Messages

11

General Mach Discussion / Re: How to stop servo spindle gracefully on Estop or stop button?

« on: October 11, 2019, 04:39:25 PM »

After looking at the options you suggest in the manual again, you are saying that I should set a torque limit. This can take 2 forms, either a global setting (PA34 CCW rotation and PA35 CW rotation), or only when the input pin 25 (FIL) is high, or on (PA36 CCW rotation and PA37 CW rotation).
I am interpretting this to mean that these settings shouldn't affect the motor torque in normal continous speed operation, but only alter the maximum torque applied to the motor when changing speeds.
This means that since I am using this motor as a lathe spindle, it shouldn't affect normal machining, but only affect speeding up and slowing down.

Do I understand this correctly?

Thanks

Dave

12

General Mach Discussion / Re: How to stop servo spindle gracefully on Estop or stop button?

« on: October 11, 2019, 04:08:49 PM »

Thanks Craig, your suggestions are appreciated. I'll give that a try later this morning and let you  know.

13

General Mach Discussion / Re: How to stop servo spindle gracefully on Estop or stop button?

« on: October 10, 2019, 04:57:35 PM »

I have had a read through the manual (yet again) for the servo driver (GSK DA98B) from this link http://gskcnc.com/Support/DA98B_ACDriver.pdf
The terminology in the manual is a bit different to that which I have in my head, for example they use the terms "Pulse and Sign" which I interpret as "Step and Direction".
Perhaps someone on this forum has a better understanding than I of what they are saying in the manual?
To slow down the motor decceleration perhaps it is the PA05 setting?
Any advice / clarification here would be appreciated.
Cheers
Dave

14

General Mach Discussion / Re: How to stop servo spindle gracefully on Estop or stop button?

« on: October 10, 2019, 04:05:36 PM »

Hi,
either <Stop> or <Estop> do not de-accelerate, they crash stop.

There is settings within your servo drive that limit current, or analogously torque, which will be a bit more graceful.

If you make this setting just a little more aggressive than the max acceleration you have set Mach to then it will not interfere
with normal operations but will effectively provide a max de-acceleration slightly in excess of that.

Craig

Thanks Peter and Craig,
Yes Peter I know it is an emergency stop, necessitating a stop as quickly as possible, and it does make sense to turn everything off immediately, regardless of the cost in mechanical terms.
However I did hope that there was perhaps an option for the stop button on M3, that perhaps wasn't quite so aggressive as an Estop.
Craig I think you have the answer with your suggestion about the decceleration period of the spindle motor being set within the servo controller, is the answer. I'll try it and get back to you with the result.
Thanks
Dave

15

General Mach Discussion / How to stop servo spindle gracefully on Estop or stop button?

« on: October 09, 2019, 11:12:45 PM »

Hi, it's been a while since I posted, but there is a minor issue with my lathe that I have been meaning to ask for help about for a couple of years.
The issue is as follows: When I start and stop the servo spindle using M3 and M5, or the spindle on / off button, the spindle starts and stops gently, it takes a couple of seconds to stop.
If I panic for some reason and hit Estop or the stop button, the axis movement stops immediately and the spindle tries to stop immediately with a loud clunk. Unfortunately this overloads the servo controller and it comes up with the appropriate error.
I think the error is something like "what the hell did you just do to me?".
There is probably a setting somewhere in Mach3 to tell it to be more gentle when stopping the spindle, even in an Estop situation.

16

General Mach Discussion / Re: Intermittent probing

« on: May 01, 2019, 02:18:47 AM »

See attached for a NORMALLY CLOSED probe

I think I've got a probe like that somewhere....

17

General Mach Discussion / Re: Intermittent probing

« on: May 01, 2019, 02:15:01 AM »

I was thinking debounce for the probe should be as low as feasible for better sensitivity.


BUT for future:-
I would recommend you make a probe using Quality NC (normally closed) metal switch for better reliability and absolute foolproof operation.

I am in process of making one (almost completed) even though I do not have no problems with my STD probe. But I once broke a bit because I FORGOT to clip the ground wire to the bit (an operator error).
With a NC switch, the top could be replaceable hard (cabinet door bumper) plastic to protect the bit tip and the probe could be used for non-conducting ceramic and diamond bits too. Switch opening to trigger is theoretically much most reliable.

I agree and when I get around to working on my mill I probably will make my own probe. I didn't mention my application in this instance, but it is to route circuit boards. Given that the surface of the board is clean conductive copper, the router is all metal and the sharp bit (my finger will attest to its sharpness) is steel, I think my setup should work.

18

General Mach Discussion / Re: Intermittent probing

« on: April 30, 2019, 10:55:06 PM »

Try to set your denounce - But DO NOT set debounce TOO HIGH
ref
https://warp9td.com/index.php/faq/faq-mach3#Debounce

A long time ago, I tried a new type of controller called a USB smoothstepper. It had endless problems with electrical interference from the VFD that drove the spindle on my lathe, and I tried all sorts of filters etc to try to remove some of the noise. Greg eventually added the adjustable "debounce interval" to the driver and that was certainly a big help with that type of interference. When the Ethernet version of the smoothstepper came along, electrical noise was not such an issue because of the way that Ethernet works, but I have noticed that the debounce interval is still there in the ESS driver.
You are suggesting that I increase the debounce level, and to be frank I hadn't even thought of that as a possible cause - Ill try it now. I will set the probe debounce to 20 micro seconds. Thanks for the reply.
Dave

19

General Mach Discussion / Intermittent probing

« on: April 30, 2019, 06:54:50 PM »

