Too much throttle before B7 accelerates
 

I just got back into 10th scale racing since my town finally has a track. Been out of the hobby for 10 years so feel like a newb again. I just assembled a Team AE B7 and I'm using a HW xerun xr10 stock spec g2 with a 21.5 motor and flysky transmitter and receiver. It seems like I have to give the car way more throttle to get the tires to start turning than what I remember. My transmitter is showing 20% throttle before the tires start spinning even sitting on a stand. Does this seem right? Once the tires start spinning it's like the drivetrain is out of balance as tires fluctuate in speed. What should I start looking at? Thanks for any help.

Return your radio settings to default. Recalibrate the esc to the radio.

If it is a low end flysky it's possible it just has bad throttle feel.

Seems like you didn't calibrate the ESC to the radio.

check neutral width settings

Thank you everyone for the suggestions. I'll recalibrate the ESC again and check the neutral width settings and report back.

If the problem persists after calibrating, then it could be a bad potentiometer (pot) in the radio if it's an older system that has been sitting around for a long time. Moisture causes pots to fail if the radio was stored outside in a garage or shed especially.

I'm starting to lean more toward moving the diff and transmission and double checking everything. I feel like something is bound up causing this throttle delay and rpm variation once the tires start moving. The transmitter and receiver are brand new. It's a Noble NB4+

That should be easy to check without removing anything. Slide the motor away from the spur so the pinion isn’t touching the spur, give the wheels a spin. See if the roll smoothly or come to an abrupt stop

Do you have the sensor wire connected properly? It's possible that the wire may be bad, try swapping out a fresh sensor wire. Also verify everything is zero'd out on the transmitter throttle settings and ESC.


If you are using expo then disable it, because expo is doing just as you describe. If all else fails, take it to the track and have an experienced driver examine the car.... verify A-B-C wires are soldered in proper slots, etc...

Here is a quick video of what is going on. Figured this could help explain the throttle delay and rpm variation. I did go through the calibration process again to make sure everything was calibrated properly.

I had suspected your sensor wire above, note that it's missing!


https://cimg3.ibsrv.net/gimg/www.rct...53d9c8248a.jpg



your soldering is also questionable, I would re-solder your B wire on the motor, maybe visit your track and ask an experienced driver to show you how he solders his motor wires ;)


1) use a chisel tip soldering iron - in a pinch I have used my dremel to grind a fine point tip into a chisel tip

2) use soldering paste on bare metal before adding solder

3) tin the wire with solder

4) tin the motor tab

5) sandwich the solder iron between wire and motor tab until both liquify then press wire into pool of liquid solder, remove iron and hold in place until solder cools to solid


*** VERY IMPORTANT****


go back and read all the manuals for your ESC, Radio and Motor... take your time learning all the features, it will save you lots of frustration at the track!

The motor has a lower sensor port and is where my sensor wire is plugged in. Hard to see on the video I posted. Should I be using the top port instead?

Thank you for the soldering tips and recommendations. I'm definitely rusty on my soldering skills with my lapse in being in the hobby

Take your car to the track and have another driver look it over... in the video it appears that you're trying to make it "crawl" and that's not realistic, I'd be more interested to see how the car handles under load in the chicanes, it's possible that it's working perfectly fine.

I didn't see any sensor wire and if there is a lower port then that should be fine :)

I'll have to do that. Just wanted to be as prepared as I could before showing up. I plan to go tomorrow when they open for off-road practice this week. I took a better video showing where the cv axles go into the diff. You can see this movement that I'm hearing and seeing with the rpm fluctuation. Doesn't seem right to me.

kinda looks like your arms are fluctuating up and down as the wheels spin, I recall that happens if you don't properly assemble the CVD's, chances are the pins are not aligned in the right holes, be sure to read the manual closely when assembling these parts and inspect to verify the pins are in the barrels right ;)