see if they also believe that this is normal.
 
Darn, I called Horizon customer support and although the guy wasn't interested in watching the video, the answer was basically, "It's normal to have a delay going to reverse from forward, but not the other way around. You could send it into the service center if you want."

I kinda wished they would have taken a look at the video to tell me if it looked obviously faulty before I spend money shipping a potentially defective/working-as-intended part back to them and then having a non-functioning truck for a couple weeks. I'd hate to get it back with them saying, "Yeah this is within performance tolerances" and be out the time and money.

I guess another option is for me to cough up more cash to buy an ESC from a different brand. I just wish I know what this setting was called so I could Google it and make sure I buy one where this option is tunable.
 
Well... The Dynamite ESC in my AMP and Boost cards both required a "double tap" to engage reverse. It should be: pull trigger for forward, push trigger for brake, push trigger twice-and-hold for reverse.

What I'm seeing in the video just seems completely wrong. Have you tried resetting the ESC?

My AMP/Circuit now uses Hobbywing's excellent XR10 Justock ESC and 3650 13.5t brushless motor and the tuneability and responsiveness is AMAZING.
 
Yeah - I've reset, recalibrated, and done it again a dozen times. At this point I have to assume the ESC is faulty in some dimension, or that this is simply what's expected for this device.

Thank you so much for the recommendation on a setup you know performs well and is responsive - I'll buy that specific one, and look forward to getting my truck back. :)
 
Quick note: I run a Hobbywing 3650 G2 Justock 13.5T motor in my AMP MT/Circuit so I can race in the Stadium Truck class. (I run a Reedy M2 17.5T in my Boost) A 13.5T motor is roughly equivalent to 2800kv. The 17.5T and 13.5T are pretty torque-y so I run my cars with Associated 48p spur gears (have to drill out the hole with a 5.2mm drill bit) and slipper pads. So I'm running 28/72 with the 13.5T and 31/69 with the 17.5T. If you stay with the stock 87t spur you would probably want to go with a 10.5T (3200kv approx).
 
I had similar issues with the KXSS0501 The throttle was finicky and eventually started melting steering servos. We tested it with other receivers at the hobby shop and determined the problem was in the esc. I sent it back to Horizon and they are replacing it, but it's on back order till mid June. I put a Kyosho Le Mans 240s esc in it to run in the meantime and have had no trouble. There is still no grace to the throttle which I believe to be the stock Spektrum radio. It mashes just fine, but there's not a very good range of speed in the throttle. I'm upgrading the radio next.
 
I had similar issues with the KXSS0501 The throttle was finicky and eventually started melting steering servos. We tested it with other receivers at the hobby shop and determined the problem was in the ESC. I sent it back to Horizon and they are replacing it, but it's on back order till mid June. I put a Kyosho Le Mans 240s ESC in it to run in the meantime and have had no trouble. There is still no grace to the throttle which I believe to be the stock Spektrum radio. It mashes just fine, but there's not a very good range of speed in the throttle. I'm upgrading the radio next.
 
Update! Horizon sent me a new 4000 kv esc and motor combo, so it's in your best interest to mail it to them. Now I have a spare.
 
I bought a car equipped with this setup a few weeks ago. The previous owner barely ran it and had no problems with it. I am having a similar problem with this esc. How can I contact them about the problem
 
I wish I could give you advice - after all this time, this damn ECS is still causing me trouble. It has been a non-stop source of problems, and even though I'm learned to tolerate it, just today it finally has pushed me past the edge by being so erratic I finally gave up and decided to actually buy a different brand (and stop purchasing the Horizon Hobby parts).

I wish they were reliable, and performed as one would expect, and that their customer service cared. I guess it's just money down the drain.
 
I wish I could give you advice - after all this time, this damn ECS is still causing me trouble. It has been a non-stop source of problems, and even though I'm learned to tolerate it, just today it finally has pushed me past the edge by being so erratic I finally gave up and decided to actually buy a different brand (and stop purchasing the Horizon Hobby parts).

I wish they were reliable, and performed as one would expect, and that their customer service cared. I guess it's just money down the drain.
Is it possible that you had the motor running in reverse. If that’s the case try reversing the throttle on the remote and if that doesn’t do what you want it to try reversing a set of motor wires with the reversed remote channel. An easy way to tell if the esc is running in reverse (even if the car is driving forward) is when you go full throttle then tap the brakes just a little bit and the motor locks up (like 100% brakes) also the motor will run really fast the other direction and have a smoother proportional brake.
 

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