Turret Mechanism

[DiscipleOfDean]

Hello, I am from Team 2526 and we are trying to make a turret for this year's challenge, but we are having some difficulty making the rotating mechanism. We are thinking of using a lazy susan style rotating mechanism but are not sure if this is the best way to go. Does anyone have any experience building one of these mechanisms?

[onenerdyguy]

Take a close look at team 254's robot from last year, Dropshot. They had exactly what you're talking about, just a bit fancier.

[Roboshant]

There are a couple options:
Andymark turret: Probably a bit too big for the fuel this year (unless you're doing a double shooter lol)

Use a belt wrapped around some type of tube with a pulley as the pinion
-399 did this in 2012
- You would need an outer circle dimension for this.
- You could probably find this dimension for the HTD belts that AM and VEX sell if you look hard enough
-Another option would be to use McMaster belts/pulleys (could possibly interface pulley on to a cim output versaplanetary)
-This method is like making a turret gear without actually making it. Could be something to look at if you don't have good machining capabilities.

Gears
- Custom cut if you have waterjet access ( inventor has a tool for auto-generating gears)
- make sure any pinion gear you use is compatible with the turret gear (standard FRC sizes 20 dp with 14.5 degree pa or 32 dp with 20 degree pa)
- Would probably be easier to interface with current FRC COTS components
- As mentioned above take a good look at 254s 2016 robot. Also look at TBA design hub for 2012 robots with turrets. 1114 2012 is also a good robot to look at (cad here).

to actually mount these on to your robot look at some of turntables found here: https://www.mcmaster.com/#lazy-susan-bearings/=15xunfe

edit: you can find outer circle in mm for 5mm pitch htd belts here

[onenerdyguy]

My concern with any turret this year is the size. I've yet to find a good way to have a turret that didn't kill your carrying capacity so badly it made it nearly impossible to be worth while. just my 2c.

[Chris is me]

When experimenting with a turret, be sure to test to see if the direction of the turret relative to the loading mechanism affects the accuracy of the shot. This may be an issue depending on your design.

[garyk]

Originally Posted by Chris is me

When experimenting with a turret, be sure to test to see if the direction of the turret relative to the loading mechanism affects the accuracy of the shot. This may be an issue depending on your design.

2643 had just this problem in 2012 "Rebound Rumble." We used tubing as a conveyor system feeding a shooter mounted on a lazy Susan - shooting characteristics varied as the turret rotated.