Mighty bot




Build a bot with the highest Power to weight ratio!

Two classes, PUSHERS and PULLERS


  1. maximum voltage of 18v
  2. wieght in grams/kilograms
  3. Efficiency = load pulled or pushed (g) / Mass of bot
  4. must use a video to demonstrate capabilities


  1. Test area will be a 50cm x 1m rectangle, contestant drags or pushes object from the forward most portion of the object to the end of the testing area
  2. Mass moved will sit inside or on top of a box or towel, contestant must demonstrate that the container does not help the robot in any way to move the mass
  3. any box may be used if the contestant chooses to do so as the containers mass will be added to the mass of the object/weight being moved
  4. the container carrying the mass must be pulled via rope and hook, or pushed by the robot itself
  5. the mass and the robot must be tested on a flat surface, preferably a linoleum floor or gym floor(urethane coated wood)



I think some interesting

I think some interesting research could come out of this!

I hink some (one) example on the details would help understand / inspire to participate.

Does it need to be able to
Does it need to be able to do anything except push/pull things? or can I just attach some uber strong motors to a battery? or maybe find the object to be pushed/pulled? any certain distance etc?

Wait so is this total

Wait so is this total voltage? Parallel vs Series?


Because I am making a bot that uses two 12v SLA batteries in series. And when you wire in series, the voltage stays the same, while the current is doubled.


Series connection adds up the voltages, parallel connection adds the current.

ahh your right, thats what i
ahh your right, thats what i meant :wink:


OKay, so how about the

OKay, so how about the testing area is a 50cm x 1m rectangle, the robot (self-contained autonomous or radio controlled device) must pull the greatest weight to fit in a cardboard box no larger than 30cm x 30cm x 30cm. The robot must start form a dead stop i.e. not moving with no head start.

any more suggestions?

If you would kindly address
If you would kindly address my question

sorry, I guess its just
sorry, I guess its just preference, but the total votage across the two terminals providing power to the motors and the controlls should not exceed 18 volts, so using both batteries is not allowed

Nice, I always like seeing

Nice, I always like seeing new challenges posted, thanks for making this. Should be an interesting one. I don’t think boost circuits are a big problem, because my understanding is that as you raise voltage you lose the ability to provide current, so you generally get about the same amount of actual power out of the battery. Parallel batteries isn’t really a problem either, because two batteries can provide double the current, but it also has double the weight, so it may not be much of a net gain in the power-to-weight ratio.


exactly, just as Torque is
exactly, just as Torque is proportional to speed, voltage is proportional to current, which is funny since both are key factors in this challenge

Now is 150 how much we spend or how much new parts are worth? Lets say I wanted to "borrow" that nice 1150CCA 12v battery from my truck does that count against the 150? That could translate into well over 50HP especially for a meager 3ft.

spend, scrap parts and
spend, scrap parts and prebought parts dont count towards the total, but remember, its the strength to WEIGHT ratio thats being scored

yea, my entry is almost
yea, my entry is almost finished, its the sum V2, (lobotomize) I only hope to push 3 kilos though

Yea so if it is 900g then
Yea so if it is 900g then you are in first place with %555 efficiency

I think i meant it to be
I think i meant it to be october 4th

It’s a shame it doesn’t

It’s a shame it doesn’t count on water; I’ve got a video of my model tug Eric towing a fully laden ~2M tanker around a pond. By my guess, the volume of water in the tanker (it was basically flooded with water to give it some mass) was around 15x30x200cm = 90000cm3, which, at ~1gram per cm3 of water, puts it at ~90kg, with the boat weighing maybe 0.5kg.

Drat; just realised when

Drat; just realised when this dates from. Followed a link to it, and thought it was still current; Sorry.