To Drum or Not to Drum that is the question!

Ok we have been contemplating the drum to beater designs for my students robots. They are hoping for a beater but we have used drums in the past.

The Bots are 12 lb.

My question is this....

What are the magic heights- speeds-angles used in a drum design and does that design change any if a beater was used instead?

We have used EFLM Power 46-670 Kv brushless motors on 80 and 60 amp Esc's and have went with a 12-32 tooth set-up in the past. The drums were 4 inch and 6 inch and spinning on a good bearing set-up for a drum design. The teeth have been a 2 tooth design from .5 to 1.5 from a 3 inch drum.

Has it been bad designs or not enough speed that makes us chatter more than smack during a bout?

Bots have used 4Cell and 5Cell A123's

We are thinking about going to a beater design and or changing the gear ratios for this year...

The info is for a rebuild design and a Flatline w/drum design

As you can tell I am trying to show my students how to put as much info about the robot as possible so people will better visualize their problems.. Hopefully they follow my lead here!

Thanks,

Frisco

Oh hahaha. I was just having this SAME debate with the new EWCTC guys.


Would take FOREVER to type what i said out...


Basicallly. A LOT of factors go into what to choose.

Read Marco's book ...the section on speed/drive speed,etc and start there.

I can tell you from experience, that a drum without absurd tooth overhang will require a lot less power to run.

On my 3 pounder, drum went 40k at 17 amps, while beater wouldn't get over 18k with same motor and drawing over 30 amps

That's funny, I have told my kids the exact same thing....... Read Marco's book!!!!!

BUT.....

KIDS DONT WANT TO READ IN THESE DAYS !!!!

They would rather see it posted on the ShamWOW! internet !

On a side note, they were thinking of S7 or Titanium for a beater design ???????

I thought S7 would be heavier but how brittle is Titanium ????? Would it hold up????

My thoughts are definately a drum over a beater but what about getting the bite?????

We have raked the back sides but never put a cove in the impact side....

Frisco

You haven't seen this??
SHow this hit to your kids and tell them to read the book

https://battlebots.forumotion.com/ready-to-rumble-combat-robots-f25/sting-makes-it-s-debut-at-rmp-t229.htm

Ti is ok against soft stuff, but against hard steel....not so good