Hardinge CHNC retrofit- Another one on the way!
22 Jan 2013 18:12 #28952
by andypugh
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.
Replied by andypugh on topic Re:Hardinge CHNC retrofit- Another one on the way!
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.
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- Alloy Craft
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23 Jan 2013 06:43 #28989
by Alloy Craft
Replied by Alloy Craft on topic Re:Hardinge CHNC retrofit- Another one on the way!
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.
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23 Jan 2013 07:10 #28990
by andypugh
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.
Replied by andypugh on topic Re:Hardinge CHNC retrofit- Another one on the way!
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.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.
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.
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23 Jan 2013 13:38 #29003
by Alloy Craft
Replied by Alloy Craft on topic Re:Hardinge CHNC retrofit- Another one on the way!
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. When I changed w2 and connected to channel 4, the max I saw was around .6 volts and min .2. the spindle speed readout fluctuated between 300-1100 but also it fluctuated at a much slower rate than before.
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23 Jan 2013 13:50 #29004
by PCW
Replied by PCW on topic Re:Hardinge CHNC retrofit- Another one on the way!
That cannot be right.
If you do not get very close to 0V at the 'nulls' there is not much hope for it working right. It may be wired wrong or the wrong type of resolver
If you do not get very close to 0V at the 'nulls' there is not much hope for it working right. It may be wired wrong or the wrong type of resolver
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23 Jan 2013 17:14 #29010
by andypugh
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.
Replied by andypugh on topic Re:Hardinge CHNC retrofit- Another one on the way!
There seem to be two things wrong here.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.
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.
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24 Jan 2013 11:07 #29060
by Alloy Craft
Replied by Alloy Craft on topic Re:Hardinge CHNC retrofit- Another one on the way!
I think i may be measuring wrong, should i be measuring from cos+ to cos-, or cos+ to frame ground?
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24 Jan 2013 12:18 #29062
by PCW
Replied by PCW on topic Re:Hardinge CHNC retrofit- Another one on the way!
from COS+ to COS-
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28 Jan 2013 07:44 - 28 Jan 2013 07:45 #29210
by Alloy Craft
Replied by Alloy Craft on topic Re:Hardinge CHNC retrofit- Another one on the way!
I was measuring from cos+ to frame ground. If I measure from cos+ to cos- with w2 normal I get 0-3.7 volts, with w2 down, I get 0-1.7 volts. I think I may switch it out for axis resolver since I have 2 extra. I just need to get a extra tiny allen wrench since the coupling uses a size smaller than I have seen before.
Anyway here is a photo, I will post a video later tonight of the spindle problem. Also having a little trouble calibrating the axis's.
Anyway here is a photo, I will post a video later tonight of the spindle problem. Also having a little trouble calibrating the axis's.
Last edit: 28 Jan 2013 07:45 by Alloy Craft.
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28 Jan 2013 10:38 #29214
by PCW
Replied by PCW on topic Re:Hardinge CHNC retrofit- Another one on the way!
Yow! thats quite a bit too much
You might check the axis sin/cos outputs as well
There is a 7I49HV version that works with 1 --> 2 ratio resolvers that we could swap if need be
You might check the axis sin/cos outputs as well
There is a 7I49HV version that works with 1 --> 2 ratio resolvers that we could swap if need be
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