Nairobi, week five (july 6 to 9):

this was a week of re-evaluation, both of the engine and the design of the drivetrain; it all started with the engine, which doesn't mean the engine started, it means the problems started with the engine; so after getting the trike to an essentially completed state, all we had to start was start the engine and drive it ... many times we were able to get a sputter of life from the engine, but no sustained operation; it took several (score) pulls of the pull start to break the recoil spring in the pull-starter for the first time; so after a couple different attempts to fix the spring, success was finally attained and the engine was reassembled to produce an additional several (score) pulls to again break the pull starter, all the while with only minimal signs of life from the engine; so that day was essentially spent fixing and re-fixing the pull start (needless to say, i can assemble and disassemble it in my sleep); towards the end of the day, there was one moment of success where we got the engine running and driving the wheel (held off the ground) for just under 5 seconds, however, that was the high point for the day; before going home that evening, we determined that yes, the engine runs, and yes, it drives the wheel (no human tests unfortunately), but the engine that we have isn't really worth any more time ...

so i come back the next day (wednesday), with a stubborn attitude, and decided to go out and try to start the trike for a bit more; the pull start mostly behaves that day, which allows the discovery that for the last day, i was not giving the engine enough gas to actually make it fire and run; the idle was set at closed, and so after fiddling with holding the throttle handle partly open and adjusting different nuts, we were able to get the engine running with a somewhat consistent pattern; there were a couple times where i could let it idle, and almost hop on to go for a ride, but as soon as i would touch the throttle handle, i'd kill it; so again, we never got any actually human-riding tests, but several instances of wheel propulsion under engine power; and again, after several failed attempts at riding it, we concluded that our design indeed worked, but was failing at the fault of the engine ... lesson number one when buying a used engine: make the seller start and run the engine for you before agreeing to pay money and take the engine home (something i should have known with great certainty before now, but alas ...)

the rest of the week we spent working on brakes and re-evaluating our engine choice:
- the brakes that we were using were difficult to set up correctly and we were increasingly disinterested in their implementation; so we switched to a mountain bike wheel with a flat side where we could use a different style of brake, one that is more easily actuated by regular cable; so the set up and fabrication of the brake system has been mostly completed, now we just need to figure out a parking brake for the trike
- the engine choice evaluation was mostly taken from the team last year, and had been concluded as a small, ~50cc engine with pull start and centrifugal clutch assembly, but with the non-availability that we are encountering with such an engine, we decided to look at our choice again; without detailing why which engines were determined to be better or worse in which areas, we essentially looked at pulleys and v-belts instead of chain, and a larger (125cc) engine instead of the small one; but in the end, we decided the the initial choice was the best and that we would order one from a company in the states; so we talked to a few more shop owners and found that we might be able to show them the engine when it arrives so that they can import it direct from china instead of us going through the states; in short, we are still hopeful for the long term, but have resigned ourselves to getting an engine in the middle to the end of my last week here, possibly leaving completion of the trike to the final week that maddie and wes are here (with me tagging along through skype and email)

the two days that we were out in the parking lot/driveway with the trike, there were countless inquiries as to where someone could get the trike, when could they get it, how much does it cost, and so on; unfortunately, we were only able to give the answer that "no, this is just a prototype; but APDK will be producing them at the end of the year" ... so as we have heard from the people we work with and the people who walk by every day, there is much interest in the completion of the project; we're getting close to the end of our time, and i'm starting to wonder at what state of completion will we leave the trike? i think we'll at least have a completed trike, something they can follow to build production models, but we hope to add a production manual/set of instructions to make the whole process easier; but that may be a write-up we complete back home in the states and send to APDK when it is finished