Mini K0b@y Mrc

[SilverRidge]

It's a loooooonng time since the last time I show something here: 2011 , never really been away from rc crawling but lack of time for forums

last year after the french BIG I was thinking of building a mini but still not much free time, so it only started after The BIG this year since october:

first step: find a cheap used MRC, I was hesitating for a brand new kulak/ecxeed instead but finally parts are not exactly the same



it's not a pro mrc so a lot a improved parts are missing but it has the metal lockers and the upgraded shocks
stock "miserable" steering


front axle with 3 racing cvd's , a bit better 45°

the following idea was to try to adapt drift driveshafts

Description
- Ultra Wide Angle - up to 55 degrees

- Must be used if SAK-D310/PK has been installed

- Low profile bearings included



Optional Ultra Wide Angle Driveshafts for use with SAK-D310/PK Alum Steering System ensures smooth power delivery to the front wheels at steering angles greater than 45 degrees.

The standard Sakura D3's steering system has a maximum steering lock of 45 degrees, by installing the optional SAK-310/PK Alum Steering System, maximum steering lock can be increased to 55 degrees, but to use the increased steering lock beyond the standard 45 degrees, the SAK-D331 Ultra Wide Angle Driveshafts must be used.

10$ a pair, the xr10 mod cost more than the mini itself plus it's becoming hard to find in France

but when the inner ball is cut the driveshaft is too short, so it needed a new longer spool












the larger spool needs to grind an half mm in the axle tubes

in the same time the new driveshaft doesn't work with the stock knuckles
so i tried many home made 3d printed one until i found the good alignment
v1 (grey)







v2 (yellow)




V3 (black ones)



thinking of the batteries:

3x 1s 300MAH same size as an half of a std servo


3s 460mah
tried a plastic wheel for make up waiting for a carbon one



plastic hub test

I really don't know if it can hold the torque

then one of the first marking fact about mini's seems the difficulty to over and underdrive

in my basket of ideas were:

sdi spool:1/2 gearing and almost the good size:

but the 6mm outputs make a 10 or 12mm outside bearing and the mrc axle is mold for a 11mm


reduction gear unit with two different outputs














video of the tranny:
https://youtu.be/L9vV6lyENWI
front output is 1.333 faster than the other (Rear or whatever you want )
it also needs to reverse an axle as it's counter rotating
for now final version is 40 mm wide , I was hopping to make something around 32mm but it's still far from the stock skid width


chassis cut template V1





not enough room for a tranny

chassis template V2



maybe too big ?? but at least it accepts to come back to a 400 stock motor

lower links holder v1

http://monsite.woopic.com/PP/ipcam2/...?_t=1445279252
V2

[SilverRidge]

[phishead1101]

Whats your plan for taping for screws? I've been having a tough time getting clean threads that are strong enough.

[SilverRidge]

good question! usually it' recommended to make a groove for a steel nut on 3d printed parts , in almost one year of printing mostly useless parts I found that completely fill parts are stronger , but for sure it's not as glass fiber nylon,
it should be ok for the roof... seeing as it's hold on my 2.2

I have a badly dimensionned wheel hub here with 6 M3x5 threads can't tore them off by force of hand

I 'll try to find a way to mesure the force to break it and make a video of it

[SilverRidge]

found cheap "dynamometer" to test the traction on one thread

http://www.youtube.com/watch?v=qDurh...ature=youtu.be

hold 12kg of traction very well