Dons robot projects

[Don Doerfler]

Still 'n Shock 2 15lb
1st swpa regionals March 2012
1st swpa finals April 2012
Coolest robot swpa April2012
2nd nrl nationals May 2012
national grand champ May 2012
2nd rage in the cage May 2014
best engineered rage in the cage may 2014
1st Franklin institute October 2014
overall 22-4

working on getting a drum for it and converting it to brushless



Chibi Blackout 6lb
2nd place botsblast july 2014
overall 4-1

Fixing the frame and the drum, also using 3cell 12 dewalt battery.



CMU 15lb
So I designed a single asymmetrical tooth vertical spinner for rage in the cage and nrl nationals
This is how much progress I have made in the past 2 weeks

[BD]

Very pretty- looking forward to progress

[Don Doerfler]

So I disassembled C Blackout and the middle frame member deformed a lot....assuming due to the notches for the wires I put in and also because of the slots. So I remade the middle piece and the pieces that mount to the motors on an actual mill and not a drill press. So now I will feed the wires through the already existing hole



pic with new frame pieces


The 380 motors I were overvolting that I was running on 4s lipo.... I had 2 of the plastic backs melt. So im using 3s 12 dewalt lithium ion 2000mah batteries hoping this wont catch the motors on fire 




On one that decided not to work the back wasn't melted but the brushes on the inside cracked somehow

[Harry Hills]

Could you not try using the dual rates on the transmitter to try and save the motors while retaining the higher voltage for the weapon system? Or search around to see if there is a version of the motor made with a metal endcap.

[Don Doerfler]

maybe I can test out with dual rates if the lithium bats don't work cause the lipos I were using are currently .....gone. There is a version with a metal back but I have a lot of them that came with the gearboxes.

[Koolaid64]

you could also try using smaller batteries. a 4s for the weapon and a 2-3s for the drive. you wouldn't really need that big of a pack to drive for 3 mins

[Don Doerfler]

http://www.batterysupports.com/dewalt-dcb120-12volt-max-12v-2ah-lithium-ion-repair-battery-pack-p-195.html
im currently using these

[Koolaid64]

I guessed some of you values for your gearbox/wheel diameter and plugged everything into the tentacle torque calculator (http://www.architeuthis-dux.org/torquecalc.asp) and got about 150mah for your drives for three minutes. I would probably try a 300mah 3s lipo to give you a little extra then you could run a 1200-1500mah 4s for the weapon. I'm not super savvy on this though could someone confirm this?
-Kyle   

[Don Doerfler]

I Picked the option for
-banebots 36mm 16:1 rs 385
- 2.5in wheels
and I got a value of 26 mah for 3mins for each motor

[Koolaid64]

I tend to not use the preset values because they are usually off in some way. I plugged the stats off of banebots for the 380 in and got this

[Don Doerfler]

12lb/15lb Blackout 2.0  in cad currently weighs 11.7lbs
will run on 2400kv turnigy trackstar 540 sized motors to 16:1 banebots gearboxes at 3s a123
the the weapon is a 1900kv tacon 540xl running or 4s a123

[Lucas Grell]

Why are you using 540s for drive? Seems way overkill; Uppercut, Wedgey, and all of Proctor's good bots have used 380s, even with 16:1 gearboxes you get plenty of torque.

[Don Doerfler]

I meant they are 380s really but they have the cooling fins built on so they have that 500 face mount
http://www.hobbyking.com/hobbyking/store/__27867__Turnigy_Trackstar_1_10_17_0T_2400KV_Brushless.html

[Lucas Grell]

Ah, that makes sense. That's kinda nice; I've been scavenging our old 3xx P60 plates, since we have mostly 5xx 16:1 boxes. Most of the older ones are stripped out because idiots.

[zacodonnell]

Isn't C Blackout a 6 pound bot?  And you were melting the end caps on the motors at 14v?  You must be pulling a metric boatload of current through them.  I used the Kitbots 1000 RPM motors on 1.75" foam wheels at 4S A123 and they lasted 8 minutes when I grudged Phoenix.  The got a little warm to the touch but worked fine, and they're smaller than the 380 motors.  Nowhere near melting the endcaps for sure. Could you have binding problems in the drivetrain that were causing higher current draw?

I think dual rating could help you a lot. It will keep the motors cooler for sure, and you can set a switch up on the transmitter to turn it off if the weapon goes out and you need to be a wedge for the rest of the fight.  Failing that, long can 400s would be way, way overkill and handle 14v great. They are a bit longer but not too much heavier than the 385s

-Zac