How to Make a Mechanical Cow Flag

How to Make a Mechanical Cow Flag

A flag is a handy tool for training cow horses and cutting horses. Better than the "bicycle" model, here's how to make a homemade mechanical flag on a budget.

mechanical flag

text size

The American Quarter Horse Journal logo

A flag is a necessary item for training a cow horse. 

The best option is to buy a professional flag, but sometimes their price tag can be a problem. A quality flag starts around $1,500 and, while it is worth every penny – and much more economical than keeping practice cattle, sometimes “it isn’t in the budget” is a final answer. 

Another option is to set up a flag with a person-powered stationary bike. This is much more economical and great exercise for the guy riding the bike, but sometimes it is hard to find someone to ride the bike at the same time you want to practice. 

The late AQHA exhibitor Charles Padilla of Santa Fe, New Mexico, shared the plans for his homemade mechanical flag, which is something that any handy person can “MacGyver” together for less than $200.

All of the material can be purchased at your local home improvement store or via common online retailers. Once the materials are gathered, it is a weekend project to put together. 

However, this requires a few notes before you start. 

First, if you are not comfortable working with electricity, this project is not for you; safety is imperative! 

Second, another common phrase – “you get what you pay for” – is also in play here. This flag is very functional and certainly better than nothing, but it is not quite as versatile or powerful as a professional mechanical flag.

Basically you will build the mechanical part of the flag inside a 16-inch toolbox. A 12-volt battery powers a reverse-polarity controller, which is attached to a 600-RPM high-torque motor, all wired together in series. This will power the string (and thus the flag) back and forth. The battery can be unscrewed and replaced as needed.

What You’ll Need to Make a Homemade Mechanical Flag

You’ll need basic tools – screwdriver, hammer, pliers, drill, saw and a pocket knife. 

Shopping List:

  • 12-volt lantern battery
  • 10 ft. roll of galvanized hanger iron 
  • 16 gauge electrical wire 
  • Wire splice connectors
  • Reverse-polarity controller with remote 
  • 3 inch hose clamp 
  • 12-volt 600-RPM high-torque electric geared motor 
  • Scrap wood and fasteners
  • Two 3-inch pulleys
  • 16-inch plastic toolbox 
  • 325 feet of polypropylene mason string
  • Fabric scrap and safety pins to use as a flag


  • One 80 lb. bag concrete
  • T-post (cut in half and capped for safety)
  • Two plastic buckets
  • Strapping or wire

Building the Mechanical Flag

The majority of the flag mechanism is housed inside a toolbox, which also has convenient small pockets in the lid for storage of things like the remote, string and flag when not in use.

Cut a hole in the bottom of the toolbox, and place the motor so that motor shaft sticks through the hole.

Secure the motor using scrap wood, screws and hose clamp. Secure the pulley to the motor by pinning it to the motor shaft. 

Secure the controller to the toolbox. Wire the controller to the motor.

Secure the battery using hanger iron and screws. Then wire the battery to the reverse-polarity controller, which in turn connects to the motor. As a safety measure, disconnect the battery when you’re not using the flag.  

It is important that the controller is reverse polarity so that it goes back and forth. If you purchase the right one, it will come with its own remote control so you don’t have to program the remote control to operate the controller. You might also consider adding a wrist hanger to the remote so you don’t drop it while you’re riding.  

The 600 rpm motor is powerful enough for a slow trot when working – if you want it faster, you’ll need a bigger motor and modified pulleys. 

Next, you need standards – the stationary posts between which the flag moves. You might already have something in your arena like a wall or portable panels, but if not, T-posts, set in concrete in a plastic buckets, will work as a mobile setup. Make sure the top of the T-posts have caps for safety purposes. The off-side pulley is wired to the standard. 

Then, it’s a simple matter of hooking up the toolbox, looping the string through the pulleys and adding the flag. Decide how big you want your flag setup to be – usually 50-80 feet is enough. 

Create or install your standards. Install the toolbox housing and the far side pulley, add the string in both pulleys and add the flag.

Then you’re ready to get to work.