Kyosho ST-RR conversion

[Jason]

im back from trying a feigao 540c 8xl 2084kv on my st-r and motor and esc overheat battery are cool ... im using a heatsink on the motor and I run with no body ... and running on the tarmac ( speed run )

motor : feigao 540c 8xl
esc : mamba max 1/10
gearing : spur 50t pinion 17t
battery : truerc 4s 6400mah 15c


motor run about 175f

esc run around the same temps ...

BEC was disabled...

the top speed was only around 40mph something wrong ?


Differential Ratio: 4.3
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 50
Pinion Tooth Count: 17
Total Voltage: 14.8
Motor KV: 2084
Tire Diameter (inches): 5.5
Tire Ballooning (inches): 0
Motor Current Draw: 83
Motor coil Ω: 0.0073
Spur/Pinion Ratio: 2.94 : 1
Total Ratio: 12.64706 : 1
Tire Circumference (inches): 17.28 inches (438.88 mm)
Total Motor Speed: 29580.5 RPM
Vehicle Speed: 38.27 mph (61.48 km/h)
Effective KV Value: 1998.68
KT constant: 0.65 oz-in/A
Motor Torque: 0.28 ft-lbs
Final Torque: 3.55 ft-lbs
Final Power: 1228.4 watts (1.6 HP)

[Jason]

[nitrostarter]

Buy a CC/Neu motor, all your temp issue's will be gone....

[Jason]

medusa 36-60-2000kv on 4s geared for about 40mph should run without any heat issues on my 1/8 truggy st-r ?

[brushlessboy16]

might get warm. go with a bigger motor.

Shark! Just wondering if you're still running mech brakes on your ST-RR. I tore mine down yesterday, and found that the servo tabs were cracked and they broke off fully. I would imagine it's because I have it mounted side on and the end sticks out into the mud guard.

I had a run with 60% motor brakes, but everything got quite a bit hotter than normal :( Running a 16T pinion, 50T spur and 6s1p LiPo on a Medusa 70mm 1600kv.

-Sid

[Shark413]

Originally Posted by cdis

Shark! Just wondering if you're still running mech brakes on your ST-RR. I tore mine down yesterday, and found that the servo tabs were cracked and they broke off fully. I would imagine it's because I have it mounted side on and the end sticks out into the mud guard.

I had a run with 60% motor brakes, but everything got quite a bit hotter than normal :( Running a 16T pinion, 50T spur and 6s1p LiPo on a Medusa 70mm 1600kv.

-Sid

Cdis, I have not run my ST-RR in a few months but it still has the Mech brakes and I have no issues with them. I am currently running a Losi 8ight-T using motor brakes (Tekin t8 motor, 48/15 gearing, MMM esc) and temps are good. At first I had to get used to the lack of brake bias, but now I can pretty much get around the track at the same speed as I do with my ST-RR.

[George16]

Yesterday was nice. The track was still wet but that didn't stop us from running our trucks. The MMM ESCs on both the truggy and buggy stopped working for a while because of water on the track.

[George16]

Well, I finally was able to solder and install the Tekin truggy combo into my ST RR. I ran it for a about 15 minutes today (just straight passes on asphalt) and I was surprised at the smoothness of it. It seems to be more powerful compared to the Castle/MMM combo because I was able to ride wheelies on the the truggy when normally it would not do it with the Castle combo. I will be changing the center diff oil to about 10-15K later to prevent wheelies. The Tekin motor is 2000Kv (equivalent to Neu 1515 2D).

Here are some pictures of the install.

My new Weller soldering gun:


Tekin RX8 and T8 2000Kv motor:


Soldered the wires. Tekin does not supply battery wires.






Side by side against Castle's combo:




Installed on the truggy:




Nice stickers:

[Shark413]

[QUOTE=George16;357657]Well, I finally was able to solder and install the Tekin truggy combo into my ST RR. I ran it for a about 15 minutes today (just straight passes on asphalt) and I was surprised at the smoothness of it. It seems to be more powerful compared to the Castle/MMM combo because I was able to ride wheelies on the the truggy when normally it would not do it with the Castle combo. I will be changing the center diff oil to about 10-15K later to prevent wheelies. The Tekin motor is 2000Kv (equivalent to Neu 1515 2D).

George very nice truggy. One thing I wanted to mention, I am also using a Tekin motor and if you have the motor wires soldered on out towards the back like you do the mass/momentum of the wire can pull the motor solder tabs away from the circuit board. I have rerouted my wires so they are mounted out towards the front of the motor and I have had no issues with the motor solder tabs.


Wire pulling the tabs away from the circuit board


Rerouted wiring over the motor vs out towards the rear.

[George16]

I see what you mean. Thanks for the tip. I'll be rerouting them tonight.

[Gee]

Hey Lito, I got a similar weller soldering irons but my tips don't last. Is there a special way to clean the tips or maybe don't clean the tip like a normal soldering iron? Mine always seem to get a hole on the end of the soldering tip if that makes any sense.


3 years later and my st-r is finally a st-rr. Got the final piece in the other day. The front center universal shaft.


Nice work on your truggy!

[George16]

Originally Posted by Gee

Hey Lito, I got a similar weller soldering irons but my tips don't last. Is there a special way to clean the tips or maybe don't clean the tip like a normal soldering iron? Mine always seem to get a hole on the end of the soldering tip if that makes any sense.


3 years later and my st-r is finally a st-rr. Got the final piece in the other day. The front center universal shaft.


Nice work on your truggy!

Thanks bro.

I can't say for sure if this gun's tip will last long or not. On my 80W Weller iron, I tin the tip and remove the excess solder by using a wire brush. I brush it lightly prior to putting it away and so far, the tip is still intact.

Congrats on converting your ST R to ST RR.

I'll post pics of my re-routed wires tomorrow after I get off of duty from the ship. Can't access photobucket from a gov't computer .

[George16]

I removed the hardened gears from the Hot Bodies center diff and installed them into the Kyosho cup. I also went with 20K center diff oil but it will still wheelie on demand. I can flip my truggy if I want to. I'm also running a plastic 46T kyosho spur now with a 15T pinion.

I also flipped around the motor wires.

Pictures:

[George16]

I was able to run the truggy in our track today for about 2 hours shared with the X2 buggy. The following were the temps after my Neuenergy 4100mah 5S battery hit the LVC:

ST RR temps with Tekin System (10Apr2010)
46/15, 5S, 20K CD oil

ESC -113
Motor – 146
Batteries – 98

Ambient Temp – 68F


I'll run it again tomorrow afternoon and will be monitoring the motor temp. If it still get to about 146F with about the same ESC and battery temps, I'll replace the pinion with a 16T and go from there.