How to measure with a Galil card...

[REVCAM_Bob]

Hi all, I have a 2 axis galil card, that I think has some auxilary encoder inputs.

I am trying to figure out how to as "inexpensively" as possible measure the
bottom position of a block for flatness while it is in a fixture.

I have to be able to measure withing probably 0.0001" or 0.00005" would be better. The range is quite small probably less than +/- 0.010"

I need to figure out somehow to interface with a galil card also...

Any thoughts?

Thanks!

[kevin swan]

do you have a manual

[REVCAM_Bob]

Yes, I have a manual.

[kevin swan]

How do you usualy measure it. that is a small amount ?

[REVCAM_Bob]

Currently we have this fixture on posts which hold it suspended above
a surface plate.... (the posts are very accurately ground etc.)

then we use a 0.0001" dial indicator on a stand... not sure the name of it,
but its an indicator holder that slides around on the top of a surface plate.

we can run that indicator back and forth under the fixture that holds the detail, and tell how flat the detail is sitting in the fixture. This allows us to then make adustments to the block until it is flat.

I am trying to figure out how to measure this automatically.....

[Al_The_Man]

What is the Galil card type? and do you intend using it purely for this function, IOW do you intend control or just measure?
What operator interface do you intend to use? Or just native commands.
Al.

[REVCAM_Bob]

Hi Al, I have an 18x2 card using it for 2 axis servo motor control, and
it has 2 encoders hooked to it now for the 2 drives.
I think it will accept another encoder input, if that ends up being the way to go.

The interface is a vb.net interface, but I also use the terminal windows with it
to do most of the code etc.

I could of coarse add more boards to the system if I have to... but then that also involves trying to get communication between programs etc....

thanks, Bob.

[CarbideBob]

What are you planning on measuring with?

I've done it two ways.
Use a DC output LVDT, wire the output to one of the ADC inputs on the Galil card. Scan the part and record the measurements. ( @AN[n] function )

If one axis is perpendicular to the plane to be checked wire a touch probe or touch switch to one of the latch inputs (inputs 1 and 2) and latch the encoder position while probing with the axis. (commands AL.. and RL.. )

Bob

PS: The 18x2 card (a two axis would be a 1822 card) is the econo series and doesn't support auxiliary encoders.
Both above methods will work on this card though.

[REVCAM_Bob]

Thanks Carbided Bob