Robo-roadtrip:

Everything packed into the wagon neater than usual:



Just kidding; its packed to the roof racks with extra parts, tools and anything that 'might be useful'. The trip was quick but its absolutely pissing down in Canberra, making it hard to move tools & bots from the car to the room. I don't really have much to do; just changing the connectors on two battery packs to the new bullet connectors that Shiny & Mr Mangle now use.
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

I am working on a full event report but the hotel internet speed is too slow to upload pictures. Until I get home, here is the TL;DR version:

I got drawn in an incredible eight wedge matches (there were only eight wedges in the feather competition) and hardly any spinner matches. Shiny and Mr. Mangle did plenty of damage but didn't win enough matches to make it past the quarterfinals. Sawnado did better than expected but had drive problems and many of the other sportsman bots are immune to horizontal saws anyway.
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

Terrible run of luck there man, looking forward to your event report.
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Mechanical engineers build weapons, civil engineers build targets

I have to say Nick you had a TERRIBLE run. It was horrible being a judge for many of those fights where you were dominating only to get stuck due to a an unfortunate stack. The drive issues were odd too for sure.
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YEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAH

If it's any consolation one of those wedge fights was spectacular enough to make it to ABC news nationally

Event report:

Day 1


First, a massive thank-you to Steve, his mum & dad and Erika! The event ran so smoothly and the new arena is world class.

Round 1

Shiny VS rusty venture

A short sharp fight; Shiny charged Rusty’s wedge and sent it flying across the arena and bounced it off the arena wall at face height – the biggest hit of the day. Rusty landed upside down for a knockout. Steve had the wedge repaired in no time and kept Rusty running after major spinner matches.



This picture shows why I don’t bother with single tooth spinners – two consecutive hits in probably one revolution of the beater with excellent bite depth.

Sawnado VS Skeletor

I wasn’t expecting Sawnado to be very effective but it managed to knock off some of Skeletor’s claws and cut into the tube frame a bit. The match went the full 3 minutes and Sawnado picked up an unexpected win on damage points. As predicted, every carbide tooth was knocked off – I need to find an old all steel blade that can be resharpened.

Mr Mangle VS Crudity Model

After much pushing & shoving, Mr. Mangle couldn’t get under the wedge. Mr. Mangle got propped on it’s side and couldn’t self-right – a real surprise after I made stronger hoops! After the match I found the rear hoop wasn’t as wide as it used to be; adding a small spacer where it touched the floor made it self-right properly.

Round 2

Shiny VS Crudity Model

Shiny and crudity chased each other around the arena and I chipped away at Crudity’s wedge without getting much of a bite on it. Shiny eventually got in a big hit on the side to prop Crudity on the arena wall for a count-out



Mr Mangle VS NC

I fitted the anti-wedge forks but Mr. Mangle still couldn’t get under NC’s wedge. I got in a few small hits before NC pushed Mr. Mangle backwards into the arena wall; on the rebound, Mr. Mangles’ forks dug into the floor and propped the bot against the wall for a count-out.



Jake paid a high price for the win; one precious and irreplaceable DeWalt motor was written off with smashed magnets.

Sawnado VS Warboy

Sawnado started out well although the saw blade was pointless in every sense of the word by now.



After plenty of attacking by both bots, Sawnado appeared to lose drive and was counted out. After the match both drive motors were working fine, so the bot must have been high-sided by some arena floor garbage.


Round 3

Shiny VS Whizzbee

Shiny got a bye after Whizbee’s central shaft snapped. Much disappoint!



Mr Mangle VS Bender 3

The last fight of the day didn’t disappoint! It was an all-in brawl between two strong spinners and neither Garry or I was going to back down. After trading blows we pushed each other around in a corner before Bender drove up the front of Mr Mangle and got caught in the front hoop. After a separation & restart, Mr. Mangle bent Bender’s blade and broke a drive motor to win by count-out. My backup entry for ‘Most Destructive Bot’ award!



Day 2, Round 1

Mr. Mangle VS Face wreck

Yet another wedge fight! I went in for the wheels and ripped one off each side to force a count-out for the win.



After the fight, we found the motor mounts were bent and one drive motor was almost ripped off.

Sawnado VS Face Slasher

The most pitiful match of the day! After driving to our starting positions, both bots had major driving issues and could hardly move. I eventually nudged Sawnado over to Face Slasher and got in a couple of tiny hits before we were counted out. Sawnado won due to the one hit and slightly more drivability.
After the match I discovered that the key in one hub was not engaging with the axle and the wheel was only turning via friction. I fitted Shiny’s spare wheels, cleaned them up with WD40 and then cut a tread pattern with the Dremel.

Sawnado VS Disassembler

With new wheels fitted, I was confident Sawnado would have better traction. Driving to a corner showed plenty of speed and control, but once in the corner I lost most of the control and Disassembler pushed Sawnado around and eventually tipped it on its front for the win. Back on the bench, I found that one Lipo cell was at .1 volts. After a quick battery change, I had a test drive and Sawnado drove better than ever, even in the radio ‘dead-zone’ corner. Sawnado’s battery packs are at least four years old, so its not surprising they are wearing out.

Round 2

Mr Mangle VS Prowler VS Crudity Model

Two wedges at once (if you count the dual front wedges on Prowler) for the last spot in the finals – how many wedges can I fight in one event? I fitted the extra low forks and decided to attack Prowler first as it could easily saw into a battery pack if I got pinned down by Crudity Model. The strategy worked for once and I got the beater under Prowler to do some frame and wheel damage and then propped it on the wall. Turning to Crudity, I caught the wedge in the same place that I damaged in an earlier fight and bounced it off the polycarb hard enough to break the base plate and remove the lipo pack. My official entry for ‘Most Destructive Bot’ award!

