Hello, and a modular arduino controlled bot.

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InternalCakeEngine
Posts: 8
Joined: Sun Jan 07, 2018 6:34 pm

Hello, and a modular arduino controlled bot.

Post by InternalCakeEngine »

Hi,

I'm new to the forum and this is me saying hello.

Inspired by the last series of Robot Wars and my purchase of a 3D printer I've decided to build an antweight-ish 'bot. I help run an electronics club so wanted to do something modular which other people could quickly pick up and modify.

So I designed a 10cm square chassis with 2 wheel drive (from a pair of FS90R continuous rotation servos) and scope to add one of a variety of weapons (or another couple of drive wheels to make a 4WD shunter) via a fixing at the front. The electronics are managed by an Arduino currently on a breadboard balanced on the weapon platform. This will get shrunk down to a PCB in due course.

The current version has drive control via IR but I've got some 433Mhz radio modules to replace that with. I hope to get a few bots built and have some PlayStation 2 controllers plugged into another Ardunio which will relay instructions to all the 'bots. Will hopefully be cheap (ish) with more control options than standard RC boxes.

So yeah, video, with forward/backward at around 50% power: https://www.youtube.com/watch?v=uQsgtNhBE5g

..and a photo
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...and a 3D model
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Last edited by InternalCakeEngine on Sun Jan 28, 2018 4:25 pm, edited 1 time in total.
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MarkR
Posts: 375
Joined: Mon Dec 18, 2017 12:46 pm
Location: Reading Hackspace
Contact:

Re: Hello, and a bot

Post by MarkR »

That is cool, I'm currently designing (/building when parts arrive) a 3d printed antweight which uses Raspberry Pi Zero as a receiver (I'll use the common Dasmikro speed controller and have the Raspberry Pi spit out PWM - I've done that before).

I'm hoping using the Pi could enable more "interesting" control options :)

PS: been researching meltybrain body spinners today :)
Robots: Betsie - RaspberryPi controlled flipper bot with gyro stablisation - too clever for her own good?
Stacie - tidy flipper; 4wd driven by hair bands
Derek Dudge
Posts: 135
Joined: Thu Dec 07, 2017 9:32 pm

Re: Hello, and a bot

Post by Derek Dudge »

Modular front ends for different weapons and plans for 150g meltybrains and I'm looking at my coffee table bodge job workshop and thinking damnnnnn.

I love this forum lol. I can't wait to get my entry level stuff wrecked by all these fancy things.
My robots:

Third Law (antweight) - push/ram bot
Manticore (antweight) - hammer bot
MrEnDo
Posts: 16
Joined: Mon Jan 15, 2018 9:39 am

Re: Hello, and a bot

Post by MrEnDo »

Nice one dude, out of interest what 3D printer did you go for?
InternalCakeEngine
Posts: 8
Joined: Sun Jan 07, 2018 6:34 pm

Re: Hello, and a bot

Post by InternalCakeEngine »

My printer is a Wanhao Duplicator i3 Plus. It's pretty much the defacto standard cheap printer but it's been pretty good for me.

I had an unplanned afternoon off today so I had a go at getting my flipping parts working. Much work still to do; many flaws in the base platform discovered.

https://www.youtube.com/watch?v=XFt0brpm6-s

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InternalCakeEngine
Posts: 8
Joined: Sun Jan 07, 2018 6:34 pm

Re: Hello, and a bot

Post by InternalCakeEngine »

I spent a bit of time doing building and soldering and coding yesterday. I've rejigged the body, the wheels and the flipper (i.e. all of it), it's got its brain stuffed properly into its head and is now radio controlled. Woo!

This is the base, 3D printed in PLA, version 20 billion or something. I have a box full of nearly identical ones now but this one is lighter than the others with holes and clips in useful places.
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The wheels are also 3D printed with sections of bicycle inner tube for tyres. They don't have axles - the protruding inner rims sit in recesses in the body shell so there's less strain on the servos in case of impact. In theory.
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The flipper mechanism with its servo already in place.
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And this abomination of soldering is the electronics. There's an Arduino Mini Pro, a 433Mhz radio receiver, a 5V voltage regulator, a connector block for up to 4 servos and a battery connector. Getting the radio to work took several minutes of programming (by which I mean hours) but all good fun.
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And it does actually all fit together. First off the 2 cell LiPo battery slots in under the drive servo casing whilst the servos and attached wheels go inside it.
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The flipper mechanism is bolted onto the weapons platform using the access holes I stupidly forgot to include in previous versions.
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And the electronics bend around 90 degrees to fit in the remaining gap.
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The lid holds everything in. The drop-down bits rest just about the drive servos so they can't jump out of their housings. They also hold the electronics in place laterally. No screws or bolts; it clips in securely. Theory again there.
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Aside from the excess of servo lead it's done. Maybe the lid could do with coming forward and down a little more though.
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And it actually works although the remote control currently looks like this. More 3D printing when time allows.
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It weighs 153g :-( and I'm not sure there's 3g of excess servo lead in there. A smaller battery is the obvious solution - this one is 370mAh which probably more than needed. OTOH I bought four of them so I'm financially pretty keen to save the weight elsewhere.
Paulmchurd
Posts: 227
Joined: Sun Dec 10, 2017 4:39 pm

Re: Hello, and a modular arduino controlled bot.

Post by Paulmchurd »

Looks awesome. Those leads weigh a surprising amount some times.
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