Motor Test Board/ Multi Phaser

I have been working on creating a multi motor testboard/phaser, that doesn’t require a program to run. What is the best way to go about this? We don’t haven any of the new components that recently came out. We need ot to run without the use of the roboRIO or the radio

I built one with a servo tester and two sets of Andersons to hook up drives to. An automotive fuse led to the standard battery connector.

I’ve seen folks publish designs with a literal plywood board and drives on it. A little microcontroller board can turn pots into multiple pwm sugnals.

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That’s exactly what I did.

Here are a few pics of the variant that generates PWM signals to drive motor controllers (just about everything in our universe can be controlled at a PWM-level):

It uses an Arduino to generate the PWM signals and with the Solid State Relays controlled via the Emergency Stop switch (cheap Amazon deal).

Arduino code at Hardware-wise you want some conventional linear taper potentiometers (10k is fine but the value is not critical) and some center off SPDT or DPDT switches (you only need one pole but DPDT center offs are easier to find). You can easily work out the wiring from the Arduino project (one analog input, one PWM output, and two directional control pins per motor).

CAD for control panel at Onshape

It’s a fun and useful project to make and encourages incremental testing while engineering which is a good thing.

Wood-wise I think I stepped it up to a 1x8 made of aspen or something like that sprayed with a little polyurethane to keep the eventual grubbiness to a reasonable level with some rubber feet on the bottom for traction.


It might be worth looking at regular relays instead of SSRs, I’ve heard they can suffer with large inductive loads. Otherwise that looks like a super nice setup.

I had them left over from some other project that never used them so in here they went sort of deal - the first generation used center-off spring loaded rockers as the “emergency stop” (let go of the switch and it stops) with the down side of needing a senior, a junior, and 2 freshmen to run multiple motors so I wanted something a little easier to actually operate and to kill in a hurry if things got weird.

Since these drive the power into the motor controllers, I’m counting on the motor controllers to handle the inductive load part of the control - so far so good but it’s a good point because something has to explicitly handle the inductive load characteristics.

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We did something similar. Here’s the writeup on ours, which has 2 Sparks and 4 SparkMax’s and can drive any 4 of them at a time from an Arduino based control board. That link includes the Arduino sketch and a schematic of the control board. We used automotive-style self-resetting breakers to protect the 4 power channels.



I love being able to build cool useful things with what you can find around the shop and give it a new life.

I flash back to the George Foreman muffler commercials: “I’m NOT gonna pay a lot for this muffler!” - my version is “I’m gonna build as much of this as I can with stuff I’ve ALREADY got!”

We use an inexpensive commercial hobbyist PWM generator and an old Talon motor controller of some model so we have no computers or code at all. Internet search “rc hobby PWM generator” and a few of the hits will be what works. Avoid the adjustable frequencies - you want a fixed frequency (period) and adjustable pulse width. There are a few models that have high current capability and can run small motors without a Talon/Spark/etc.

We have not used these new models but our old ones are similar. The cheap ones today are flimsy compared to the hard plastic boxes of yesteryear but maybe a 3D printed box would do. The one with the aluminum case looks good. As usual quality varies a lot (see the reviews). The 3 channel versions have all the motors running at the same speed and are no benefit over making a Y connection from one channel. We use only one channel of two or three on each generator. You need 3 generators to get three different speeds simultaneously.

On these new models the neutral mode isn’t useful for quick stops of the motor. You have to push the mode button then the neutral button. We use a robot master breaker/emergency off on our setup.

I’m with you! I’m an old geezer who likes to tinker. Recently can’t find like-minded students thus we buy COTS complete devices since robotics isn’t much interest to students until January.

We use an AndyMark motor tester wired to some older speed controllers on a lexan board. Here is a not so great picture:



I don’t see the product on their website anymore, but it’s a favorite tool for testing proto-types…

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