Hi everyone, is been a long time between visits to this forum, but I've finally realised a need for probing on my cnc router.
I am using an Ethernet smooth stepper with the latest plugin for motion control.
To keep things simple and avoid complications I am initially using the standard Mach3 router screen set.
I have the tool on the router connected to signal gnd and pin 16 on parallel port2 connected to a piece of circuit board material. The input for the probe is configured in Mach3 to match these physical connections.
When I jog the Z axis tool down, upon touching the for surface of the board, it always lights the probe led in the mach3 diagnostics screen.
My probing results are inconsistent however, using G31 Z, for example, sometimes Z motion will stop when the probe touches the surface of the board (as expected) other times, despite the led in diagnostics coming on to show the input for probing as active, the Z axis to will continue to bury itself in the circuit board until I hit stop, or the Z axis motor stalls.
Other than this new issue, all of the inputs and outputs work well on what has been a workhorse router.

20

General Mach Discussion / Re: Spindle servo on lathe is 10% fast

« on: April 30, 2019, 05:05:26 AM »

Craig I'm very sorry, but your posts somehow slipped through tho the keeper. I had stopped thinking about the hexagon turning and moved onto my 3d printer, but I can always come back . I'll have a read tomorrow and reply.
Cheers
Dave

Hi Dave,
I have a little bit of code here, its just a table of moves between A and X axes over a 60 degree segment of the A axis.
Its R dimension is 25mm, so your hexagon would be 50mm across the points.

Code: [Select]

G1 A0.0  X24.9975
G1 A0.5  X24.875
G1 A1.0  X24.7525
G1 A1.5  X24.635
G1 A2.0  X24.52
G1 A2.5  X24.4075
G1 A3.0  X24.2975
G1 A3.5  X24.19
G1 A4.0  X24.0875
G1 A4.5  X23.985
G1 A5.0  X23.8875
G1 A5.5  X23.7925
G1 A6.0  X23.6975
G1 A6.5  X23.6075
G1 A7.0  X23.52
G1 A7.5  X23.4325
G1 A8.0  X23.35
G1 A8.5  X23.2675
G1 A9.0  X23.19
G1 A9.5  X23.1125
G1 A10.0 X23.04
G1 A10.5 X22.9675
G1 A11.0 X22.8975
G1 A11.5 X22.83
G1 A12.0 X22.7625
G1 A12.5 X22.7
G1 A13.0 X22.64
G1 A13.5 X22.58
G1 A14.0 X22.5225
G1 A14.5 X22.4675
G1 A15.0 X22.4125
G1 A15.5 X22.3625
G1 A16.0 X22.3125
G1 A16.5 X22.265
G1 A17.0 X22.22
G1 A17.5 X22.175
G1 A18.0 X22.1325
G1 A18.5 X22.0925
G1 A19.0 X22.055
G1 A19.5 X22.0175
G1 A20.0 X21.985
G1 A20.5 X21.95
G1 A21.0 X21.92
G1 A21.5 X21.89
G1 A22.0 X21.8625
G1 A22.5 X21.8375
G1 A23.0 X21.8125
G1 A23.5 X21.79
G1 A24.0 X21.77
G1 A24.5 X21.75
G1 A25.0 X21.7325
G1 A25.5 X21.7175
G1 A26.0 X21.7025
G1 A26.5 X21.69
G1 A27.0 X21.68
G1 A27.5 X21.67
G1 A28.0 X21.6625
G1 A28.5 X21.6575
G1 A29.0 X21.6525
G1 A29.5 X21.65
G1 A30.0 X21.65
G1 A30.5 X21.65
G1 A31.0 X21.6525
G1 A31.5 X21.6575
G1 A32.0 X21.6625
G1 A32.5 X21.67
G1 A33.0 X21.68
G1 A33.5 X21.69
G1 A34.0 X21.7025
G1 A34.5 X21.7175
G1 A35.0 X21.7325
G1 A35.5 X21.75
G1 A36.0 X21.77
G1 A36.5 X21.79
G1 A37.0 X21.8125
G1 A37.5 X21.8375
G1 A38.0 X21.8625
G1 A38.5 X21.89
G1 A39.0 X21.92
G1 A39.5 X21.95
G1 A40.0 X21.985
G1 A40.5 X22.02
G1 A41.0 X22.055
G1 A41.5 X22.0925
G1 A42.0 X22.135
G1 A42.5 X22.175
G1 A43.0 X22.22
G1 A43.5 X22.265
G1 A44.0 X22.3125
G1 A44.5 X22.3625
G1 A45.0 X22.415
G1 A45.5 X22.4675
G1 A46.0 X22.5225
G1 A46.5 X22.58
G1 A47.0 X22.64
G1 A47.5 X22.7
G1 A48.0 X22.765
G1 A48.5 X22.83
G1 A49.0 X22.8975
G1 A49.5 X22.9675
G1 A50.0 X23.04
G1 A50.5 X23.115
G1 A51.0 X23.19
G1 A51.5 X23.27
G1 A52.0 X23.35
G1 A52.5 X23.435
G1 A53.0 X23.52
G1 A53.5 X23.6075
G1 A54.0 X23.7
G1 A54.5 X23.7925
G1 A55.0 X23.8875
G1 A55.5 X23.9875
G1 A56.0 X24.0875
G1 A56.5 X24.1925
G1 A57.0 X24.3
G1 A57.5 X24.4075
G1 A58.0 X24.52
G1 A58.5 X24.635
G1 A59.0 X24.755
G1 A59.5 X24.875
G1 A60.0 X25

It doesn't have any Feed word or any Z moves. Study it at see what you think.

Craig