Dragon Con Bot Blitz

Dragon Con is (technically) still going on, and Robot Battles microbattles was yesterday. I already planned on bringing Cake and DDT, but Charles, Xo, Aaron, and I decided a fleet of "Assbots" were in order. By this time it was Friday the 2nd. Isn't Robot Battles on Sunday?

Charles was nice enough to donate an old Pop Quiz frame with some motors still attached. Remove weapon motor, blade, receiver and escs, as well as one motor. Three drive motors, a sturdy frame, and a dead 4-cell lipoly. This could work.

I left my shop camera at the apartment, but the result was pretty clear.

Introducing, Prop Quiz 0.5: waaaay too light.

Seriously, that is a 3 blade prop designed for baby helichoppers. Does it fly?

YES.

Unfortunately, it had some issues expressing flight in practice.



Xo and Aaron designed a melty style robot, where the entire frame rotates to give a 100% weapon mass.

And this is how that venture went:



Looks like it would have been pretty dangerous if it was made of metal or plastic and NOT WOOD. Seriously, the only piece of material we could find Saturday evening was a 3/4" block of wood. We decided to waterjet a pocketed frame that housed all the electronics. It also weighed approximately 1lb,5oz for a 3 pound class. I just wished it had hit the opponent instead of the wall.

And here is Charles' assbot, "$20,000 per year Enjeering Degree". Of course, the robot is in the arena, not the person on the left.

A resurrected sumobot back when speed hacked servos were still valid methods of power transmission. It also had a fair number of trinkets and symbolism: "the hand is symbolic of begging for money and the weight of student loans; the duct tape wrapped around the galvanized roof flashing is representative of the challenges students face in pursuit of fulfilling their engineering degree requirements; the threaded rod represents front-end ballast mass."

The serious business robots put on a great show as usual. DDT threw robot guts all about the arena and Cake probably threw a roof shot or two. Both robots were removed by Thomas Kenny's robots, who are great in design and quick as usual. The flaws in my robots were the same as usual, and I'll probably not fix them as well.

[rumble video]

So what's next? This upcoming Saturday is the Mini Maker Fair hosted by our very own Georgia Tech Invention Studio/Maker's Club. This means this week will be yet another hectic blitz to put together the scooter I hope to feature along with Charles' equipment. Be there if you can! We promise over 60 different exhibitors, a far greater turnout than expected.

Busy on Holiday

I'm currently on my two weeks holiday between work and institute but I'm kept relatively busy by upcoming events. Dragon Con and the Georgia Tech Mini Maker Faire are both coming up, which means I have about 5-6 things I need to get done.

Robots:
Running the bots at PA Bot Blast was a good way to test their metal against some real north east powerhouses but now I am left with no satisfactory running robots. Dragon Con doesn't run the 150 gram classes, but I still like to make a showing with an ant, beetle, and maybe a macro-class robot this year. I should have enough extra frame parts to revive Cake (I want to rebuild!) but the drums are just so fucked up I don't see too much in point in it. I would like to bring something different from DDT. The main idea is to not spend any extra money so we'll see how that turns out.

Costume(?):
If I go to any of these conventions, I like to put a little extra into it by dressing as something and then saving it for Halloween. As awesome as Tony Stark is, I DO NOT want to recycle a costume past a year. Hell, multiple conventions was pushing it. Right now I am looking into something Matrixy but those long coats are really damn expensive...

On to the interesting parts...

Scooter:
I bought this. Do I really need to state my intentions?


Safety Razor v1.1 is still in deployment, but I am putting foot down... on something other than concrete for braking. There are a few minor inconveniences in the current iteration that I am wanting to address in a new revision.

• Braking - my left foot is unacceptable, and I just bought a pair of Nike shoes
• Heft- At 13-15 pounds, the scooter weighs on the heavier side of objects. The motor alone weighs about 6 pounds, and the frame is unpocketed aluminum. All aspects of it (except the handlebars) are overspec'd.
• Waterproof- it is not, and wetness has hurt it before
• Switches - periodic replacement of switches due to destructive arcing is unacceptable. A precharge circuit is needed, or a high amperage switching method.
  
