Let's Make Robots!

Hormes all terrain robot

drive, torment neighborhood dogs

This is not a cat toy.

My first personal robot after being involved in the FIRST Robotics Competition since 2006, an outdoor robot named Hormes, after the Greek spirit of setting oneself into motion. It has an all steel frame, an arduino for a brain, listens to a regular xbox controller, and runs on 12 volts and over most terrain. Current weight is 52.5 pounds / 23.8 kilos. 

Top speed is around 10mph, determined by opening a gps speedometer app on my phone, setting the phone on the robot, and driving about 100 yards flat out. 

The controls suite has an arduino uno with a usb host shield so it can listen to the usb xbox radio reciever. The motor controllers are Talons from Crosstheroad electronics. Each motor has a 20 amp auto-resetting circuit breaker on a surplus power distribution board from the FRC. A 10 amp hour 12 volt battery supplies the power for a short run time, but that can be upgraded.  I've added temporary headlights in the form of LED flashlights ziptied to the front corners of the frame, but eventually I want to have them remotely switched.

The frame is 1 inch sqaure steel tube with holes predrilled every inch with custom corner brackets made from 3" x 1/8" steel stock. U-bolts hold the 5/8" steel axles to the frame. 

Cameras have a macro setting for a reason.

A pair of 2.5" diameter CIMs make it go, each going to an AndyMark CIMple box with a tandem sprocket on the output shaft. All four 10" wheels are driven with #35 roller chain.

Northern Tool sells sprockets with a hole pattern that matches many of the wheels they have, which is what made this project possible. These are 10" tubed pneumatic wheels with two part hubs. To attach the sprockets, I cut 2"dia PVC spacers and got bolts long enough to hold it all together with nylock nuts.

EXPLODED view! Woo Sketchup!

The next improvements I have planned are to contain the electronics, and add a roll cage and headlights. Further down the pipeline are at least one camera, a radio with a much greater range, and some kind of manipulator. 

A few things that have been suggested I won't be adding are a flamethrower, machine gun, and the ability to fly. At least on this robot, no promises on what's next. 

This is also my first post on here, so I'm not sure how much detail to go into. Video and better pictures to come.

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Are those Magmotors you are using?


The motors are CIMs from andymark.com and have been the unstoppable workhorse in the FRC for years. They stall at over 130 amps but are never run past 40, per the rules.

I'm still figuring this site out :)

I am curious why you didn't use an idler and a single long chain per side to drive the wheels.

I used two chains per side to maximize ground clearance between the wheels and chain wrap on the sprockets, as well as redundancy.

Your reasons are so logical and simple. If I ever decide to build something following your current format, making use of your power transmission method makes great sense.

Wow, that's a big one indeed. We mostly see the little of mid sized robots which can not harm any cat but only a few bigger ones like yours. Are you planing of making him autonomous some day or will he always be relying on that XBox controller?

I agree with mogul, as more the better. You might post everything you have, even to failures, since we all learn the most of failed attempts.

Is there a way to delete comments?

I cut my teeth on robots close to 140 lbs in the FRC when I was in 8th grade, so I'm glad to raise the average weight of entries on this site by a little. On the topic of autonomy, I enjoy driving these things too much to give them too much say in where they go. :)

Yep, please do that average weight raising, as we need some of the big guys here :-)

Well, you could run that simultaniously, RC and autonomous, depending on the requirements. As soon as there is no RC signal it could switch to autonomous mode. 

Wow, 140 lbs, that's big ^_^

No, there is not such function to delete comments, but as long as nobody commented under your comment you are able to edit it.