Drum or beater

http://members.toast.net/joerger/root/spinner.xls

I've tested this one afew times, did the math by hand and it seemed pretty accurate.

hallboy8222 wrote:

I would go with a drum they are a lot harder to break for one and it's ur first time with a beater /drum u don't want to break it
Oh and there not that hard to build the hardest thing to build i think is the teeth But we just sent them to a shop to build them

But Im unexperienced and have no idea how to even start building a beater so it's ur decision

I think that until a while ago, aluminum drums with bolted teeth seemed like a great idea...recently, solid 1 piece drums have done well vs the alu/bolted teeth. The smaller diameter faster spinning drums also seem to do well vs horizontal undercutters.

Personally, I think that many beaters are designed with not enough meat around the shaft/bushing/bearing areas, and in some cases, perhaps the hardening was not ideal?

A good test of your setup is to spin in the opposite direction .....resulting in a hit that can be the combination of forces from both robots. If your beater/drum or whatever can survive this, then you should be in good shape. Many setups fail, some in a rather spectacular fashion.

Some are caught up in wanting to see the BIG hit, bots hitting the ceiling, etc. which is easier to do with a big beater or a drum with lots of tooth projection (and slower speeds). The MLEC drums rarely get big hits. They are more of a defensive weapon, hoping to break the opponent's weapons.

Our Rattler 1 drum has a pretty good history of breaking opponents weapons, at least so far.

The latest FLUFFY 2 bot could be very tough to beat this year. Solid tool steel drum (and kind of big), ALL steel armor and brushless drivetrain with true invertable operation. If Will gets it ALL done in time, this could be very, very robust and lethal.

how do you design a single tooth drum/disk, like the one on general dissaray?

can solidworks do that? if so which button do you press?
OT: yep i fly helis and airplanes. (still learning though, can always do better)

It's no specific button - in solidworks and inventor, there is a menu you can pull up giving physical data on the part. We produce an initial model (centered on one of the primary axes) and then tweak that model until the location of the center of gravity is exactly along that axis. It's a somewhat involved process.

thanks, are 1 tooth drums/ blades better than offset tooth drums?

The advantage of single or offset teeth is that you can spin the drum at twice the speed and get the same bite as a 2 full toothed drum.

Double the speed = much more energy

Out to lunch = Rumor has is that a few foolish people use single or staggered tooth small diameter drums and spin them at 30 to 40k......All they do is grind unless slowed down, except against other drums/beaters and horizontals, in which case they sometimes just get lucky and might win by having more tooth speed than their opponents weapons?????

The disease seems to be kind of limited to south florida at the moment...but that could change

then again it could be just rumor....

On a side note, a 15 pound staggered tooth drum doesn't have to be REALLY expensive like someo f the solid S7 drums

A simple 1/8 wall steel tube with welded staggered teeth can be made on the cheap and be very well balanced as well.

Paul V's 12 pounder Ntertainment is a perfect example of this.

yes austin, solidworks can do that