11/28/2025 1 PM - I Found a base shuffle drive module and a base weapon

Today I started the cad of the robot, which consisted of finding a suitable shuffle drive module which i found from repeat robotics on Grabcad. So far i have slightly modified the shuffle drive to suite my needs by making it thinner and changing motors and mounting of everything. I switched the motor from a mk2 to a cheaper n20 brushed motor.
Here is an image of the normal version compared to my modified version
doing it this way also allows me to use a smaller shaft, and it saves more weight, in the middle you can see a test chassis I made so I can see if this works well.

11/28/2025 8 PM - Changed the shufflers

I printed the shufflers so i could test how well they work before i put them on the robot, and my reaction was mixed. They would work decently well but they generated way too much friction and the n20s got so hot that one of them stopped working. So, i started by finding a new version on yet again grabcad, after doing some modifications to it because it was an incomplete version I'm going to print it out and test it again. This time instead of it used a brushed n20 it uses a brushless 1805 motor, which is much stronger and cheaper, but it needs to be geared down because it's too fast for normal use.
This is how the new version works, it's longer which prevents it from tipping over as easily and it should have more torque because of the stronger motor

here is a video of the old version

11/30/2025 - Designed the base of the robot and modified the shufflers

I forgot to make the journal for yesterday so this is hours for both days that's why theres so many. I started on the design of the robot and went through three major changes throughout the process, I started with a 17 in wide robot, make the body and armor then I realized it was way too big, then I changed it to 12 in, then a started weight calculations and I thought I was going to be underweight until I made the uprights and figured out the how heavy the drive pods were. In the current version I have a 5.5 in weapon which is smaller than the original 6 in weapon I had. I also made the uprights which is going to be made out of UHMW. The main bot is going to be made out of 95a tpu and the bottom floor is going to be 1mm thick carbon fiber along with the roof. The weapon is 3mm of ar500 steel. The drive pods went through 4 different versions before I landed on the current working one. The biggest issue was friction and the feet flying off because of the speed, i fixed that by making spacers and a cross support bar which also helped to stop gears slipping.

This is what all 4 versions look like, they look almost the same but they each have small changes that make them run much smoother.
Here is a video of the new version of the drive pods working

and this is what the robot looks like

12/8/2025 - Fillet all the corners and building a test frame

Today I made the chassis printable by filleting everything and doing some structural changes like changing the holes from screwing into the back to the upright going back farther and it screws in from the side. I also made the top lid and the way I'm doing it is its going to be two layers with a tpu insert to fill the gap between them, the two layers are going to be 1mm thick carbon fiber. Here is how it looks

I also printed out a chassis out of pla to test everything
Here is how it looked I'm very happy with it

But I learned the hub motor I was going to use didn't have enough torque to flip it over when it was needed so I then changed the motor to be a separate motor that will be on the side of the upright, the motor will be significantly stronger, the old motor was a 2207.5 motor while the new one is a 2807 which is a large difference in power. The new motor will be gears down slightly to the weapon and that is how it will connect. Here is how the new version looks its not fully though out yet but this is somewhat how it will look

12/13/2025 - Remade the drive pod and redesigned the body again...

So, the drive pods did work well :( they just didn't move right, they were super bumpy and really slow because the motors were struggling really hard to even get it started moving on the ground with a robot. And that dual cam style, I found out also has a few more weaknesses than other types, the biggest one is that if the gear slips even once the entire drive side can lock up and not be able to unlock, also the way everything was mounted wasn't great either. With the new redesign I think I'm going to change it to a single cam but still use the same motor and if that doesn't work, I'm going to redesign again and use mk4 minis but those are more expensive. Here is a video of my new custom version of drive Screen Recording 2025-12-13 012415
Now I just have to figure out mounting
Here is how the old version looked before I realized the drive is just too weak

12/14/2025 - Finished the Bot!!!

Today I finished the bot! The hardest parts were making the weapon system to connect the motor to the weapon and adjusting the robot to fit the new drive pods. I originally started trying to have the weapon belted to the motor because that would be better because of less risk of something going wrong like a tooth breaking off or something like that, but with how close the weapon and motor are I couldn't use belts so I'm going to use solid TPU gears. I added metal forks, but I had to remove them because of weight. A majority or the time I spent went into pocketing to save weight because I forgot to add a shoulder bolt in the weight calculations. Overall, there's not a single thing that's going to be solid this is going to get cooked lol.

12/16/2025 - Looked over prices

In the last rereview of my project i was told to try to find a better deal on my amazon order which was uhmw and carbon fiber. I did look on aliexpress for both and the price was around the same for the carbon fiber but i coudlent find any uhmw, and i dont want to risk the structural stability of my robot.

2/18/2026 - Remade the drive system

This wasn't today, but over the past week or so, I remade the entire drive system and went to a normal non-shuffle type, which removed the weight bonus, so I had to spend some time shrinking everything that wasn't already bought, and somehow I succeeded. The new drive system uses two n20s, one on each side, that are belted to the rear wheels. The weapon system is still the same, so I didn't have to change that. The body itself is now tiny. The carbon fiber was changed to be Tergis for weight purposes, and it is still similar in strength. I had to remake the armor and it now only covers half the wheels and it uses a standoff to connect in the middle

4/8/2026 - Built the robot!!!

I've been meaning to journal this for a while now, but I'm finally doing it. When I first built it, it looked awesome with the big, giant weapon and the lacking drive. So I went to test it, and I was plagued with the same issue; no matter what I did, the nut that connects to the motor always fell off. I tried to use JB Weld to fix that, but because of the sheer amount of torque it needs to resist, it still failed. You can see that towards the end of this video, when it starts squeaking and stops moving https://youtu.be/AFhIDF4VoWo. After trying to think for a while, I asked my dad, and he said just move the motor to the other side, but I didn't do that for a while because I didn't think it would work. When I finally did it, though, it magically worked and didn't fall off anymore, even when it had hard hits. You can see the new version in this video https://photos.app.goo.gl/xXhm4NthCuKJQigz9. Overall, this took way longer than I was expecting it to, just for the fix to be something so simple.