Grassroots RCsports - Chinese Knockoff Review Edition

I got my son one of these for his birthday:

http://www.gearbest.com/rc-cars/pp_351315.html

The WLtoys No. 12428 buggy. It is pretty much a knockoff of a Vaterra Twin Hammers. In fact, they have parts that can swap:

https://www.youtube.com/watch?v=gXfVu-zWnj4

I paid $68 shipped from GearBest. It took three weeks to get it from China. but it showed up intact. In the box you get the assembled car, the remote, a 7.4v lithium battery (not a LiPo), and battery charger.

I broke it in by flipping it over and running it at half throttle for half an hour, with varying the throttle at times. I wanted to get the brushes on the motor set and get the gears bedded in.

I gave it a nut & bolt check and found everything tight. The only adjustments I made was to lower the rear suspension by swapping the locations of shock mounts. That gave the rear u-joint a smoother angle. I slapped a heat sink on the motor just in case (dirt cheap insurance and it fits like a glove: https://smile.amazon.com/gp/product/B01DIOV756/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1 )

Steering trim is okay. The steering is not as precise as my Associated drift car but it is VERY forgiving to taking a beating.

Driving it is insane. With the throttle trim set at 60% of WOT it will lift the front right tire from a stop until the tires are broken in, then it will just spin all four tires until it find traction. The car is VERY floppy on the street, but it soaks up the bumps in the yard very well. The shocks are not oil filled, but that can be fixed easily.

Technically it is my son's car...which I why I ordered one for myself this morning. The way I see it I can swap the entire electronics setup to standard R/C stuff pretty cheap if it ever fails.

When mine comes in I'm going to start looking at how I can drop on a Model A body on it. I'm thinking a Nux car-type build would be awesome:

Cool. Definitely keep us updated. My little nephew wants more speed, and I'd rather toss him this than the B5M.

How does it do on gravel or in the grass?

I'm looking for something cheap and fun to chase my toddler with, and have been watching cars like this for a while.

In for grass and gravel review. My daughter is showing interest.

It charges through grass like a beast, but it is hard on the motor. That's a problem with almost every R/C car, grass is hard to run through and drives up motor temps. But slapping the heatsink on the motor will hopefully help. We haven't hit thermal shutdown yet, just low battery cutoff.

I only have a small patch of gravel, but the suspension works like a trophy truck on it. The body stays level while the suspension soaks up the bumps.

The only thing I found odd was trying to jump it over my driveway lip like I do with my HPI WheelyKing. I get a nice slap wheelie usually at part throttle, or full flight at top speed. This thing just soaks up the bump and keeps going. Same thing with the exposed tree root that launches my WheelyKing like a shuttle launch. The WL 12428 soaks up most of the initial shock and only catches about 6" of air.

When I mow our front yard this week I'm going to scalp the areas with very little grass so we can have a race track.

Last year when my son expressed interest in racing RC cars, I got him a WL Toys A959 4WD buggy for a similar price. It's more of a high speed, smoother ground sort of thing than in the original post. It's pretty quick on a paved driveway, but it bounces around too much on a gravel driveway. I'm sure slefain's car will be much better on not paved/smooth surfaces. It took me awhile to figure out that a one inch high driveway seam is pretty huge to a 12 inch long car with half an inch of ground clearance.

Just like slefain, I decided I had to have one, too, so we could race. Then we needed to buy another one to keep the first two running as they aren't the most robust things in the world (one speed controller, one motor, two differentials in over 50 hours of use between the two cars.)

For what it's worth, we chose this model because replacement and upgrade parts are readily available on Amazon and elsewhere online. I didn't want something that you had completely throw away and replace, and with this car, you can upgrade most things that might fail multiple times.

pkingham wrote: Last year when my son expressed interest in racing RC cars, I got him a WL Toys A959 4WD buggy for a similar price. It's more of a high speed, smoother ground sort of thing than in the original post. It's pretty quick on a paved driveway, but it bounces around too much on a gravel driveway. I'm sure slefain's car will be much better on not paved/smooth surfaces. It took me awhile to figure out that a one inch high driveway seam is pretty huge to a 12 inch long car with half an inch of ground clearance. Just like slefain, I decided I had to have one, too, so we could race. Then we needed to buy another one to keep the first two running as they aren't the most robust things in the world (one speed controller, one motor, two differentials in over 50 hours of use between the two cars.) For what it's worth, we chose this model because replacement and upgrade parts are readily available on Amazon and elsewhere online. I didn't want something that you had completely throw away and replace, and with this car, you can upgrade most things that might fail multiple times.

The A959 has a more traditional suspension layout, more like my old 2wd buggies.

I priced out replacement electronics a few months ago:

$21 ESC http://www.amazon.com/HobbyWing-QUICRUN-1060-Brushed-ESC/dp/B00LXCM3Q8/ref=sr_1_5?ie=UTF8&qid=1454094988&sr=8-5&keywords=hobbywing+esc

$37 radio http://www.amazon.com/FlySky-FS-GT3B-2-4GHz-3-Channel-Transmitter/dp/B00FS2UAHS/ref=sr_1_2?ie=UTF8&qid=1454095057&sr=8-2&keywords=radio+sky+fly

$7 receiver http://www.amazon.com/Flysky-FS-GR3E-Receiver-FS-GT2B-FS-GT3B/dp/B00IZUIHPM/ref=pd_bxgy_21_img_2?ie=UTF8&refRID=02CP3MG6PSAWK0HJDTVP

$12 servo http://www.amazon.com/Futaba-FUTM0031-S3003-Standard-Servo/dp/B0015H2V72/ref=pd_sim_21_3?ie=UTF8&dpID=41bJ6ryi1oL&dpSrc=sims&preST=AC_UL160_SR131%2C160&refRID=02CP3MG6PSAWK0HJDTVP

So I can have all new hobby grade electronics for $77, which is still pretty cheap all things considered.

