Total Time spent: 28h

Found basic parts to use!

In this session, I found some basic parts I can use for the bot, mainly the drive and hub motors. I started designing a basic frame to mount all the parts to. Pictured here is my innitial motor mount concept.

Time spent: 3h

Started designing the frame

In this session, I continued building out the frame for the bot, prioritizing having well protected wheels and began making a space for the weapon motor to be placed. I will be designing one half of the frame at a time and mirroring it so its easiest. This is my first attempt at a protected wheel.

I also decided to change the front so its more of a wedge shape, hopefully this will help with getting under other bots. I also rounded off some of the sharp corners on the sides to hopefully make the bot more impact resistant. I increased the protection around the wheel here and reflected the body so its one piece.

Time spent: 4h

Designed weapon motor mount and blade

In this session I designed the hub motor mount and blade. I spent a lot of time looking at other robot's designs for blades, and with @tortlegod's help eventually landed on the design you see here. It has one tooth, as I want to make sure the motor can spin up enough before being ready for a hit. I am using a 2400kV motor from Repeat Robotics. I had to raise up the motor mounting position because the tooth on the blade was longer than I expected it to be. I plan to get the blade cut out of steel, or even titanium if it fits within the budget. I also changed the back of the frame to be more curved, which should help with getting thrown around.

^ innitial hub motor mounting position

^ added the blade and raised the verticals

^ current blade design, using the mounting pattern from existing blades for this motor

^ rounded back

I also worked on a color scheme for this bot. Not sure if I will keep it this way, but it doesnt look bad imo

Time spent: 4h

Redesign time!

I realized that the positioning of my spinner wasnt great in this configuration. The tip of the weapon barely stuck out of the bot and it would be hard to get hits in on low to the ground robot. I decided to redesign the weapon mount, making it angle slightly forwards instead of back.

As you can see, its now basically vertical, which should make it easier to get hits in on bots. I also lowered the position of the motor with the goal of getting under low bots easier. I also changed out the motors for smaller ones, as the large motors I was using before were overkill for a bot of this size.

I also spent time designing forks to help lift the other bots into my spinner. I took insperation from bots like get shrekt and Kreigmesser v2 for these. The forks also double as my front wheels, basically stopping the bot's weapon from scraping on the ground. I had to remove a good chunk of the center of the bot to fit the weapon in, so these forks should keep it high enough off the ground to not contact.

One thing im worried about is that it seems very front heavy, which could be an issue in fights.

Time spent: 3h

oops!

I messed up with the forks, as I rigidly mounted them at two points instead of one. Attatching it at one means that it can rotate up and down a little, letting it glide across the surface easier. I also removed the little lumps on the bottoms of them, and replaced it with replacable lumps in the body itself.

I also rounded out the back of the bot and made the wheels bigger. This will help the bot flip itself if it gets stuck upside down.

In this picture you can see the new fork design and the larger wheels. You can also see the little blue pads that can ride along the ground. I plan to print these out of PETG, because it has some self lubricating properties. I took insperation for the rounding from Tech V3, as the fights I have seen seem to be fairly successful. My only worry with this setup is that my back wheels are now very exposed, which could become an issue in fights.

Time spent: 2h

Final Touches

In this session, I added some of the final touches to the bot. This included a top plate, electronics compartment, and support for the hub motor. I also decided on the wheels I was going to use, instead of custom sillicone ones I landed on COTS wheels for simplicty and cost saving. Im also using COTS wheel hubs, which should be super strong.

As you can see in this image, the top plate is fairly thin. I was having issues keeping the whole bot under the 1lb weight limit, so I may need to add pockets or even cut it out of carbon fiber. Overall I am very happy with the design of this bot. I really like the shape of the spinner and I am optimistic for its performance in fights.

Time spent: 2h

More Changes!

I made a couple changes to my vertical assembly in this session. I decided to add some 1mm carbon fiber plates to the verticals and made them thinner overall. This was important because TPU is very flexable and likely not hold up to the vibration of the motor. This will also make the frame slightly lighter, as I am worried about the total weight of the bot. I also added a cable routing channel for the main motor.

Time spent: 2h

oops! (again)

I printed out the frame for the battlebot out of TPU and found out that it was way too heavy. It was about 167g in total. This made me decide to figure out how much the rest of the components weighed, and it ended up being over 600g. I was about 160g over the weight limit. I decided to cut down on weight by reducing the walls and infill on the print (from 6/6 25% to 3/3 15%) which helped, but didnt get me close enough. I then moved on to frame modifications, where I reduced the size of the wheel protectors and cut out some big blocks of material. This helped a lot, bringing the weight for the frame down to about 90g. I also added two small ears to the bot which should help with the bot being able to flip itself back to being upright after a big hit.

I also found that a big part of my weight issues were coming from the wheels I chose. They were nearly 20g each! I already ordered them, but I am trying to return them. If I can't, I'll pay for the other wheels out of pocket. They are foam and weigh less than 2g, plus the hubs which are about 5g. Im still slightly over the weight limit, but some slicer optimizations should help.

Time spent: 4h

More Tweaks

I decided to reduce the weight of the bot by making the forks thinner and adding pockets. This is unfortunate as I have already ordered them, but I will hopefully be able to get a refund or exchange. If not, I'll just buy it myself. I also spent some time cleaning up the frame, adding fillets to sharp corners and reducing weight where possible.

Time spent: 2h

Renders!

I thought my bot could use some nice renders that Onshape cant do, so I pulled the step into Fusion and started messing with materials. I'm pretty happy with the results of my renders, and I think that it looks pretty cool.

Time spent: 2h