Outcast Are all the ARRMA 6s similar in noise to the Outcast?

[crunchtime]

Do all of the ARRMA 6S generate about the same amount of noise?

Opened our new Outcast 6s EXB this evening. I'd say our yard is just barely large enough for the Outcast to not be too bad of a fit, but I didn't consider how much noisier it would be compared to our 3s trucks. Kind of bummed about it actually.

Now that I read about it, I find it's normal for ARRMA 6s and we just need to accept it. I'm not sure if it is mostly the pinion/spur gears, the magnets in the motor, the limited slip action in the center diff, or all the above. Well, I feel fairly sure that at least a chunk of it is the pinion / spur. Our neighbors are pretty cool, but if we do a lot of this it might become annoying to them when they're just trying to relax outside in the fairly quiet neighborhood.

I've been scouring this forum looking for ideas. I see some things that people have tried, maybe with a little improvement. But it seems mostly that people don't have a lot of success unless they swap out for a quieter motor. I'd be willing to try a plastic spur gear if it helped, even if I had to replace it once in a while as it gets trashed. Or maybe try to enclose the exposed pinion/spur gears with some sound insulating material, although I've read where someone tried that and it didn't make much difference.

I only ran with 3S so far. Two of our 3s 6000mAH batteries together didn't fit. I don't yet want to take them out of their hard cases. I don't yet have a 4S or 6S. The performance just on 3S wasn't actually as terrible as I expected. Even on 3s the steering wasn't always so great as the front tires wanted to lift (we knew this is a limitation of the OC due to the SWB).

I was kind of surprised how hot the motor got, even when we were running on 3S. It seems like ARRMA should have gone ahead and included it as part of the RTR package.

Anyway, if you have any ideas, I'm all ears.

 

[abh16]

My outcast is much louder then my kraton but I've been been told it's because the mesh is too tight on the kraton. I dunno but I kept it cause I need it quieter like you....it doesn't have that loud clunk clunk gear clicking sound, just a quiet whirl a bit louder then the entire 3s lineup. on the other hand,, my 3s vorteks and 3s infraction are both significantly quieter then my big rock. Go figure.

 

[crunchtime]

@abh16 I might try a tighter mesh just to see if it helps. If it does, then I might sacrifice lifespan for less noise, like you on the kraton.

Is your outcast an EXB? I kind of think the limited slip differential, particular in the center diff, may contribute to the noise as well. And that might also explain why your kraton is quieter (if your kraton is not an EXB but the outcast is). This is my only 6S so I don't know what the regular diffs are like. But on my outcast if keep the back two wheels on the ground not turning, and I manually turn the two front wheels together in the same direction, it forces the center diff to do its thing (right?). When I do that, its a pretty loud clunkity / ratchety type noise that at higher speed I think could be pretty dang loud.

 

[N.Mango]

Metal straight cut gears are going to be loud.
Too tight of a mesh and the sound gets lower and too loose and it gets louder. (both not good)
If it's properly meshed the sound it makes is normal. Loud but normal.

 

[Diem Turner]

I can't say if the all do that as I only have one vehicle. Maybe the 6S lineup needs a bit of TLC to get them running smooth and quiet. On my Infraction I found that my car got a lot quieter after swapping in a PPS motor mount, 3rd party gears and better center drive shafts. I don't know if there was something off in the alignment that caused excessive gear mesh noise, the gears themselves, drive line vibration or all of the above. The motor also makes a bit of difference, my CC 1721 is ridiculously quiet. If I let the car just idle past me it makes almost no sound at all. Maybe that was just my car and shouldn't be used as a metric for other vehicles. But that was my experience. I can get my gears a few dB quieter by applying a thin coat of MXLR anti-wear grease to my pinion and spur/spool gears with a brush. I really like this stuff.

 

[crunchtime]

@N.Mango I'm going to experiment some with the mesh this weekend, to see how much difference it makes, and then set it back to normal.

