TRAXXAS T-Maxx 1999 - RC Monster Truck Repair and Conversion to Electric

Описание: Converting an old and broken 1st generation T-Maxx Monster Truck to electric. I got this RC Car for my birthday in 1999 as the kit version. I built it and ran it for a couple of years before I overheated the engine and it never really ran again. Spending 24 years in storage, I came across it one day and decided it was time to get it running again by converting it to electric (blasphemy!) It was an incredibly fun project to work on and actually probably made me even more motivated to buy a new Nitro engine and convert it back! The electric motor just isn't the same as that banshee scream!

00:00 Intro
00:42 3D Printing new battery door for the remote control
01:11 Investigating the status of the old RC components
01:53 Removing Nitro components: Fuel tank and engine
02:49 The T-Maxx 2-Speed Transmission overview and breakdown
05:46 Electric Motor and Electronic Speed Control (ESC) Mounting
07:46 Servo wiring and assembly
09:04 Designing and 3D Printing ESC Enclosure Mount and Battery Caddy
09:43 First Test Drive
11:02 Speed Testing and GoPro mount

For the Motor and Electronic Speed Control (ESC) I just bought one of the cheapest combo packs for 1/10th scale. I was really just trying to see whether this was going to work because I couldn't get a clear answer about how to use the 2-speed Nitro transmission with the electric motor. In the end I bought a 3660 brushless motor with a 60A ESC and 2S batteries. To immediately and easily increase performance I could instead get a 3S battery to increase voltage on the motor, or get a higher amperage ESC and more powerful motor. But, there is only so much spacing from the transmission input gear and the back framing without more significant modifications.

As for the transmission, I took the whole thing apart and learned all the ins and outs of the dog clutch gears and how it shifts and in the end I didn't actually have to do anything to it. The ESC and Motor (and most as far as I can tell) have some safety programming built in (or programmable on the better models) that actually work quite well in the end. The old Nitro version throttle trigger on Channel 2 used to run the throttle and disc brake. With the throttle removed, now the servo only engages the disc brake when pushing reverse on the controller trigger. If you have been powering the ESC forward at speed, there is an automatic reverse delay built in, so the motor actually turns off while the disc brake engages and stops the truck. That is perfect, because initially I was worried about fully revving the transmission in reverse every time I wanted to slow down. That does kind of happen when sitting at a standstill if I want to keep the truck from rolling, but both 1st and 2nd gear inside of the transmission slip when the input is spun in reverse, so nothing can get pushed to the drive axel by spinning the electric motor in reverse. Also, the ESC actually only does reverse at ~30% power, so it isn't a problem at all.

I also wanted to keep the 2-speed transmission even though researching online everyone seems to say that electric conversions require the single speed conversion kit. I bought that and intended on swapping out the gearing, but there's no need. The only reasoning would be the pretty minor weight savings. The gearing really is ingenious with the 1-way bearing on 1st gear and the high RPM clutch on 2nd gear. When 2nd gear engages, the drive system is actually spinning the axel faster than the 1st gear is being driven so now it is "slipping" ever so slightly compared to the now-engaged 2nd gear. Hopefully my diagrams can explain that because it was one of the hardest things to understand while plotting this out.

The other really fun part was designing and 3D printing the custom parts for mounting the ESC and the LiPo batteries. What my younger self could have done with 3D Printers!