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Messages - IanMcMahon

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Event Results / Robot Rebellion 1.4
« on: December 18, 2017, 11:01:34 am »
0,Wedgey,Time Of Death
0,George Wedge-ington,Time of Death
1,Domepiece,Cronenberg Krombopulous

Unlisted due to no BotRank category:
75 Gram:

75,Super Flea,Field Medic
75,75 Grams of Cheese,Super Flea
75,Super Flea,75 Grams of Cheese
75,75 Grams of Cheese,Super Flea

BotRank Matches:
0,Speed Wedge UK,Potentially Self-Destructive
0,The Green Faerie,Stumpy Unleashed
0,Scoop,George Wedge-ington
0,Raven,Potentially Self-Destructive
0,Zeep,Blue Tooth v1.2
0,Speed Wedge UK,Schmittyworbenyajerminjazne
0,Pizza Roll,The Green Faerie
0,George Wedge-ington,Blue Tooth v1.2
0,Stumpy Unleashed,Schmittyworbenyajerminjazne
0,The Green Faerie,Raven
0,Stumpy Unleashed,George Wedge-ington
0,The Green Faerie,Deathbell
0,Speed Wedge UK,Zeep
0,Pizza Roll,Wedgey
0,The Green Faerie,Zeep
0,Stumpy Unleashed,Wedgey
0,The Green Faerie,Stumpy Unleashed
0,Speed Wedge UK,Pizza Roll
0,Pizza Roll,The Green Faerie
0,Speed Wedge UK,Pizza Roll
1,Trailer Park Warrior,Zip
1,The Minions,Eclair & Bonbon
1,Death by 1001 Cuts,Domepiece
1,Pizza Slicer,Cronenberg Krombopulous
1,All Defense,Hope
1,Physique Black,Juggernaut
1,Eclair & Bonbon,Lemonade
1,Trailer Park Warrior,Chooch
1,The Minions,Twilite
1,Pizza Slicer,Death by 1001 Cuts
1,Physique Black,All Defense
1,Eclair & Bonbon,Death by 1001 Cuts
1,All Defense,C-Thru-P-O
1,Eclair & Bonbon,All Defense
1,The Minions,Trailer Park Warrior
1,Physique Black,Pizza Slicer
1,Eclair & Bonbon,Trailer Park Warrior
1,Pizza Slicer,Chooch
1,Pizza Slicer,Eclair & Bonbon
1,Physique Black,The Minions
1,Pizza Slicer,The Minions
1,Physique Black,Pizza Slicer
3,Unknown Avenger,Wasp
3,Scary Terry,Quicksand
3,Pizza King,Death from Above
3,Apparatus,Unknown Avenger
3,Scary Terry,MomBot
3,Hailstone,Pizza King
3,Unknown Avenger,Death from Above
3,Wasp,Pizza King
3,Unknown Avenger,Quicksand
3,Hailstone,Scary Terry
3,Unknown Avenger,Scary Terry
3,MomBot,Unknown Avenger

Event Results / Sparkfun AVC 2017
« on: December 05, 2017, 12:40:55 pm »
I believe that this is now ready to bu uploaded.

Forfeits (Not Included):
30,Crippling Depression,Huge
12,Little Blue,Egg-salted
3,East Side Bot 2,Brain Storm
3,Pistachio,DCA Bot
3,Demon Spawn,Doomforge
3,RoboJackets Radiii,Torchy
3,Flutter,West Side Bot 1
1p,TARS. 1,AntiMatter
1p,Abs of Plastic,AntiMatter