@Diem Turner Thanks for the suggestions. I'm going to try some anti-wear grease. So far I don't see the MXLR through the online places I typically shop. I do see this one on amazon, which apparently is pretty thick (but I would apply very thin like you said). https://www.amazon.com/Tamiya-300053439-53439-Anti-Wear-Grease/dp/B00061HCX6

 

[Diem Turner]

@N.Mango I'm going to experiment some with the mesh this weekend, to see how much difference it makes, and then set it back to normal.

@Diem Turner Thanks for the suggestions. I'm going to try some anti-wear grease. So far I don't see the MXLR through the online places I typically shop. I do see this one on amazon, which apparently is pretty thick (but I would apply very thin like you said). https://www.amazon.com/Tamiya-300053439-53439-Anti-Wear-Grease/dp/B00061HCX6

Yeah, this stuff is thick. It has to be so that it has a high level of adhesion (centrifugal force will fling it off over time). You'll lose most of it over the course of a drive but it definitely makes a difference in noise. I'd give that stuff a shot, I'm sure it's similar.

 

[Moirae]

Motor plays a big part too. The wifey notorious is loud af too though with the stock combo. My talion when it had the castle 1717 combo was really quiet. I think you will need to get a castle combo if you want to be as quiet as possible.

 

[Diem Turner]

Motor plays a big part too. The wifey notorious is loud af too though. My talion when it had the castle 1717 combo was really quiet. I think if you will need to get a castle combo if you want to be as quiet as possible.

The 1717 is supa smoove too. My 1520, by comparison, was a lot more "chunky". The 1721 is on another level of smoothness. If you ever decide to get one, you'll Tiffany cufflinks.

 

[Moirae]

The 1717 is supa smoove too. My 1520, by comparison, was a lot more "chunky". The 1721 is on another level of smoothness. If you ever decide to get one, you'll Tiffany cufflinks.

I bet it's nice. My tp 4070 1700kv that's in my talion XXL sounds like a damn transformer rolling down the street. I feel so bad running it down the street at night. Don't let it stop me though

 

[Diem Turner]

I bet it's nice. My tp 4070 1700kv that's in my talion XXL sounds like a damn transformer rolling down the street. I feel so bad running it down the street at night. Don't let it stop me though

It is. It just rolls down imperceptible gradients all by itself. My 4080 is pretty chunky, but not too bad when I'm driving. My 5680 on the other hand...holy balls. That thing has sooo much "compression", it's ridiculous. I'm not able to turn the shaft with my bare fingers (I have weak hands and they're usually covered in lube, but that's a different story altogether....get your mind out of the gutter). I think that lunch box is going to be loud.

 

[Moirae]

My 4080 is pretty chunky, but not too bad when I'm driving. My TP 5680 on the other hand...holy balls. That thing has sooo much "compression", it's ridiculous. I'm not able to turn the shaft with my bare fingers (I have weak hands and they're usually covered in lube, but that's a different story altogether....get your mind out of the gutter). I think that lunch box is going to be loud.

I know what you mean for sure. I have a few tp motors I struggle to turn by hand. I have to use pliers to spin shaft to flat side .

I actually started to think maybe using medium start power in castle esc setting would be a good idea for those motors. I tried it and liked it a lot.

 

[N.Mango]

I know what you mean for sure. I have a few tp motors I struggle to turn by hand. I have to use pliers to spin shaft to flat side .

So you got lube on your fingers too?

 

[Diem Turner]

I know what you mean for sure. I have a few tp motors I struggle to turn by hand. I have to use pliers to spin shaft to flat side .

I actually started to think maybe using medium start power in castle esc setting would be a good idea for those motors. I tried it and liked it a lot.

I've only ever used low power. I'll have to give that a try and report back. Cheers for that

So you got lube on your fingers too?

In perpetuity

 

[AIan]

Rent a Harley for the weekend that they have lots of friends and family over and go for lots of rides reving the engine a LOT then after bringing it back on Monday go over to your neighbors and apologize and say you took a hit but you returned it cause you felt bad it was so loud in this peaceful neighborhood. They’ll never mind a little rc car after.

 

[Moirae]

I've only ever used low power. I'll have to give that a try and report back. Cheers for that

In perpetuity

Yea it definitely makes them a lot snappier. I first tried it on my k8s with the 5670 and it was actually a night and day difference. Truck felt almost like the 6s version lol. I've been using it on the 5650 in my felony too and it's been great there as well. I definitely lower the punch a little when I do it though.

