Team Antiquarian & Anthony's Ant Army ready for battle

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MySolderIsOlder
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Team Antiquarian & Anthony's Ant Army ready for battle

Post by MySolderIsOlder »

Well, it's been a while since I posted - busy trying to get my head around 3-printing and Fusion 360 but I like to think the effort's been worth it. Finally got our two teams (mine and my son's) ready for AWS60. Found an AirBnB within 10 mins walk of the venue so we'll make a weekend of it.

Anthony's got one robot unchanged from the Open, one completely redesigned - and a new cluster.
The complete redesign (and his best hope for Saturday) is Recycler 3.

In terms of the evolution of this drum spinner, the first attempt, which came to Basingstoke and even managed a couple of lucky wins (before Avagadro 'did a number on him' and put us out of the competition). In my defence, Recycler 1 was the result of a last minute botch as I had to strip away most of the planned bodywork to reach the weight limit - and I never managed to balance the drum properly, causing lots of drive problems:
Image

Recycler 2, who never made it to competition readiness, was my first attempt at a 3-d printed body and although I still like the aesthetics, I couldn't get the weight below 165g without too may compromises. Also still couldn't get that drum (polycarbonate tube with titanium cap-head screws) balanced right:
Image

Which brings us to Recycler 3, who will be making his first appearance at AWS60. This time I admitted defeat vis a vis the polycarbonate tube drum and instead decided to print a drum core, into which I could insert blades cut (slowly and painfully) from 2mm Titanium. I've also beefed up the wheels and given them a bit of side protection. The Boudica's chariot projections either side are just m2 screws, which should snap off easily if struck but should reduce chance of getting stuck on it's side:
Image
Very much looking forward to seeing this one in action as it's too dangerous to play with at home.
Incidentally, the blue printed bits are all done using some dirt cheap polycarbonate filament (£10 per kilo from HobbyKing). Nightmare to print with as it shrinks spectacularly but if you can design shapes where the warping isn't an issue then it's impressively tough.
Last edited by MySolderIsOlder on Wed Nov 27, 2019 5:02 pm, edited 1 time in total.
Stuart (Anthony's dad)

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Re: Team Antiquarian & Anthony's Ant Army ready for battle

Post by MySolderIsOlder »

Completely unchanged from Basingstoke (I've literally done nothing except recharge the battery and change the acetate) is Other Way Up - Anthony's 'bog-standard invertible pusher'. This one will have to take its chance in the lottery:

Image

But the new kids on the block - and my personal favourite - are my first attempt at a cluster. Introducing "Maxi & Molly" (modeled on the family moggies):
Image
Maxi (him on the right) is a simple pusher, powered by a 1-S 75mah cell and weighing in at a measly 55g. Deliberately made him first so I'd know how much weight I had left to play with for Molly. She's a 95g flipper with a surprising amount of strength (thanks to the little Inservos D0474HT 7.3g servo). Unfortunately the servo boards I used for Molly's ESCs are the kind that generate a steady 0.3v in the dead band - so unlike her namesake she has trouble sitting still! Too late to change now so I'll just have to hope she can calm down enough to avoid disqualification. Maybe some bluetack,,,

Really enjoyed the discipline of designing a cluster. It's like a haiku - the extra constraints are a real creative challenge. Too late for AWS 60 but I think for the next project I may try to do a 3-bot cluster. Maxi's a bit too wide to be a flea but have just got hold of some N10s, which are about 4mms shorter than an N20 so Maxi's fleas are a possible for AWS 61.
Stuart (Anthony's dad)

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Re: Team Antiquarian & Anthony's Ant Army ready for battle

Post by MySolderIsOlder »

As for my own ants, "Try Again, Flail Again, Flail Better..." (it's from Samuel Beckett's "Worstwards Ho!", in case anyone was wondering) has had one massive upgrade in that the insulating tape that I was using to close the battery compartment has been replaced with Gaffer tape. Well, I had a bit of weight allowance left so why not? This one will be my wildcard entrant - it's got a certain entertainment value but pretty useless in combat, some I'm hoping we can have some fun in the melee.
Image


