Hardinge CHNC retrofit- Another one on the way!

Alloy wrote:

Spindle speed readout is still bonkers, it jumps form 400 to 20,000 rpm even though spindle speed seems constant, .

This might be because the resolver output is swamping the Mesa card.
Have you checked the magnitude of the return signal from the resolvers? A multimeter in RMS AC mode is good enough. You may need to move the range jumper.

If the sin or cos output exceeds the input range of the measuring system then the resolver angle calculations go wrong (the angle calculated changes more slowly than the actual angle)

My spindle resolver has a different output ratio to my axis resolvers, luckily the Mesa card lets you run two different gains.

Alloy wrote:

The spindle resolver is different than the axis resolvers, see page 2 of this thread I posted the data sheets. They have the same transformation ratio and excitation frequency, the only real diffirence is that one is a 2 speed and the other is a single speed resolver. Not sure what that means or how it affects the output. I did measure the voltage coming from the resolver with the spindle running it was 1.2-1.5 volts ac but very jumpy. The axis resolvers measure around .6 volts under motion and seemed more stable.

How did you measure the voltage? (multimeter or scope?) It probably needs to be done with the spindle stationary, or you will simply see the effect of the rotating spindle.
If you manually rotate the spindle you should see each AC waveform increase and decrease steadily in amplitude.
I _think_ 1.5V is too much. But that might depend on if that is a peak-to peak or RMS measurement.
See page 2 of the 7i49 manual, and try putting the spindle on channel 3, 4 or 5 with W2 in the down position.

Alloy wrote:

I spun the resolver by hand and the voltage did rise and fall like you woule expect. the max and min was 1.4, and .4 volts, using a cheap multimeter.

There seem to be two things wrong here.
Firstly, the output of this resolver ought to match the output f the others. It is "2x speed" one, but that just means there are two electrical cycles per rev.
Secondly, the output should get right down to 0. If it doesn't then something is wrong.

Are you absolutely sure that it is wired up correctly? Can you check the resistances between the three windings, and of the three windings, to see if there is a sign of an internal short (possibly in the wiring)

Do you intend doing rigid tapping or spindle alignment? If not then it _might_ not matter, you can probably still get a spindle speed reading with some filtering.