Cars Traxxas car problem

[bigone5500]

Neighbor kid brought this to me but can't get it to run. It's old with an am xtal. Any ideas what to check?

 

[Tony]

Wow, I have not seen a Mechanical Speed Control (MSC) in YEARS!!! That car just needs an upgrade. Get a good speed control and brushless motor and it should work. I would also highly suggest a new Tx as well. With those MSC's, they arc and those AM Tx's start going NUTS! So that is where I would start. You can find really cheap ESC/Motor combos online all day long. And it looks like it is just a 540 size motor. Oh yea, and the brushes could be worn flat out on that car as well. Yet another reason to upgrade.

I want to see this run when you get it going!!!

 

[bigone5500]

The steering doesn't work either. I plugged the battery initially and the rear wheels jumped. Then nothing.

 

[Tony]

Could be a bad MEC not supplying power to the Rx, or it could be the rx.

 

[bigone5500]

I told him he needs to get a DSMX Rx and transmitter. But then again by the time he gets new stuff to get it going, he could probably get a new car altogether.

 

[bigone5500]

Ok. Not sure what happened. But I'm thinking that the battery is probably bad. I checked voltage before I tried to run it and it had somewhere around 7.8v. It's a 7.2v pack. After some troubleshooting, I decided to check the battery again. Zero...dead. I placed it on my charger and let it charge for about 15 minutes and put around 450ma of charge into the battery. I got around 1 minute of run time from that. As a last resort, I'll set my charger on cycle mode and see if I can get it to revive. The pack doesn't look all that old but looks can be deceiving. As of this post, the charger has been going for 30 minutes and has injected 900 mA of charge. The pack is a 1500mAh pack. I'm thinking 45 minutes and it should be done. I'm also charging it at 2.0 amps in auto mode.

I'll post back with my findings tomorrow.

Thanks.

 

[bigone5500]

Coolest thing is he got it at a garage sale for $20.

 

[Tony]

Put a 2s LiPo in it. That will give him the run time he needs and the power.

Those batteries are a pain. They keep a memory and if you do not take great care of them (more than with a lipo), they will die or not charge to full capacity. I have thought about doing a video on those batteries, but not many people are running them anymore.

 

[bigone5500]

So I bought this thing from my neighbor for $25. Maybe I won't regret it.

 

[Tony]

get rid of the mechanical speed control and put an ESC on it. Might as well just get a brushless setup for it. Just trust me on this.

 

[bigone5500]

So traxxas said this is a replacement would work. It's the XL-5.

https://traxxas.com/sites/default/files/KC1761-R01_3018R-XL5_INST_140430-EN.pdf

Here's the specs:

Specifications:
Input Voltage.....................................4-7 cells NiMH; 2S LiPo
Case Size.............................................1.23”W x 2.18”L x 0.75” H
Weight (#3018R)................................2.0 Ounces / 57 grams
Motor Limit.........................................15-turns (540 Size) / 12-turns (550 Size)
On Resistance Forward ..................... 0.005 Ohms
On Resistance Reverse........................0.014 Ohms
Peak Current - Forward.......................100A
Peak Current - Reverse........................ 60A
Braking Current................................... 60A
Continuous Current ............................ 15A
BEC Voltage..........................................6.0 VDC
BEC Current..........................................1A
Power Wire ..........................................14 Gauge / 5”
Input Harness Wire.............................26 Gauge / 9”
Transistor Type....................................MOSFET
PWM Frequency..................................1700 Hz
Thermal Protection...............................Thermal Shutdown
Single Button Setup..............................Yes
Low-Voltage Detection.........................Yes (User Enabled)
Profile Selection:
Sport Mode (Profile #1): 100% Forward, 100% Brakes, 100% Reverse
Race Mode (Profile #2): 100% Forward, 100% Brakes, No Reverse
Training Mode (Profile #3): 50% Forward, 100% Brakes, 50% Reverse

I want a cheaper version. What do I need to look at on these specs to determine what to buy?

 

[Tony]

I'm telling ya, go brushless!

Racerstar 3650 Sensorless Brushless Waterproof Motor 60A ESC For 1/10 Monster Truck Truggy Cars

 

[bigone5500]

[pirate]Arrrggghhh! So which KV will ya be recommendin'?[/pirate]

 

[bigone5500]

That one is out of stock. I'll look some more. I'll bookmark that one too so I can have the 'secret' number at the end.

 

[Tony]

The lower the KV, the more torque, the higher the more speed. Depends on what you are wanting out of the car. lol

 

[Tony]

Here is another one.

Racerstar F540 Waterproof Brushless Motor 45A ESC For 1/10 Buggy Racing Cars

 

[bigone5500]

I guess a mid range would be ok. I'll need to get those shocks rebuilt first. It doesn't handle bumps too well right now.

 

[bigone5500]

Thanks Tony. I'll be orderin' that one then.

 

[tntpoof]

bygone .. if you go brushless in that old school truck you will destroy transmission and drive shafts.. just get a good brushed esc..do not go brushless you will regret it..sorry tony for stepping on your replys

 

[Tony]

It's ultimately up to him. I can get brushed motors that are way more powerful than brushless. It's whatever.