Sync spindle ratio with encoder

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LenelyWolf
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Sync spindle ratio with encoder

Post by LenelyWolf »

Hi there
I’m trying to get my encoder synchronised with spindle. My motor is geared with spindle by ratio 0.55. I got no way to connect encoder with spindle directly so i have connected my encoder with motor. The encoder has 8000 steps. To get right reading i had to divide 8000 with 0.55 which is 14550 and put it to spindle encoder counts in acorn wizard. I thought that changing spindle speed ratio in low and middle range would calculate it automatically but apparently those setting do nothing at all… no matter what ratio i put there the reading is exactly the same… does it suppose to be like that?
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tblough
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Re: Sync spindle ratio with encoder

Post by tblough »

Sorry. The spindle encoder most be connected at 1:1 with the spindle. It may take some work, but there is usually a way to get an encoder directly connected or connected with a 1:1 toothed belt to the spindle.

The issue is not really the encoder counts, but the index count which MUST occur only once per spindle revolution and always in the exact same spindle orientation.
Cheers,

Tom
Confidence is the feeling you have before you fully understand the situation.
I have CDO. It's like OCD, but the letters are where they should be.
LenelyWolf
Posts: 118
Joined: Sun Jan 17, 2021 3:13 pm
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Re: Sync spindle ratio with encoder

Post by LenelyWolf »

tblough wrote: Mon Sep 13, 2021 8:05 am Sorry. The spindle encoder most be connected at 1:1 with the spindle. It may take some work, but there is usually a way to get an encoder directly connected or connected with a 1:1 toothed belt to the spindle.

The issue is not really the encoder counts, but the index count which MUST occur only once per spindle revolution and always in the exact same spindle orientation.
Thanks for reply. I really can’t connect it directly. It would require huge modification so i rather don’t want to do that.. my spindle speed are now pretty accurate so would this setting somehow affect rigid tapping?
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cncsnw
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Re: Sync spindle ratio with encoder

Post by cncsnw »

For spindle speed display, and for following thread lead in rigid tapping, you can do what you ask by adding 16 to Parameter 36. This will tell CNC12 that it needs to divide the spindle encoder counts by the active gear ratio parameter (P65, P66 or P67) when not in high gear.

As Tom points out, you will not be able to use rigid tapping to peck tap, nor to tap the same hole twice, since your index pulse will come around at a different location every time.
LenelyWolf
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Re: Sync spindle ratio with encoder

Post by LenelyWolf »

cncsnw wrote: Mon Sep 13, 2021 11:14 am For spindle speed display, and for following thread lead in rigid tapping, you can do what you ask by adding 16 to Parameter 36. This will tell CNC12 that it needs to divide the spindle encoder counts by the active gear ratio parameter (P65, P66 or P67) when not in high gear.

As Tom points out, you will not be able to use rigid tapping to peck tap, nor to tap the same hole twice, since your index pulse will come around at a different location every time.
Great thanks.. peck tapping or repeat tapping would not be even impossible on this machine since the spindle doesn’t have any break and i can’t even break it with changing direction. I will have to wait until spindle stop which means give it some time dwell when changing direction. Fiy is there any setting for adding time dwell when changing direction in wizard or do i have to edit tapping macro or something?
tblough
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100327
102696
103432
7804732B977B-0624192192
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CPU10 or CPU7: No
Location: Boston, MA
Contact:

Re: Sync spindle ratio with encoder

Post by tblough »

The Intercon tapping cycle has a dwell setting.

Looks like to me you could make a timing gear which fits over the clamp collar above the drive sprocket on the spindle and set an encoder off to the side. You could switch to a double sided drive belt and mount an encoder to the front or side with an identical sprocket to the main drive.
double sided.jpg
double sided.jpg (12.27 KiB) Viewed 1322 times
Heck, the way the main drive belt is riding, you could put another narrow one on top of it on the same sprocket and drive an encoder from that.
Cheers,

Tom
Confidence is the feeling you have before you fully understand the situation.
I have CDO. It's like OCD, but the letters are where they should be.
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