Novak 3.5 from 4.5 Brushless

[Benh]

I raced a Novak 4.5 brushless this weekend for the first time since i bought it. It didn't seem to run to well, then it cut out. After checking all the connections that are perfect I took it apart. I also took apart my 6.5 motor to see if I could spot any differences and why it was making a funny tapping sound.

My 6.5 has black spacers around the shaft. My 3.5 doesn't. Is this correct?

Has anyone experience this problem before? The rating is 4.5 and the shaft was changed to a 3.5.

Any comments including "you're a noob but...." would be much appreciated!

Many thanks

[mark christopher]

poss yuor 3.5 is a sintered rotor and your over geared hence the shut down.

changing a 6.5 to a 3.5 rotor will not alter the performance unless it being changed from a no sintered to a sintered, the windings are in the can

[lazerboy]

Si senor, exactly correct. Was your motor or esc hot? if it was, you got saved a couple hundred dollars from novak. Being sensored it knows when the rotor is locked, over heating, spinning too fast, etc. use a 10 tooth or lower.

[PaulRotheram]

10 tooth?! the guy hasnt even posted what car he runs..

[lazerboy]

yes, a 10 tooth pinion and 65 spur. good for a 3.5.

[Zipper]

I was there with Mr Ben H on Sunday and can confirm:

• The soldering and wiring was spot on.... because I did it!
• The motor & speedo were not hot, so it wasn't thermalling
• The motor shaft seemed stuck. You would turn on, hit accelerate but nothing would happen. You would give the pinion a turn by hand and then re try the acceleration and the motor would turn. It would turn very slowly and not smoothly.
• We took the motor to bits and checked the bearings were free.
• We tried different sets of cells
• We compared the inside of the Novak brushless motor to that of another Novak brushless and found no differences other than the black spacers around the shaft.
• We wanted to try and swap the shafts around.... but the pinion was stuck on one of them!

We just can't work out what is wrong?

[Zipper]

Originally Posted by PaulRotheram

10 tooth?! the guy hasnt even posted what car he runs..

He was running an XXT.

[bert digler]

Originally Posted by Zipper

He was running an XXT.

was it damp weather ie damp sensor wire classic fault on brushless

[Zipper]

Originally Posted by bert digler

was it damp weather ie damp sensor wire classic fault on brushless

It sure was damp! That must be it then. I'll get him to test it now it's dry...

[lazerboy]

electricity doesn't like water. so on your xx4 what's your spur? And as for my car it should be pretty obvious.(the one i'm getting anyway) Right now all i have is nitro.

[mark christopher]

Originally Posted by lazerboy

Si senor, exactly correct. Was your motor or esc hot? if it was, you got saved a couple hundred dollars from novak. Being sensored it knows when the rotor is locked, over heating, spinning too fast, etc. use a 10 tooth or lower.

Originally Posted by lazerboy

yes, a 10 tooth pinion and 65 spur. good for a 3.5.

Originally Posted by lazerboy

electricity doesn't like water. so on your xx4 what's your spur? And as for my car it should be pretty obvious.(the one i'm getting anyway) Right now all i have is nitro.

so you know what to run on his car even though you dont know his car or internal drive ratio are and to top it all you dont even have an electric car LOL

[Benh]

Originally Posted by bert digler

was it damp weather ie damp sensor wire classic fault on brushless

Firstly - Thank you Zipper for helping everyone with a much clearer explanation.

Secondly - Thanks Bert, your comments just saved the Noob spending more money!

Going to put it all back together today and test it. I have a sneaky suspicion that the Diggler is right.

Thanks again - I'll let you know the outcome.

[lazerboy]

mark christopher, where did you come from? and for most cars with a 3.5, anywhere from a 12 to an 8 tooth is good.

[Northy]

The trouble with small pinions is getting them to mesh. Anything smaller than about a 14 tooth has so few teeth relative to its diameter that the tooth profile goes all to cock.

At best it will result in a noisy mesh, at worst a stripped spur.

G

[lazerboy]

if you can make an electric soud like a nitro SWEET! but it's not so sweet if it destroys your spur.

dont post a link of that thing at unbelievable rc.

[Chris Doughty]

I really didn't think it was possible for a 48dp pinion to be smaller than a 14?

are we talking 32dp?

[super__dan]

You start to notice at a 16 I think (a little), more noticable on a 15 and very noticable on a 14.

I'd be amazed to see anything like an 8???

[mark christopher]

Originally Posted by lazerboy

mark christopher, where did you come from? and for most cars with a 3.5, anywhere from a 12 to an 8 tooth is good.

if you mean what racing back ground i came from electric off road from late 80's last 5 years have been both nitro and electric,

if you mean which planet did i come from , that would be planet Zogg

[lazerboy]

no, i mean what universe!
i looked at the xx and it's a big spur, so a 16 will probably work. The cars i had used 56 tooth spurs, so small pinions were a must.

[Northy]

Originally Posted by lazerboy

no, i mean what universe!
i looked at the xx and it's a big spur, so a 16 will probably work. The cars i had used 56 tooth spurs, so small pinions were a must.

But what about the overall ratio of the transmission?

G