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I built an esk8 stress testing rig, now I need help with numbers!

I’m in the midst of building a dyno rig to stress test boards. Here’s how I did it.

Building the frame out of aluminum extrusion 40x40mm




And that’s where I’m at currently.

Now, I need your help. How do I get some data as to how much I am pushing a board?

The rig is hooked up to two 190kv 5065 motors, to two single flipsky 4.12s, and a 9s2p pack, running on 16/44 gear ratio.

Also, I may or may not be doing some things right, so do advise! This is fairly experimental for now.

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Damn I wish I had a store that sold all that metal near me!!

This seems like a pretty awesome project!

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Great work on this!

I’ve got a crazy day at work ahead of me but I’ll chime in this evening. I’m in the process of designing something similar.

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Off the top of my head:

Efficiency - how much power the board is outputting vs how much the dyno is receiving
Top Speed - how fast a board can go, both with no load and simulated load
Torque/Acceleration - how fast to get to top speed with load and simulated load
Braking Power - how efficient the brakes are or how much braking can you apply before lockup
Regen Efficiency - how efficient the regen is
Range - see the distance a battery can last

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ummm… can i have that? please?

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How are you planning to get the data from the rig? Are you using the motors and esc’s as sensors? If so, you’ll need to account for efficiency losses in the motors and esc’s on the rig…

One thing that might be interesting would be to hook up the rollers to a flywheel with a known moment of inertia and plot the rotation speed of the flywheel over time… That’d let you accurately measure the output power of the board.

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where does one find those square rods with the channels and the corner connectors… never noticed them in Home Depot or Lowe’s. What are they called?

oh wait…they are literally called aluminum extrusion?

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Its called the 80/20 T-Slot System.

https://8020.net/?SID=7g50h5si2t10ttj0u5r6do3l64

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thanks Santa

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No worries brudda :slight_smile:

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I’ll connect one of the VESCs to the VESCTool and get some telemetry from there.

Actually i’m not too sure, i’ll fit the roller pulley on tomorrow, and will be able to do a quick test on a board. And by quick test, i mean engaging brakes on the rollers and have gun the throttle on the board to see which survives :crazy_face:

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Would you like to pay $300 for shipping or build it yourself for less than $100? :sweat_smile:

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LOL it probably wouldn’t be less than a $100 for me. Nobody around here sells extrusions like that, or custom machined end plates, or rollers… i’d have to order everything off the internet anyway.

I’m definitely building one though once the data collection is figured out. We were talking about converting an old treadmill but this is a way better idea.

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Mellow has quite an advanced testing rig here in Munich:

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Salvaging parts from bike rollers is also an option. Something like this Tacx antares:

image

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I dug up some pdf files from some time ago related to testing rigs for cars, its in German but I guess that you could use deepl or google translate if you find it usefull :slight_smile:

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Fit the pulley onto the rollers. Ready to run!

Here i am testing a secret board that i can’t reveal much yet.
The rig works well! I have the rig’s remote on one hand, engaging the brakes lightly, and accelerating the board with the remote on my other hand.

Now it’s math time… how do i start :rofl:

@DerelictRobot! Is there a right way to go about doing this?

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@professor_shartsis

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  1. put the entire rig on the floor.
  2. put the board on the rig
  3. place a fan on a stand directly in front of the board
  4. stand on the board
  5. turn on the fan and hit the throttle hard so that the board makes a lot of noise and your hair is filled with breeze
  6. have somebody post the video on youtube
  7. profit
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what are you trying to measure… i’d like how long escs can put out a given motor current before they thermal throttle

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