Big Rock Big Rock 3s Grinding Noise

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matflat

Active Member
Messages
71
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75
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158
Location
South Africa
Arrma RC's
  1. BigRock 4x4
  2. Typhon 3s
Hello Arrma Forum Members,

I am a new poster and just took ownership of a Typhon 3S and a Big Rock 3S. The first week of owning them was awesome. However, the shop that sold them to me is unhelpful, so I am turning to you all to ask for some guidance and help. It is very difficult to get parts in the country (despite the shop being the main importer), so would really appreciate some guidance before I order parts from overseas.

The issue with the Big Rock is in the attached video, and I am hoping that it is a normal noise. But you will see in the video that if I push the car forwards and backward, there is a noise. I can't call it grinding, but it sounds like it. Does anyone have any idea what could be the culprit?

This is what I did to check various parts. Firstly I took out the driveshaft. Then moved the car by hand again forwards and backward. I get the noise. So I take the motor out. Then I turned the motor by hand once it was out of the car, and no noise there. I opened up the motor to check if there was any dirt and found nothing. Checked the plastic teeth and they are tip-top. The metal pinion also is fine, and the gears look like they are meshing just fine. I also then heard that the slipper clutch might be an issue. I check this, make it tight, and then untighten it a little bit (as I was advised, and also because in another post I will explain how I sheared the bolt on my Typhon :-) ).

With everything out of the car, I move it forwards and backward again. No noise at all. So I put all that back together again. Motor first. Move it forwards and backward and I get the noise again.

Each component on its own doesn't make a noise, but when added back together it seems to do something I can't work out.

Really hope someone can help me out. And if there is anyone from South Africa that has knowledge of parts shops that can help that would be really appreciated. I love these cars, and me and my kid are like unhappy dogs because we can't go blast around the park :)

Thanks,
Mat.

 
That noise is perfectly normal. It seems that your troubleshooting is on point. I believe the sound you hear is just the product of the magnets in the motor and the nature of the slipper/spur gear design. Keep an eye on your motor though. The bearing at the pinion side tends to wear out and eventually fails due to dirt and debris getting sucked in there. If you try to wiggle the pinion and there is any side to side movement and clicking, it's on its way out. It's much easier to replace before it completely fails. As that bearing goes, it can also keep you from maintaining a proper mesh, eating up spur gears. Also keep an eye on the motor mount plate as it can bend and affect the mesh as well. Just some stuff to look forward to!
 
Hello Arrma Forum Members,

I am a new poster and just took ownership of a Typhon 3S and a Big Rock 3S. The first week of owning them was awesome. However, the shop that sold them to me is unhelpful, so I am turning to you all to ask for some guidance and help. It is very difficult to get parts in the country (despite the shop being the main importer), so would really appreciate some guidance before I order parts from overseas.

The issue with the Big Rock is in the attached video, and I am hoping that it is a normal noise. But you will see in the video that if I push the car forwards and backward, there is a noise. I can't call it grinding, but it sounds like it. Does anyone have any idea what could be the culprit?

This is what I did to check various parts. Firstly I took out the driveshaft. Then moved the car by hand again forwards and backward. I get the noise. So I take the motor out. Then I turned the motor by hand once it was out of the car, and no noise there. I opened up the motor to check if there was any dirt and found nothing. Checked the plastic teeth and they are tip-top. The metal pinion also is fine, and the gears look like they are meshing just fine. I also then heard that the slipper clutch might be an issue. I check this, make it tight, and then untighten it a little bit (as I was advised, and also because in another post I will explain how I sheared the bolt on my Typhon :) ).

With everything out of the car, I move it forwards and backward again. No noise at all. So I put all that back together again. Motor first. Move it forwards and backward and I get the noise again.

Each component on its own doesn't make a noise, but when added back together it seems to do something I can't work out.

Really hope someone can help me out. And if there is anyone from South Africa that has knowledge of parts shops that can help that would be really appreciated. I love these cars, and me and my kid are like unhappy dogs because we can't go blast around the park :)

Thanks,
Mat.


That's the normal sounds it makes.
It's got plastic spurs and differentials..

You should heard the 'normal' noises on the 6S rigs..!!! 😆
 
Welcome to the forum!

Yep, absolutely normal (y)

It's the sound of the gears (pinion and spur) chattering since the rotor is fairly "bouncy" (snapping from one stator position to the next) when it spins at low RPM. Every RC model has a distinct "signature" noise like that. Kind of fun to hear the various ones honestly!
 
That noise is perfectly normal. It seems that your troubleshooting is on point. I believe the sound you hear is just the product of the magnets in the motor and the nature of the slipper/spur gear design. Keep an eye on your motor though. The bearing at the pinion side tends to wear out and eventually fails due to dirt and debris getting sucked in there. If you try to wiggle the pinion and there is any side to side movement and clicking, it's on its way out. It's much easier to replace before it completely fails. As that bearing goes, it can also keep you from maintaining a proper mesh, eating up spur gears. Also keep an eye on the motor mount plate as it can bend and affect the mesh as well. Just some stuff to look forward to!
So many thanks 🙏 at least I managed to get some of the fault finding right - you guys rock (like the Big Rock).
Welcome to the forum!

Yep, absolutely normal (y)

It's the sound of the gears (pinion and spur) chattering since the rotor is fairly "bouncy" (snapping from one stator position to the next) when it spins at low RPM. Every RC model has a distinct "signature" noise like that. Kind of fun to hear the various ones honestly!
Thank you Hector 👍🏻👍🏻👍🏻🤩
That's the normal sounds it makes.
It's got plastic spurs and differentials..

You should heard the 'normal' noises on the 6S rigs..!!! 😆
Thank goodness. I’m new to this game so strange noises freak me out 😊
 
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