 

[crunchtime]

I tried a few little things this evening to reduce the noise on the outcast. I was going to first mess around with the mesh, but I'm ticked off at the top motor mount screws. I have a high quality set of allen wrenches that I've had for many years, but the fit in those screws was so sloppy I could just tell it would strip the heads. The hex in the screws head seem oversized. I'm going to look at some other allen wrenches this weekend or maybe see if one of the SAE sizes happens to fit it better.

The anti-wear grease hasn't come in yet (Monday). So I was going to try some old white lithium grease that has been making my throw-around tool box smell bad for as long as I can remember, but instead tried just a little bit of petroleum jelly. That seemed to make a little bit of difference, not much.

Next I built a temporary shroud from cardboard over the motor, pinion area and even the ESC. Bad cooling I know so I only ran it for like a minute, just to see. I couldn't notice any difference in the noise.

Then.....I made a very small cardboard shroud over just the pinion gear area, and tucked a rag over the motor, shrouded pinion area, and ESC. Would be a thermal nightmare but I only ran it for a minute or two. I felt this made a lot of difference. Not sure what I can do with that information, because thermally it can never work. But it might lead to some ideas. If I add a really good fan to the motor, and with sound absorbing material not block air from getting to the motor fan and ESC fan, then maybe some improvement in the works.

Still only running on 3s, which is still at least a little fun, and isn't destroying the yard as quickly. Going to have to get to 4s or 6s soon.

 

[Diem Turner]

I tried a few little things this evening to reduce the noise on the outcast. I was going to first mess around with the mesh, but I'm ticked off at the top motor mount screws. I have a high quality set of allen wrenches that I've had for many years, but the fit in those screws was so sloppy I could just tell it would strip the heads. The hex in the screws head seem oversized. I'm going to look at some other allen wrenches this weekend or maybe see if one of the SAE sizes happens to fit it better.

The anti-wear grease hasn't come in yet (Monday). So I was going to try some old white lithium grease that has been making my throw-around tool box smell bad for as long as I can remember, but instead tried just a little bit of petroleum jelly. That seemed to make a little bit of difference, not much.

Next I built a temporary shroud from cardboard over the motor, pinion area and even the ESC. Bad cooling I know so I only ran it for like a minute, just to see. I couldn't notice any difference in the noise.

Then.....I made a very small cardboard shroud over just the pinion gear area, and tucked a rag over the motor, shrouded pinion area, and ESC. Would be a thermal nightmare but I only ran it for a minute or two. I felt this made a lot of difference. Not sure what I can do with that information, because thermally it can never work. But it might lead to some ideas. If I add a really good fan to the motor, and with sound absorbing material not block air from getting to the motor fan and ESC fan, then maybe some improvement in the works.

Still only running on 3s, which is still at least a little fun, and isn't destroying the yard as quickly. Going to have to get to 4s or 6s soon.

Replace the motor mount screws with cap head screws, 3mm Allen heads if possible. They limit how close you can slide the motor mount in, but they're a lot more robust and won't round out. Just be careful not to strip out the threads in the motor mount plate.

 

[AIan]

If you do decide on new hex wrenches MIP makes the best you need for all your rc stuff 1.5, 2, 2.5, & 3mm straight not ball end. are all you ever need, but just 2 & 2.5mm will get you started for 90% of your arrma rigs
And yes a socket hex cap screws for the motor mount top screws are great I used a couple washers too

 

[Diem Turner]

If you do decide on new hex wrenches MIP makes the best you need for all your rc stuff 1.5, 2, 2.5, & 3mm straight not ball end. are all you ever need, but just 2 & 2.5mm will get you started for 90% of your arrma rigs
And yes a socket hex cap screws for the motor mount top screws are great I used a couple washers too

I do hear a lot of good things about MIP. I'm a Wera tools man myself. I love the ergonomics of the handles on their hex drivers and their ratchets are a thing of beauty. I'm also a huge fan of the DeWalt gyroscopic screwdrivers. Those things are fantastic. A little pricey but a real joy to use.