Brakes installed and (almost!) running!
(click on each image to view the larger pic)
My valuable assistant during all this brakes project, was my son Jason!
The bike with the parts to be modded...
Finally I managed to finish this project mainly thanks to Pat and Shaun from Australia, who made and sent me the brakes and cables respectively, and of course Dave of CrazyNutRacing.com for the Yamaha-logoed wheels and the carbon-fiber double stack servo plates.
I installed the CF plates easily, then mounted the servos, brake servo on top, steering servo below it. I realized that I fI put the steering servo on top, the front brake bracket was fouling the frame crossmember. So, putting the brake servo on top proved to be the only way! Mounting the rear brake bracket presented a small problem (see above left), not letting the seat/tank lexan cover fit smoothly. I relocated it to the lower left bolt (above right).
The steering linkage went on quite easily, unitl I realized it was binding with the bike's bodywork, hence the cutout! Of course it needed some readjustment from its previous position (oh, and reversing the steering servo!).
I fitted small springs between the caliper and brake lever, that I cut from a soft pen spring, just to ensure that there is some return action into the brake cables. Extra care should be taken when messing with the inner cables because if they bind they are hard to return. Thank God, Pat included a few spare ones, and I really needed two more, after fiddling with the first two and managed to bend them here and there! The collets and other small stuff I used, I bought from my friendly LHS Fanatix Models, in Kifissia, also being the HPI and Futaba dealers for Greece!
The -almost- finished bike. Almost because, it still needs some tidying up of the servo wires and cables' ends, here and there!
I used my 15-year old Futaba FF3 and its original FM Rx. For the first time in its life I used the 3rd channel as it should properly be used. I plugged the brake servo on the 3rd channel slot, in the Rx and fiddled a little with the FF3 adjustments:
It has a PMX-2 mixing function between channels 2 and 3, the 2nd being the master and the 3rd the slave. I eliminated half of the 3rd channel's travel with the proper adjustment, so that the brake servo moves ONLY when I push the throttle stick to "brakes". I still have to find a way to eliminate the ESC brake function (I think I will do this shortly) so that I can use the bike's brakes only to stop the bike.
Bench-testing the brakes, I realized that the front was locking the wheel rather abruptly, so this is why I came to the spring solution, to soften its action a bit. Interestingly, it became a bit more progressive. Thanks to Pat's ingenuity for making the blue anodized bolts as adjusters; these proved to be very valuable in doing fine small adjustments. Still bench-testing I have two brakes that decelerate the wheels, but they do not lock them even when the brakes are pressed hard. I temporarily removed the drive chain so I had a freewheeling rear wheel better being able to check how it stops.
Performance-wise the only thing I can say so far is that the brakes DO work in a certain way: Before installing Pat's brakes, when you hit the brakes hard, the ESC would lock the rear wheel resulting in nice S-shaped brake patterns, which at (most) times would end with the bike tumbling here and there! Now, slamming the brakes - at least at my home street - results in the bike tracking straight despite the rear wheel being locked by the ESC.
More testing is due during the weekend!
Page was updated September 10, 2004
Further update, Sunday, September 11, 2004, after Shaun and Pat's recommendations...
Stay tuned for more!