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I got my son the AMP... what should I get?

RCNoob

Member
Messages
8
Hello,

Great forum you have and I've enjoyed reading through the threads.

Could I please get a recommendation?

As the title says, I bought the AMP monster truck for my 9 years old birthday - he loves it - and we've already replaced parts!

So, I'd like a new toy too...

• Something that shares parts with the AMP so when have a shared bucket of parts, I assume all ECX come from a similar part list?
• 4WD? 2WD is really fun on the dirt, but maybe I'd like to go in a straight line now and then...?
• So offroad/monster truck or similar.
• NiMh - I don't like LiPo
• Maybe it should be fractionally faster....
• USD250/AUD350 is my budget (I'm in Australia)

Open to any suggestions!

Thank you so much.
 
Last edited:

Steve g

Well-Known Member
Messages
272
Location
Massachusetts
Well, you could get another amp mt, or even the amp crush, which has a different chassis and bulk heads, but tje drivetrain is the same. Its like a higher amp mt, which means more ground clearance, but it won't handle as well. I would stay away from 4x4 from ecx, they jusy dont hold up like the 2wd. And hardly any interchangeable parts.
If you do want 4wd, which is a good choice, I'd recommend either an armma granite 4x4, or the traxxas stampede 4x4. The traxxas has more aftermarket support, but I've read the armma is a little more durable.
Honestly though, don't shy away from lipo. They can be dangerous, but don't let the internet hype scare you. You get more punch (faster acceleration), less weight, and longer run times. Could use lipo in your truck, and the nihm in your son's, and that would get you a slight edge with identical trucks..In the very least, get a decent charger that does all batteries, with at least a 60w output (80 to 100 would be better). I would even recommend getting a dual charger, to charge 2 batteries at once.
 

RCNoob

Member
Messages
8
Thank you for the reply Steve.

When my Dad passed last year he left me a huge mountain of gear (petrol/electric RC planes) and the only thing I didn’t give away was a good chargers he had, so luckily I’m sorted there!

LiPo - it’s more that I want my son and his friends to be able to use the two cars and I don’t trust him with the charger etc just yet.

Thanks for the advice. I’ll check out those cars now.

I guess a strong option is just to put a faster motor in the same AMP and leave the rest of it?
 

Lephturn

Well-Known Member
Messages
60
I would get a second Amp. I did something very similar and got a Redcat Volcano for the second truck. 4WD is nice but I would have been much better off with two identical trucks. That way you can race them etc. The Amp is much tougher as well.
You can get a faster brushed motor if you want but LiPo is absolutely the way to go. The boost in run time alone is so much better plus it’s the minor speed boost you want. Only use 7.4v 2S LiPo and just zip tie the voltage alarm to the battery hold down. A good charger can overheat a NiMh easily too and although they don’t burst in the same way I dont think it’s safe for a 9 year old to be running chargers on his own. With LiPo he will get so much more run time out of it that you can charge them and he ad his friends won’t have to swap batteries like they need to with NiMh.

Finally I think your best upgrade is tires for handling. Play with the suspension until you get some negative caster in the rear and it will take some of the over steer out of it but a set of stickier rear tires will do wonders.
 

RCNoob

Member
Messages
8
I would get a second Amp. I did something very similar and got a Redcat Volcano for the second truck. 4WD is nice but I would have been much better off with two identical trucks. That way you can race them etc. The Amp is much tougher as well.
You can get a faster brushed motor if you want but LiPo is absolutely the way to go. The boost in run time alone is so much better plus it’s the minor speed boost you want. Only use 7.4v 2S LiPo and just zip tie the voltage alarm to the battery hold down. A good charger can overheat a NiMh easily too and although they don’t burst in the same way I dont think it’s safe for a 9 year old to be running chargers on his own. With LiPo he will get so much more run time out of it that you can charge them and he ad his friends won’t have to swap batteries like they need to with NiMh.

Finally I think your best upgrade is tires for handling. Play with the suspension until you get some negative caster in the rear and it will take some of the over steer out of it but a set of stickier rear tires will do wonders.

Thank you for that.

Can you please explain the voltage alarm, why is that required? What is it doing exactly?

How much of a boost does just a fast brushed motor give, or is it a slippery slope and you need to start updating gears etc..?

I do want to keep it simple - so if I can just swap out the motor without breaking/replacing everything else, that would be ace.

I like the idea of having the same car - especially for parts!!
 
