I recently built a new 30lb fighting robot for the NERC Sportsman class and Dragon*Con Robot Battles events. This instructable will follow the build process and will include links to parts suppliers, machining resources and .dxf drawings of the custom components used to make the robot.
If you are serious about building your own version of this robot, contact me and I'll be happy to help where I can.
If you are serious about building your own version of this robot, contact me and I'll be happy to help where I can.
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Signing UpStep 1: A pile of parts and the first day of the build
The pile of flat stock was waterjet cut by Westar Mfg. out of 6061 aluminum and 4130 steel.
Drawings for this collection of parts along with materials, thicknesses and quantities can be found here.
The top armor and two supplimental weapons were not included in that collection to allow modifications to be made for weight purposes. Those files are located here.
These drawings were done with the intent that most would be made on a waterjet, and as such did not require dimensioning. Each of the drawings that was meant for waterjet cutting has a 1" reference square on the sheet.
With the great deal of interlocking components, the order of assembly is important. The first components to be assembled are the weapon hub, support hubs and weapon sprocket. Doing this first also showed the first issue in the build. The sprocket model on McMaster.com did not have the correct hole spacing which meant only 3 of the 6 planned bolts would fit. These holes are all meant for a #10 bolt, and without a clearance hole bit on hand, one had to be ordered.
The other main piece of the day was countersinking the holes on the inner rails to ensure there would be no contact between the moving roller chain and the bolt heads. The front threaded spacers also needed to be added and loctited as the bolt heads will be covered by the D shaped bearing blocks during assembly. A product called Nutstrip is used to connect the panels together, allowing for quick assembly.
Drawings for this collection of parts along with materials, thicknesses and quantities can be found here.
The top armor and two supplimental weapons were not included in that collection to allow modifications to be made for weight purposes. Those files are located here.
These drawings were done with the intent that most would be made on a waterjet, and as such did not require dimensioning. Each of the drawings that was meant for waterjet cutting has a 1" reference square on the sheet.
With the great deal of interlocking components, the order of assembly is important. The first components to be assembled are the weapon hub, support hubs and weapon sprocket. Doing this first also showed the first issue in the build. The sprocket model on McMaster.com did not have the correct hole spacing which meant only 3 of the 6 planned bolts would fit. These holes are all meant for a #10 bolt, and without a clearance hole bit on hand, one had to be ordered.
The other main piece of the day was countersinking the holes on the inner rails to ensure there would be no contact between the moving roller chain and the bolt heads. The front threaded spacers also needed to be added and loctited as the bolt heads will be covered by the D shaped bearing blocks during assembly. A product called Nutstrip is used to connect the panels together, allowing for quick assembly.
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http://www.youtube.com/watch?v=f9MLRGWG5nE
Playlists:
1 and 3lb:
https://www.youtube.com/playlist?list=PL381AC5277547FC6B&feature=view_all
12 and 30lb:
https://www.youtube.com/playlist?list=PLD9E62E0B9714FE3E&feature=view_all
Near Chaos Robotics:
https://www.youtube.com/playlist?list=PLCE1BDB41F8F284AE&feature=view_all
One loss was due to the motor wires unsoldering themselves. Trims on the radio were turned down to 75% and that functioned as a temporary fix to the issue. The other loss was due to Nyx ending up in a position it couldn't get out of which resulted in a loss by countout.
I'm very happy with performance and I think the addition of a torque limiter to the weapon system will be the final touch the robot needs to start winning tournaments.
I've seen the videos and i must admit, your robot massive as hell!
Have Nyx suffered serius injuries from the confrontation with Enforcer?
What happened to "Battlebots" on TV? That was one of my favorite shows.
On the west coast, the big group is Combots ( http://combots.net/ )
On the east coast, NERC puts on some of the biggest open events ( http://nerc.us ) and has an event coming up at Motorama in Harrisburg PA in a few weeks.
Robot Battles ( http://www.robotbattles.com/ ) puts on some good events as well in the southeast. Their biggest event is each year at Dragon*Con.
Most events around the US use http://www.buildersdb.com/index.asp to manage registration.
Also, the side plates holding your wheels look fairly weak. A spinner hit to the corner of the bot and the long spacer bolts will bend right off.
P.S. My most successful bot is Micro Vice http://www.buildersdb.com/botdetails.asp?botid=6135 uses a steering gyro and is a blast to drive.
This bot was built for the NERC sportsman class and Dragon*Con robot battles. Neither event allows high energy spinning weapons, so they're not a major concern for this build.
MV looks pretty good, same with Vice and Insomnia. Planning to take any of them to events again?
No plans to compete right now. While Insomnia had a wicked weapon, it was lightly armored, so it got "retired" in it's last battle. (certainly still competitive with enough spare parts) I botched up the execution of Vice, so it's mostly a sculpture now. Micro Vice was born as a test-bed for a rebuild of Vice, but is FAR more effective than I expected. I was slowly iterating the design when I got a good idea how to make an AWD motorcycle. The motorcycle has since chewed up all my time.
P.S. the GWS P-03 was my gyro of choice. Cheap, fairly symmetrical CW to CCW, and a minimal dead zone.
How much did this cost?
I saw your other robot, what lessons did you learn from the other robot that you applied to the design of this one?
Do the "nano-tech" batteries really make a difference over traditional Li-poly?
I'm trying the nano-tech batteries on this robot and won't know what differences there are besides cost for a bit, as the first event it will attend is in a few weeks.
Yes. I said Iron. :)
They have a carbon fiber case, and the one I bought for my Sportster weighed less than 1 lb. and was half the size of my stock battery. The neatest thing about them is, the hotter they get, the more efficient they are, so in an enclosed space with hot motors running right next to it/them, voltage losses should not be an issue.
Good luck with your competition!
http://www.shoraipower.com/c-1-batteries.aspx
The current pack is 2.65Ah and provides a nominal 22.2v
That said, LiPO4 can offer a lot of energy/kg. It's not particularly volumetrically dense, though, and can take as much as 1.5 or 2x the space of bare LiPo packs. Overall, nanotech beats LiPO4 in almost all measures except 1) safety and 2) lifespan.
Anyway. I also wanted to comment in case someone pops up and says "no, you're wrong. Lithium/Fe is _____ type of battery." Because i'd love to hear about something new.
As far as I can tell these are just relatively new LiPo's that seem to have decent performance.
I'm not familiar with nanotech batteries, but if there is a safety issue, or for that matter a cost issue, then maybe the LFX batteries ARE worth a look. It wouldn't do to have the robot explode when a titanium spike pierces it resulting in mass destruction and death of the audience, would it? ;)
Here's the FAQ section, in case you didn't see it before.
http://www.shoraipower.com/t-faq.aspx
Also, I like the way you offset the wheels in order to fit the drive chain and sprockets in. That's an great potential solution to a problem I've been mulling over for my next 3-lb robot. (Though I'd be doing it with timing belts, not chain.)