Spindle encoder and fine boring

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Fueler1
Posts: 83
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Spindle encoder and fine boring

Post by Fueler1 »

Working with the canned fine boring.
I have an elrod spindle encoder mounted and working as far as rpm and tapping is concerned. no problem there.
However
It does not know it's location in degrees which makes the fine boring offset unusable.
Such as
inputs for parameter 136
0 = Y+
90 = X-
180 = Y-
270 = X+

The spindle will not stop in a particular spot.
Let's say I line my cutter tip up to 0=Y+ How do I get the spindle to know where 0 is?
Is there something I need to turn on or have someone write me some code to make this work?
cncsnw
Posts: 1756
Joined: Wed Mar 24, 2010 5:48 pm

Re: Spindle encoder and fine boring

Post by cncsnw »

Parameter 136 is used by CNC12 to know in which direction to retract X and Y, to move the (oriented) cutter tip off of the wall. It is not used by any component to control the angular position at which the spindle stops.

CNC12 assumes that the M19 macro will (somehow) work with the spindle drive to orient the spindle to a repeatable location. How exactly that is done is outside the scope of what CNC12 does. Different machines and spindles and spindle drives use different methods to orient the spindle.

Your machine has a simple open-loop VFD (Automation Direct DuraPulse GS3). That VFD does not have the ability to read the spindle encoder, or orient the spindle; nor does it have the ability to hold position.

The macros we have experimented with in the past have done something like this:
1) Get the spindle running at a low speed (e.g. 50RPM)
2) Wait for the spindle encoder index pulse to come around
3) Tell the spindle drive to stop the spindle

However, in the absence of a friction brake, the amount of coast at step (3) is indeterminate.

The best solution, of course, would be to either install a friction brake that the PLC can apply, to make the spindle stop more quickly; or to change out the spindle drive for one that is capable of orienting and holding, with reference to the spindle encoder.

Barring that, there may be room for improvement to changing the minimum output frequency, or perhaps by adding DC injection braking on stop.
Fueler1
Posts: 83
Joined: Fri Apr 13, 2018 10:04 am
Acorn CNC Controller: No
Allin1DC CNC Controller: Yes
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MPU11 & GPIO4D -w/ 3rd Party Drives: No
DC3IOB: No
CNC11: Yes
CPU10 or CPU7: No
CNC Control System Serial Number: 101981

Re: Spindle encoder and fine boring

Post by Fueler1 »

Thank you
I could whip up an air cylinder to apply the brake handle or replace the VFD.
VFD sounds more useful.
Would you have a recommendation for a suitable replacement VFD?
martyscncgarage
Posts: 7163
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Location: Mesa, AZ

Re: Spindle encoder and fine boring

Post by martyscncgarage »

Fueler1 wrote: Mon Dec 28, 2020 11:59 pm Working with the canned fine boring.
I have an elrod spindle encoder mounted and working as far as rpm and tapping is concerned. no problem there.
However
It does not know it's location in degrees which makes the fine boring offset unusable.
Such as
inputs for parameter 136
0 = Y+
90 = X-
180 = Y-
270 = X+

The spindle will not stop in a particular spot.
Let's say I line my cutter tip up to 0=Y+ How do I get the spindle to know where 0 is?
Is there something I need to turn on or have someone write me some code to make this work?
Dave, ALWAYS load a fresh report when asking for help. It shows how you have the control configured.
Marty
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
Fueler1
Posts: 83
Joined: Fri Apr 13, 2018 10:04 am
Acorn CNC Controller: No
Allin1DC CNC Controller: Yes
Oak CNC controller: No
MPU11 & GPIO4D -w/ 3rd Party Drives: No
DC3IOB: No
CNC11: Yes
CPU10 or CPU7: No
CNC Control System Serial Number: 101981

Re: Spindle encoder and fine boring

Post by Fueler1 »

OK,
While studying and shopping I ran into a dark hole.
This automation GS3-25po spec is stated as requiring 3 phase incoming.
I have 220 single phase incoming.
How is this working? Is there something in the centroid control that changes it so the GS3 sees 3 phase?
martyscncgarage
Posts: 7163
Joined: Tue Mar 28, 2017 12:01 pm
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CNC11: Yes
CPU10 or CPU7: Yes
CNC Control System Serial Number: none
Location: Mesa, AZ

Re: Spindle encoder and fine boring

Post by martyscncgarage »

Fueler1 wrote: Wed Dec 30, 2020 3:27 pm OK,
While studying and shopping I ran into a dark hole.
This automation GS3-25po spec is stated as requiring 3 phase incoming.
I have 220 single phase incoming.
How is this working? Is there something in the centroid control that changes it so the GS3 sees 3 phase?
There is a selection matrix on the left side. Select the proper input power
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
Fueler1
Posts: 83
Joined: Fri Apr 13, 2018 10:04 am
Acorn CNC Controller: No
Allin1DC CNC Controller: Yes
Oak CNC controller: No
MPU11 & GPIO4D -w/ 3rd Party Drives: No
DC3IOB: No
CNC11: Yes
CPU10 or CPU7: No
CNC Control System Serial Number: 101981

Re: Spindle encoder and fine boring

Post by Fueler1 »

left side of what?

Marty,
I don't have an issue. The machine has been running for a few yrs now.
Just trying to upgrade the machine capabilities.
I need to understand how the GS3 sees 3 phase when I have single phase feeding the machine.
martyscncgarage
Posts: 7163
Joined: Tue Mar 28, 2017 12:01 pm
Acorn CNC Controller: Yes
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DC3IOB: No
CNC12: Yes
CNC11: Yes
CPU10 or CPU7: Yes
CNC Control System Serial Number: none
Location: Mesa, AZ

Re: Spindle encoder and fine boring

Post by martyscncgarage »

Remember, we can't SEE what you SEE. We can only go on the information provided.
I was under the impression you were LOOKING for a GS3. In that case when you are on the Automationdirect website, there is a selector on the left side of the screen, you input your requirements and it pares down the selection to the unit that best fits your requirements. One of those selections is "Number of Input Phases" in your case needing single phase, you would check the box with ONE.

If you bought the GS3-25P0, then you BOUGHT one of their VFD's requiring 3 phase input. It will likely work, but may not work to its full HP capability.
https://www.automationdirect.com/adc/sh ... e/gs3-25p0

IF your motor is indeed 5hp, there is no GS3 rated for 5hp with single phase input. There is a GS4:
https://www.automationdirect.com/adc/sh ... e/gs4-2015

I don't understand clearly your statement about "Just trying to upgrade the machine capabilities"

Marty
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
cncsnw
Posts: 1756
Joined: Wed Mar 24, 2010 5:48 pm

Re: Spindle encoder and fine boring

Post by cncsnw »

There is a difference between what the manufacturer is willing to guarantee, and what will usually work in practice.

The GS3 drives do not appear to have input phase loss detection, so they will happily run on single-phase power. You probably cannot get full rated output from it, but few people take 5HP cuts on their 5HP bed mills anyway.
cncsnw
Posts: 1756
Joined: Wed Mar 24, 2010 5:48 pm

Re: Spindle encoder and fine boring

Post by cncsnw »

For Marty's benefit, I expect Dave's search could be described as follows:

"What VFD can I buy to replace my GS3-25P0? I need it to drive a 5HP motor; run on 240VAC single-phase input; and control the motor in closed-loop vector mode with orientation capability, using an encoder that is separated from the motor by a V-belt".

I do not know the answer to that question. It is going to take some research.
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