Botworld Tether

[Darios Uclaray]

Arguablythe most important parts of a robot are what we call the transmitter and receiver. The transmitter is the controller we hold, transmitting instructions to the robot. The receiver receives those instructions and sends them on through little 3-pin connections. You might often see these referred to as a Tx and Rx respectively. When purchasing these, make sure they can talk to each other! Different pieces of equipment run on different protocols.

Brushless motors are similar to brushed motors, however the commutation (switching energy through different coils) is done by an electronic controller instead of by switches inside the motor. These tend to be more expensive and the need for an electronic controller means they have 3 input wires as opposed to 2.

To power combat robots, many people use a battery technology known as LiPo, or Lithium Polymer. These can be volatile but when treated well are extremely useful, having a very high amount of power stored compared to their size. These will always need a suitable charger.

Lifters and Grabbers

Lifters and grabbers can be achieved by using servo motors (on ants and beetles) and linear actuators (on feathers). Plug them straight into the receiver and attach your weapon of choice!

Spinners

Spinners are more complex. To build an effective spinner you need a brushless motor and brushless speed controller. Please consider building a different type of robot as your first robot, and even then, never test outside of a safe arena! You will most typically see vertical spinners (verts) and horizontal spinners.

Soldering is a frequently used technique to connect wires and one you get better at with practice. Investing in a good quality soldering iron, good quality solder and watching some tutorial videos is highly recommended!

Firstly cut off the circled two black connectors , these are the motor outputs. You can shorten the wire a bit if you like to save a bit of weight and space.

Strip a bit of wire insulation off each side of the red wire and solder one end to an outer pin and the other end to the middle pin of the switch. Use heat shrink or electrical tape to cover the pins and exposed wire.

If all has gone to plan you have bound your receiver to your transmitter! You can now waggle the right stick and you should see both motors moving. If one or neither are moving then double check your connections with the steps above.

To do this, cut a baseplate out of the sheet using scissors. Make holes in the polycarbonate for the mounting points. Screw the motor mounts down into the polycarbonate. Then add some sides, and maybe a wedge! Cable ties and small screws and nuts (M2, M3) are your friend! You could prototype the chassis first with card or cardboard then trace that on to the polycarbonate to cut out for your final chassis.

2b) Size limit: robots must fit completely inside a four inch (101.6mm) cube of the following dimensions, it does not have to sit flat on the floor of the cube. Robots may only expand from their size limit once a fight has begun, and only if the expansion is instigated by remote control (i.e. not just by being springy).

2i) Weapons are not permitted to deliberately detach completely from the robot, but may be partially separated as long as it is connected by a tether of no more than 3 feet (914mm). The tether may not be used as an entanglement weapon.

Antweight World Series robot rules (above) apply apart from the four inch cube size limit. Instead the whole robot must start within a 200x200mm square on the arena floor with no overhangs. Cluster bots wider than 200mm must start stacked. BBB Competition rules apply.

BBB PLANTS (plastic ants) are a 2v2 (doubles) antweight ruleset, legal at BBB pub-based events. The class is designed to encourage newcomers into destructive fights while also allowing more flamboyant designs for seasoned builders. Antweight World Series robot rules (above) apply apart from the following modifiers:

No acetate or similar flexible thin material acting to eradicate ground clearance or slide under opponents. All entries are at BBBs discretion and these rules are subject to change. Please consult us in advance if you have queries. BBB Competition rules apply.

A UK beetleweight combat robot is a 1.5kg robot! Unlike UK antweights, there are no size restrictions, and unlike US beetleweights they have a slightly larger weight limit at 1.5kg instead of 3lb / 1.36kg. Beetleweights have only been a significant weight class in the UK since around 2014. Check out our rules page for more info on the rules we run.

Removable Links are, along with a power light, an essential safety component. These need to be accessible externally of the robot without any tools. One pro tip is to use appropriately rated fuse wire to connect your link terminals, as a fuse is another UK essential!

