Event Recap: Smashbotz Sessions 1/8/22

This is a smaller, lighter weight event and as such will get a smaller, lighter weight combined assembly and event recap post. Lets get into the ‘bot upgrades first.

I only brought my 150g Netsplit this time around, as they weren’t running Beetles and I didn’t want to design a whole new bot over the holidays. Since it did so well last time, my upgrades to Netsplit were pretty limited. If it ain’t broke don’t fix it right? I added some speed vents to the top and bottom which saved me a couple grams and look pretty cool. The fasteners for the lid are now the full height of the chassis, and are moved a little inboard to accommodate the washers and give me some crumple zone when I take corner hits. I also added a label to the back. That’s pretty much it.

On to the event. The bracket was pretty tough this time around with lots of powerful spinners, not many first timers in the crowd. I attended this one solo and didn’t have anyone to film, buy luckily SmashbotzTV was there and streamed all the fights on twitch. The videos below are taken from that livestream.

My first fight was against UpL, which is half of the plastic antweight UpLift. I went into the fight pretty confident, not realizing that UpLift is the top rated plastic ant on BotRank. Oops.

I think I was in with a chance here, I had good maneuverability on the aluminum floor to start with and my weapon was able to cut pretty good chunks out of UpL. Unfortunately one brilliant maneuver basically took me out. UpL’s lifter tipped me onto my side and caused my weapon to hit the floor, which sent me flying into a wall shattering one of my drive gearboxes. I was able to limp around and even got a chunk of UpL’s lifter, but I had no more control in that fight. Eventually they shoved me into a corner where my wheel got stuck in the closed pit and I was counted out. Later in the tournament they started doing unsticks in that edge, but this was only the 2nd fight of the day and honestly I had already lost, so no reason to press the issue.

Now I get to explore somewhere I’d never been before… the losers bracket! First up was Baby Bunny, a very old grabber from the Team Malice.

Baby Bunny had some radio issues which prevented us from getting a true fight, even after a reset. Not a lot to say about this, I got some good contact but didn’t do too much damage. I think I might’ve gotten a bit of their tail fuzz off. The tried to shove me in the corner I got stuck in earlier, but since both wheels were working I was able to get out. Eventually it just got stuck full on driving into the wall.

Next up was Micro Malice, again from Team Malice. Regular readers will remember that we went 1:1 at the last Smashbotz. I was excited for this match to be the tie breaker.

I start the match upside down because I know their weapon tooth is at the perfect height to destroy my weapon motor. Unfortunately the first hit throws me across the arena and right side up. I was able to hit their wheels a couple times, which affected their mobility, but then blew my lead by charging weapon first into their spinner. Their broken wheel was still preventing them from translating, but I reengaged to try and shove their weapon into the wall. Then one hit took out both of my drive gearboxes somehow, and that was it.

This loss took me out of the tournament, but I appreciated having a couple hours to just attend the event without being worried about who my next fight would be or what was going on with my repeated gearbox failures. I got some great advice about using Isopropyl alcohol to soften up the O-Rings I use for tires, it makes them almost tacky and greatly improved my traction. I also the way a few of the bigger bots shock mount their N20s, something I might copy in the future to make my drive a little more reliable.

Next up for me was the rumble! The plastic ants and fairies were combined for this which explains the couple of huge robots.

I’ve been eagerly waiting for a rumble so that I can run my obscene single tooth weapon. It’s not balanced so it destroys my mobility, but it hits really hard. Almost immediately I lost both of my gearboxes again for a total of 5 drive gearboxes this weekend. Even as a wiggly arena hazard I was able to get some solid hits and throws on other robots. Eventually I was just watching the other robots with my weapon at 50% throttle in case anyone came close.

Even though I didn’t win much this weekend I consider it a huge success. I had a lot of fun, chatted with lots of cool builders and learned a bit more about my robot’s weaknesses. I’ve got some concrete ideas for how to improve the reliability of my drive, I just hope I can get more motors in before the next event!

Smashbotz 2021 Event Recap

Wow, that was cool. It was awesome meeting so many kind people, seeing tons of cool bots who’s fights I’d seen online, even getting destroyed by one.

I entered two robots, a 150g Fairyweight called Netsplit, and a 3lb Beetleweight called Failover. This was my first event so I wasn’t expecting much.

I didn’t take many pictures of the event, I was pretty distracted the whole time, but I did get a video of every fight.

My first fight was with Netsplit against Impulse Robotics’ Azrael, a super experimental non-wheeled bot. Unfortunately it didn’t quite work on the floor, and after a couple uncontrolled flips he decided to tap out before I really hit him. Fair enough.

The second was a bit more dramatic. I was fighting Failover against… Droopy. The beetleweight final was always gonna be Lynx and Droopy and I was just in the way.

As brutal as that was I have to say I’m pretty pleased. Failover tanked a lot of really dramatic hits, and the wedgelets all stuck around much to my surprise. I also think I did a pretty good job keeping the ablative wedgelets between us at least for the first minute or so. The aluminum wheel guards even protected the wheels, until they got pushed into ’em. Thankfully I practiced driving with a bunch of variations of dead drive and was able to keep feeding my armor into Droopy, but it was just too reliable.

In the end Failover just stopped moving. After turning it off and back on again it worked fine though, not sure what that was about. I had to borrow a hammer from another pit to pound the aluminum belt back into shape away from the wheels, but other than that everything was fine.

My next fight was with Netsplit again, this time against Team Ice’s Scoop.

Pretty bland fight, the most interesting thing was realizing I could choose what side to come down on when it’s doing a gyro stand. Their wedge geometry was great and they always made sure that was my first point of contact. Nobody did any damage, but I got a few lucky hits around the side and kept my aggression up, so I think that’s what tipped the scales in my favor for a close Judges Decision.

Next up is Failover, this time against PART’s The Dryer, a FingerTech beater bar bot.

I had barely finished putting the bot back together before this fight and actually started it with my transmitter off, oops. Something about that first hit knocked out the right side drive, so it was back to crabwalking. Also all the bending and hits from the Droopy fight had messed up the geometry of the wedgelets enough that they swung all the way down instead of stopping. Getting stuck on those wedgelets was something I’d worried about, I’ll have to come up with a better solution for that.

Carrying the bot back to the pit I could feel the heat coming off the speed controller. When I cracked it open the hot glue I’d used to fortify the receiver cables and screw terminals was liquid because of how hot it was. There aren’t any wires crossed and I’ve verified all the drive motors work with a backup speed controller. Pretty disappointed with how the Scorpion Mini seems to have killed itself, so much for the current and temp limiting, I would’ve been able to back off the wedgelets if both sides of drive worked. Maybe I just got a bad one.

Netsplit after two devastating fights

At 2 losses that takes Failover out of the tournament which is about how well I expected to do. I’m very pleased with its overall performance in the face of two very experienced and very destructive bots. The ablative wedgelets worked perfectly and the aluminum belt took some terrific hits before it caused any problems. Plus now I can focus all my energy on my other robot which is currently undefeated.

Next up is Netsplit vs Butt Farts, a modified Hexbug Bite Force toy running on 2s with a steel bar, expertly piloted by Repeat Robotics.

See what I mean about expertly? I’ve tried to drive those things and struggle to control them even on the best of surfaces, and this smooth steel floor was terrible for my tires. That only got worse as the night went on.

Not a ton to say about this fight, it was super fun to do. I’m really surprised how durable those Hexbugs are, if it had a more powerful weapon motor it would’ve been a lot closer. Peter from RR was nice enough to gift me what was left of Butt Farts as a trophy.

Next I was against Orange Eyeball Slicer’s vert Little Bite.

This little vert was surprisingly powerful, it easily won the first couple weapon on weapon exchanges and was capable of flinging me across the arena, something I didn’t expect a vert in this weight class could do. I’ll have to go back and rethink my 150g vert!

This fight also had my most swag moment of the tournament, at the beginning I wasn’t getting the bite I wanted, so I hit the wall to flip over and it worked perfectly first try. I never managed to repeat that move (intentionally) but it was pretty cool in the moment.

