Team Kaizen Build Diary

[Ocracoke]

Extreme Robots Doncaster 2024
The format of EXR shows has changed slightly to account for some changes ongoing and for middleweights, that meant our pre-show got pushed forwards. So if the show starts at 12pm, you have to be ready to go into the arena by something like 11:20. This change, and a couple others, is not something I would have liked for reasons as will become obvious in a moment.

For those wondering what had happened from my last post - the 60A Roboclaw did not power on at all so I debated shoving in a 60A Cytron board but there simply isn't enough room in the robot. However, a pair of 40A board just fit so I went with that. On the Wednesday, I put the boards in... one wheel spun, the other didn't. After examining, the board was deemed dead and a new one ordered, leading to Friday night after work (for me, this usually means 6.30pm or later) being a hectic scramble to get the boards in, wired up and tested.

The test showed the drive working, albeit poorly meshing and the axe worked nicely. So on the Saturday, minor modifications were made to the drive mechanism to get the gears to mesh.

Saturday
Arriving at Doncaster, we got setup at a table and got to to work charging a battery and working on the speed controllers. Bear in mind, less than 12 hours prior to the event, Jibril was in pieces owing to the Roboclaw situation and a quick change over to the Cytron boards. Directional controls were sorted, the drive was OK... and just as the first battery was charged up... we were called in.

The competitors for the weekend were Jackpot, a robot well known in the MW community, Gremlin, a loanerbot and Tilly (or F7, I am not sure). Tilly was an axebot which given my polycarbonate panels and the relatively smashed state they are in, I had concerns but in the fight, Tilly was less effectual than I feared, leaving me with the only active weapon MW in the arena. Jibril left its mark on all three competitors, especially Gremlin and came out of the fight the winner.

Off to a good start, I thought things would be plain sailing. Nope. Remember that battery charge? The uncharged battery had ballooned and was probably on the verge of exploding. Had I had the 20 or so mins like last year, this would have been less of a problem. Luckily, Dan of Jackpot fame swooped in and sold me a new 4.5AH 6S LiPo, saving my bacon there.

However, the trials were not yet over. I had the new axes available for a while at this point and wanted to try them out so I swapped over the light Scythe for the heavy Sycthe. However, during lunch, a power test showed no life in the robot which was diagnosed as a broken battery cable. If anyone has ever seen Jibril, you can imagine a 300x200x100 space is not a lot of room and I was getting quite flustered by my soldering at this point. Got it mended and guess what? We were called up again well before the second show started. Only then for EXR to tell us that we had been bumped to a post-fight because of timing issues.

Argh. Oh well.

Before the second fight, Gremlin was pulled out. The reason was a lockup on the drive which turned out to be a smashed motor caused by Jibril (that is two in a row now...) and with Tilly/F7 in pieces itself, it was just Jibril and Jackpot. Sadly, the drive issues came back to haunt me again and would weirdly only go backwards in a straight line. This turned out not to be the biggest issue though.

The new axe arrangement meant the swinging weight of the axe had lept from 1kg to around 4kg (not 5 as I had originally thought) and was substantially bigger than the old axe. There were questions around wherever the 10:1 ratio axe gearbox would work with this.

It did - once.

The axe fired once to a almighty bang and then stopped working, leaving me with only partial drive and Jackpot easily winning the fight. Looking it over post the show, the axe just was not working. I assumed this was a blown fuse.

Sunday
I was late getting in so had 5 or 10 minutes before being called up. The drive looked OK but the motors just didn't sound right. The axe connection turned out to be more problematic than just a blown fuse. The EC8 connector beween the axe and speed controller was burned up and was cutting off the supply to the motor. Not having any brass brush tools to clean it with, I scraped off what I could and replugged in - it works.

Great, so in we went. This time, Audacious was in attendance and Gremlin had replaced the motor so that was back in too. Jibril goes in, axe no work. The drive was being weird but worked enough to do an in place spin and become a thwackbot. Now, Jibril is not a thwackbot and lost the fight to Jackpot. Post battle examination showed that the M10 Titanium bolts holding the axe on had popped off and more importantly, a drive motor shaft had snapped and the other side looks bent, probably explaining the odd drive issues.

Post event thoughts
Overall, Jibril did well this time around.It might be a bit of a glass cannon but honestly, this is the most solid it has performed in a while. I'll have more thoughts later on this week.

[Ocracoke]

Videos of the first two fights of the weekend

Fight 1


Fight 2