if we switch out the driven gear to a 36t gear and made the driven sprocket 12t
the entire module can be shrunk by 2 holes and the ratio would be .66:1 torque and 1.8:1 speed which is perfect
we will probably make those changes and duplicate the other side on monday or tuesday :)](team 1107B transmission (credits to team 4194B) - YouTube)
if we switch out the driven gear to a 36t gear and made the driven sprocket 12t
the entire module can be shrunk by 2 holes and the ratio would be .66:1 torque and 1.8:1 speed which is perfect
we will probably make those changes and duplicate the other side on monday or tuesday :)](http://www.youtube.com/watch?v=XGDpsimDC60&feature=youtu.be)
Wow, You’ve just made it simpler. I was having trouble understanding how the original actually worked, but now I understand it.
if we switch out the driven gear to a 36t gear and made the driven sprocket 12t
the entire module can be shrunk by 2 holes and the ratio would be .66:1 torque and 1.8:1 speed which is perfect
we will probably make those changes and duplicate the other side on monday or tuesday :)](http://www.youtube.com/watch?v=XGDpsimDC60&feature=youtu.be)
I can’t tell from the video, does it shift speeds by spinning the motors in opposite vs. same directions?
Edit : I can see it now because of the large set screws. That’s pretty cool and looks like a pretty simple and doable vex transmission
I took the one my team showed you (the one we made in our hotel) and rebuilt it. It has alot more support and rollers so the chain does not sag and slip. I am actually putting it into a robot now. I will post some video of it when im done with it.
whatever it is called, it is awesome and I do not know why its just now being discovered in the VEX community. We now have 3 seperate planetary gearsets made in our class.
(this is the first time i straight up copied a concept, so i want to get the credentials right :))
well they openly published it
it is proven to work reliably on a competition robot
it doesnt take too much/too complicated to build and incorporate into your design (no pneumatics)
and its effective, thats why it is getting so much attention
(we’ve seen lots of pnaumatic transmisisons, but they dont get as much attention because not all teams have $300 pneumatic sets to use just to shift the gears)
This is probably an innovation similar to 1103’s Round Up linear lift system and maybe the 6-bar parallel linkage over the 4 bar. Maybe junior teams will have troubles trying to understand/make it without too much friction though (our prototype has bit of resistance on it still).
With the 393 rule, you might see a return of the simple, motor-shifted transmission, too. These date back to the dawn of VEX, but they have become less popular with the obsession with giant 10-motor robots. I can see 6- or 8-motor robots with a 3-wire shifter. The sliding-rail shifters aren’t nearly as cool as the planetary units, but they are easy to package and work on.
Did you all know that the Ford Model T used a planetary gear transmission?
You still need to use some kind of lock (pneumatic or motor or something that activates from the transmission itself) to prevent backdriving in high-torque mode, so it’s not entirely shiftless unfortunately.
Mine doesnt use pneumatics or any sort of mechanical lock. I just ease a little power into the motor so the gear does not back drive. It kinda works like a clutch
When you run it in high-torque mode and stall it by stopping the ouput, do the motors keep turning? If they do, you’re not actually running at full torque.
I’m assuming your output is a wheel.
Hold the wheel so it doesn’t turn and run your contraption at different speeds. I’ll bet you that at the lower speeds the motors will continue to turn even when the wheels are stalled, but at the higher speed it will stall the motors.
How are you getting 3 speeds? Do you use one output from one planetary and run that into a second planetary with 2 more motors?
