Near Chaos Robotics

[MikeNCR]

This weekend's post is a bit short on raw text, but it's got the power point portion of a presentation I'll be giving at Freeside Atlanta included with it-

http://nearchaos.net/combat-robot-building-micro-bots/

[zacodonnell]

I think some people might have trouble with the .rar format for that archive.  Would it be possible for you to post a zip format version too since that is handled natively by windows?

-Zac

[MikeNCR]

I think some people might have trouble with the .rar format for that archive.  Would it be possible for you to post a zip format version too since that is handled natively by windows?

-Zac

Done.

Upcoming topics in no particular order:
Wiring Harnesses/Internal Battle Hardening
Wheels and Wheel Protection
Chaos Cube Repairs and Upgrades

If anyone has topics they'd like me to cover, feel free to post them or email me.

[zacodonnell]

I think a lot of new teams could use a tutorial on battle-hardening the internals of a bot. Specifically hot glue / tape for rx leads, loctite on screws, foam around batteries, wire ties for loose wires, keeping things away from moving parts, etc.

I saw quite a few of these being missed by the rookie teams this weekend, and I know I never thought about them for my first bot.

-Zac

[MikeNCR]

Good idea, I think I'll blend that in with the wiring harnesses, as it's all pretty tied together.

[zacodonnell]

Definitely. I think the #1 type of failure for rookie bots is electrical unplug or accidental short when something comes loose or gets sucked into a sprocket or wheel. That's probably followed closely by "set screw worked loose" failures.  Actual mechanical damage is less common, partially because it can only happen if a working weapon is also involved between the two bots.

-Zac

[Infernaltank]

I look forward for the future installments.

[FingerTech]

Please stress the use of loctite.  The number one failure I've seen is screws and setscrews coming loose.  I've got it in all my instruction manuals but new builders still think it's unnecessary.

[MikeNCR]

On that note, here's the post:

Battle Hardening the Inside of Your Bot
http://nearchaos.net/battle-hardening-the-inside-of-your-bot/

[zacodonnell]

Excellent.  I will be sending this link to any new builders I talk to. Just the connectors, tape, zipties, and loctite sections would make SO MANY more fights go the distance.  I had several different people ask my how I made my shell spinner "so reliable" and pretty much everything I did is in this post. 

The only other thing is that I try to not push the parts to the breaking point in normal use because when stuff gets bent / something is a bit crunchy the parts all have to work a lot harder. This is much harder to quantify in the design stage and probably is beyond the scope of your series. I guess I have to also say that my bot broke more this year than any time in the past 2 years so maybe I'm losing my touch .

I've never used acid flux before. What do you find that it helps the most with?

-Zac

[MikeNCR]

I've never used acid flux before. What do you find that it helps the most with?

It's fantastic for the initial tinning of the wires. Really helps with the solder flow. Most of my connections have solder pretty well permeated throughout the first little nub of wire.

[zacodonnell]

When you do ring/spade terminals do you put solder on them too, or just trust the crimp?  I try to solder all my connections and have never met a crimp I trusted on its own but of course the crimp is probably mechanically stronger.

I have always been overspec on my wire gauge too. I could probably get a lot of weight back in my bots by downsizing the wiring. I basically use 14 ga for the drive motors in my 12/30 pound bots, and 12 ga for anything in the weapon or power system.  In my 6 pounder I use 18 ga for everything. I have had to retrofit the drive controller on the 30 with the same 18ga wire at a competition before and it has been holding up since then, so I'm sure I'm way overkill with 14 ga.

What sizes do you use in those ranges? 

-Zac

[MikeNCR]

When you do ring/spade terminals do you put solder on them too, or just trust the crimp?  I try to solder all my connections and have never met a crimp I trusted on its own but of course the crimp is probably mechanically stronger.

I have always been overspec on my wire gauge too. I could probably get a lot of weight back in my bots by downsizing the wiring. I basically use 14 ga for the drive motors in my 12/30 pound bots, and 12 ga for anything in the weapon or power system.  In my 6 pounder I use 18 ga for everything. I have had to retrofit the drive controller on the 30 with the same 18ga wire at a competition before and it has been holding up since then, so I'm sure I'm way overkill with 14 ga.

What sizes do you use in those ranges? 

-Zac

I tend to crimp then solder for most connections. Not really necessary, but a bit of extra security for no real weight gain.

As far as wire goes, for the most part I use Deans 16ga in the 30's. The ants are mostly whatever came stock on the motors/escs/battery/etc

[Lucas Grell]

I've been using 12 and 10 gauge wire in my bots, and I need it, too
When I was using powerpoles, I crimped and soldered, it's definitely worth it. Crimps tend to pull apart eventually, but the solder holds it all in once piece so it can't slide out.

[MikeNCR]

It's a bit later in the evening than I'd have liked to finish this up, but that's what happens when you spend the weekend working on a bunch of small projects-

Bringing an Arena Out of Retirement
http://nearchaos.net/bringing-an-arena-out-of-retirement/