Okay, I did some of my own very special, hackneyed "I think I know what I'm doing" math.
This is the conclusion I came to when comparing this design to 45's shift-on-the-fly transmission. I assumed different gearing for this comparison such that the output RPM in high and low matched those of the Technokat's design. The gearing I have now is far slower, but correspondingly more powerful.
In low, assuming the drill gearbox is in *high* rather than low (to achieve 375 RPM), with a 4:1 reduction, the output is 50.8 Nm. 9% more powerful.
In high, with the Chiaphua geared down to 1500 RPM via a 3.6:1 reduction, the output 9 Nm. 23% less powerful. The transition between motors would also overload the breaker on the Chiaphua motor.
In high, with the Chiaphua geared to 1000 RPM (67% of the Technokats top speed), the output is 13.5 Nm. While more powerful than 45's extreme end, it's still 23% less powerful at its own top speed.
All of these numbers are skewed because 45's whitepaper only gives the RPM under load conditions. My RPMs are assumed for no load. So, take the numbers with a grain of salt and assume that, for all speeds, 45's shift-on-the-fly transmission is more powerful by as much as 30%, I'd guess. Andy, can you give an idea of what the no load RPM of high and low is? I'm interested in seeing how far off I am.
So, that poses questions about the viability of the concept. Teams already have access to the Technokat's whitepaper for a more powerful gearbox and drivetrain.
My immediate conclusion is yes, it's still viable. Mostly, it's because I spent some time fleshing this out
. But, also, I think there are still two distinct advantages.
- It's still an automatic transmission. It will react to increased load on its own, it doesn't require pneumatics or additional motors, and, though less powerful, the moments saved could be crucial. It also seems to reduce the risk of popping breakers because it'll automatically distribute the load to the right motor.
- It's easier to manufacture. Given Jeremy's mention of the clutch bearings available at McMaster-Carr, I think that manufacturing this, after it's redesigned, will be within reach of most teams with access to a manual mill. There's really no complex machining work left once the spiral clutch is eliminated.
It has its advantages and disadvantages, I suppose. While not as powerful or fast as I'd hoped, it is a simple solution that seems like it could, at the very least, be competitive with the Technokat's and other's transmissions.
Again -- thank you everyone for offering your insight into this. Threads like this are the best kind here on CD because we can all learn from one another's ideas, successes and failures.