Monday, 27 November 2017

Hobgoblin II

Hey, remember this?

No, I barely do either, but how about this.

Yeah I made that. Somehow.

Yes a few months later,  not much wise and certainly not richer it was Robot War-ing time again. I have annihilated most of the memories of the rebuild/revamp of Hobgoblin for whatever reason (such is the way with robo-trauma) But I have enough pictures than I can probably drag out a rough timeline out for those interested. All 3 of you. Two of which are blood relatives.

So this is where Gob has existed in hibernation for the months since S2. On the floor. Used as a shelf. I expect a letter from some Abused Robotics Foundation soon.

Anyway, the thing about gob in its current state is that it has no real damage (bonus of lasting less than 5 seconds) and since I tweaked it, it functions! However functional it may be it still kinda just sucks.  The drive was feeling anaemic and clunky. I left the last post on my first set of higher voltage testing. I concluded after some monkeying about that this was defiantly the best option. and set about overhauling the electrical system.

The drive was going from a single ESC to two, allowing a greater current handling ability and  therefore less "why does my robot not move" syndrome - a terrible affliction. In addition to this the voltage was jacked up from 6s (22.2v) to 8s (29.6v) to get a bit more grunt out of the cheapy ebay drive motors.

This basically meant twice as much shit in the same space. I was already struggling fitting everything in! This called for drastic streamlining of my electronics system. Now, since I identify as a British local council from the 1970's (message me for pronouns) my solution was to build some kind of ugly flat block to house all my problems in. Thus TOWERING RAGE was born.

Yes, I have stacks. Mad stacks.

a HDPE (shock absorby) and aluminium (heat sinky) set of shelves was my of getting the electronics footprint as small as possible without making anything awkward. Entrance through the ground, two floors of Ragebridge's  with en suite cooling and balcony with wire view, the penthouse taken over by the contactor, relay and the RX.

This was clamped in place by two pieces of watercut 5mm aluminium, bolted into the heatsink and mounted to the frame by a standoff.

You get the idea. This also became one 'wall' of the battery box.

Batteries. Oh yes. I now had a better idea of the current required in a heavyweight, especially one with a low voltage lynch motor trying to make 20 odd kilos of hardox twat around at several thousand rpm.

The drive was on four 4ah 4s packs to give 8s 8ah while the weapon was four 4ah 6s packs to give 16ah 6s. Yes I know my drive voltage is higher than my weapon. Ass backwards is our byword at Team Hobgoblin.

Finished electronics unit and stack o' lipos. You can also see a removable link block I originally intended until they changed the rules - Links needing to be accessible from whatever way up the robot is.

I also ended up making these 30mm standoffs to join everything together along the width of the robot, I felt they were quite a neat solution to holding everything in place. They are 6082 alu with a threaded portion one end and tapped hole the other.
Next on the list of upgrades was some form of can support for the weapon motor. There is a possibility that on large impacts and shocks that the rear of the motor can move backwards and... well... fall off. In order to limit the possibility of unintended arse detachment I designed another aluminium clamp that would join to the existing motor mount that keyed into the front bulkhead.

The watercutting wasn't brilliant on the soft alu so a wee clean up on the belt sander was required, alongside a cleanup of the bores. The small hole was just drilled out and the larger one required the boring head on the mill.

 #safetyphoto #actionshots #workpiecenotactuallytouching

The front bulkhead had a pocket milled in it to take some thick foam to support the batteries and a slot milled along it to key the motor support to the frame.

its all kinda coming together! nearly done right? (yeah no, s3 applications hadn't even gone live yet if memory serves)

Now eagle eyed readers may have spotted some other watercut bits and bobs that came alongside the motor support. These were some steel parts instrumental to unfucking the drive.

The printed pulleys were a cheap neat idea but they felt way too delicate, especially now the drive power has increased. The pulleys were now steel, with a bronze bushing pressed in and another one in the wheel. The steel plates key to the boss of the pulleys then bolt to the wheel hub. This is all retained by a 35mm circlip

You can get a bit better of an idea of the assembly with this picture, just imagine the steel hub.

Again, a bit of a convoluted solution to a stupid problem. I think I want that written on my headstone.

These are the same wheels as the first Hobgoblin.

The finished front wheels, they run on polished hardened steel shafts. a lot stronger than their printed counterparts.

The driven shafts at the rear work in much the same way, except the steel plates are threaded for the wheel to bolt onto and the pulleys are keyed to the shafts.

