Feigao 540 xl or Neu castle 1512 weapon motor

I am having trouble deciding on which motor to go with for my 15lb battle bot with 3in diameter drum any help thanks

I can vouch for the Feigao motors, that's what we run. You could definitely get some high speed with the right drive ratio to the weapon.

I don't know much about the New Castles, except that they seem to be taking a sizable chunk out of your pocket.

What motors were you guys using before?

we were using the feigao motor at pre lims but are looking to get higher rpms out of our drum for finals well probly go wit a different pulley ratio any recomendations

You guys didn't have any problem on spin-up right?
Just increase the motor pulley size and decrease the weapon pulley size until you still have spin-up but a higher speed.

Another thing is that your weapon is spinning fairly fast already, your issue is that you aren't getting any bite. I tried to help you guys out in saying to take off the little steel teeth between the drums larger teeth because that made it effectively have "4 TEEH" Which means you will never get bite in your life unless with the weapon at slow speeds while your robot drives fast.

Here is the Riobotz tutorial pages 160-161 explaining why having the least amount of teeth as possible is better:



Furthering the table for 4 teeth would show a maximum RPM to avoid grinding being:

2640rpm @ 5MPH:
5280rpm @ 10MPH:
7920rpm @ 15MPH:

We should never count on the 15MPH soeed because that is unlikely to ever occur unless you have a nice run up and make superb contact with the other robot in a "bite-able" location. Even the 10MPH speed is fairly fast, but your robot can drive pretty well so it isn't impossible.

I will give you that this is all theoretical, but Riobotz knows much more than I do so I'm in no place to question it.

yea i remeber you telling us that we did eventually take those teeth out for our bout against kiski but we had traction issues since your bot bent our bottom plate. Plus they had a really good driver

I thought I saw that, but I wasn't sure.
Aw, my bad I went for kill shots.
They did have a good driver!

I wish you good luck on whatever you guys decide to do. I'll try my best to help out because I like Scar.

your bot was a good bot. think of it in these terms. If you have a ceiling fan with 5 blades spinning and you try to stick your hand through it, the blades will skip off the tips of your fingers. now remove all but two. keep it the same speed. your fingers will make it into the blades and even your hand. you need a faster robot wheel wise because your robot has to force a piece of any other robot in BETWEEN your teeth to get a bite. the only time i believe weapon speed to be fastest wins is weapon to weapon. but that doesn't matter right now.

I'd say just stick with the Feigao 540 Xl never seen anyone have issues with them myself, maybe for higher speed change the pulley sizes.

plus the feigao pulls a lot less current from your batteries, were runnin a mamba monster 2200 kv and our batteries are gettin a lil toasty at peak performance

huh...so to make full contact, I shouldn't spin my shell more than 5k rpm...ok.

Well, Camden, your teeth are positioned in a way that only a very tall, uniform bot would encounter all 4 teeth. At the floor it's a 2-tooth shell. Also, shells tend to require less rpm because the tip speed is really fast at large diameters.

However, keep in mind that I have never been associated with a successful shell spinner (only drums, lifters, wedges, disks, and the occasional vacbot. We've had a few horizontal bar spinners, but they haven't done well . . .)

Camden W wrote:

huh...so to make full contact, I shouldn't spin my shell more than 5k rpm...ok.

Not this is not the section from Riobotz on full-body-spinners, it is on beaters, vertical disks and drums.

As rdubard said and as I've seen yours is similar to 2 teeth lower which puts you around 10,000rpm.