Losi 8ight-T & TP4070 (40x102mm) motor - RC-Monster Forums

Dr_T · 02:27 PM

Hi,

Newly registered here and thought I'd show you my 8ight-T 2.0/3.0 cross-over running a TP Power TP4070 motor. Current set-up:

Losi brushless conversion kit;
Turnigy Heavy Duty Series 5Ah 6S 60C-120C batteries;
Hobbywing Xerun 150A ESC + 2x1000uf 35V Panasonic FC caps;
TP Power TP4070-1200kv 3.5Y, 40x102mm motor with DIY low-tech 8->5mm shaft reduction;
8T 3.0 ring and pinion gears (12/47 ratio instead of 10/43);
Turnigy TGY-DS2509MG servo @ 8.4V (rebranded KST DS2509MG);
Turnigy TR302-AD Gyro – I know… training wheels, and real men don’t use stability augmentation… they race toy cars on 2S or 4S, right?
LOSB3528 Heavy-Duty Differential Cases;
Diff oil: 20k/2.000k/10k cSt;
3.8 Badland Tires wrapped with (32kg) fishline, as I suck at taping and gluing tires;
Gearing: 23/43 for 63 mph nominal (3.7V/cell), zero-timing, no-load wheelspeed; off-road use, mainly grass.

Arrived at the TP4070 after trying out a Leopard 4082-1600 and Alien Power Systems 4092-1380. Both of which I could not keep temps under control with 45-50 mph gearing. Wanted a big motor to be able to run higher loads at lower temps, but didn't want to spend Neu 1527 money, and the TP4070 seemed to be the closest thing for about 1/2 the price. I have a Castle 1717-1650 on the way to compare to the TP4070. Also very interested in seeing results of the recently released Poseidon 1527-1500 car motor.

The TP motor isn't bad at all and I'm still practicing not to crash everytime I try and open up the throttle. Motor temps typically stay on the good side of 65°C driving hard for a full pack, unless doing crazy high RPM doughnuts in grass for a while, in which case I have seen motor temps of a little over 70°C; I guess everything has its limits. Center diff typically stays below 60°C with some 2.000.000 cSt diff fluid I tried from Lizard. Ran around 110°C and 85°C with 130k and 500k respectively.

I am looking to replace the Xerun ESC sooner or later. It is ok and holding up well, but I'm missing the ability to set a Current limit. I'm running the 6S 5.0Ah 60-120C Turnigy HD batteries and even with fully charged packs an uncareful throttle blib can trigger my external Lipo alarm, indicating Voltage sag to 3.3V in at least one of the cells. Limiting Current to say 200 Amps max would probably not be noticeable in performance (I won't be able to put down 4+ kW anyway), but it will make life on the batteries a bit easier. Also eventually I would like to up the Voltage to 8S, as 6S might not be the most efficient on the 1200kv TP motor. Let's hope Castle's XL3(?) will be announced soon and turns out to be designed as a true car ESC with a footprint that can be used in 1/8 too.

Vids or it didn't happen:

Early test set-up:
[YOUTUBE]UFQ0ClP0JsA[/YOUTUBE]

Badlands without fishline:
[YOUTUBE]Gx9fpKwcHBw[/YOUTUBE]

Little street test:
[YOUTUBE]h0KgGJm7VVU[/YOUTUBE]

Fishlined Badlands:
[YOUTUBE]Fbop3mgcPCE[/YOUTUBE]

Tredecuple-flip cartwheel - personal best so far:
[YOUTUBE]7RJZK1WDnrQ[/YOUTUBE]

Some pics: