Púca V3 (and 2)

Puca V2

Wait a minute, Puca 3? What happened to 2? Let’s cover that real quick. So after Puca won Norwalk in January 2023, it fought at Motorama the next month where it would slowly obtain a negative win/loss ratio.

Pictured above is Puca’s big secret. The 4-in-1 ESC actually sticks out the back of the robot, completely except for a single piece of Gorilla Tape. Puca fought at both January NHRL and Motorama like this. But why? There was a different set of ESCs I was originally planning to run in the robot but they were out of stock when it came time to build. Puca is a very tightly built robot with almost no space left to spare, so other alternatives rated for 6s were too big. The best option for a last second replacement was this 4-in-1 at the cost of cutting a hole in the back plate for it to fit. Stupid? Yes.

This was the biggest thing to fix, but there were a few other things too:

  • The screws that mounted the side pickles to the chassis often needed to be replaced
  • Top/bottom panels were too thin
  • My weapon belt could be easily hit

The fixes to these involve adding a lot more weight to the robot. So for V2, I made the bot even smaller and made my chassis rails a little thinner.

So here’s a size comparison of Puca 1 on the left and Puca 2 on the right. As you can see, V2 is smaller in both width and length! The top and bottom plates are now twice as thick (2mm) and I have a belt guard integrated into the side rail. (Oh and I added a sweet decal too.)

Making the robot less wide means there’s even less room for a 4-in-1 ESC to fit. However, I had plenty of vertical space, so the solution was to switch over to 3 individual ESCs. For drive, I chose LittleBee 25a’s and ran a NeutronRC 80a for the weapon.

Fast forward to NHRL September. Time for a new and improved Puca to prove it still means business and beat experienced bots instead of just new ones. Unfortunately, the LittleBee ESC’s on drive exploded after about 3 seconds of actual driving… It turns out these are hot garbage, and while some people have had success running them on 4s, 6s was just was too much despite being rated for it. It doesn’t help that I’m running way too high of a kv on my drive motors either. 2300 is just way too much for my wheel size. Then of course, it did the same thing in its next fight. Puca finished the event with a disappointing 0-2 record. But this all goes back to me never finishing a robot until the night before (or morning of) an event.

This screenshot is hilarious to me. Peter released his brushless AM32 ESCs a day after I ordered my LittleBees. A DAY! Had I waited just a little longer to order my electronics, I would have gone with the Repeats instead. So of course, a few weeks later right after I got home from NHRL with four toasty LittleBees I ordered some Repeat AM32 ESC’s. I’ve to say, these things are fantastic. AM32 is impressive and does feel a step closer to brushed in terms of responsiveness.

So now, Puca is equipped with quality ESCs and new 1500kv MegaSparks! But at NHRL Finals and ARC December, it has more issues to work out. Bolts are still getting ripped out of the side pickles, the drum chips too easily, and sometimes the robot gets nearly split in half fighting horizontals. At least it was a step in the right direction, I had an absolutely incredible fight against Wicked Twister that you should all check out 🙂

As you can see from the pictures above though, there are still a few issues to work out, mainly the entire robot being SPLIT IN HALF.


Puca V3

Ok, now we can talk about the current version of the robot. The two big things I wanted to do for V3 were keep the robot from splitting and beef up the weapon teeth so they don’t split. 

So to keep the robot from slitting, I replaced the three Plastite screws that hold the front of each side pickle with regular machine screws. Then I have a cutout on the inside of the frame rail where a tapped titanium plate sits for the bolts to screw into. Then, in the side pickle itself, I have a ti plate that’s integrated into the plate itself. This is done by pausing the print, placing the plate inside its hole, and then continuing the print so that the titanium is embedded inside the part. I’ve only fought one horizontal since making this change but the robot survived! So far, so good!

Up next is the drum. Weapon on weapon hits (especially when I was upside down) would tare huge chunks of my teeth away. This has now been fixed by making the teeth extra thicc.

Now all I had to do was find a way to make weight for the extra titanium and thicker teeth. This ended up being done through a combination of making the drum just a smidge shorter and switching the bolt I use as a shaft for a hollow tube.


Closing Thoughts

So far V3 has been doing fantastic! It just won Sonoran Showdown down in Tucson Arizona, so hopefully the worst for Puca is behind me now! I’ll also probably make an event report on this event too. So keep an eye out on the Team Small Robots Youtube channel for more!

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