Shiny VS Renegade

What, seven wedge fights in one event??? Shiny was originally scheduled to fight Bender but that got changed due to some ranking thing in the draw. As Renegade was fighting without it’s self-righting lifter arm, Shiny only needed one good hit to win.



I got in a few scrapes but the bots got into a pushing match and one of Shiny’s out-runner drive motors caught fire, ending the match. The drive motors have been super reliable up to now so a flame-out was a real shock. One of the wires in the sensor cable had broken; it might have confused the ESC into overloading the out-runner – we may never know.

Sawnado VS Crushinator

Sawnado has already done better than I ever expected but this fight was un-winnable; Crushinator has a heavy steel frame and stronger drive motors than Sawnado. Crushinator latched on to Sawnado’s wheel pods and while it didn’t do any real crushing damage, it took control and clearly won on points. It didn’t help that one of my old brushed drive motors burnt out.

Mr Mangle VS the Undertaker

OK, eight wedge fights is just silly! Undertaker is fast and well driven but I figured that Mr Mangle could catch it with the anti-wedge forks. I got in a couple of small hits but Undertaker was just too fast and it got under the back of Mr Mangle and tipped it onto it’s face. It used to be that the beater could still hit the arena floor and right the bot, but the new front hoop holds the beater a fraction too high and Mangle was counted out.



Chief engineer Gizmo checks out the lack of self-righting; With a little thermo-forming on the front hoop, the beater will have enough bite on the floor to bounce Mr. Mangle back on it’s wheels.

Postmortem:

Mr Mangle needs the hoops altered, which is easy with the heat gun now that I know what to change. I will also change over to the microgroove belt after it worked flawlessly in Shiny.

Shiny needs more drive motors and more front forks so that I can alter the height of the beater for wedges. Apart from the motor problem Shiny won all it’s matches and I am pretty happy with it.

Sawnado did better than expected as I really didn’t put any effort into it. The bot only weighs 11.8 Kg, so it should be fairly easy to improve the wheel pods and fit a stronger brushless drive with extra grip. The bot only used 2AH from the 4.2AH battery pack, so I can save further weight by using a 3.7AH pack. I will try to find an antique all metal saw blade to replace the pathetic carbide one that went totally blunt after one fight.
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

Awesome event report, but unfortunately the pics aren't loading for me

That's odd! Are pictures on earlier pages loading OK? Anyone else having problems loading them?
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

Odd, and now they're loading.

Aussie Interweb
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

Post-event fix-up #1

Mr Mangle's rear hoop is the first thing to get some attention. First, I traced the current shape of the hoop on to MDF, then I added a wider curve at the ends and cut out a new bending form:





This is a neat magic trick - making UHMW disappear:



Even with the wider hoop, Mr Mangle still needs the extra screw to self-right - but now it works from every angle I tried so that's one issue fixed
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

Post-event fix-up #2

Mr Mangle used to self-right when faceplanted but the new front hoop keeps the beater from hitting the arena floor. There are two fixes for that: first, the front hoop is curved back a little with the heat gun so that the beater gets full contact with the floor:



Its fairly subtle, but gets the job done. The problem with this fix is that the beater has to be spinning, which might not always be the case. To 'fix the fix' I will add a removable titanium finger to the the hoop like this:



This stops Mr Mangle faceplanting all together and should also prevent getting tangled in the UK arena's pit button. On the down-side it will keep tall bots like Mini-Moth away, so for some matches it will be removed.

Post-event fix-up #3

I found two possible causes for Shiny's drive motor catching fire: First, the sensor has a broken wire:



That looks frayed rather than melted to me, so it could have happened earlier on and confused the ESC in to burning out the motor. I also found this mess inside the gearbox:



The pinion disengaged from the planetary gears and then stripped them, jamming the gearbox - that looks like the main cause of the fire to me. The motor doesn't have a front circlip (its a design problem) so I will add a tiny aluminium spacer between the pinion and the front bearing.

The bots have evolved, now bring on the next event!
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

Broken sensor wire won't do anything any favours.
Got weird loading on the pictures again, I think your host might be a bit down on bandwidth, perhaps stick cloudflare in front of it free CDN ftw?
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Mechanical engineers build weapons, civil engineers build targets

Post-event fix-up #4

Sawnado definitely needs a better drivetrain. After looking at several options, the best idea is to duplicate Decimator's drive components: instant spares for both bots, fairly cheap motors and ESCs, some parts already in stock and the list goes on.



Decimator's drive on the right is only 240 grams heavier than Sawnado's brushed drive on the left, yet it has 10 times the peak power output (probably around 400W continuous) and isn't being over-volted 2X.

Its going to take some time for this fix; I still have to design larger wheel pods and get them water-jetted.
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

Sportsman bots:

I found a potential replacement saw blade for Sawnado - a 250mm, 150 tooth HSS cold saw. Its not what I had in mind but the price is OK and it will last longer than the cheapo TCT saw blades.

Minion had a major design overhaul after I got a feel for the strengths and weaknesses of sportsman bots at the event. It now has tanks treads and looks even more like a bulldozer:



The tread weighs 2Kg without any drive components, so I really need to save some weight! The frame is getting updated with aluminium and the lifter is being lightened as well.

With the right drive motors and weight distribution, the bot should have a ton of pushing power, ideal for stacking opponents up against the wall.
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion