XRT Build issue

[XRTJusten]

Hey guys new to the forum. My name is Justen and I’m from Texas. I’ve been having issues with my XRT build. Basically it’s just a stock XRT with a max 6 g2 esc. Removed the stock motor mount with the pin system and put a pnwrcmadness motor mount with the stock motor. Upgraded the shocks to the ultimate shocks. I put ec5 plugs on the max6 to match my ovanic 9500mah 130c 4s batteries. When I try to run this thing it coggs really bad and won’t allow me to get any speed all. Occasionally I’ll ease on the throttle and it runs good. I need help with this. The truck has a 20/50 gear setup. RR pinion and steel Traxxas spur. Mesh is perfect. I’ve updated firmware to the latest firmware edition. Idk anymore. Please help.

 

[CreepyQuarryCrawler]

Hey Justen, Welcome to RC Talk!

That's a lot of fan on there, my gut says the gearing is way too hot.

My first thought would be to try gearing down. I don't have this platform, but if everything checks out (chassis rolls smooth) and you're still having this issue then I would try stepping down on the pinion.

Go down to something like a 15 tooth and see how the truck behaves.

I suspect it's going to be much happier off the line and you may find going down (maybe 12t) helps further.

 

[XRTJusten]

Hey Justen, Welcome to RC Talk!

That's a lot of fan on there, my gut says the gearing is way too hot.

My first thought would be to try gearing down. I don't have this platform, but if everything checks out (chassis rolls smooth) and you're still having this issue then I would try stepping down on the pinion.

Go down to something like a 15 tooth and see how the truck behaves.

I suspect it's going to be much happier off the line and you may find going down (maybe 12t) helps further.

It comes stock with 20/50 gearing. I’ll try stepping the pinion down and see what happens.

 

[CreepyQuarryCrawler]

It comes stock with 20/50 gearing. I’ll try stepping the pinion down and see what happens.

Yeah, I looked at the parts list. They offer other pinions too though.

Another thing to look at would be ESC settings. Perhaps your starting power or initial settings are dialed up?

 

[TeknoJ]

If you changed out the esc, you now need to mess with gearing and settings on the esc. Play with the start up power/punch, I think it’s your gearing. This is usually what a non sensored brushless motor does at low speed. I don’t care for the Traxxas stuff and I don’t have the platform.

 

[ferrebee88]

Might help to re-calibrate the radio to the ESC.

 

[XRTJusten]

Yeah, I looked at the parts list. They offer other pinions too though.

Another thing to look at would be ESC settings. Perhaps your starting power or initial settings are dialed up?

Yes I maxed out the punch and the initial throttle startup cogging still persists

 

[XRTJusten]

Might help to re-calibrate the radio to the ESC.

Done that numerous times already. It’s calibrated!

 

[CreepyQuarryCrawler]

Yes I maxed out the punch and the initial throttle startup cogging still persists

Okay, that's part of the problem.

Right now the ESC is trying to send a lot of power into a motor isn't doesn't know the rotation of.

So it blips the motor rotor (cogs - rotor giggles around - can sound like a mechanical buzz), that's to sense the rotor direction, then it applies power to the correct direction once it knows it.

When you have high gearing and cranked up ESC settings on a sensorless motor you are creating the perfect setup for this to happen.

I would lower the Initial Punch and any Boost settings or anything down.

I'm familiar with the Castle Link app where you can play with settings and throttle curves.

I am not familiar with HW's offering but I would assume they have something similar if you wanted to fine tune.

My attack plan would be to lower those settings and see what happens.

I'm not a Traxxas hater but they tend to under spec their electronics and gear their platforms aggressively. They then put fans on it to try and get by. I know when I ran Traxxas electric bashers I was always trying to jam the biggest motor I could into the platform.

So after lowering the settings if it is cogging badly I would look at dropping a few teeth on the pinion to start.

Good luck

 

[XRTJusten]

Okay, that's part of the problem.

Right now the ESC is trying to send a lot of power into a motor isn't doesn't know the rotation of.

So it blips the motor rotor (cogs - rotor giggles around - can sound like a mechanical buzz), that's to sense the rotor direction, then it applies power to the correct direction once it knows it.

When you have high gearing and cranked up ESC settings on a sensorless motor you are creating the perfect setup for this to happen.

I would lower the Initial Punch and any Boost settings or anything down.

I'm familiar with the Castle Link app where you can play with settings and throttle curves.

I am not familiar with HW's offering but I would assume they have something similar if you wanted to fine tune.

My attack plan would be to lower those settings and see what happens.

I'm not a Traxxas hater but they tend to under spec their electronics and gear their platforms aggressively. They then put fans on it to try and get by. I know when I ran Traxxas electric bashers I was always trying to jam the biggest motor I could into the platform.

So after lowering the settings if it is cogging badly I would look at dropping a few teeth on the pinion to start.

Good luck

Yes I’ve lowered the punch and initial startup as well! I will say the stock Traxxas esc in this xrt was junk it lasted 2 runs with the Traxxas batteries and about 1/2 run with the new ovanic batteries I got. On that last run with the ovanic batteries the esc gave me the 4 red lights of death!! It never impressed me very slow on it reflexes goin from forward to reverse. Crappy air control. But I have a maxx v2 and it has been great no complaints on there 4s platforms.

 

[9x19]

Quick and easy is to try recalibrating the ESC... and if you have a program card, check the settings for punch, brake, etc.

Good luck.