Spur to pinion gear ratio help

[z71baja]

What's up fellas, electronics and doing the simple math to combine a good motor set up is not my specialty. I looked everywhere in HH's site and couldn't understand the lingo. This is basically my issue........

I'm running a HH crawl master 27t with an 87t spur and a 14t pinion. I'm getting very little run time as I think I'm damaging my motor, or I already fried it. How many teeth should I change my pinion too?

Thanks for the help.

Happy crawl'nt

[HahnsB2]

That's plenty of gearing.

How much time is on the motor? Need new brushes? Does the comm need to be cut? What size battery?

[z71baja]

It's a brand new motor. Only has about one hour of run time. I'm running a 2s 3500mah 25c battery

According to HH tech support they are advising to re-gear it

[HahnsB2]

5:1 is what they recommend, you're already well over 6:1.

[k7zpj]

I would check for the spur / pinion mesh for being tight or for binding somewhere in the drive train.

[allanon1965]

is the motor getting hot? how much run time are you getting? 15 minutes? 45 minutes? couple hours? As mentioned already, make sure nothing is binding and the spur/pinion mesh isnt too tight... you are at 6.2:1 gear ratio, on 2s that will not be over geared or under geared..should be good. If you want more speed, you could go to a 3s battery..what is HH recommending for the gearing?

[z71baja]

I checked for binding and mesh tightness and everything is free and clear. the motor does not get extremely hot, but the problem is I'm only getting about 5 mins or less of run time before power is lost. HH was getting too technical for me as I am completely lost when it comes to ratios and gearing. That's why I opted to try here. All four of my rigs are set up identical (Integy 35T 87T spur 14t pinion on 2S and they run fine)

What I do notice when the motor looses power, I give it throttle while putting my finger on the motor and I can feel a clicking sound. Maybe this was a defective HH motor from the get go, or my gearing fried it, like HH seems to think.

How do I calculate my ratio?

[Soldat Vaillant]

Originally Posted by z71baja

How do I calculate my ratio?

spur gear tooth count (87) divided by pinion gear tooth count (14) will give you your spur/pinion ratio

87 / 14 = 6.21

set your gear mesh with a small strip of printer paper between the spur and pinion gears, then remove the paper once the motor screws are tightened down. this will give you the proper mesh for 48 pitch gears

[allanon1965]

A 6.21:1 ratio is not going to fry a motor....

[TacoCrawler]

pull the motor and run it stand alone...
still clicking ?

Maybe the clicking you here is coming from
inside the tranny ? original plastic gears ?

Maybe the clicking you hear is a bad tooth
on the idler gear ?

It's possibly a combination of issues causing fault.

You sure that your battery is fully charged when you start ?