Shrapnel - Feather Vert Spinner

[Revsmin]

INSOMNIA 61

Belts and shaft arrived the day before the event so frantically put it all together that night and boom, the ESC blew testing the drive with belts. Thanks to Dave W for lending me his FeatherTwo which was perfect, will be getting myself one rather than replacing the Scorpion XXL. So, all together all wired up at the event:



And in weight and with 900g to spare!



Fed it some wood on the Friday for tests and utterly demolished it



Starting to believe it could be nasty! So, draws done, and I get:

Impulsor and Persephone - Two wedgebots
Legion and Binky - A flipper and another big vert disc
Neon and Steve - MASSIVE undercutter and grabby wedge thing
Shard and Carcinus - Horrible vert disc and horizontal pinchy thing

Starts pretty nice and gets progressively nastier!

Fight 1:
https://www.youtube.com/watch?v=s74CsSl9vMA

Ok so it hits harder than I expected
Impulsor is all mild steel so when I hit it I left a massive cut down the side, top to bottom:



As for the other one... ow?

I was taken aback by how well it performed in its first fight, I was expecting something to break or explode but it came out and only needed the battery charging! However at this point I did realise it was drawing too much current for the battery and had used half the capacity in that one 50sec fight alone :/ . So I guess keep fights short!

Fight 2 never happened, Binky and Legion withdrew and I got a bye for max pts which put me on 8 for the first day of fighting

Fight 3:
https://www.youtube.com/watch?v=9sGtEMQ6-jE

I think that may be the biggest impact of the entire competition! Neon ripped out the drive link and one of the shaft bolts sheared, bodywork damage was non existent bar a few dents on the disc. Most of the damage was self inflicted; the disc managed to hit the motor pulley and destroyed one side. Motor circlip imploded but the motor itself was mostly fine. I had a spare but left it in as I would rather not put in the brand new motor just for it to get killed against Shard later on. I removed the snapped rear drive shaft and replaced it with another, good as new.

SLOWMO IMPACT GIF



Fight 4:
https://www.youtube.com/watch?v=3yx7ZpeU4ew

succ

Carcinus wasn't around so I just had a one on one with Shard. So I had a throttle cut setup on my tx to limit the throttle to 50% to prevent gyro, unfortunately if its on when the robot is powered on it prevents the weapon ESC from arming so on activate my weapon wouldn't spin
By the time I realised it was already too late and it was in the Standard Ripto Loss Position:



Sad
But at least its authentic to the original I guess, and I think I would've come off with a lot more serious damage if I hadn't got stuck

So the last place and second place gained me another 3pts bringing my total up to 11pts. They informed us that there were 2 too many machines on 11pts for us all to go through, so we would have to fight in two 3-way melees to eliminate the two extras.

Fight 5:
https://www.youtube.com/watch?v=r4F7o3KUXcM

BOOM
No real damage to Omega, that things a brick. However you can see the belt come off after the hit; The disc actually wobbled a tiny amount and hit the pulley again, this time much harder, snapped the shaft clean off, pulley and all. So, replaced the motor with the spare, and repaired the other drive shaft which had bent and come loose as well.

Obligatory gif I can't stop watching



THROUGH TO THE FINALS



And still looking pretty damn good despite those big hits!

Draw for the finals was done, I got Straddle aka British HUGE.
Straddle's a weird one, a hybrid of Gabriel meets bar spinner than really I had no idea what to do with

cont...

[Revsmin]

Fight 6:
https://www.youtube.com/watch?v=J_rkG3WRQAo

We traded blows, each left some marks on the other:





Fatal blow for Straddle seemed to be a power cable coming loose, which was a shame. I managed to smoke a drive motor in that fight, not sure how because the gearbox was fine but replaced it with a spare given my Rory of team Nuts who also helped wire it into the bot while I bummed about sharpening the wedge ready to fight my next opponent: Explosion

Fight 7:
https://www.youtube.com/watch?v=v_Uqja0HixM

And here's a gif taken from the judges table where it hit the wall:



The lead up to that was very dull really, just two very low bots trying to keep facing the other until we finally figured out Explosion was marginally lower :P
And yeah it bounced off the wall and landed back in the arena! Unfortunately for me as soon as you hit the outer wall you're eliminated so I didn't get a second shot but it was pretty incredible all the same! Oh and I left a nice great gash in the wall:



So, out at the quarter finals, which for a brand new robot at its first event is pretty damn good! Finished 5th overall which I'm extremely happy with! Some modifications to make before next time, mostly just small things though as I'm very happy with the overall shape, design and performance.
So then:

THE GOOD
- Contact wheels: tons of grip and they show no sign of wear at all, really impressed with the quality
- Cheap HK carbon fiber: Been through all that without so much as a small crack, incredibly strong stuff for the weight
- NTM heli motor: Absolutely buckets of power, disc was reaching full in just over 2 seconds and no issues with it breaking bar the shaft getting hit by my own disc!
- Shock mounted drive: Zero gearbox issues at all, none of the shock went through them and they just kept going
- Shoulder bolt shaft: Didn't get a chance to cut and tap the titanium shaft so went with a £12 M16 shoulder bolt instead, no problems with it at all, not bent in the slightest.

