Granite Arrma granite 4x4 blx help

[Mk_Rc]

Hi, im new in arrma family...i just got my arrma granite 4x4 blx ?

But i already noticed one problem...when i press gas triger on my controler, my car has a trouble an struggle to move. Its shakes and you can hear strange noises...when i lift car from the ground don't have that problem and wheels spin smooth, only when tires are on the ground car its almost immpossible to drive. I don't know what is a reason for that? I need your help ?

 

[chevys10zr2003]

Does the motor spin? If so, you may just have to tighten up the slipper clutch.

 

[razorrc]

If it's some nasty grinding noises, then one of your gears is probably bad (spur, diff, or input gear most likely). Also possible just your pinion slipped off the motor.

 

[Jerry-rigged]

Could it be cogging? Next time it does this, give it a push with your foot, and see if it takes off. If yes, it is cogging. If no, something else is wrong.

 

[MysTiC27]

Hi, im new in arrma family...i just got my arrma granite 4x4 blx ?

But i already noticed one problem...when i press gas triger on my controler, my car has a trouble an struggle to move. Its shakes and you can hear strange noises...when i lift car from the ground don't have that problem and wheels spin smooth, only when tires are on the ground car its almost immpossible to drive. I don't know what is a reason for that? I need your help ?

View attachment 24905

Slipper Clutch !!!
You need to aim more tightly.
He did the same thing as you and after I adjust the slipper clutch you will find the motor skills you want.
Yvan

 

[Mk_Rc]

First thank you all ? No motor spine fine and also this doing only on start! when i get to car move its work everithing normal can drive it normal...
but when I want the car to go it starts to tickle and shake and don't want to move properrtly.

My first car with slipper clutch... and so this could be a problem that slipper clutch is not tighnet enougt.

When i finish with work i would try your recommendation ?

 

[Jerry-rigged]

No motor spine fine and also this doing only on start! when i get to car move its work everithing normal can drive it normal...
but when I want the car to go it starts to tickle and shake and don't want to move properrtly

This really sounds like it is cogging. If it was the slipper, the motor would be revving smooth, and the truck would be slow / not moving at all. And the slipper would not start to run fine once the truck starts to move.

If you installed a larger pinion, that is probably the cause of the cogging. If you are running the stock pinion, then your ESC may be having issues, contact Horizon. Horizon is great about making stuff right.

 

[Mk_Rc]

i try to tight a slipper clutch but stil same problem... It looks the same like this ?

 

[bicketybam]

That's cogging. Is contact Arrma/Horizon for a replacement.

 

[Jerry-rigged]

Yes, that video is 100% cogging. This has nothing to do with the slipper.

let's talk basics for a moment (sorry if this get long, or too basic, but it can be important to understand what is going on here)-

With a electric motor, there is a Fixed Magnet(FM), and a Electro-Magnet(EM). when the EM gets power, it gets either pulls toward the FM or pushes away from the FM, depending on the polarity of the magnetic fields. To make the motor spin, as the EM and FM align, the EM must briefly switch off, then switch off, then switch on in negative polarity - so it begins to push off that magnet, and pull towards the next one.

In a brushed motor the FM are attached to the can, and the EM are on the rotor, with a Commutator/brush to control the flow of electricity, and insures that the EM in the rotor is always pushing/pulling at the correct time. The Comm is fixed to the rotor with the EM, and the brushes are fixed relative to the FM. It is always in sync with the relative position of the EM and FM. Because of this, the ESC only needs to apply power, and the motor turns smoothly. The Brushes and Comm are doing all the power switching.

In a brushless motor the EM are fixed to the motor can, and the FM are on the motor rotor - there is no Commutator to control the flow of electricity. The ESC uses the three wires to pulse electricity to the EM coils. To figure out which coil to send the power to, the ESC needs some way to figure out the position of the magnets on the rotor. With a sensored motor, there is a physical position sensor inside the motor, reporting back to the ESC. This allows the ESC to always know where the rotor is, and which coil it needs to send power to, to make the rotor spin the correct direction.

But - with our sensorless setups, the ESC does not know the position of the rotor. So how can it run the motor? It relies on electrical feedback. When the rotor is spinning, the EM coils that are Off become generators. ESCs made for sensorless motors have extra sensors in the ESC that can read this feedback, and use it to keep up with the position of the rotor. Pretty cool, right?

But - what about when the rotor is not spinning? When the car is not moving, there is no feedback, so the sensorless ESC does not know the rotor position. In this case, it kind of give semi-random, blind pulses to the motor, in the hopes that the rotor will spin enough to give some feedback that the ESC can use. During this blind faze, the motor will "Cog" - that is vibrate and shake. Sometimes it will roll the car forward slowly, with much jerking. Once the ESC gets the feedback it needs, it knows the rotor position, and can apply power to the correct coils, and the motor spins smooth again...

If everything is working correctly, a sensorless motor should not cog much - most of the time we won't even notice it. However, if there is a problem in the system, it can be a nuisance, or even a problem. One cause of cogging - gearing too high. During the cogging faze, the ESC is not providing much power, so the motor does not make a lot of torque. If the gearing is too tall, the motor may not have the power to move the car enough to spin the motor enough to start the feedback loop. If this is the case, you can lower the gearing (smaller pinion) and sometimes reduce cogging to acceptable levels. Another issue - If the ESC has a weak/bad feedback sensor, it will cog. In this case, you need to replace the ESC.

TLDR - if you have not changed the gearing, contact Horizon. They should warrantee the ESC.

 

[Mk_Rc]

Thank you all ? you are the best! Yea i would write on arrma horizon and i hope for the best ?

here is my video clip

 

[Mk_Rc]

I have one question when I bought the car I put the battery new from the box and I connected it. are the lipo batteries at the start filled? Is this could be maybe problem in my case? I have already sent her to the horizon hobby to see what is the problem but now i just looking for reason.

 

[bicketybam]

I have one question when I bought the car I put the battery new from the box and I connected it. are the lipo batteries at the start filled? Is this could be maybe problem in my case? I have already sent her to the horizon hobby to see what is the problem but now i just looking for reason.

They came with a storage charge. It’s like 30% of capacity I think. In any event, that wasn’t causing your problem.

 

[Mk_Rc]

They came with a storage charge. It’s like 30% of capacity I think. In any event, that wasn’t causing your problem.

ok. thanks for the quick reply.

 

[Mk_Rc]

hi, finally i got my granite blx back from service....it was take almost 2 month from my
purchase today i do a little test on asphalt with 2s an 3s battery and car is fantastic can't wait to try car on dirt, snow and gravel!