*** Start of the Results***
Sparkfun AVC 2017
30,Undisputed Champion,Def Smooth a.k.a. Dr. Sheet
30,60 Seconds of Glory,Zues
30,Speed Wedge 30,Undisputed Champion
30,Crippling Depression,Sassy Kitty 2
30,60 Seconds of Glory,Something Appropriate
30,Undisputed Champion,Centennial
30,Sassy Kitty 2,Zues
30,Huge,Something Appropriate
30,Def Smooth a.k.a. Dr. Sheet,Spirit
30,Sassy Kitty 2,Undisputed Champion
30,Huge,Def Smooth a.k.a. Dr. Sheet
30,Crippling Depression,Speed Wedge 30
30,Poptart,60 Seconds of Glory
30,Speed Wedge 30,Huge
30,Sassy Kitty 2,60 Seconds of Glory
30,Speed Wedge 30,Sassy Kitty 2
30,Crippling Depression,Poptart
30,Poptart,Speed Wedge 30
30,Crippling Depression,Poptart
12,Quicksilver,The Goat
12,Little Blue,Large Data
12,Footlong,Tough Love
12,Typhoon,Little Blue
12,Minor Threat 3,Footlong
12,CATBox,Tough Love
12,Fork,Large Data
12,Footlong,The Goat
12,Little Blue,CATBox
12,F-13,Minor Threat 3
12,Minor Threat 3,Little Blue
12,Quicksilver,Minor Threat 3
3,Robot 1,East Side Bot
3,FooBar,Blasty McBarface
3,Oreo Typhoon,Pistachio
3,Crocubot,DCA Bot
3,Captain Hook,Torchy
3,Just A Wedge,Topogon
3,Margin of Safety,Golden Bepis
3,RoboJackets Snutti,Zooz
3,Rum Ham XL,Doomforge
3,Spinderella,West Side Bot 2
3,Animus,Pizza King
3,Project Darkness,West Side Bot 1
3,RoboJackets Radiii,Flutter
3,Hardwork,Whirly Dirly
3,Icky Mouse,Brain Storm
3,Unknown Avenger,Robot 1
3,Egg-Salted,Demon Spawn
3,Pizza King,West Side Bot 2
3,Blasty McBarface,Robot 1
3,Anti-Beetle,Golden Bepis
3,Whirly Dirly,East Side Bot 2
3,Crocubot,Oreo Typhoon
3,Just A Wedge,Captain Hook
3,Margin of Safety,Robojackets Snutti
3,Project Darkness,RoboJackets Radiii
3,Icky Mouse,Hardwork
3,Unknown Avenger,Foobar
3,Rum Ham XL,Egg-salted
3,Oreo Typhoon,Pizza King
3,Flutter,Captain Hook
3,Robojackets Snutti,Whirly Dirly
3,Demon Spawn,FooBar
3,Egg-salted,Blasty McBarface
3,Flutter,RoboJackets Snutti
3,RoboJackets Radiii,Hardwork
3,Demon Spawn,Oreo Typhoon
3,Spinderella, Egg-salted
3,Margin of Safety,Just A Wedge
3,Project Darkness,Icky Mouse
3,Unknown Avenger,Crocubot
3,Rum Ham XL,Animus
3,Just A Wedge,Spinderella
3,Demon Spawn,Icky Mouse
3,RoboJackets Radiii,Crocubot
3,Just A Wedge,RoboJackets Radiii
3,Animus,Demon Spawn
3,Margin of Safety,Unknown Avenger
3,Project Darkness,Rum Ham XL
3,Unknown Avenger,Animus
3,Rum Ham XL,Just A Wedge
3,Rum Ham XL,Unknown Avenger
3,Margin of Safety,Project Darkness
3,Project Darkness,Rum Ham XL
3,Margin of Safety,Project Darkness
1p,Skippy,JuicerBot 2.0
1p,Charlie,Abs of Plastic
1p,Nessie,Splash Damage
1p,TARS. 1,Hungry Hungry Hippo
1p,JuicerBot 2.0,Splash Damage
1p,Abs of Plastic,Flippy
1p,Hungry Hungry Hippo,JuicerBot 2.0
1p,Nessie,TARS. 1
1p,Hungry Hungry Hippo,Charlie
1p,TARS. 1,Abs of Plastic
1p,Hungry Hungry Hippo,TARS. 1
1p,Hungry Hungry Hippo,Nessie
1p,Skippy,Hungry Hungry Hippo
1,Mallowbot Alpha,Anti Matter
1,Sgt Cuddles,Sweet Tooth
1,Physique Black,Foiled!
1,Odium,Meerkat Mreow
1,Cat .5,Tortuga Robustus
1,Panda Machine,Raw Jaw
1,Angry Accountant,Spinelli
1,Ikazuchi,The Highlander
1,Ventito,Row Boat O
1,Foiled!,Sweet Tooth
1,Spinelli,Raw Jaw
1,Double Stuff,Mallowbot Alpha
1,Physique Black,Sgt Cuddles
1,The Minions,Kazoo
1,Maverick,Cat .5
1,Angry Accountant,Panda Machine
1,Pizza Slicer,Ventito
1,Mallowbot Alpha,Row Boat O
1,The Highlander,Sgt Cuddles
1,Odium,Tortuga Robustus
1,Meerkat Mreow,Cat .5
1,Egg-cellent,Panda Machine
1,Ventito,Anti Matter
1,The Highlander,Mallowbot Alpha
1,Meerkat Mreow,Egg-cellent
1,Double Stuff,Physique Black
1,The Minions,EXP
1,Maverick,Angry Accountant
1,Tsunami,Pizza Slicer
1,Physique Black,Meerkat Mreow
1,Angry Accountant,The Highlander
1,Odium,Pizza Slicer
1,Physique Black,Ventito
1,Angry Accountant,Odium
1,Double Stuff,The Minions
1,Angry Accountant,The Minions
1,Physique Black,Maverick
1,Angry Accountant,Physique Black
1,Tsunami,Double Stuff
1,Angry Accountant,Double Stuff
1,Tsunami,Angry Accountant

