RC 4x4 models (EN)
HG P402 Rock Crawling
2015-08-24: Heng Guan P402 Rock Crawling

How about some rough terrain? Yes, we took the Heng Guan P402 for a rock crawling session and here are our findings.
Axle crossing is reasonable, approach and departure angles are limited by the bumpers as by the real Mercedes G63. However, the bumpers can withstand really hard driving on the HG P402 .
The car has a reasonable ground clearance. One needs to pay just a little attention to the differentials, but as you can see in detail in the video, hitting a stone with the differential casing does not cause any damage. Differentials are placed in the middle of axles. If you are used to your Land Rover, where the differential is not in the middle of the axle – there is no higher ground clearance beneath the driver at the HG P402 ;) .
Steering servo had a hard time in some cases – it is not strong enough if you want to move a large piece of rock with the wheels. This is logical and one should think about it, not to overheat the servo and/or damage the steering rod.
The car would greatly benefit from much slower gear transfer ratios in this terrain. The electric motor does not have enough power to turn the wheels very slowly, one must give it tiny pulses to get the wheels move. Furthermore, the car is not standing still on a steep slope. It has some kind of brake, but it is not capable of holding the car still.
This is what bothers me most about – to crawl the rocks really slowly with great precision, the car would need to be equipped with a CPU control to force the electric motor turn regardless of load (within reasonable limits of course). At least that's what I did on my Tatra 130. Again, this is a general problem of almost every RC car/truck.
The P402 can even take a shower, its a great fun :) . The body is made of one piece and it is waterproof, so hardly any droplets get inside at the battery and/or the electric motor. You can stand under a waterfall and take beautiful photos ... as long as the water stream does not snatch it away :).
In the previous video I've shown some moderate diving. This time we went a bit deeper – you can see at the photo how much you can dive the car, before the water level get even close to the electric motor. Moreover, if you know the correct technique of wading at the right speed, a wave gets created before the car and a depression just under it, so even less water actually gets inside.
Conclusion Generally, I'm impressed. The P402 managed to get through actually very well. It's not a natural rock crawler – it's similar as if you took a series Mercedes G-klasse in such a terrain. It will make it through, but you should carefully pick the right path. Only one small issue appeared – rear tire got partially stripped from its rim. There was no damage to the chassis, drivetrain or bodywork.

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