The Barrage Doomsday is going to be out soon, and I want to either snag a complete body, or at least the exhaust/engine parts kit:

The pipes/engine are $12, which is reasonable:

Very cool! I have a Tower Hobbies short course truck that I beat on.

Can those run 3s packs? Mine is NUTS on 3s. Good shock oil and some 200k weight in the diffs is awesome.

I've seen some videos online of guys running 3S through one, but I'd be hesitant to push it on the stock electronics. The chassis can barely handle the power as it is stock. I've run ours on a 7.2v NiMH pack and the stock 7.4v lithium pack, and both give plenty of power. I zip-tied the 6-cell NiMH stick pack onto the back of the car to try and give better run times, but the greater weight made it a bit easier to tip. Next I'm going to test running two lithium packs in parallel.

Welp, the first chink in the armor. It ate the diffs already. Technically, it wallowed out the bevel gears that attach to the ends of the metal axle stubs. The gears themselves are not chewed up, but the keyway that holds them to the axle has gone from I-shaped to rounded. I'm going to JB Weld them back on and see how it goes. I also order two sets of diffs just in case, a whopping $14 on Amazon.

Now I'm not going to lay blame, but my son may have been part of why the gears stripped, as he likes to make his R/C cars dig holes with their tires. I may lock the rear axle when the spares come in and see how it goes.

Almost forgot. Diffs are $7 for both front and rear: https://www.amazon.com/gp/product/B073RYBGZK/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

And I picked up a complete rear end from a similar model that supposedly has metal gears. We'll see if it works: https://www.amazon.com/gp/product/B01LZVAYZC/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Upon further consideration I realize the fried diffs may have been my own fault. I slapped in a NiMH 6-cell pack that weighs in at 12oz. The stock battery only weighs 4oz. Couple that with the power on tap and the tire grip, I think I found my problem. Time to just order a few more battery packs as spares.

I'm putting the JB Welded axles back in this afternoon, so we'll see if I fixed it.

Perhaps metal diffs could hold the powa?

pheller wrote: Perhaps metal diffs could hold the powa?

Looking for metal diff options now. The complete axle assembly I bought may have metal gears, but I don't know til I crack it open. It may also have a different axle ratio, so I'll have to do the math on that.

There is a metal rear axle option for $36, but I'm going to wait on that for now.

JB Weld didn't stand a change, it blew the repaired diffs in just a few seconds. We'll see what the new axle assembly brings tomorrow.

(edit) post mortem on the diffs. One gear held up, but the other stripped. I tried melting the back the gear into a square pattern to give the JB Weld something to lock against. Trying JB Weld again, since the replacement diffs won't be in til next week.

The KELIWOW Rear Axle works perfectly! https://smile.amazon.com/gp/product/B01LZVAYZC/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1 It also included metal hex drives, which are a nice upgrade from the stock plastic pieces.

It has all metal gears inside and out. It was a dead nuts bolt in to mount in the car. The gear ratio is slightly off from the stock unit, but it doesn't seem to affect it. I had to flip the ring gear to make it rotate the right way, remove a tab inside the pumpkin to allow for the relocated ring gear, and file two flat spots in the pinion shaft to give the stock driveshaft set screws a place to lock into.

I'm going to go ahead and order another rear axle for my car and drop it in as soon as I have the drivetrain broken in.

It's been a few days and the new rear axle is holding up perfectly.

Also, my own car showed up in the mail! I had to lower the rear suspension as the driveline angle was making the U-joints click. Other than one part being a different color, it is the exact same car as my son's. I gave it a good thrashing around the yard yesterday and it seems good to go. I can't decide if I want to go ahead and drop in the metal rear axle, or run the stock ones til they blow.

For a brief second last night I wanted to make my car look like the MegaForce buggy, but I can't find a 1/12 Lexan body that is similar enough.

You might have luck with a OG RC10 or JRX2 body.

You might have luck with a OG RC10 or JRX2 body.

Oooh, good call on the RC10 body. Tower has them for a whopping $12. It is 14" long but so is my buggy. That paint job will be hell to replicate though. Lots of masking. Maybe it will be "inspired by" and not a replica.

Now that my B5M is up and running I'm going to need something a little quicker for my nephew to play with. He's 4 but has been playing with RC cars for half his life - no exaggeration. Still, I'm thinking the stock top speed of the 12428 might be a bit much for him at first. Any ideas on how to limit top speed easily?

Keith Tanner wrote: Now that my B5M is up and running I'm going to need something a little quicker for my nephew to play with. He's 4 but has been playing with RC cars for half his life - no exaggeration. Still, I'm thinking the stock top speed of the 12428 might be a bit much for him at first. Any ideas on how to limit top speed easily?

I have the throttle trim set at about 60% for my son. The throttle trim on this car acts more like a speed limiter than a neutral point adjustment. I had my car dialed down to about 40% while I gave it a few practice laps around the yard. As long as he keeps his fingers off the "more faster" knob, he should be fine.

Sweet. Thanks.

Keith Tanner wrote: Now that my B5M is up and running I'm going to need something a little quicker for my nephew to play with. He's 4 but has been playing with RC cars for half his life - no exaggeration. Still, I'm thinking the stock top speed of the 12428 might be a bit much for him at first. Any ideas on how to limit top speed easily?

Depending on your esc (I'm guessing it's the race one still) it's programmable. All of the ones I have are castle sidewinder, so I can completely control throttle trim, delivery, ramp up, etc. Alternatively you could tape some foam to your radio handle to physically prevent the trigger from going wfo

I'm not asking about the ESC in the B5M, but in the WLToys unit here. Looks like it can be trimmed back pretty easily.