Best industrial tachometers according to redditors
We found 9 Reddit comments discussing the best industrial tachometers. We ranked the 3 resulting products by number of redditors who mentioned them. Here are the top 20.
We found 9 Reddit comments discussing the best industrial tachometers. We ranked the 3 resulting products by number of redditors who mentioned them. Here are the top 20.
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:
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.
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
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.
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.
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.
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)
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?
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