And finally, PolycarbonAnt has got new end blades. The old ones had a few notches taken out of them (mainly by "Here's Johnny"). Nothing serious - I could have just replaced the acetate and carried on - but I had several grams allowance to play with and fancied a change. So on with the Ti sheet. It's only 0.5mm so probably less tough than the Polycarbonate it replaced but might make some pretty sparks against the spinners. Also replaced the old ToughHubs with some of my own wheels (complete with 'flappy' tyres - looking forward to see if they make a difference).
Image

So.... roll on Saturday!
Stuart (Anthony's dad)

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Re: Team Antiquarian & Anthony's Ant Army ready for battle

Post by Ant Ipodean »

I will be interested to see how your 'flappy' tyres work out, as I have been thinking about moulding something similar but with even longer 'flaps'.
My thinking being that the tyres will tend to run around on the tips of the flaps when at speed, but dig in like a wiper blade when needed for serious low speed pushing.

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Re: Team Antiquarian & Anthony's Ant Army ready for battle

Post by MySolderIsOlder »

In answer to Antipodean, I'd say the flappy tyres felt pretty good, though I don't think we got into enough straight-out pushing contests to say with any certainty how much difference they made. TBH it was all a bit of a blur so I will have to wait until the vids appear on YouTube.

At this stage, all I can say with any confidence about AWS60 is that:
  • My driving still sucks, though it took me slightly longer to run into the pits this time
  • 'Try Again, Flail Again' is still pretty useless but lots of fun.
  • Recycler III is a significant improvement on the original and maybe has the potential to be 'a contender'. Considering he'd had zero chance to drive it before the event, I thought Anthony handled the driving pretty well, especially once he realised what happens when you're driving upside down. Still can't believe he beat 'Termite Cluster' twice in almost identical fashion. Got a few more design tweaks lined up - and I'm also planning to print a 'safe drum' (no blades but the same overall weight) so we can practice driving and get used to the gyro effects.
  • Maxi/Molly, though Maxi got ejected and Molly was eventually incapacitated by RMBK in their first fight, soaked up a lot more punishment than I'd expected. In the end it was a failed ESC rather than any bodily disintegration that forced their premature retirement from the rest of the competition
  • Other Way Up showed how durable a basic polycarbonate parallelogram 4WD pusher design can be. Actually beat Anticyclone, thanks to a combination of Anthony's driving and its ability to soak up endless punches ("I can do this all day you know...").
So, some minor repairs to do (largely thanks to the melees), then it's back to the drawing board. Priorities are Recycler 3a upgrades, a downdraft propeller blade for 'Try Again, Flail Again' instead of the current flat bar, plus some brand new bots. Key amongst the latter is a daft idea for a vertical flail bot inspired by the Sherman 'Crab' tanks used on D-Day and hence given the working title "Percy Hobart's Funny Ant".
Stuart (Anthony's dad)

James Williams
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Re: Team Antiquarian & Anthony's Ant Army ready for battle

Post by James Williams »

Was rather impressed by some of your bots, especially Recycler. Am looking forward to seeing that vertical flail as well.

P.S. I've already ordered a propeller for Epic Flail, this similarity thing is getting weird.

AndrewC
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Re: Team Antiquarian & Anthony's Ant Army ready for battle

Post by AndrewC »

I wouldn't say that try again flail again is useless. It put a pretty hefty dent in the bottom of one of my robot's (Kaizo, flipper) metal cased servos. It still works, but if that hit had been on the chassis then it probably would have done some damage.
Team Biscuit

Junk In The Trunk (Wedge)
Kaizo (Dual Servo Flipper)
You Only Wedge Twice (Wedge Cluster)
Underbite (Grabber)

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Team Antiquarian & Anthony's Ant Army - build diary updates

Post by MySolderIsOlder »

Since we couldn't make it up to Antfreeze, I spent the weekend messing around in the workshop. As well as getting my first fleaweight spinner just about done (details to follow in due course), been having lots of fun with the flail...

