unnamed

hi - i'm about to build a frog kit w/ the kids and was wondering if there's anything i should be upgrading to before the build so we don't have to rebuild it a week later?

we're adding a new motor (standard sport tuned), but just curious if there are important upgrades, if any, for a basic kit to help it run more smoothly or last longer?

i'm sure out of the box is fine, but hoping i can avoid any known weaknesses (x wears out fast, etc.) by asking some experienced builders.

Any thoughts?

suburban_hooligan

<div>if the kit does not supply them add ball bearings in the gear box and axles/wheels.  makes everything freer/smoother and more efficient.</div><div> </div><div>oil shocks if they are available for that kit.  makes the suspension smoother and makes the car handle better.  also a good mod if you plan on jumping it a lot, even if its just off the curb.</div><div> </div><div>an ESC if you don't already have one.  more efficient, better control, longer run times</div>

john01374

I've built a couple of frogs and brats (same chassis) over the years. First upgrade is bearings. Get the bearing kit before you build. The Frog chassis is a pain in the butt to take apart. Since you are using the sport tuned motor make sure you build the kit with the smallest pinion and largest spur. The kit comes with 3 pinions and 3 spurs to chose from. Start at the lowest gearing so you don't burn up the motor or ESC.

There are a lot of fasteners that screw into metal on this kit. Most are in the front suspension. Use blue (not red) Loctite on every fastener that screws into metal. A small amount is all you need so don't glob it on. Also make sure it is only on the threads.

The front steering also needs some help. The stock kit uses thin wire to connect the servo to the front wheels. Upgrading this to some good heavy duty turn buckles is a good idea.

Feel free to PM me if you have any questions during the build. I'm actually putting together my 3rd Brat kit right now. It's going to be a shelf queen so i'm polishing all the metal etc.

unnamed

thanks to both... this is great info. will probably look into that front suspension post-build. thanks again for the helpful info and tips!

john01374

You'll want to make sure you use that Loctite during the build. an RC car vibrates a lot and without Loctite on the metal to metal threads they will work themselves loose pretty quick and you could lose them. The Frog uses a bunch of Tamiya specific parts in the front suspension that can't be easily picked up at a hardware store. I'm going to start building my Brat next week. There is a Brat build thread over in the offroad section. Come on over and check it out. It's the exact same chassis.

mechanizeddeath

Built a Brat kit myself a few years ago, in fact it was my first RC. I did kind of a shoddy job assembling it, and an even worse job of driving it, so now it is a box of parts. But it was a great learning experience, and I hope to pick up another one soon.

As the others have said, make sure you get bearings. It comes with gearbox bearings, but you will still need them for the wheels. Threadlocker is essential, just be careful not to get it on the plastic. It is especially important on the 3 piece wheels, you will lose those tiny screws in just a few packs unless threadlocker is used.

mechanizeddeath

Another item of note: If you ever decide to buy a Grasshopper kit, the pinion from the "middle" gear pair (18t) paired with a 540 motor is a direct drop-in replacement for the stock 380. I also used the sport-tuned "black can" motor on my Brat, so I had the parts laying around when I got the Grasshopper.

One upgrade a lot of people like is the universal shaft kit: http://www3.towerhobbies.com/cgi-bin...?&I=LXNKY5&P=Z

unnamed

thanks, i will definitely be picking up the loctite and already have the bearings... regarding the shaft kit, what does this translate to as far as performance?

also, random battery question... i'm have an old 1500 nicad from the ninja, but am thinking about upgrading to a couple of 7.2v 4200 nimh packs. it says that they discharge at 42amps (specifically, Continuous Discharge Rate: 10C ( 42Amps)). is this something i need to be looking for when i purchase batteries?

and, i was thinking of picking up an onyx 210 as the charger? any experience w/ this? no worries, if not.

john01374

The shaft kit does nothing for performance. What it does is prevents you from losing the stock drive shafts. If you don't install the rubber boots correctly you run the chance them coming off and the axles being lost. I personally have never lost one but it COULD happen.

When buying batteries you need to consider the motor you are powering. If you where powering something like a brushless system then available amps should be considered but running a sport tuned it really doesn't matter all that much. I would always recommend someone go to Lipo packs but in all honesty you don't need that kind of amp delivery. I do recommend you go with a good 4000+mah NiMh pack as it will give you much better run times and more power than the 1500 NiCd you mentioned.

mrgoodbar

The Frog-series were/are notorious for spitting dogbones, probalby more so than any car in the history of RC. The CVD shaft kit he referenced does away with that problem entirely.
Compared to those old nicads you have, any of the newer packs will be night and day better. Don't be too obsessed with discharge rates, as they are really more applicable to racing and high powered motors and BLsystems witha neccessity for high discharge rate batteries.

unnamed

thanks to both... good to know, i just wasn't sure if the discharge rate was something that i needed to be concerned about (i.e., if it were something the motor or esc can't handle).

i think the shaft kit might be another that i'll look at later. thanks again for all the great info!

i still might be pm'ing you john if we run into issues on the build (we'll be starting this week... i may be more excited than the kids).

john01374

Sounds good. I'm on here a few times a day so i'll reply as soon as i can.