Team Kaizen - Shu!

[Ocracoke]

So this one has been quiet as I've been working on The Honey Badger and preparing for building Kaizen (the heavyweight) but I've made some headway with Shu! in that I've decided, as Theo pointed out, the 298:1 micro motors were simply too small so I've put them towards a antweight robot called Osu ("push" in Japanese) which I challenged myself to finish by Friday (built most of it on Monday) with recycled components around the house - a old Skittles sweet tub and a chopped up wooden whiteboard frame.

All of the stuff that Shu! had is now in Osu but I've bought some Como 15:1 motors (here) that should be plenty beefy enough. I'll donate a set of LiFePO4 batteries from The Honey Badger for the cause and I have a Como 50:1 motor for the lifting/jacking arm (here) so it needs:

• A chassis and armour
• RC controller
• A secondary mixer
• 2x speed controllers

I'll see about finishing Shu! off over the Christmas period in time, potentially, for the UWE event in Bristol.

[Ocracoke]

Feeling a bit rubbish since Maidstone but found some time to work on Shu! Managed to place the drive and weapon motors on the 3mm PVC board I've got for this. I now worry it looks a bit too... big compared to other Beetleweights (about 28cm wide!) but I am working on it.

DSCF5906.JPG

[Deathly Hallows]

My current design is coming in not that far away at 240mm in the CAD.

Is that the final materials for your base? I was thinking of 1.5mm Aluminium
Also curious what the second mixer you referees to is for?

[Ocracoke]

Is that the final materials for your base?

Yeah, it will be (probably with a few weight saving holes). The rear and the sides will be also be PVC covered.

Also curious what the second mixer you referees to is for?

I must confess, I've no experience with secondary mixers beyond what I've read here, The Honey Badger uses a proper tank RC controller so doesn't need a mixer and Osu uses a Sabretooth dual 5A so again, doesn't need one. I was considering something simple like this.

[Ocracoke]

So scratch the last couple of posts.

I've taken the electronics out of Osu and put them in Shu! as the former needs to be rebuilt into a legal Antweight anyway. The Sabretooth and the LiFePO4 battery are in and now Shu! is running, although probably wants a better battery. Next job is to get a compliant power light in and mount the wheel hubs to the wheels.

I also cut Shu's width in half so it looks a bit more graceful and bit more weight saving.

[Ocracoke]

So with Shu! now running, I decided again to change the design again and have finally settled down on it. Just need to get the weapon speed arm/controller/battery/motor mounted and then we'll see how effective it is (the below is just a cardboard mockup of what it may look like). The plan is to allow the arm to swing through ~180 degrees so in theory, the arm can act as a grabber and do a nice contortionist manoeuvre.

Also made a cradle from old The Honey Badger chassis parts.

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[Ocracoke]

So bigger 1500 m/ah 3S LiFe batteries and a speed controller arrived today and they were eventually wired in to the robot. However, I think I've made a silly move, the ESC only appears to work in one direction. Doh. I've ordered a replacement, checking that it does have forward and reverse and it is local, so should be with me by Friday.

I'll see if I can get some time tomorrow to build the shell and sort out the wiring.

[Ocracoke]

A few videos showing where Shu! is up to.

[Ocracoke]

Today was about fabricating the lifting arm, which marks another tick in the stuff that needs to be done list before Feburary. After a session with the Dremel and a sheet of PVC...

DSCF5926.JPG

It still needs a bit of refining but that is the general shape it'll likely take the form of. Then came the testing. With a 600g weight on the end of the arm, the whole robot does a backflip onto itself when the arm attempts to raise. I suspect this is down to where the lifting motor is in relation to the rest of the robot and how the weight is distributed. If it was further in on the chassis plate, I suspect it might be OK.

A video of the problem.

[daveimi]

Your robots are magical to me lol

[Ocracoke]

Haha, sometimes they are magical to me as well I repositioned the motor further back onto the plate and it was a bit better, it managed to flip the cookie pack once but when the weight was properly on the arm, it did its backflip act again. I think either I'll need to:

• Add some forks to the front to support the robot as it lifts the arm up OR
• Shorten the arm

Depends on the weight situation, the scales have acted up so I can't weigh it at the moment.

[Outlaw]

I'd suggest doing the former. And that first test drive of Shu! in the kitchen made me laugh. Reminds me of my first test drive of Ratatoskr, same thing happened, haha!

[Ocracoke]

Haahaaha! I do have proper wheel hubs for the shaft but none of my M3 bolts appear to fit it so I think I might have a US measurement hub, which would appear to be ever so slightly narrower (4-40 by the looks of things). In the video was just the wheels glued on and not very well :P

It is likely to be a case of both shortening the arm and adding forks at this rate, again weight permitting.

[Ocracoke]

So the new bidirectional 10A speed controller arrived this evening. A quick soldering job to fit it in (and a burnt fingernail), the arm now works as I hoped it would though there are still question marks over the arm length/forks required. The video below is Shu! flipping 400g of steel right at the very end of the arm, which needs a bit of reshaping to make it more flush with the floor.

Replaying the video in slow motion, I think I may swap out the 67:1 motor for a 131:1 motor simply for the extra torque. Once the shell is completed, I'll be disassembling the entire electrical system and reposition the LiFePO4 batteries to the back of the robot for extra counterbalance.

[Albear]

Looking really good! I like the fact that it swings over the top of the robot in a axe/flipper fashion. Yu should design your own wheel hubs that have tiny nun-chucks sticking out the center!