Est. 1998 — 27 years of woodworking knowledge
Speed Sensor?
Tom Norton
On a recent post I am inquiring about a variable speed motor. One of the replies mentioned a speed sensor. Can someone educate me as to how this would be installed? Also a source?
I will be speaking with Dealers Electric isoon.
Re: Speed Sensor?
John Stegall
This was shared with me by another turner, Pat Miller. Here is the link he sent to me: http://www.ebay.com/itm/Digital-Blue-LED-Tachometer-RPM-Speed-Meter-Hall-Proximity-Switch-Sensor-NPN-/172543627901?epid=538228917&hash=item282c66d27d:g:2yUAAOSwL7VWkg3W
He is using it on a Oneway which I also have.
John
Re: Speed Sensor?
John Stegall
If you send an email to me, I will send the pictures.
I did...
Brian Roberts
I mounted the magnet that triggers the sensor on the outer perimeter of the indexing plate in my PM45 lathe that I upgraded.
It was mounted such that the magnet was spinning in a circle roughly 8-9 inches in diameter.
I had problems with very erratic operation of the sensor and display.....especially as I increased the speed.
The seller replaced it as defective.
Next one.....same problem......hmmmm.....
Finally discovered that the magnet can not be swinging such a large circle....I am assuming it moves past the sensor too quickly.
I remounted the magnet and sensor such that the magnet was spinning a 2.5" diameter path and it works great.
I took the magnet and sensor to work and mounted them on our $20,000 metal lathe to compare my speed read-out to the one on the work lathe.
I was surprised to discover that the two read the same rpm's (within one rpm of each other) UNTIL I increased the speed of the work lathe (I don't remember at what speed it began to fail...it's been a while) then THE DISPLAY ON THE WORK LATHE began to read erratically in the same manner that my setup did before I changed the mounting to a smaller diameter!
My sensor and display, however, remained rock steady....as I had mounted the magnet to a piece of stock about the same 2.5" diameter.
It was quite disappointing to discover that the rpm display on the work lathe was basically defective....by design!
The one I have...
Brian Roberts
was bought on Ebay.....and looks identical to the one John links to.
There are MANY sellers of the same set-up....most from China (as was mine).
Look carefully at the ship time!!!
Mine was about $10 with shipping and arrived in less than 2 weeks.
I have a supply of used power supplies so was able to find one that output what the sensor/display needed.
Re: Speed Sensor?
Tom Norton
John, would appreciate the pics!
tnorton770@yahoo.com