After those first few hits I took his weapon out and it just became about survival. Traction on the floor was getting worse and I already knew Little Bite could easily push me, so for the last minute I just tried to hug the wall as far from the pit as possible. I picked up the judges decision and the only damage I took was a couple of nicks on the weapon bar.

Next up is Logic 404 with Angry Paperweight, a really mean horizontal undercutter.

Unfortunately, I can’t take full credit for this win. Angry Paperweight destroyed my weapon motor in that second hit, but also embedded its weapon bar into its own body. In a pushing match it could easily shove me around, and the traction had gotten even worse so I was really struggling to get around.

Then they got their weapon up to speed again and came in for the kill, but as soon as they hit my wheel they self destructed! After that we were on much more equal footing, and I even got a pin in like a proper control bot. Judges decision went to me.

Back in the pits I quickly replaced the motor. I saw there were some small cracks in the chassis and weapon retention button, but decided to smear some CA glue into them rather than swapping the whole chassis out.

Next up was the final against Micro Malice, another brutal horizontal from a team that competes in actual Battlebots! I’ll admit I was a little starstruck.

Obviously my CA glue repair was… not sufficient. The first hit liberated the weapon bar from the motor, and the second hit ripped the whole front off. Since I was undefeated at this point I knew going in that I’d get a rematch if needed, and I was worried about how exposed my lipo was without the weapon protecting it, so I went ahead and tapped.

So on to the rematch, this time with the B robot that had a mostly fresh weapon motor and chassis.

Unfortunately both of us had some significant drive issues, by this time I had no traction on the floor and Malice looked like it had some drive mixing struggles. We got lots of great weapon on weapon hits with fun sparks, I got good number of hits around the side and the back. Ironically when their wheel came off they became a lot more responsive, probably because everyone practices driving without a wheel. They managed to get one good hit on my chassis that split it in half again, but this time I wasn’t gonna tap under any circumstances. Luckily since I was upside down that kept the innards in, and I was able to reengage a few more times before the end of the match.

The judges decision went my way in the end, which made me the fairyweight champion!

That was so much fun and I exceeded my wildest expectations for my first event. I was really planning lose both fights with both robots and get to enjoy the show, and I’m sad I missed almost all of the 3lb and 12lb fights. I did catch the Droopy vs Lynx final though, that was awesome.

I’ve already got tons of ideas for how Netsplit can improve, and some thoughts on what my next beetle will be. Stay tuned!

PS as a final bonus @Hotkoin made some awesome fanart of the winners including Netsplit!

Netsplit Assembly and Test

Developing a combat robot has been a lifelong dream of mine, I’ve watched tons of builders on YouTube and elsewhere, and even as a young kid watching Robot Wars on PBS begged my dad to help me make one.

The standard advice when starting in combat robotics is to begin with a wedge. While I think that’s reasonable advice, I chose to ignore it and make a clone of Tombstone instead.

Well, that’s not strictly true, I made a few different robots. Including a wedge and drum spinner found on Tinkercad, and a vertical spinner I might finish up for a future competition. Vertical spinners don’t seem to work too well at this weight though, I don’t think you can really get enough mass into the weapon while still having a controllable machine.

Early on my plan was to run a steel ruler as my weapon, but it wasn’t as destructive as I would’ve liked. Also while iterating on the chassis design and electronic components I just kept picking up extra grams, so something a bit chunkier was in order. AR500 3mm bars from SendCutSend to be precise.

I know (from my own testing) that PLA isn’t a great material for robot combat. However it sure is cheap and easy to work with. I’ve printed and destroyed a couple dozen of these chassis in various ways and strengthened it each time, but I definitely don’t have the same variety of bots I’ll face in competition. My biggest concern is going up against another big horizontal as the 3d printed wheels I’m running come off pretty easily, and the weapon motor is exposed right up front.

Check out the assembly video for some fun test footage and more commentary about my concerns and design intentions.


Finally here are some hero shots with the bars. You can find the designs to make your own Netsplit on Thingiverse.