Event Results / Battles at Houston Maker Faire 2017
« on: October 24, 2017, 01:11:30 pm »
Battles at Houston Maker Faire 2017
0,Time Of Death,Z-Wedge
0,Deathbell,Speed Wedge UK
0,DARC House Bot,Orange Crusher
0,Deathbell,Orange Crusher
0,Speed Wedge UK,Z-Wedge
0,DARC House Bot,Time Of Death
0,Speed Wedge UK,Orange Crusher
0,Deathbell,Time Of Death
0,DARC House Bot,Z-Wedge
0,Orange Crusher,Z-Wedge
0,Deathbell,DARC House Bot
0,Speed Wedge UK,Time Of Death
0,Speed Wedge UK,DARC House Bot
0,Time Of Death,Orange Crusher
1p,C-Thru-P-0,Purple Power
1p,C-Thru-P-0,Pizza Sword
1p,Purple Power,Pizza Sword

Progress Reports / Re: Team Slaughterhouse
« on: August 13, 2016, 09:03:42 pm »
The real reason for today's post.

I recently bought ten of these $3 used gearmotors from eBay. They are constructed similarly to the larger 25mm Chinese gearboxes. I thought that they might be of value to the new builders who are being very penny conscious.

I have run them through my motor testing methods and have the following data.

Theoretical Operating Specs         
Voltage         7.4   11.1   V
Stall Current  0.9   1.3   A
Stall Torque  16    24   oz-in
Speed          555   833   rpm

For a more direct comparison with Kurtis' products, the following table has the coefficient of kV*kT shifted from 1352 to 1111 to match the specifications of the Mabuchi FK-050SH. This changes the kT to 15 oz-in/A.

Derived Operating Specs with Mabuchi Efficiency      
Voltage           7.4   11.1   V
Stall Current   0.9   1.3   A
Stall Torque    13   20   oz-in
Speed           555   833   rpm

10 of them had an average mass of 29.4 grams with a standard deviation of 0.1 grams.

My tachometer is only accurate to 60 rpm, so that causes the majority of the error in the calculations.The kV therefore could be anywhere from 70 to 80 rpm/V. This would change the kT value from 17 to 19 oz-in/A.

Progress Reports / Re: Team Slaughterhouse
« on: August 13, 2016, 08:59:46 pm »

I basically never check SPARC, so I didn't see your post. I used three 8mm wide bearings in the hub. Good idea to be concerned if I was only using one.

General Robotics Discussion / Re: Newbie Help
« on: July 12, 2015, 01:47:07 pm »
Thought: it might be having turning issues because the drive motors are trying to drive both wheels equally rather than acting like a differential. I remember something about needing to wire the motors in series if you want differential action, but I may be completely off base.

If you disconnect one of the drive motors, does it turn better or worse? What about if you wire the motors in series?

Event Results / Re: Sparkfun AVC 2015
« on: July 12, 2015, 01:37:36 pm »
The first Spinny  vs. Speed Wedge 3 match [3,Spinny,Speed Wedge 3] was not supposed to happen and was not scored as part of the tournament. We just both thought our bot names were called and put the bots in for a fight.

I also forfeited Speed Wedge 3 to Project Darkness so that Project Darkness would get the tournament win.

No autonomous bots were entered into combat at Sparkfun AVC. There was a team using a laptop to control their beetleweight though.

Skills / Tips & Tricks / Chinese 25mm Gearboxes (For Beetleweights)
« on: July 12, 2015, 01:34:27 pm »
I spent 4 hours today going through my 25mm Chinese beetle gearmotors and have the following results:
1.   The gearboxes can use motors with a bolt pattern of 14mm or 17mm. These correspond to Mabuchi 280 and 370 motors.

2.   The stock pinions are brass 12T 0.4 mod with a 2mm bore. Steel versions are available here although they will probably need to be filed to reduce the width.

3.   The 500 RPM gearbox has a ratio of 24.7:1. The gearbox is longer because they added a 20T to 12T stage. I bought this one: . It actually runs at 600 rpm at 12 volts. The motor stalled at 2.3A at 12V. The gearbox itself might be a good choice for the brushless drive crowd.

4.   The 1000 RPM gearboxes have a ratio of 14.8:1.

5.   The Kitbots gear motor stalled at 1A at 2.3 Volts. At 12V, it should stall at 5.2A. I think this is why Pete sells that particular gearmotor; it is roughly twice as powerful as the other 1000 rpm motors.

6.   This 1000 RPM gear motor stalled at 2.1A at 12V.

7.   The motors are consistent between batches but are not all the same. The motors seem to have a kV between  1240 and 1300 rpm/V. I have tried to look up the model numbers, but they seem to be from assorted lots sold for other purposes and datasheets aren’t really available.

