Listen to my X10

[martinpal]

I've finally completed my X10 build. Yay!

When testing the drivetrain with motor with the tires off everything was great it sounded smooth, once I put the tires on and set it down I was surprised to hear such a strange sound at low speeds. This maybe normal since I am used to 2WD cars at low speeds.

The mesh is fine, I've tried 2 different motors both the same sound. The transmission seems very smooth with the motor off so I don't believe it's binding.

Maybe this is a normal sound from a 4wd with modified motor at low speeds if anyone can confirm that would be great. Just a note at higher speeds its fine and drives very well just around my small apartment

Thanks for the help.

Movie Click Here (1mb) --> 65.93.238.114:4000/rc/MVI_7399.avi

Mesh Area ( Are people setting the pinion this way? I also put the pen spring in the shaft to push the spur towards the back)

[YoKoMo-MX4]

martinpal said:

Maybe this is a normal sound from a 4wd with modified motor at low speeds...

Sounds normal to me. Modified motors are a bit 'un-smooth' at very low speed. The 'noise' may even be reduced one things have bedded a bit.

'nuff said,
MX4

[craig]

That sounds like a Gear Mesh issue. Not sure where it is coming from. You say the front and rear gearbox is fine so it could be from the Pinion/Spur Mesh.

Try backing off the Pinion Gear on the Motor just a little and see if it is any better.

[bigboss]

Mesh problem definitely.
First thing that comes to my mind is it's the wrong pitch, meaning it might be metric pitch pinion(like tamiya or kyosho use, 0.5 module, I believe it's called). If you change to another pinion, that is known to be
a 48 pitch pinion does it still make this noise?
Next thing, listening to that vid you made & looking at the pinion's teeth it seems to be worn unevenly (look at the tooth that's perpendicular to the camera, the one that's a shiny sliver of metal, see what I mean) that could also cause a noise.
Finally, just as a precaution make sure the motor mount is in line with spur gear.
Most chances are it's the pinion's wear that is causing the noise.
noise = drag = low efficiency = more heat = shorter run times, ect.
What motor & ESC are you using any way? looks like a Tekin.
hope this helps.

[chris burgess]

it doesn't sound quite right, but it's not far off. Have you tried a different pinion, just to make sure?

to ensure you have the correct mesh, put a piece of paper between the spur and the pinion, and mesh it so that it's tight. then remove the paper by turning the spur gear, and voila! A perfect mesh!

[alfonzo]

Doesn't sound quite right to me, it's the 'pulsing' sound i don't like, as if something isn't running true? Mind you, the Pred is not the quitest of cars to be fair. The bevel gears front and back do generate noise.

[Cooper]

all the ideas have already been given, but I must say thank you for such a good question! even with sound! ;D brilliant!

(for me it's also wrong/worn pinion or pinion to tight)



or maaaybe a wobbly prop shaft that rubs your pack, but only 10% of my brains thinks that

[martinpal]

Wow, I just wanna thank everyone for their input on this problem, I will try a few things today and get back to you.

[Northy]

Mesh too tight would be my guess.

Once I have meshed any car I always turn the spur gear and check the mesh in at least 5 different spots on the gear, not all spurs are created equally! This is not just TTech specific either.

G

[Cooper]

northy said:

check the mesh in at least 5 different spots on the gear, not all spurs are created equally! This is not just TTech specific either.

Grmmmbl.. I noticed that grmbl stupid grmbl B4 spur ...

[martinpal]

Good News ;D

I replaced the spur gear with my spare and everything is working great! I am very happy with how it sounds now.

The old spur really did seem ok, I am not sure if the pen spring could have caused this but I did remove it from the shaft as well, however it's running great and not about to take it all apart now just to check that theory out. I also removed the motor mount and remounted that as well.

Thanks again for the comments this forum is great.

[craig]

I'm glad you fixed your X10, good job!

[bjl]

How much backlash do you get using this method? The first time I set my backlash I adjusted it as per every other vehicle I run and stripped the spur on the first pack (with a stock motor, my mistake, everyone told me to run a tighter mesh). I then adjusted it so there was virtually no backlash, the propshaft still floated without friction but it made a similar noise as to the one martinpal posted. I assume somewhere in the middle would be a happy medium

admin said:

to ensure you have the correct mesh, put a piece of paper between the spur and the pinion, and mesh it so that it's tight. then remove the paper by turning the spur gear, and voila! A perfect mesh!

[chris burgess]

how much backlash? Just enough!

I have never stripped a sput gear on a Pred using this method. The spurs usually strip because the motor moves, not because the propshaft moves.

The "float" on the propshaft is nothing to do with the meshing of the spur gear. The float refers to the back and forth movement of the shaft, which is important for the meshing of the pinions inside the gearbox, allowing for slight chassis flex on bumps, jumps and impacts, without destroying the gearbox.

There should be no lateral (side to side) movement of the propshaft in this area of the car at all.

The spring in the propshaft also will not affect any of the above, and it is worthwhile putting it back in!