Siren 150g Drum Spinner Combat Robot (UK Antweight US Fairyweight)

I designed this drum spinner combat robot in TinkerCAD. I called it siren because of the sounds it makes as it spins. I am still tinkering with a true whistle or siren to incorporate into the drum itself. So far I've had success when spinning in reverse. I think I'll have to do away with the teeth to get he right airflow.

Siren was designed to maximize the size of the drum spinner. The wheels are protected and their location make driving inverted possible. The bot can also self right, thanks to an idea I took from the Sgt Cuddles design. While inverted, high throttle the drum quickly.

I battle tested tested the bot at the Southern California October Obliteration 2018. I learned that I REALLY need lock nuts for the drum. I had two bodies. One in orange to start and one in translucent to continue in the losers bracket as a ghost of the first. Sadly I needed both.

A new version with a right side motor is now up. The right side motor causes the screw to tighten instead of loosen while the drum is spinning. Minimizing loosening of the screw if you, like me, forget to use a lock nut or loctite in the midst of switching drums.

I also added a photo montage to show the assembly of the internal components. Check out the build video: https://youtu.be/Edj_XLIhTDw.

Check out the design competition over at Endbots:http://forum.endbots.com/thread/41/endbots-design-contest-october-2018

Items needed to complete the build and some instructions:

n20 motors. Motors simply slide into the motor mounts and are held securely. No screws required. Thanks to https://www.thingiverse.com/thing:1547777 for this inspiration. (https://www.aliexpress.com/item/12MM-N20-Reduction-Metal-Mini-Micro-DC-3v-6v-12v-Electric-Geared-Motor-For-RC-Car/32770564311.html?spm=a2g0s.9042311.0.0.210c4c4dt0i33b). Use 2 300rpm, 500rpm or 600rpm motors. Corresponds to 50:1/30:1 gear ratio.

DYS BE1806 2300KV Brushless Motor (https://www.amazon.com/gp/product/B076H261PX/ref=as_li_ss_tl?ie=UTF8&psc=1&linkCode=sl1&tag=drcameron-20&linkId=1b68cb9e20b9d6d463e2efa52d3bb987&language=en_US or https://www.banggood.com/DYS-BE1806-2300KV-Brushless-Motor-2-3S-for-Mini-Multicopters-p-933192.html?p=@T25030878732012108C). Press fit into the drum. Use tape to protect the wires from the drum spinner.

3mm bearing (https://www.amazon.com/gp/product/B076H261PX/ref=as_li_ss_tl?ie=UTF8&psc=1&linkCode=sl1&tag=drcameron-20&linkId=1b68cb9e20b9d6d463e2efa52d3bb987&language=en_US) and an M3 lock nut (https://www.amazon.com/gp/product/B076H261PX/ref=as_li_ss_tl?ie=UTF8&psc=1&linkCode=sl1&tag=drcameron-20&linkId=1b68cb9e20b9d6d463e2efa52d3bb987&language=en_US) and M3 x 16mm screw (https://www.amazon.com/gp/product/B076H261PX/ref=as_li_ss_tl?ie=UTF8&psc=1&linkCode=sl1&tag=drcameron-20&linkId=1b68cb9e20b9d6d463e2efa52d3bb987&language=en_US). Press fit the bearing into the drum. Use a small amount of glue to keep it in place or melt the plastic around it.

Additional screws are used to make teeth in the drum (flat tops are best: https://www.amazon.com/gp/product/B076H261PX/ref=as_li_ss_tl?ie=UTF8&psc=1&linkCode=sl1&tag=drcameron-20&linkId=1b68cb9e20b9d6d463e2efa52d3bb987&language=en_US) and for the bottom to adjust he height of the drum from the floor (round tops are best: https://www.amazon.com/gp/product/B076H261PX/ref=as_li_ss_tl?ie=UTF8&psc=1&linkCode=sl1&tag=drcameron-20&linkId=1b68cb9e20b9d6d463e2efa52d3bb987&language=en_US). I've been using a variety of different screws here and sometimes none at all.

Polulu 40mm wheels (https://www.pololu.com/product/1452). The wheels need to be put onto the motors AFTER the motors are installed. There is room to slide the wheels down and onto the axel. The wheels should be adjusted again once the top is placed on.

DasMikro 2S6A Micro Dual Bi-Directional Speed Controller: https://www.banggood.com/2S6A-Micro-Dual-Bi-Directional-Speed-Controller-for-Tank-Crawler-and-Boat-without-Brake-p-1032413.html?p=@T25030878732012108C or https://www.aliexpress.com/item/1PC-Dual-Way-Bidirectional-ESC-2S-3S-5A-Brushed-ESC-Mini-Speed-Controller-for-DIY-RC/32901482253.htmlspm=a2g0s.9042311.0.0.5add4c4d9ICLcg

ZTW Mantis or Mantis Slim 15A SBEC 2A/5V Brushless ESC: https://www.amazon.com/gp/product/B076H261PX/ref=as_li_ss_tl?ie=UTF8&psc=1&linkCode=sl1&tag=drcameron-20&linkId=1b68cb9e20b9d6d463e2efa52d3bb987&language=en_US. The slim version is just over 6g (https://www.banggood.com/ZTW-Mantis-Slim-15A-SBEC-Brushless-ESC-Speed-Controller-For-RC-Models-p-1247457.html?p=@T25030878732012108C) and the larger version is 10g. The slim version goes in an out of stock at various merchants.

2s Lipo batteries: https://www.amazon.com/gp/product/B076H261PX/ref=as_li_ss_tl?ie=UTF8&psc=1&linkCode=sl1&tag=drcameron-20&linkId=1b68cb9e20b9d6d463e2efa52d3bb987&language=en_US or from HobbyKing directly.

FS2A 4CH AFHDS 2A Mini Compatible Receiver : https://www.banggood.com/Flysky-FS2A-4CH-AFHDS-2A-Mini-Compatible-Receiver-PWM-Output-for-Flysky-i6-i6X-i6S-p-1214269.html?p=@T25030878732012108C

Transmitter: Flysky FS-i6 for use with the above receiver: https://www.amazon.com/gp/product/B076H261PX/ref=as_li_ss_tl?ie=UTF8&psc=1&linkCode=sl1&tag=drcameron-20&linkId=1b68cb9e20b9d6d463e2efa52d3bb987&language=en_US Or if you want something compatible with multiple protocols including the Flysky one above and also spectrum and frysky: https://www.amazon.com/gp/product/B076H261PX/ref=as_li_ss_tl?ie=UTF8&psc=1&linkCode=sl1&tag=drcameron-20&linkId=1b68cb9e20b9d6d463e2efa52d3bb987&language=en_US or https://www.banggood.com/Jumper-T8SG-Multi-Protocol-2_4G-10CH-Compact-Transmitter-for-Flysky-Frsky-DSM2-Walkera-Devo-Futaba-p-1189811.html?p=@T25030878732012108C

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