Okay so roughly about this time the application had been sent off and the waiting around for an answer had begun. I wasn't overly hopeful seeing some of the upgrades on existing machines, and some cracking new builds

A few days before the deadline, I had an email asking to see Gob spin to confirm how the weapon worked. I stopped the rebuild and redesign to quickly chuck the old setup back together to get a clip for them. When Mentorn ask, you don't say no!

So lumpy still but it does the rotating thing! Right now that that's out of the way, strip it back and on with the Hobgobgrades!

Welcome back to yet another episode of "Stupid Objects Taken On Public Transport" Any Brighton and Hove locals who spotted a gormless youth toting a large silver lump around in early 2017...yeah that was me. I'm probably on some more watch lists now.

This is the main bulkheads being taken down to have the front wedge cut off. This was a semi radical design change as I felt the wedge was more of a hindrance and was busy hiding the weapon from the opponents.

The whole panel was mounted up in the mill and cleanened up. It began feeling oddly small at this point

Now, the side armour also needed shortening to match the bulkheads. In an ideal world I would have just recut the hardox panels and adjusted the mounting points - but I elected to take the cheapskates route and just slice up those panels too. They were slit with a grinder and then cleaned up with THE MOST LEGIT MACHINE SETUP EVER.

I don't claim to be an engineer or a machinist. Now you know why.

Another fairly large Hobgrade was the addition of some actual bloody armour. The current sides were 4mm hardox and... well that's it. Any decent knock would bend and buckle that.

If you look at this pre-fight OG Gob you can see that its just a single thin plate of hardox on the side

 I didn't have the weight or budget for thicker steels so I went with the old crowd favourite, HDPE. Strips of 1" thick went over the existing hardox.

The reasoning behind it is having something soft and thick protecting the tougher core. The principle is proven, my execution is whack sub optimal

Both sides of Hobgoblin!

Assembled side, all the shortened parts lining up and working well. The black also works quite well to break up the purple and green colour scheme.

That side of the robot needed a few more bits of machining. Robot Wars rules were changing, meaning that the removable links needed to be accessible even if the robot is inverted, which meant i had to change my intended positioning. I elected to put them in the side of the robot where they could be pulled even if the robot was upside down.

Simple slot milled allowed the links to be a really tight fit. and not too exposed.

I elected to put the powerlights on the "shoulder pad" panel above the links.

Which meant holes in hardox. A job for the milling machine. I made myself some witness marks so I could double check placement and not screw up a part I didn't have spares for.

Close enough! You can also see where the links bolt to into the robot .

The link wires being run through. Lots of heatshrink and shielding to stop the cables rubbing and being damaged.

I employed this style wherever I could to try and minimise faults - so there's at least one documented case of good intentions on Hobgoblin!

Some rather snazzy decals were also applied at this point! Great, now I can't forget what I named my robot!

More or less at this point in the build the phonecalls went out in waves. Hurrahs for the confirmed and commiserations to the rejected. It was a bit disheartening seeing some of the incredible and unique machines made by friends knocked back. But all was still weirdly silent in Camp Gob (and it's much nicer associate, Coyote) About a day after all the yay/nay we got out calls, we were in! As reserves!

All the fun of being at robot wars with only 90% of the stress! Fantastic, I was so happy to be given a second chance to prove that Hobgoblin could do more than trundle 6 feet forward and fall over! Aiming for at least 8 feet and a twirl before it fucks itself up this time.

Being reserves we kind of had low expectations (good!) We basically just had to turn up and well, just work.  So with that great news behind me, the build powers on!

Onto the last big machining job for gob.  The huge timing pulley used on the first version was just a bit too huge and fragile to be much use. Also the beater was geared very conservatively. Spin up was gutsy and instant but it was just far too damn slow

To solve this a toothless, smooth aluminium pulley was called for. The smooth surface would act as a kind of ghettoclutch which would let the belt slip on huge impacts and save the weapon motor. I also reduced the weapon gearing from 2:1 to 1.5ish:1 which brought the beater into the 3k range theoretically.

LEM170's just don't have any fucks left to give, I'm pretty sure they would spin it up on 1:1 just fine. Incredible motors really.

 A 6" billet of 6082 aluminium was turned into a suitably gob shaped lump

Final job was getting the pulley set up in the mill and the square bore (which engaged on the square portion of the beater) machined in.

I then machined some new spacers to keep everything lined up.

It fits! and the belt tension was perfect. Not too tight, not too slack.

All mounted back onto the frame and starting to look all gob shaped again.

With the belt installed. The motor pulley is the same one as before.

Side note, to all those "put a self righter in it" comments... WHERE. HOW. SOME IDIOT DESIGNED THE ROBOT WITH NO SPACE HELP.