The battle for low ground has developed a lot over the years in beetleweights. While many robots found and still may find success with a flat wedge front as seen with robots like Snappy above, and would still be recommended for those less confident (5mm HDPE with a nice air gap behind is your friend!), you may wish to investigate adding forks to your robot. You can see 2 examples from Bish Bash Bosh and Aggro Wobba below.

These are the general rules run at regular Bristol Bot Builders Beetleweight events. Other events may run other rulesets with different requirements, or even modifiers. Check below these rules for links to other rulesets, and if in doubt, check with your Event Organiser.

1.1 Sharp Edge Protection: All Robots not in an arena or official testing area must have secure protective covers over any sharp edges. Sharp edge protection must be designed in such a way that they cannot be dislodged unintentionally.

1.2 Dedicated Locking Bars: Any moving weapon requires a locking bar that completely stops motion. The locking bar must be marked as such with a tag or tape, and not used for any other purpose than locking your robot. Steel split pins are a great option and can easily be marked or have a keyring added. A clamp is not permitted. The locking bar must not be loose. The locking location on the robot must be easily visible for the arena marshal.

2.1 Weight Classification: Maximum 1.5kgs. No allowance is given for any margin of error. It is recommended robots are designed in such a way that excess weight can be removed easily, since scale calibration may vary. Weight includes all consumables and any part of the robot that remains inside of the arena such as gas bottles, removable link(s), and safety tethers. Locking bars, transmitters, and tools required to activate the robot that are removed from the arena are not included.

2.3 Interchangeable Panels and Weapons: If used, the weight is measured with the heaviest set-up in place. All configurations need to known prior to the competition starting and spot checks may be performed at any time.

2.4 Clusterbots: Clusterbots are more than one robot fighting as the same entry, sharing the total weight allowance in a considerable split. As per our competition rules, a multi-bot entry requires 67% elimination by weight. Judges/Refs must know weights of each segment pre-fight. Cluster bots with both a shuffling and wheeled robots: the weight bonus to the shuffler will be applied to the remaining left over weight after deducting the wheeled robots combined weight.

2.5 Minibots: Minibots are extra robots accompanying the main entry that take up a small proportion of the total weight allowance. If a Minibot is under 150g in weight, and does not have a continuously rotating weapon then it does not require a link, locking bar, power light or fuse.

4.2 Power Light: Robots must have at least one surface mounted non-filament power light that is illuminated when the main link is fitted. The power light may be any colour but must be non-flashing

and in contrast with the surroundings.

5.1 Safety: must be adequately protected within the body and securely fixed to minimise the chance of being punctured or coming loose during combat. In addition, packing such as high density foam is recommended to reduce the shock of impacts.

5.2 LiPos: Roboteers using LiPo batteries must provide a LiPo sack. Lithium batteries must not be left unattended at any time during the charging process. LiPo batteries showing any evidence of damage or swelling must immediately be placed a LiPo sack and removed to a safe, well-ventilated area such as outdoors.

5.3 Fusing: A fuse rated below the maximum burst discharge of the battery MUST be fitted. The

maximum burst discharge current is calculated by multiplying the C rating by the capacity. E.g. 25C 2200mAh = 55 Amp

6.2 Restrictions: No Invisible Damage (electricity, radio jamming, electromagnetic fields), no entanglement, no shatter-able rotating blades, no untethered projectiles, no fire, no smoke or bright lights, no hazardous materials.

6.3 Unusual Weapons: If you are planning to bring a more unusual weapon type, including but not limited to pneumatics, contact-based heat weapons, or spring loaded weapons, please contact BBB prior to signup to ensure safety.

Anything not covered by the rules above should be checked prior to the event with BBB, this includes but is not limited to the aforementioned pneumatics, contact-based heat weapons, or spring loaded weapons. Any robot may be denied entry at tech checks (see our home checklist) if it does not comply with the above rules or anything not covered above has not been approved prior to signup. All entries are at BBBs discretion and these rules are subject to change. Please consult us in advance if you have queries. BBB Competition rules apply.

Our good time with slightly less destructive beetles in a pub setting, non serious, no strict reffing and mob rule (crowd) judging. Only ran at specific BBB events. Four modifiers to the beetle ruleset above:

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