Brushless Kyosho ST-RR

[shark413]

I purchased a Kyosho ST-RR a few months back to replace my tired CEN TR Arena. I added an O.S. 28xz, JP-4 pipe, 300 oz servo, FASST, etc. The thing was so much better than my TR. Longer chassis, big bore shocks, chormoly drivetrain parts, excellent handling and powerful. It was the only nitro vechicle I actually drove, everything else was brushless (E-Revo, 1/8 buggy, Jammin CRT.5, Stadium truck). So after I split two fuel tanks and almost burned up my truggy, I thought about converting it to brushless and switching between nitro and brushless was throwing my driving off as well. The O.S. 28xz is an amazing engine so I had to have a good brushless motor I picked a Neu 1515 1y. I picked up a spare chassis on E-Bay and started the conversion. After turning my CEN brushless truggy chassis into swiss cheese I wanted to minimize the number of additional holes I had to put in the chassis. For all my previous conversions I used my own custom built motor mounts, this was mainly so I could set the motor back a little so I could use the mech brakes. For this conversion I decided to use the RC-Monster mount and a motor spacer. I only had to drill two additional holes in the chassis.

http://i142.photobucket.com/albums/r115/shark413/chassis.jpg

[shark413]

Update:

As I was putting the conversion together I wanted to use the stock Kyosho chassis braces but they hit the can when using smaller pinions. So as I was removing the braces I noticed the motor flexed when I pressed on the side of the can. The motor mount was flexing a little and I figured this could not be good for the drivetrain. I decided to make a rear support bracket to support the motor and keep the flex down. The bracket had to provide complete support (side to side and up and down) and had to be movable so I could adjust gear mesh. I came up with a bracket that surrounds the entire motor can and also slides laterally for gear adjustments. Since I had to make a new servo mount I decided to lay the steering servo down and turned the braking servo 90 degrees for better gear access. I added a carbon fiber plate to the top of the servo mount for a place to put my rx. I then utilized the nitro motor mount holes to make a ESC mount.


http://i142.photobucket.com/albums/r115/shark413/brace-2.jpg
Motor rear support bracket, also switched to King Headz chassis brace. Brace uses the radio box holes.

http://i142.photobucket.com/albums/r115/shark413/servo.jpg
Servos and rx tray

http://i142.photobucket.com/albums/r115/shark413/esc.jpg
ESC mount. Uses the nitro motor mount holes.

[shark413]

I now have most of the truggy together, I added a carbon fiber battery tray, the front and rear suspension parts. Added a Futaba FASST rx, CCBEC, Center diff with a Losi 48T wide spur, Kyosho bonded brakes. Just waiting for a Mamba Monster Max to finish.

http://i142.photobucket.com/albums/r115/shark413/DSC00620.jpg
Almost finished truggy with a Neu Energy 4s lipo and Mamba Max installed ready for a test run.

http://i142.photobucket.com/albums/r115/shark413/bottom-4.jpg
Bottom of chassis, I only drilled to additional holes, added front/rear skids. Still waiting for the side guards to arrive.

http://i142.photobucket.com/albums/r115/shark413/sidebyside-1.jpg
Next to the nitro ST-RR.

http://i142.photobucket.com/albums/r115/shark413/skid.jpg
The rear skid has a lip that protects the alloy suspension bracket.

Stock Kyosho ST-RR Kit
RC-Monster Kyosho Motor Mount
RC-Monster Hardened 14T pinion
Robinson Racing Losi 48T wide spur
King Headz chassis braces and rear suspension bracket
Futaba FASST rx
CCBEC
Mamba Max (coming soon Mamba Monster Max)
Neu Energy 4s lipo
Neu 1515 1y motor
Hitec 5955 servo
Custom made servo mounts and rx tray
Custom made ESC tray
Custom made skid plates
Custom made battery tray

[porra]

Looks awesome. Keep me posted on how well the drive shafts and axles handle the BL power.

[shark413]

After some discussion on another forum I am going to ditch the rear motor brace. The issue is chassis flex, all (most) off-road trucks/buggies have some flex built to help handling. When I anchored my motor front and rear chassis flex was now being transfered to my motor/rotor/gears. I am going to work on making my center diff supports a little stronger to eliminate motor flex.

[shark413]

Here is an updated picture.

http://i142.photobucket.com/albums/r115/shark413/strr.jpg

[GTX]

That truck looks SICK!!!

[joshy1991]

any videos of it. that looks cool. chassis looks really plain at the back (lol) but really good. what shell have you got for it

[shark413]

Ok Joshy, here is some video. Still need to fine tune the suspension. Please forgive the terrible You Tube video quality.

http://www.youtube.com/watch?v=GC9rYX8hLPk