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Lephturn

Well-Known Member
Messages
60
LiPo batteries need to stay in a certain range, 3.5-4.2 volts per cell. The Amp ESC does not have a low-voltage cut-off like ESCs designed for LiPo so to avoid damaging the battery you need to know when any cell gets down to a certain target voltage and stop running that battery. These little voltage alarms are under $10 each. I zip tied one to the battery hold down. When it alarms it beeps very loudly - you won’t miss it. You click a button on it to set the alarm at the voltage you choose - often recommended by your battery manufacturer. It also constantly cycles through a display of total voltage as well as the voltage for each cell. If you set the voltage alarm for say 3.4 it will alarm if a single cell hits 3.4 even momentarily under load.
 

Lephturn

Well-Known Member
Messages
60
A 2S LiPo battery will give you a good initial boost in speed as well as run time. I suggest starting there.
HRB 5200mAh 7.4V 2S 50C LiPo Battery Hard Case with Traxxas Plug for RC Car,Trucks, Boat https://www.amazon.ca/dp/B073RFV2DC/ref=cm_sw_r_cp_api_i_PxE-EbDDX7SZX

Here are the voltage alarms. Just get a 5 pack - they are cheap and I’ve lost one I didn’t secure well enough.

DROK High Accuracy 1~8S Battery Monitor Voltage Detector with Loud Beeping Sound Low Pressure Alarm Digital Battery Display 0.5V~36V for Remote Model Aircraft Battery~ https://www.amazon.ca/dp/B00WQW4I9E/ref=cm_sw_r_cp_api_i_YBE-EbG9FGM66

Whatever battery you get you can order an adapter to EC3 - the blue ones that come on the Amp. Or you can go the way I did and swap everything to a common connector type. After researching and looking at ease of soldering I think XT60 is the best choice. That way I can buy whatever batteries are on sale.

Amass 10 Pair XT60H Bullet Connector Plug Upgrated of XT60 Sheath Female & Male Gold Plated for RC Parts … … https://www.amazon.ca/dp/B074PN6N4K/ref=cm_sw_r_cp_api_i_nGE-EbVQ4201H

If you don’t want to get into soldering you can get batteries with connectors/adapters for EC3.

HRB RC LiPo Battery 2S 7.4v 5000mah 50C-100C XT60 Plug for RC Evader BX Car RC Truck RC Truggy RC Airplane UAV Drone FPV(EC3/Deans/Traxxas/Tamiya https://www.amazon.ca/dp/B0759YHCTX/ref=cm_sw_r_cp_api_i_xKE-EbDEPAXWX
 

Lephturn

Well-Known Member
Messages
60
I have just chewed up a couple of teeth on the Amp spur gear while running 2S LiPo but I won’t need to upgrade to metal gears. If I go brushless I think I will go with the metal gear set, but for now I don’t see the need to do it. If you go to a more powerful brushed motor you need to be prepared to adjust gearing with different pinion and or spur gears and monitor motor temperatures.

Here are some videos you should watch about motors. Learn to set your gear mesh properly, brushed motors require break in and cleaning, and set your slipper clutch so it actually slips when needed. I had to back the nut way off on the slipper clutch to get it to slip. If I had done that and set my gear mesh the first time I would have saved my spur gear.




 

Lephturn

Well-Known Member
Messages
60
Yes that is exactly what I am saying. I run this exact battery in it: Gens ace 7.4V 5000mAh 50C 2S LiPo Battery Pack HardCase with Deans T Plug https://www.amazon.ca/dp/B00WOAWHUK/ref=cm_sw_r_cp_api_i_kUtaFbQEB3XSP
I cut the deans off of it and soldered and XC60 on there, but you can find similar LiPo batteries with EC3 connectors that the Amp comes with.

Clean your motor, set your gear mesh properly and set your slipper clutch and you will be fine. Worst case you ruin a plastic spur gear but they are only $5 a piece. I’ve only ruined one and that was with 2S LiPo and the slipper clutch too tight when my son landed a jump from a skateboard ramp about 6 feet up on the back wheels and wide open throttle. On pavement and with almost no forward velocity when it landed. Munched a couple of teeth but I filed them a bit, adjusted the mesh and got 3-4 more runs out of it before I really ruined the spur gear.

I get a good half an hour out of that battery and that is alarming it at 3.7v. I zip tied a voltage alarm to the battery hold down and it works perfectly. I used some foam to ensure the battery is in there snug and doesn’t slide around.
 

Lephturn

Well-Known Member
Messages
60
Glad to help. I’m thinking of doing some YouTube videos to capture what I am learning my first few months to save other new folks some time and expense.
 
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