RC10 goes slow, gets hot, stops, please help!

[Rizzo]

This is my first RC10 so it's been a bit of a learning experience. I went to a vintage meet last week, took off on my first heat, thought the car was a little slow, it did 4 laps & just stopped. The esc had turnd it off as it was hot.

Now, I have fully ballraced the 6 speed gearbox, bearings for the wheels, it runs a Tamiya Sport Tuned, standard Tamiya esc & a 4200 pack. This is the setup that I run in all my cars so thats why I went for the same in the RC10. In my frog or brat or Wild One, this combo flies & is more than quick enough for me, but the RC10 is noticibly slow.
I just finished installing the bearings, went for a drive in the backyard, it drove for 5 minutes before heating up & turning off. I have tried it with a different battery , same deal. The esc is burning hot & the motor smells like it's cooking. The leads to the motor & for the battery are not hot so there is no resistance there
The gearing is the kit supplied 54 tooth spur gear, with a 13 tooth pinion.

I also have , but havn't tried yet, a 78 toothed spur & 12,18 & 19 pinion gears. They are of a different pitch.

What am I doing wrong?
Help

Jak

[RETRO R/C]

Hi mate,

Could be a number of things - I imagine that your gear mesh is nice and free and not too tight? You should always set up with a little "backlash".

The standard cheapie Tamiya speedies shut down or "thermal"with regularity if you are running close to the edge with gearing.

Just make sure everything is free spinning too - those six gear trannies can be painfull to get free at times. Your biggest problem though is that sports tuned motor mate - they are like hand grenades!! Like I mentioned in the enduro thread - I have had them last for ages - and had them last for only barely a battery pack. Put a standard 540 in and see if you get the same drama's. The gearing may be a little low - but it should not be doing what it is doing. Make sure you lightly oil the bushings of the motor too.

Cheers

Darryn

[THUNDERSTRIKE1]

Sounds like the wheel nuts are too tight to me.Loosen them and run it again to see.Don

[Bugle]

Wheel nuts can't be done up too tight, the only problem you can have with them is if you have too many shims between the bearing and the wheel pin so the taper in the wheel doesn't meet the taper on the axle. Then it'll start preloading the bearings toward each other..

[Rizzo]

Thanks for the reply Darryn, I had Bugle check the backlash for me at the track. I moved the esc up on to the rear shock tower so that it gets a little air flow, rather than being down in the tub, I also changed the motor for the sports tuned out of my Brat as I know that flies. I just went out into the back yard & it lasted 5 minutes again before shutting down. I can't quite tell if it was any faster as I don't have an area big enough to wind it up.
I'm now thinking it's the gearbox, should I try a smaller pinion first though? before I tear the gearbox apart?

The wheels spin so freely that I can spin them, go make coffee, come back & they are still spinning.
regards
Jak

[THUNDERSTRIKE1]

The rear ones do bind up if nuts too tight ive had to loosen a bunch in the past to get it right and freewheels now.Don

[Bugle]

Would be worth trying the 78/18 gears you've got, 48 pitch is probably smoother too. I just went to 48 pitch as soon as I got mine.

How tall is the grass in your backyard? That can put heaps of strain on it driving through grass..

Thunderstrike you'd have to have the axle setup wrong for tightening the nut to bind the wheel, like I said with too many shims on 1/4" axles , or with 3/16" axles if you leave out the crush tube between the bearings.

[Rizzo]

I'll try the different gearing first.
I deliberatly drove it on the grass to see if it would overheat again, I just put a whole battery through the Wild One on the same grass, & it has the tallest gears i can put in it's Frog gearbox.
I'll change the gears now & give it another go.
jak

[Rizzo]

it doesnt' get any easier does it? Installed the 74 tooth spur but the smaller diametor, coupled with the small pinion, they can't reach each other. The motor has no more room to slide up as it hits the white gearbox.
Any ideas mate?
Jak

[RETRO R/C]

You want the biggest spur gear - and the smallest pinion you can find to lower the gearing.

I reckon it must be the speedie........cant see it unfortunately - but it seems to be pointing that way mate.....

Wish I was there to help you out "live"...

Not much else it can be other than an electronics issue really - as that gearing is already quite low.

Cheers

Darryn

[Bugle]

Might have to just get a bigger spur to give you the best range of pinion options and be possible to mesh them, I run 90t which is the biggest you can fit dunno if it'll fit inside a standard gear cover, 84 or 87 would probably be alright.

[Rizzo]

where can I get these from in Oz. Are they ready available still?
jak

[Bugle]

Yeah, most spur gears come with all the ball holes in them except if they're made for a B4 so it shouldn't be too hard to find one here, they're usually 12 holes instead of the original 8 though so you need the 12 balls. Liquid RC has them with $1 shipping if you can't find any around here.

[GJW]

come on jak work out the problem buddy process of elimination cant wait to hear what it is

[RC Chick]

I had a similar prob, mine was gearing. I was using a truck so I stayed with the 87 spur and had to get a 21t pinion to get it right. Ive heard you should use the same numbered pinion as the turns in the motor for a starting point. Try this link though

http://aedownloads.com/pdf/gear_ratios.pdf
http://www.rc10.com/racerhub/techhelp/marc/gearform.html