Motors, and a hello

[emisnug]

Gary, thank you for the welcome!

I'm well aware that we will have issues - there's an idea to make a 1:4 scale version to make sure we can actually do it first, but we've set aside around £2500 for the bot, not including spares. Ideally, we don't really want to spend more than that on a MK1 robot.

It would seem I'm working with some mildy outdated information regarding drum spinners. 9000rpm+ would be an excellent goal, but motor wise, I'd assume some gearing would be involved - is there a particular one you'd recommend? Do most people run 48V or 24V?

[Garfie489]

I'm well aware that we will have issues - there's an idea to make a 1:4 scale version to make sure we can actually do it first, but we've set aside around £2500 for the bot, not including spares.

Heya,

Just a tip on making a scale model, due to the lack of cross compatibility between major components, its worth building it to 13.6kg as then youll have 2 robots with which you can actively compete. Otherwise your effectively throwing away money

[Eventorizon]

It would seem I'm working with some mildy outdated information regarding drum spinners. 9000rpm+ would be an excellent goal, but motor wise, I'd assume some gearing would be involved - is there a particular one you'd recommend? Do most people run 48V or 24V?

You are looking a the larger Brushless motors, 3000W+, or large bushed motors.

Pulsar used 2 Align 800MX Brushless motors on 12S, and what looks like roughly a 3:1 ratio; usually done with pulley/chain, not gears.

Other machines use the Turnigy Rotomax 80CC to 150CC (They are designed as replacements for nitro engines), a LEM Motor (not sure on the size... but BIG), Lehner 3080 Brushless (Hypershock uses this motor), I believe Yeti uses 2 A28-400s, and Warhead uses 2 of Scorpions HK 7050's at 10'000W EACH!

To use these motors to their max, you need to run 48V, but you don't need to run the whole robot on that. You can have 2 separate power systems with their own Links and Power lights. It adds a little bit of complexity but nothing major. We used dual voltage setups in both our spinner FW's. Mine uses a 5S for drive and 12S for the weapon.

In terms of Mass, you want to be looking at 15Kg I'd say absolute minimum, 20-25Kg ideally. (This is entirely down to your robots design but anything less and you won't have the energy to do any damage.) Tombstone in the US has a 40KG bar? I think? Carbide's is 25KG.

Make sure your LiPo's or A123's are able to deliver the current that the motors demand, and take in to consideration burst currents as on impact the current draw can double for fractions of a second.

PS: Apologies for the info dump. Its all necessary though.
PPS: People will disagree with my choice of weight or motors and have their own way of doing things. Find what works for you/is in your budget/you have experience with.
PPPS: Have fun!