Reddit mentions: The best motion, speed & force measuring tools

I'd like to understand more about your motor selection and what makes you confident it's not the limiting factor. Your blower looks amazing, I could see that thing churning out a ton of air.

Another poster mentioned the Matthias Wandel video and he uses a tachomoter to measure the blade RPM. You should consider doing that to see what RPM your blades are actually getting to. He also uses a anemometer to measure the effective airflow to compare.

I'm relatively convinced if you increase the power going into the blower you can achieve the flow you need.

That should work, and might be better since the regulator will be closed loop on itself. (And if you look at the DC motor equations it's DC voltage that matters).

You still want to create a PWM map because.

In order of accuracy:

• Torque meter
  
• Tachometer.
  
• On/Off PWM.
  
  Your school should have access to the first two. I'd ask around. You can possibly make a torque meter with a kitchen scale and a bar mounted to the axle. This is where you show off what you've learned and apply your engineering degree.
  
  When you create the map make sure you go both directions with the PWM because of hysteresis.
  
  Start off with a PWM signal of 0, record the torque or speed.
  
  Repeat increasing by 5 or 10, record the torque or speed.
  
  When you hit 255 go back down to 0.
  
  Given the non-linearities of the system you may find that the motor doesn't even turn the wheels until the PWM is at a 25 or 50 (out of 255) and that 225-255 is likely flat. If you build your map correctly you can demand a torque or RPM in your program and get the accurate PWM output.

Here's a cheaper one.

If you've got a spinner with dark/matte/satin finish, you might need to tape a thin strip of aluminum foil (shiny side up) to one arm of the spinner to get a good reading.

But really, isn't any amount of money spent on something that you'll only use once and don't really need in the first place going to be too much money?

If you're concerned about the accuracy and repeatability of the dial (which you probably should be) you might want to pick up a cheap tachometer to determine the actual speed before plowing into the stock. If you want actual speed control, consider modding your spindle with a Super-PID.

Get one of these and use it.

https://www.amazon.com/Loos-Cableware-Tension-Gauge-Inch/dp/B0000AXNQV?th=1

Pick up a laser tachometer and measure the rpm at each speed setting and make yourself a chart
https://www.amazon.com/Neiko-20713A-Tachometer-Non-contact-Accuracy/dp/B000I5LDVC/ref=sr_1_3?ie=UTF8&qid=1482771726&sr=8-3&keywords=laser+tachometer

Im assuming one of the handheld laser tacs isn't an option?


http://www.amazon.com/gp/aw/d/B00EUY6FNI/ref=s9_top_hm_awbw_b1402J_g263_i3?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=mobile-hybrid-11&pf_rd_r=0W25H233HV9HTG1HXAF6&pf_rd_t=30901&pf_rd_p=ca65a094-1622-5623-ad4c-0a28d6c7472b&pf_rd_i=15729791

You need something like this

Note: you need both the load cell and the gauge. The load cell takes all the load, and converts it to a voltage that the gauge can measure. You buy the load cell in the weigh range you are dealing with.

If you are messing with hundreds of pounds, you need to be careful. Thats a lot of force, and injuries and property damage can result.

The bottom one is a tension gauge (like it says). Still made: http://www.amazon.com/Loos-Cableware-Tension-Diameter-Measurement/dp/B0038YY3W6 (And worth a few bucks, too!)

Looks like yes: DIGITEN 4 Digital LED Tachometer RPM Speed Meter+Hall Proximity Switch Sensor NPN Blue https://www.amazon.com/dp/B00VKATA9G/ref=cm_sw_r_cp_api_i_pfYpDbM6836DJ

I might hook up an Arduino to manage the alarm. Run a slow-running timer. Every pulse on the Hall effect resets the timer count to zero. Use the match compare interrupt to trigger the alarm.

No problem, though your mileage may vary. My router is aging, so it's not necessarily accurate. I used one of these : http://www.amazon.com/gp/product/B000I5LDVC (as I'm too cheap to buy a SuperPID)