Quadrature Encoder Question

[Harry_Y]

I have a Tachometer input for my spindle that
is looking for input from a Quadrature Encoder.

I do not care about reading the direction of rotation only the speed.

I hooked up a encoder I had here and only used the
output of the A channel and fed it into the A and B inputs.

It did appear to correctly read the speed once I set
the pulse rate that the software was looking for.


Is there a problem hooking it up this way?


I have done some reading on Quadrature Encoders
but have been unable to find an answer.

I could use two sensors but it is double
the parts for a simple speed reading.

Thank you

[Al_The_Man]

Usually spindle controller that accept encoder input require the A & B, I have never tried just one channel, usually the two are required for bi-directional sensing.
If it is working then you may be OK.
But the question I have is if you have an encoder with A & B, why aren't you using both?
Al.

[Bob Adams]

From what I see is you don't need a Encoder to read the RPM. May be it should be an Optical Switch. Which just makes and breaks the circuit.
This is how it works for Mach3.
Bob A
CNC Projects

[Harry_Y]

Usually spindle controller that accept encoder input require the A & B, I have never tried just one channel, usually the two are required for bi-directional sensing.
If it is working then you may be OK.
But the question I have is if you have an encoder with A & B, why aren't you using both?
Al.

The encoder I was using to test it is just a standard panel mount encoder
(similar looking volume control pot) I was using it merely to test with.

From what I see is you don't need a Encoder to read the RPM. May be it should be an Optical Switch. Which just makes and breaks the circuit.
This is how it works for Mach3.
Bob A
CNC Projects

Yes that is what I would like to use either optical or hall effect (magnetic).

Just a single sensor, instead of two needed for Quadrature.

All I care about is speed decoding

[Al_The_Man]

If the spindle tach input accept the same signal then use retro reflective sensor or gear teeth if the input can be scaled for it.
The problem may be is that optical usually means 1 pulse/rev unless you set up multiple reflectors?
You could use/make a slotted Opto with a slitted disk.
The Mitsubishi VFD's I use require both A & B.
Al.

[shiloh]

Hi everyone, this post is right up my alley. I too wanted to have feedback from an encoder to read the spindle speed on my mill. I am using Mach 3 and was wondering if the "index" pulse would be sufficient. I have an amt 102v capacitant encoder I would like to use.i have heard that length of pulse could be a problem...any thoughts, thanks....Dave

[Harry_Y]

If the spindle tach input accept the same signal then use retro reflective sensor or gear teeth if the input can be scaled for it.
The problem may be is that optical usually means 1 pulse/rev unless you set up multiple reflectors?
You could use/make a slotted Opto with a slitted disk.
The Mitsubishi VFD's I use require both A & B.
Al.

There is a setting where you can set the pulse rate
for decoding the speed so that part is easy.

I did order up two optical and two hall effect (magnetic) sensors so I
can try it both ways, I would prefer optical unless the lighting in the
room causes issues then I will use the hall effect (magnetic sensors)
and make up a disk with two magnets in it to mount on the pully.

So it pretty much looks like just try it and see what happens.

[Al_The_Man]

I have used this type for a spindle tach.
SENSOR OPTO SLOT 3MM TRANS THRU - H22A1
It is infra red and also can be used sealed in to prevent stray operation.
Al.

[Harry_Y]

The optical one I ordered are qrb1134 so I can just use a black and white sticker.

The Hall effect (magnetic) is a US1881 latching type
I figured I can get magnets locally at Radio shack etc.

I'm just trying to make it as simple as possible; I can use two
sensors if needed for Quadrature, but it just seems to be overkill.

[Al_The_Man]

What make/manuf. of spindle?
I have also used the type of Hall Effect gear tooth sensor made by Honeywell, they are the same as used on automobiles for timing.
These do not require magnets.
They are not all that expensive, cheaper if you get from a wrecker.
Gear tooth sensor.
Al.

[Harry_Y]

What make/manuf. of spindle?
I have also used the type of Hall Effect gear tooth sensor made by Honeywell, they are the same as used on automobiles for timing.
These do not require magnets.
They are not all that expensive, cheaper if you get from a wrecker.
Gear tooth sensor.
Al.

It is just a little Sherline mill I bought originally for making
PC Boards then realized it was far more capable