B44 build spur/pinion noise
 

just finished building my B44
and was able to testdrive for the first time

the pinion/spur make a very loud scratching sound
as if the spur is scraping against someting (it's not, but sound like it)
when i remove the engine the chassis is rolling smoothly without sound
i fastened/loosend the central diff but this didn't make the scratching sound stop (got even louder when the central diff became to loose)
the front and rear axle diff's are very smooth and loose (mabey to loose ?)

any idea what could cause this ? any solution ? or is this normal ?

I have a 12T brushless engine with the standard 84 spur and a 22 (tamiya) pinion

Have you got the motor meshed properly? And are you using a worn pinion with a new spur?

Sure there will be more suggestions, but, is the pinion to tight to the spur ? needs to mesh but also be a bit away - so the spur slightly rocks - but not much, try in all rotations of the spur, one side may be tighter, not to much gap or we get other problems, just right.

Tamiya pinions are the wrong pitch (tooth size) so you need to ask for a 22 tooth 48dp pinion, sorted!

Probably not , but is the ali cover above the spur on upside down ?

Try changing the pinion for a new one, i had a worn one on a new spur:blush: and that sounded BAD!!!

Long motor screws can rub against the rotor :blush:

new pinion, so that's not it
what's meshed ? (it's a brand new engine, do I need to do something with it first ?)

ok I'll try another one, my local shop has these :
atomic racing prod
http://shop.mcronse.be/index.php?cPa...&filter_id=171
or these from gw racing
http://www.mcmracing.com/catalog/ond...42-page-4.html

which size would be ok 19 - 20 - 21 -22 ?

i'll doublecheck on the motorscrews if they rub against spur, but I don't think I missed that.

Meshing is the how you place the pinion and the spur gear together. Too tight and there will be lots of noise, and everything will be very tight. Too loose and it will likely strip the spur gear.

for ideal meshing;

• take a bit of paper (thin like newspaper)
• put it between spur and pinion and mount the motor in such a way that the paper sits tight between the pinion and the spur, but still will not be torn apart when you turn the spur of pinion but comes out wrinkled.
• remove the paperstrip.

your pinion and spur will now be tight but with a very tiny amount of play and that's what you are looking for.

If that sentence refers to my post, I said that long motor screws can rub against the rotor (the rotating bit inside the motor :D), not the spur.
But as Hog said, check gear mesh first.

I think Mark probably has it nailed.

yes the meshing was not the issue :
I "eyeballed" it whitout the paper trick, even moved the pignon slightly towards and away but the noise was still the same
i'll try to get my hands on a 48pd pinion this weekend an see what happens...

in the B44 manual I see for a 12T engine a 21t pinion is adviced
should I get me one of those ?
I have a 12T brushless 23T brushed and 27T brushed engine
mabey another 22t pinion would be nice for the 27T brushed engine ?

Your going to be somewhat underpowerd with those motors in a B44, OK for simple bashing but not much else.

yes i am aware of that
but for nearest offroad rc circuit races these are (for now) the engines I can use
(going somewhere else I will need a faster engine so no problem there, i'll just buy a new one then)
just need to have the right size of pinion for these engines for now... ?
will the 21-22 do ?

i take its that it is the 12T ezrun motor a blue can? i would gear it on a 19 or 20 maybe a 21 so long as it is the one i am thinking off

nope it's a tamiya 12T brushless (engine allowed to enter the Belgian tamiya cup touring)
but i guess it will be similar to the one you are suggesting.

ahh ok then get a 21 on it and move up from there i would say maybe as high as a 24

The tamiya pinion I have is 48 pitch and makes quite a loud noise too even when seemingly perfectly meshed with the spur. Is tamiya's pitch different to everyone elses then or what?

wel got the new 48dp pinion and that works like a charm
thanks for the advice guys !