THE BAD
- Rear drive shafts: Mounting them using the thinner threaded end of the shoulder bolt was not a good idea. One sheared and the other was bent, will be doing them differently moving forward.
- Hardox 500 disc: While 500 survived ok, the tooth has worn very quickly. I think with how hard it hits it needs to be 650 next time.
- 2.2ah battery: Nooooope. Not big enough. Not enough capacity, gonna get a 4ah for next time to be safe
- Ground clearance: The big wide wedge was VERY low towards the end of the comp, but it wasn't enough for Explosion or Shard so for next time there will be some new front attachments to counter them better
- Straddle: How tf do you fight that?? Well I have a few ideas I'll be putting into CAD to try out for next time

Had a great time at the event, really happy with the robot
Shrapnel will be back next time with improvements!

[Ocracoke]

Great to see the robot in action, mighty impressive hits with it! Well done

Can the disc tooth be reshaped so it is not so much a tooth but a block (al a Nightmare from Battlebots)? Would that be more impact resistant I wonder?

[Revsmin]

Can the disc tooth be reshaped so it is not so much a tooth but a block (al a Nightmare from Battlebots)? Would that be more impact resistant I wonder?

It would but one of the reasons Shrapnel hits as hard as it does is because of the aggressive angle on the tooth, making it square would increase its lifetime but would lessen the impacts

I found a better angle on the Straddle fight:

https://www.youtube.com/watch?v=YWt7bWwniRc

It seems when the back shaft bent and the belt came off it got jammed and while I was demonstrating I was still mobile to the judges it seized and stalled the motor out :/
Definitely need to sort those shafts! Will try and get some better fitting belts too so I don't need to tension them so heavily

[Ocracoke]

It would but one of the reasons Shrapnel hits as hard as it does is because of the aggressive angle on the tooth, making it square would increase its lifetime but would lessen the impacts

I suppose that is the age old issue of outright performance over longevity.

[Rapidrory]

gonna get a 4ah for next time to be safe

Given it was never actually an issue in fights, I'd just take it up to 3Ah and save the weight for something else.

[Maxamuslead]

snip

could you use something like Ferobide and weld it to the tooth ?

https://www.spaldings.co.uk/replacem...m-thick-(pk10)

it is weld on Tungsten Carbide which is in agriculture to lengthen the life of items like subsoiler legs.

[Revsmin]

Now I'm done with Uni for a while I spent today fixing Shrapnel up ready for Manchester, got the rear shafts repaired and fitting the spare disc so it has a nice fresh tooth. See you all there

[Ocracoke]

Ooooooooooooohhhhhhh, looking forwards to seeing this! See you there!

[Maxamuslead]

god damnit two nasty Vert spinners

[Revsmin]

Three

#threevertsoftheapocalypse

[Maxamuslead]

Three

#threevertsoftheapocalypse

Hopefully you all kill each other =P

[Theo]

Ooooooooooooohhhhhhh, looking forwards to seeing this! See you there!

You still sure about that?

[Ocracoke]

I stand by what I said. In all honesty, I was just glad to see Shrapnel at all given what I've read here.

[Revsmin]

So I uh
Kinda forgot I had a build diary?
So... Stuff?



STUFF

So Manchester ended up being kinda disappointing, turns out one of my gearboxes was playing up so the drive wasn't working nice and ended up smoking a couple motors, and one of my links had come slightly loose and was constantly losing connection, meaning the brushless ESC was resetting every time it moved.
Result: no spin spin

FIXING THE PROBLEMS

Well there's nothing visibly wrong with the gearbox, but it's sticking in places and eventually jamming so not worth the risk of using. Have now got a replacement and a load of spare motors. To combat the roasting of drive motors I've sold the FeatherTwo and replaced it with a Scorpion XL; hoping that current limiting the motors to just over half their stall amps will stop them spontaneously combusting if they get a bit strained. I've fiddled with the link pins to sort them out now so no more loose link issues. Gonna be keeping an eye on them in future, apparently XT60s aren't so great at staying solid so may end up switching for deans connectors.

PREPPING FOR INSOMNIA

So now I gotta get her ready for Insomnia

First stage was fixing the kinda knackered wedge that's not super low any more. How to fix this? Easy; make a WHOLE NEW ONE OF COURSE





So now I have a nice wedge that I can keep sharp and un-twisted for fighting non-spinners, and a kinda broken one I can sacrifice to spinners without worrying! Huge thanks to Binky for busting the old one and giving me the idea for a spare!!

I've also got some new weapons prepped:




All new disc and single toothed bar cut in Hardox 600

I'm also working on some bolt-on front attachments for fighting different types of opponent, including this fancy set of HDPE forks:



There's more but I'm keeping it all under wraps for now

I'll see you all at Insomnia!