View Full Version : My MR-03 chassis hack

2011.01.16, 07:16 PM
I recently got a Toyota Vitz MR-03. Upgraded it's black plastic chassis with the gray chassis.

Now that I have a spare chassis without the gears for the steering... I decided to hack it so that a it will fit the following:

1) Micro servo

The first step was to gut the chassis so that I can fit a micro servo. After carefully gutting out the unnecessary plastic with my dremel fitted with different dental implements (dental implements was way cheaper than dremel implements)... I got this:


The black micro servo in this two photos are Vigor (stock servo for Iwaver 02M). This is the cheapest micro servo I have come across and I hope to fit the servo saver arm assembly from my Iwaver 02M for this.

Bottom view
Top view

The hack will also allow the use of Tower Pro 9g micro servo (a more popular cheap brand of micro servo).


All the other parts of the MR-03 will still fit perfectly. So if this work properly as my plan, it will utilize all aftermarket and stock parts for MR-03 front suspension.

2) Battery holders - I will still need to modify the positive pole of the stock battery contacts because it is not "tall enough" to make a good contact to the positive pole of my lithium ion battery (ICS 10440).

3) As for the ESC and motor.... I am planning to use the 10A BL ESC for car (similarly used by EQMOD in his F1 hack) and walkera WS-12-003 BL motor or an
Excelorin BL motor... both have very similar dimension.

A hack for the motor mount is still needed.

A hack for the 2mm shaft needed for the pinion is also needed because the small BL I plan to use have only 1.5mm shaft and is short by about 5 to 7mm to properly fit.

4) I plan to use the FS-GT3B controllers set for it, because it is has the smallest 2.4Ghz receiver... that will hopefully fit the MR-03 chassis.

Will just edit this as the project progress. :D

2011.01.16, 08:03 PM
If you were going for performance I would've recommended you just buy the servo parts for the MR03 -- the Iwaver and Tower servos are such a ridiculous downgrade you'll be kicking yourself after you get this car running. Keep in mind that the MR03 servo is faster and more precise than any servo I've ever seen shoehorned into a 1/28 -- if you want to even come close, your best bet is taking the control PCB out of a Futaba S3157 or JR DS285 and hooking that up to the MR03's pot and servo motor.

If you're doing this for fun... well, good luck have fun. :)

2011.01.17, 03:10 AM
hahaha...didn't know that the complete servo parts can be available (I thought I have to buy a complete chassis again)

but I will take note of that Futaba and JR models... for possible future hack.

I did notice that the configuration of the gears in the MR03 is really very different.