Is anyone using two one-way mechanisms to allow the same motors to power both shooter (motors set to +N ) and lift (motors set to -N )?
I guess the downside is that it becomes difficult to restart a false start on the lift.
Interesting idea. I haven’t heard of anyone doing that yet…
I thought of doing this back in October but i still haven’t got an actual lift to work it with so…
I know there is a video somewhere of a team that set up a rachet that will engage different gears based upon which direction the motor is spinning.
This has been an interesting idea to me since the start of the season. There are a lot of challenges though. Friction is the first one I can think of. The clicking might also get annoying. The lift would also (probably) need to be near or on the same side as the thrower which might make your robot very one side heavy. It is definitely possible though. It would just be a difficult build. It would be really cool to see! Please try and build it and keep us updated.
Would it make more sense to use to use motors from the drive to power the lift? You wouldn’t want to sacrifice your firing ability so you can load balls faster, but idk, 
The idea is to use two ratchets, facing opposite directions to power both with 100% of the motors power. The advantage is that the mechanism is relatively simple compared to any shifter that would make use of your drive motors. Basically, if you run your flywheel motors at 127, the flywheel runs and at -127 the lift is powered. The point is that you rarely fire balls while lifting.
Using ratchets to get two uses out of one motor is great, but it it very difficult for a lift. The angle of the launcher limits you to very specific releases of elastic-assisted mechanisms. We use a ratchet in order to pick up a pyramid: intake motor spins one way in order to pick up balls from the ground; it spins the other way to lift itself up and over the pyramid, and then back down again.
I considered a few different ratchet high-lift ideas, but couldn’t get any of them to work practically. The 12 motor rule this year is great, especially with ratchets that let you get the most out of every motor.
My design actually uses this principle to power two different linear punchers. One is set up for full field driver load shots and the other is connected to the intake for field balls. Since only one is used at a time, I use 2 ratchet and pawl mechanisms to transfer torque depending on the rotation direction of the motor. It takes a lot of very meticulous thought and planning to get these ratchet and pawl systems to work correctly, especially under high torque conditions (like with a lift or shooter). It would be very difficult to make a system like this work. Figuring out how to gear things so that the the pawls all engage and rotate everything in the correct direction is hard enough with two mechanisms that are right beside each other. It would be insanely difficult with two completely separate mechanisms on two different parts of the robot.
Look at the team 8900 reveal. They use their 2nd stage of intake to release the platform and launcher motors to power it.
The transmissions that use ratchets to distribute motor power between the drive and the launcher are pretty cool too.
After building 2 robots this way, I’ve come to the conclusion that it’s really not worth it. I would suggest teams try it out in order to learn but that’s about it.
We built a robot which reused the shooter motors for a lift using a gear with circular inserts containing a ratchet (just like the flywheel ratchets we see at every tournament). We used a single flywheel with three motors in a horizontal row on either side of the top of the bot, so that the lift was on the back and the flywheel was on the front. The shifter worked fine, but neither the lift nor the shooter connected to it were good 
Basically, efficiency is everything. If you can optimize both your launcher and your lift and then connect them together, great! The ratchet shifter is definitely more efficient and less space/energy consuming than a pneumatic gear shifter.
About false starts: we won several Toss Up competitions with a one-try-or-fail hanging system. The key was to design the hooks with misalignment tolerance so that it wasn’t so easy to “miss” the bar. If your partner can crash into the side of your lift and not have to realign, that’s a really good thing.
@Cyber-brains: The clicking wasn’t annoying at all. We barely heard it over the noise of the flywheel.
For our robot, we use 5 motors on the shooter, which is a bat that swings around to hit the ball. The shaft that connects the bat to the 5 motors is also connected to a 12 tooth gear that powers a 60 tooth gear. This 60 tooth gear forms a winch with another gear, so when the bat reverses direction and continuously spins, we start spinning the winch, which is hooked up to a pulley system.
can we see a video of your shooter it sounds very unique?
I actually saw a robot at state that used a string attacted from the gear ratio of the launcher to pull up their lift.
That was us!
One of our teams developed a method to deploy the lift and support bars down on the ground by spinning the flywheel in the opposite direction.
Powered by 6 motors.
2.33:1 (torque)
It can lift about 30lbs ( 6-8 secs high lift)
Lift time depends on how heavy the robot is
Here is a picture I found lifting one of our robots. I will try to find a video tomorrow.
http://i.imgur.com/AacadjB.jpg
7842D has a ratchet system similar to this.
@Samuel Crouch (7842D)