Like any sensible Heavyweight builder, the most appropriate place to wire up your robot is the kitchen.

Hey, needs must!

Now anybody who paid attention to the full 12 seconds of Ole Gobbo's television career will know that it has slight issues with being able to function inverted. Comments sections everywhere have said to put a self righter on it. well, the self righter shop was closed today so I had to get a bit creative.


Stupid solution to a stupid problem? Works for me. Yes giving Hobgob some 80mm nylon castor "ears" should prop it up enough to make the rear wheels touch the ground and be able to hobble(goblin) around.

It also makes HG 200% more cute? Where my anthropomorphic HG cosplay!? I am a very lonely man.


You get the idea

It exploded and the side fell off.

It had got to the silly part in all my builds where I have to keep taking the fucking thing apart and doing some ghetto arsemagic to it to fix some overlooked, yet highly critical wobble.

Some HDPE blocks cut from the same stock as the side armour. This has a milled out portion which alows the wedge to be mounted to the front without fouling on the wheels. It also can act as a bit of hypothetical shock mounting

The wedge. "wedge" A rather lacklustre effort comparatively I supose but as a reserve (not guaranteed a spot) and with only a few days and no money left a length of 10mm steel L channel was perfect front material.

Heavyweights are so insane that they'll bend 8mm hardox with a good hit... so kind of whats the point. I'll spend £25 and have enough material for a spare and have it a material that I can bend back with a hammer on my pit bench.

Some final wiring and jiggery pokery

The theory!

Both back wheels touch the floor and I can move it around fine as it is.... but we'll see

The probable reality.... well if it lands like this without the beater going I'll have bigger problems, I'll burn that bridge when I get to it.

And that's a goblin the day before we shipped out to Glasgow! A bit of an odd build truth told as a lot of things felt simultaneously  ready to go but at the same time totally unfinished. Plus building knowing you are a reserve slot, you're burning a time and money up on a hope. Luckily it paid of for us! More on that below.......

Obviously, spoilers and stuff from here on.

After a slightly convoluted trip from Brighton to Glasgow via Sheffield and Solihull, we had made it to the studio in fairly decent condition. Matt, our driver (both robot & car) had the most sleep out of the three of us sensibly.  There was a bit of milling around getting our pit bench set up all our passes and meal tickets (I immediately lost mine so was often hungry during filming) Despite what anyone who helped lift the robot thought, we were well in weight and our wiring loom passed inspection fine.

The above was our safety check in the arena, checking spin up, spin down time failsafe and mobility tests. We passed without hassle!

Then about 6 hours of waiting in the reserve corner with Tauron and Coyote! Tauron was first in, and then later on after Deadlock failed to really move during its testing Jamie & Co were in to the main show!

We had been waiting most of the day for Point Blank, the robot we were replacing to turn up. They did and after a few hours of rushing to finish their robot, a decision was made and we were in! It felt wonderful trundling all our gear over to the pit area to be alongside our friends at Magnetar and Coyote!

Our heat was a bit of an unkind one, the very sleek and powerful Push To Exit and the incredible Magnetar. Oh well, we weren't expecting much anyway. This just about sums it up! Flipped, fried and hobbled(goblin) Mind you, with Magetar in the fight it could have been so much worse.

Our second fight was against our reserve corner buddies and all round knockouts - Coyote! It just felt like fate at this point. With the problems with Goblin that came apparent during the melee we didn't hold out much hope for a win, but we could at least go out to a fantastic looking machine and a very kindhearted team.

Here is probably my absolute favourite photo from all of my time at Robot wars. It also gives you a sense of scale!

We lost fairly early on to be honest. We were having problems to start with but when coyote snapped the belt... well that's all she wrote!

I'm proud we managed to have a few nibbles at house robots, shearing the bolts on shunts axe head and popping a pin on Sir K's arm. We also appear to have knocked an actuator motor loose and chewed up the wheelguards which I had no idea of until watching it back!

The wiki has a much better write up than I can do, and there's no point repeating it here. I don't think any of us are fully sure of exactly what went wrong in what order as we had to leave fairly promptly after being eliminated. This meant we had to be total bastards and palm goblin off on to another roboteer (Calum from coyote is a saint!) as Matts car was in pretty bad shape with the extra couple hundred kilos of robot and tools! We got it out of storage the Friday before the episode!

Big thanks to all my opponents and fellow competitors who made the competition and the nights after absolutely mindblowing. To all the mentorn staff who made the series what it is but most of all to my team mates.

Andy my pit crew and Matt my driver. HG2 would not have been possible without you guys. Just remember....

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