• Longevity- last longer (she said that)
• Smoother Rides- make it suck less when I hit cracks in the sidewalk

These are very realistic goals that all begin with the wheelmotor.

Weren't you building one already? Is it done yet? The answers to those questions are "yes" and "no". Since it isn't done yet, the logical thing would be to design another one.



In reality, I have an issue with leaving proper amounts of space for wires. I wish they were of infinitesimal thickness. Besides, that version was fitted to a 5" wheel, and as my calculations show, I can get a more efficient package from a smaller diameter but wider wheel (assuming stator also follows).


The new wheelmotor plan has lots of space for wires to route (over 1/4" of room) and a beefy 3/4" shaft for the passage of wires. The stator comes from a Turnigy motor, has a diameter of 52mm, and a length of 30mm. The stator will be wound dLRK with ~25 winds per tooth. Each magnetic pole is composed of two N52 neodymium bar magnets. All of this will be captive in a 4" rubber wheel of 40A durometer. Air gap is currently 0.6mm ideal.



To make this motor comparable to the 400W Kollemorgen , I will be routing sensors through the motor. A tad bit of trial/error is involved because I am planning on using a 150A RC car esc to drive it. Thanks to Charles and Shane, I have the pinouts of the sensor cables but I'll still be playing the mix 'n match game to determine the "A", "B", "C" motor terminals.


As a result of the motor swap, the entire frame gets a redux. The frame rails are still Aluminum but only 19" long now, and 3/16" thick instead of 1/4" before. In fact, all 1/4" plate is changed to 3/16". The top and bottom plates are still 1/8" Al, but there is no longer a garolite fancy cover plate. Instead, I am going to try engraving on some skater's grip tape and stick that to the aluminum. Also notice there are no T-nuts. All holes will be mill drilled and a silicon caulking will be applied to the inside corners to help with waterproofing.


Why don't I need the garolite cover anymore? All charge plugs are now externally accessible. A simple cover will go on top of those to prevent crud from getting inside.

What on earth is that monstrous black tumor protruding from the back? That is the model of the 150A esc. I don't actually have it on my persons yet.

Meanwhile, the battery was upgraded to a 6s1p 5000mAh lipoly pack. Super longpak!


A slight modification to the front forks to make it look less... awkward. This is the true advantage of the Razor A2 or A3 scooters.

For now, this will sit under the Safety Razor tag, but I am open to new names. Razor Wind?

I Am Otaman!

This was so awesome I had to interrupt our regular posting fashion. I brought my Iron Man Costume (or Tony Stark Costume if it pleases you) to Otakon and found an Iron Man Dancer! I swear we were standing at the intersection of the dealer's hall for a good 10 minutes taking pictures.


I bet her boyfriend was wishing he'd dressed as Iron Man.


Also, this guy in the giant robot costume was a good sport. Tony Stark vs the giant robot man (Maybe an APU from the Matrix?)


Otakon 2011 Album

Last Week and Next Week (PA Bot Blast and Otakon)

Finally, a weekend where I am not rushing about to see new places or compete against other sentient beings. However I have stuffs to prepare for next week so after 7 hours of straight soldering, I elect to type up a post while I am still on a solder fume high (no not really).

Made the drive from Maryland to Pennsylvania for my first ever PA Bot Blast event! Driving up to Harrisburg in the wee hours of the morning but when I started up the road to Bloomsburg things sudden looked very hilly and untouched. Towns built into the valleys of the massive hills, which were covered with trees; to be honest I felt like I was in a northeastern Costa Rica. 7 halves hours later I arrived at the Columbia Mall and prepared to set up.

I brought P150, DDT, and Cake to represent the south. I hadn't really run these robots since April, so I assumed they were in working order. Boy was I in for disappointment. P150 and DDT both went 1W:2L for seemingly dumb reasons. They both lost wheels in their first matches. P150's was removed by hedgehog's angled cutter (and P150's poor control), and DDT's seem to have fallen off by chance (when Fangus and DDT hit, he popped the belt off the pulley, jamming the blade and spinning the robot, which threw the wheel off. If Fangus was the cause, my shaft would be missing). They then proceeded to defeat robots in their expected fashion only to lose again disappointingly. Some additional thought needs to be put into these robots.

Cake made a wonderful representation! 4 wins and 2 losses, both losses caused by One Fierce Lawn Boy from Fierce Robots. Every match ending up in KO. Videos below.







The money shot of the event. The final hit between Ripto and Cake in the loser's finals match resulted in Ripto being lodged between the lexan and the outer barrier. Ouch.



Jeremy ran a very professional event. Organized procedures, match listings, and even had clarifications for the grey areas of robotic combat. Needless to say, I'll be returning if I am in the area again!

PA Bot Blast 2011 Album



Next week will be Otakon, the largely anime convention in the Baltimore area. Now, I am not a huge fan of anime, but I do like to create. I had my Tony Stark, Iron Man costume shipped up to me during Independence Day break so I could work on it. A few upgrades ensued.

First I decided to add a blue tint to my LEDs. Feeling resourceful, I merely took a marker and drew on the outer surface. Nothing fancy.



The other upgrades were all for my sanity. I redid the wiring to be much more robust and clean. At Dragon Con, I had several problems with connections breaking and repairs required. This time, all solder joints were solid, shrinkwrapped, and glued.

Textual Updates

It is a loosely kept secret that I am not currently residing in Florida or Georgia this summer. As a result, summer term creativity has been pretty mute.

Some might call it slacking. I've reacquainted myself with Team Fortress 2 and all the hat(in)sanity. I've also been experimenting with this new Google+ object. Both of which I am proud to say, I HAD IT BEFORE IT BECAME FREE.

Anyway, I've not been slacking. PA Bot Blast will happen this upcoming Saturday and my robots have been ready since April. Each one of them snuggled in their little bubble wrap blankets, suffocated in duct tape. It is time to check on them.

This week I will begin cycling batteries and practice driving. I am confident each robot will put on a spectacular show, but by no means will this be an easy competition. If you are in the PA area, I encourage you to visit the event in Bloomsburg, PA.

http://www.buildersdb.com/eventdetail.asp?eventid=334

In other news, OTAKON! I've registered for an anime convention I felt like attending and so preparations begin! I had Irony Man shipped up to my location so I can work on him. Upgrades are expected. I'll be using a arduino mini instead of the Duemilanove for size and simplicity of power routing (since I can run the mini off 3.3V, and hence require only one cell). I'll also be running some Luxeon super bright LEDs instead of the current modules.

Yeah.

Enter The Wooden Man

I've been becoming increasingly interested in martial arts every day. I used to practice Northern Praying Mantis in my youth and other than athletics and personal fitness it has not been too useful until I moved to Atlanta. Things are considerably more hostile and the ability to self-defense has become the aspect that keeps me from cowering in fear of the city.

Among the other styles I've seen, I've enjoyed Wing Chun. It is a southern style, that focuses on the speed from economic movements of blocking and attacking simultaneously.

I decided to try and construct a "wooden man" to help facilitate the practice of Wing Chun.
As the name suggests, these are usually made of wooden timbres with other protrusions for the legs and arms. They can be attached to the walls, or solidly implanted into the ground. As a student who travels frequently, I need my wooden man to work, but also be collapsible and light to transport around. Digging holes and hammering on my walls are unacceptable.

So here we go:



PVC body, wooden arms, and a weighted base of water similar to backyard basketball hoops. That way I can fill the base with water to add weight, and empty it between travels. The PVC construction is significantly lighter than a 9" diameter chunk of wood, but should offer enough rigidity to take impacts. Right now those are 4" PVC pipes, but I can add padding to thicken them, or use larger tube if i know they are available.

But the key features are present. The arms and legs are removable, and the base is separable into two parts to facilitate packing all the while being light.

A major determining factor will be the mating parts for the water base. I don't actually have one, so I need to first find one I can dismantle before finalizing the design.

This will be built when I return to Florida.

Supermassive Updates

I neglected updating the blog for awhile due to life, but I promise this post has some good content. First, the summary:

• P0w3r Drive
• PA Bot Blast Preparations

Last time I assembled the endcaps to find they were wobbly by not-so infinitesimal amounts. Did I re-machine them? You bet. But this time I implemented a different technique.

You might recall, the technique I have been using to machine the endcaps was to first rough cut a disk of aluminum on the waterjet and then turn the parts on the lathe using a socket cap bolt through the center. I believed the source of the issue same from wiggle room between the starting bore in the waterjet plate and the OD of the bolt (since drill bits increase in discrete amounts not necessarily tuned to bold diameters).

So this time, I decided to apply some angular principles of self-centering. I angled the bore by using a countersink bit. Furthermore, I grabbed the appropriate flat screws for the duty and a hexagonal standoff for the opposite end. It basically worked like V-groove stands for machining tubes. The round object is guaranteed to sit in the center of the groove. Works similarly for the conical shape. This method returned a much truer endcap, and validates the technique.


Also, automatic feeds are AMAZING. Almost a mirror finish. Never before have I turned such a smooth part.




I was only able to finish one end before the term ended, so there is no way I will be able to test the wheelmotor this summer. What I can do, is wind the stator. More on that in about 12-14 weeks.

In other news, I'm finally going to fight robots again! Dreadfully Wicked Robots is hosting PA Bot Blast in the Bloomsberg Mall. Features robots from 150 grams to 6 pounds. Heavens know I don't have a 6lber, but I do have the insect fleet.

I will be taking DDT, Cake, and P150.

Wait, p150? isn't he dead? Yeah, kind of. But he can be rebuilt... better... faster... stronger...


...and more carbon-y. Seriously, lets use some of these resources I have at the Invention Studio to make some grade-A bots. P150v4 uses the old 7.4, 300mah lipoly and Jeti advance 4 esc but everything else is new. 30:1 micro sanyos, Turnigy 2204 brushless motor, HMC 3-9 single channel escs, and Spektrum AR-2 gram receiver.


Waterjetted the carbon fiber plates. Surprisingly I didnt have to use fodder plates to prevent the delamination. I just used a large lead-in, and low-pressure settings. There was some delam happening around the frame, but nothing superduper glue could fill in.


I had a moment of boredom while it was raining and decided to try engraving on Carbon Fiber. It won't cut but instead seems to melt the epoxy a bit. I guess an experience not to be repeated.


Wiring the beast is hell. I made a minor design change on the fly. Originally the robot was to use .5" standoffs to space the innards, but I opted for .375" because the motor would have required a massive hub to make up the height deficit. As a result, everything was 2x crammed in the fuselage. I had to buy the spektrum AR-whatever 2 gram receiver with the micro JST plugs to make it fit.


STILL I had to remove the micro JSTs and direct solder. [note to users: spektrum decided to be crafty and switched the positions of the 5v+ and gnd on this receiver. BE WARNED]

The HMC3-9's were angled (WTF) and flipped to fit. Only one superbus was used for power.

Somehow, it all fit.



After turning down the wheels from 1.5" to 1.125", I finished the bore on some old Vrogy blades Seth Carr of Team Lab Rat graciously donated/sold cheaply.


Bam. A robot. I added and bent some strips of grade-5 titanium to bring it up to weight and add protection. It looks very similar to Wazio's Pookie if anyone remembers that being built. Eitherway, it performs like a champ. Gryos like crazy, quicker than any version of P150, can rip through 1/32" steel like frozen butter.

Minor tune ups were made to the other robots as necessary. DDT required no additional servicing (as usual), Cake was lubricated and modified to include mechanical locks on the drum shaft instead of set screws (because setscrews suck), and P150 was rebuilt as noted above. I am concerned for the needle roller bearings in Cake because I was unable to remake the shaft so there is some audible play in the shaft. Could damage the rollers, so I'll bring the old drum as a back up.

PA Bot Blast on July. Cheers!

Also, Cheesecake.