8.   The Mabuchi RC-280RA-2485 would be a good motor choice if you want to run at lower voltage. It is available from Banebots at At 7.4 volts, it would give 880 rpm with the 14.8:1 gearbox for 2.3 ft/s with 2” wheels. The Kitbots gearmotor would only do 620 rpm at this voltage for 1.6 ft/s with 2” wheels.

Progress Reports / Re: Team Slaughterhouse
« on: March 18, 2015, 12:35:24 am »
I am leaning towards these: for the new weapon hubs for the Projects.

Rules Discussion / Re: Activation and shutdown safety procedures
« on: March 17, 2015, 11:58:44 pm »
I have mixed feelings on this. I've alternated between this method. My concern with it is if someone trips over it or bumps into it when I'm powering up the robot. Maybe a specialized area for it when powering up. What I've been doing is putting it flat outside, powering up the robot keeping the weapon lock in. I then wait a few seconds to make sure everything seems ok - no unexpected motor twitching, etc. Then I hold the transmitter with the throttle stick firmly in the LOW position in my left hand and remove the weapon lock with my right hand.

I too was concerned about someone stepping on it, so I set it on the step next to me. That kept it off of the ground where everyone else was walking. If one of my spinners went in first, I would also hold the transmitter with my left thumb preventing the throttle stick from being moved until the box was locked. I didn't touch the transmitter while removing the weapon lock.

Rules Discussion / Re: At what point do "spares" become a new bot?
« on: March 17, 2015, 11:51:57 pm »
Would it have been acceptable if i had a pre-wired set of escs, motors, and switch together ready in case some sort of mishap took place?

You also might want to install the wheels onto the motors, if possible, so that you can loctite the hubs before the competition starts. Which bot was this for? I forgot.

Rules Discussion / Re: At what point do "spares" become a new bot?
« on: March 17, 2015, 11:49:27 pm »
I get a major adrenaline rush from repairing bots at matches with time pressure. The repairs were something that I was actually missing with Speed Wedge 3 at Franklin and on the first day of Moto. Luckily, I had two ESCs and three motors fail between the 1st and 2nd Trilobyte matches. That was a rush. I couldn't even name the tools that were sitting in front of me. My ability to think about anything other than fixing the bot was shot.

On the counter point, bringing multiple bots under one name would really just be shifting the repairs to a later time, assuming that the competitor wants to salvage the damaged bots to use in future tournaments. It would mean that the builder would not have to face time constraints and reduce the need for postponements. Between the postponements for Speed Wedge 3 and In The Margins, we delayed the ending of Motorama by about 30 minutes. Perhaps spare bots would have reduced the delay.

I am proud when I look at my battle-damaged robot that I managed to keep going for 7 straight matches, but perhaps, we should investigate alternative strategies to keep more "bots" functioning towards the end of a tournament. I don't know how much emphasis we want to place on the essence of build, fight, repair, repeat.

Rules Discussion / Re: Activation and shutdown safety procedures
« on: March 17, 2015, 11:26:48 pm »
Ok, to reply to an old thread. What about turning your robot on at the door and driving it over to the square? You never have to expose more than head, torso, and arms to the bot. You are also already in the path of escape that way. The side benefit is that you can test drive the bot while driving it to the start square.

Also, place your transmitter flat on a surface with the sticks up so that it cannot fall over onto the sticks. If the transmitter is placed outside of the arena, the transmitter remains accessible and the robot cannot hit it if something bad were to happen.

Rules Discussion / Re: At what point do "spares" become a new bot?
« on: March 17, 2015, 11:15:27 pm »
True, because in theory, he would never have replaced both parts at the same time. If there is no other axe claiming to be granddaddy's, then the sole claimer maintains being granddaddy's axe.

A robot example: I have built three Scoopulas (old 12lb dustpan) over the course of my combat robot years. At one point, I sold Scoopula with all parts, and then built a new one from scratch a year or two later. The new bot was still Scoopula because it maintained the name, and no other robots were claimed to be Scoopula. It shared no metal and no electonics but the receiver and transmitter with the previous bot.

Rules Discussion / Re: At what point do "spares" become a new bot?
« on: March 17, 2015, 10:58:51 pm »
Well, I actually have been bringing two "identical" machines to competitions, but I have been competing with both. (Physique Red/Black and Project Excelsior/Darkness) This was done to help speed my development cycles by exposing the designs to double the number of competitors and because it is cheaper per unit to have multiples of a part made.

Realistically, this probably doesn't need to be legislated because peer pressure can probably keep it from being done. In theory, everyone who competes currently wants to remain part of the group and will probably conform to the expectations of the group.

By the way Fuzzy, nice job with the George Washington's axe argument.

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