A Labor of Love; aka building a Rocket III Speedster

[Claviger]

You are mad like a box of frogs. And I love it.

When I built my Norton Commando racebike from scratch I found that powder coating the frame means a few nights sanding it off on axle & suspension mounts to fit.

Good luck on this project. It sounds super cool.

Hopefully that's not the case, but I accept it may be a reality. Usually this shop is great about masking/plugging but everyone makes mistakes.

Thanks.

 

[Claviger]

eThrottle arrived.
Should work nicely, chopping at red line, leaving the two mount holes next to the line in place for mounting.




This is going to work great. The "rest" position of the eThrottle leaves it just slightly cracked open, which will serve as a limp mode. At idle it'll close it more than limp mode position, 110° sweep so connecting it to the ITBs is going to require careful adjustment so that "fully closed" on the ITB is closed beyond limp mode on the eThrottle.

I may need to remove the return springs or use 3 instead of 7 springs, on the ITBs, the internal eThrottle spring is already quite heavy.

Will be chopping it after a trip tmrw and then mocking it up on the engine to ensure no cohabitation of oil tank and eThrottle occurs. From there I can build a bracket, have it cut, and prep it all for power coating.

I'll need to sort a lever arm for the eThrottle shaft and piece together a linkage that uses 2 heim joints and a threaded joiner, like a shifter, so I can adjust length.

 

[Tripps]

You're definitely crazy, Rob, that's what I like about you.

 

[Claviger]

Heh, thanks

Of all the things that turned out to be inexpensive, I did not expect it to be this part, all in, about $25:
Collar for the eThrottle rod - $6

Matching actuator arm that will let me match length to the opposite end lever and trim the excess - $9


Super high quality parts from China to connect it all - $10


All in, about $140 for the eThrottle conversion...

 

[Kevin frazier]

 

[Claviger]

Rough cut done, motor died on my ****e sander so need to get a new one next week and dress the chop up/make it flat. If it's not one thing it's another ...



Blue will be a bracket for triangulation of the eThrottle, stability only. It's just to limit rotation/flex.

Red will be the bracket to actually hold the weight, the bolt spacing is nearly the same as the two long bolts on the TB assembly. Trivial bracket needed.

Orange will be the linkage.


Screw I'm holding is the position I'll drill and connect the linkage on the TB side.
eThrottle side I'll drill the arm to have matching length so they have the same arc of movement for linear response.

Just need to pick up some new power tools tomorrow and get it all bolted up

 

[Claviger]

Sendcutsend is pretty awesome. Downloaded Fusion360 and sketched up some brackets today. The boxy bracket will hang the actuator and once bolted up, get connected by alumiweld or TIG welding. to the actuator as insurance. The round 3 screw ring is two per throttle. One side gets welded to the top of the TB entries and the other to the intake runner. No more couplers for this guy and it makes it easier to run a forward offset intake runner and gain knee clearance.


Here's the overkill list of hardware ordered to couple the actuator and the ITBs. I decided it's better to remove the stock pieces from the brass throttle rod and use an 8mm clamp base so the two end have the exact same arms.

 

[Kevin frazier]

So much for copying

 

[Kevin frazier]

Rough cut done, motor died on my ****e sander so need to get a new one next week and dress the chop up/make it flat. If it's not one thing it's another ...



Blue will be a bracket for triangulation of the eThrottle, stability only. It's just to limit rotation/flex.

Red will be the bracket to actually hold the weight, the bolt spacing is nearly the same as the two long bolts on the TB assembly. Trivial bracket needed.

Orange will be the linkage.


Screw I'm holding is the position I'll drill and connect the linkage on the TB side.
eThrottle side I'll drill the arm to have matching length so they have the same arc of movement for linear response.

Just need to pick up some new power tools tomorrow and get it all bolted up

thats yellow Rob yellow and red and blue, I can barely follow as it is, youre gonna have to ask the wife for help with colors again

 

[Claviger]

When I've validated everything I can easily post the drawings for others. A much cheaper ECU can be substituted as well. Really, I'm making it harder than required by a lot. The easiest way is just use all the stock sensors and gauges with an ethrottle conversion running on a Maxx Sport ECU with an RCE18 from canchecked to expand inputs and outputs for control of lights etc. The Sport is the model I would expect most people would chose, the race only gains a few edge case functions, like built in EGT/Knock sensors.

If ordered from EU, the sport is $1100, the race is $1500. So with sport it'd be like 1100(ecu), 100 (throttle body), throttle body adapters(free-100), 219(mce18).

When I'm done I'll be trying my hand at converting a basically stock bike over using a Sport so I can figure out what is the minimal viable requirement.