Those who saw it at the Basingstoke Open or at AWS60 may recall that "Tray Again, Flail Again, Flail Better" (TAFA) has a tendency to throw itself into the pit immediately after striking an opponent. Always been the plan to replace the flat blade with some kind of propeller that would give a bit of down-force to help mitigate this lemming-tendency. Unfortunately I couldn't figure out how to get this precise enough using the 1mm titanium sheet, nor how to stop it flexing. Moreover, that original blade was a pig to make and I didn't fancy having to do it all again to make spares - though after losing the weight off one end in a fight at AWS60, I knew spares were needed. So... half an hour's clumsy mucking about in Fusion 360, two hours on the printer, a bit of tinkering... and now I have the first prototype 'downforcer' blade for TAFA;

Image
Instead of the 90lb trace wire I used before I've gone for the 275lb - still v thin and light but grips much better with the size of dbl-barrel crimps I have handy.
The design of the aerofoil profile is going to have to be trial and error but this was my starting point. Printed using my new favourite filament; PolyMax PC.
Image

Old vs New - figuring out a way of clamping the flail wire on the old design was a nightmare. In the ends i used a tiny offcut of titanium with a couple of m2 machine screws and nyloc nuts. With the new wing it's a piece of cake; to make the flail arm strong enough, I have a length of stainless steel capillary tubing running through the middle of the blade. By making this tubing slightly longer than the blade, I can simply crimp the ends to stop the wire sliding through:
Image

As before, the business ends of the flail are tungsten 'bullet' fishing weights, secured by passing the wire through the weight, through an m2 nut, then back through the weight and securing with a double barrel crimp. Currently just using 2g weights at each end but I think I may now be able to get away with using the 5g size, to give it a bit more 'oomph':
Image


So does it work? Well, I put TAFA on my scales, retreated to a safe distance and ran it up to 3,000rpm (measured using a cheap optical tachometer), which seems to be the 'comfortable' speed. Results not spectacular - initial test design only gave an extra downforce of around 4-5g but if I can get that above 10g I'll be happy. What I hadn't anticipated though was that it now runs a lot more smoothly - possibly because the old flat-wing design would have suffered from vibration-inducing turbulence/vortex-shedding issues. With an effective diameter of 28cm and running at 3,000rpm, the end-weights are travelling at just under 100mph, which I reckon should be ample, especially if I can get it running smoothly with 5g weights.

Lots of work to do before it's ready for AWS61. Need to optimise the 'wing', experiment with flail wire length and weights, redesign the body a bit (and finally sort out an accessible battery compartment that doesn't involve gaffer tape). Also plan to add a more 'springy' front support for it to rest on as I found that made a huge difference to the vibration problems with Recycler (currently just sits on the two ToughHub wheels and a button-head screw in the middle at the front). Might even be able to free up enough space/weight to use a 3S LiPo (the electronics were designed for it but I had to drop down to 2S to get below 150g). Watch this space!

Meanwhile, here it is in action against an old Recycler body-shell (~25g):
TAFA test (Youtube)

Obviously the results won't be as spectacular against a 150g opponent, especially one with angled sides but it should at least be an improvement. I don't expect a flail will ever win an AWS event but I still enjoy the 'disruptive' aspect of the design!
Last edited by MySolderIsOlder on Mon Feb 03, 2020 4:53 pm, edited 1 time in total.
Stuart (Anthony's dad)

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Re: Team Antiquarian & Anthony's Ant Army ready for battle

Post by MySolderIsOlder »

BTW James - forgot to ask - how did you get on with fitting a propeller on Epic Flail?

I gave up on the idea of a vertical flail ant but I am hoping to get a 1.5kg version ("Percy Hobart's Funny Beetle") ready for the Beetleweight event in March, if time allows.
Stuart (Anthony's dad)

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jes
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Re: Team Antiquarian & Anthony's Ant Army ready for battle

Post by jes »

Very cool.

Btw have you tried printing in Nylon? How would you say the PC compares? I might have to get some PC to play with...

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