G-Code for coil/pickup winding?

[HankMcSpank]

Hi there,

there's a plugin for mach3 of their site that has a nice gui, but ultimately outputs G-code.

here's an example...

wire diameter = 0.1mm
spool width = 10mm
No of turns = 10000
RPM = 50


produces this G-code

(The Y axis is the main motor, which in this case doesn't have a leadscrew - just a bobbin attached to a faceplate mounted on the stepper's shaft. The X axis is the traversal motor ...it moves left/right/left right etc)

g00 X0.0
G01 X 10 Y 100 F50
G01 X 0 Y 200 F50
G01 X 10 Y 300 F50
G01 X 0 Y 400 F50
G01 X 10 Y 500 F50
G01 X 0 Y 600 F50
G01 X 10 Y 700 F50
G01 X 0 Y 800 F50
G01 X 10 Y 900 F50
G01 X0Y1000
M30


allsimple enough, the the GUI has no facility to facyor in acceleration/deceleration...which is prefereable as the wire nears the edges of the spool.

what would be a good way to approach this (with g-Code)

Let's assume a 100mm wide spool (could be 10" if you prefer!).

As the coil winding starts, it'd be ideal for say the first 10mm to have the winding start from scratch accelerate linearly to maximum RPM speed...maintain this RPM until it is 10mm from the other end, where it then starts decelerating linearly until zero speed is reached at the very edge of the spool. Pause for a second or two & then take back off in the reverse direction with a similar profile.

i guess what I'm hoping for is the following winding 'profile'...

For the first 10% of spool width accelerate to full RPM
For the middle 80% maintain full RPM
For the last 10%of spool width decelerate down to zero.

How could this acceleration/deceleartion be done in G-Code?

[ger21]

Mach3's acceleration is set in the motor tuning. You can't override it. To get it to accelerate and decelerate at a certain point, you'll either need to adjust the feedrate or the accel to get it where you want it.

[HankMcSpank]

Fine..understood.

therefore it should be just a matter of tweaking the motors to accelerate to suit each spool width & save as a profile?

How does the acceleration come into play when the motors are moving for a cut (in this case a 'wind') ...is the same acceleration setting used as when jogging?

I ask, because when i've tuned my motors used the jog option, I can quite clearly see the motors accelerate/decelerate, but when carrying out CNC cuts, I don't see/hear this acceleration (possibly becuase my feed ratesare low).

I guess, I'm just trying to wrap my head roun the motor tuning accelerate paramater & when it comes into play.

[ger21]

Acceleration always comes into play. Physics dictates that you always have to accelerate and decelerate.

[HankMcSpank]

Originally Posted by ger21 Acceleration always comes into play. Physics dictates that you always have to accelerate and decelerate.

No I undertsand you can't go from zero to full feed in an instant, but does the 'motor tuning' acceleration paramater apply to both 'feed rates' *and* when the spindle repositions (rapids? I'm new to the genre!)), becuase if it's just the latter, then the acceleration paramater will have no effect on controlling at acceleration/deceration on the coil winding plugin (which just uses a feed rate number)

[Al_The_Man]

If I see it right the Y axis is the 'spindle' and the X is the shuttle?
would you not also want the X to correspondingly increase and decrease with Accel/Decel?
I imagine a macro could be written where the appropriate numbers are plugged in.
Such as Initial accel A and final decel B over distance C, (Y value X values), If these were written as small increments, it would be a series of multi moves but essentially would appear as smooth transition.
It could be a long macro, but would only have to be written once.
This is where electronic gearing for Mach would be nice.
You would have to go to the Galil plug in to get though.
AL.

[HankMcSpank]

Originally Posted by Al_The_Man If I see it right the Y axis is the 'spindle' and the X is the shuttle? would you not also want the X to correspondingly increase and decrease with Accel/Decel? I imagine a macro could be written where the appropriate numbers are plugged in. Such as Initial accel A and final decel B over distance C, (Y value X values), If these were written as small increments, it would be a series of multi moves but essentially would appear as smooth transition. It could be a long macro, but would only have to be written once. This is where electronic gearing for Mach would be nice. You would have to go to the Galil plug in to get though. AL.

hiya Al,

you've read it right - the Y Axis is the main motor & the X axis is the traversal motor.

Re the accel/decel ... I under stand your concept, but as an example, how would each line look in G-Code (just a couple of lines to illustrate the point ) to get the acceleration cranking up?

[ger21]

Accel is the same for any movement, whether a feedrate move or a rapid move. You could cheat kinda like Al said and break your single movement into smaller ones, each with a different feedrate to get a similar effect to a more gradual accel, which would alleviate having to reduce the accel.

[HankMcSpank]

So using that top example, would the following do it.....

First, let's build up feed rate until we get to 10% of the overall overall traversal distance (spool width 10mm)

g00 X0.0
G01 X0.5 Y5 F5
G01 X1 Y10 F20

Next,go full whack feed rate until we get to 90% of overall traversal distance....

G01 X9 Y90 F200

Now slow down for the final 10% traversal distance...

G01 X9.5 Y95 F20
G01 X10 Y100 F5

Something like that?

[mcphill]

Originally Posted by HankMcSpank hiya Al, you've read it right - the Y Axis is the main motor & the X axis is the traversal motor. Re the accel/decel ... I under stand your concept, but as an example, how would each line look in G-Code (just a couple of lines to illustrate the point ) to get the acceleration cranking up?

I think Al is suggesting to change your thinking from accel to steps of velocity. Write a macro that will calculate the speed you want by the position you are at. Start at speed 0 at X 0, increase speed in steps until you get to speed 100 at X 10, keep speed at 100 through X 90, decrease to speed 0 as you get to X 100. Seems like that would be easy enough if you are familiar with macros... I am not, personally.

[Al_The_Man]

I have not dabbled with macros for some time and not with Mach at all, But I thought afterwards, I am not sure if Mach will treat it as many independent moves, which is what they are and do a decel/accel for each?
Present Macro writers may have an idea?
Al.

[HankMcSpank]

Originally Posted by Al_The_Man I have not dabbled with macros for some time and not with Mach at all, But I thought afterwards, I am not sure if Mach will treat it as many independent moves, which is what they are and do a decel/accel for each? Present Macro writers may have an idea? Al.

As it goes, that was my suspiscion too!

Therefore, I guess one other the way to do it, is to forget about lot of little feed rates...just one long one with a high feed rate. then i I guess set slow acceleration setting in the motor tuning ...tweak to suit until it's right for the particular spool width - save the settings in mach on a per spool basis?

I suppose when they came up with G-Code (& Mach3 come to that), they weren't thinking of coil winders!