Messages

1

G-Code, CAD, and CAM discussions / Re: MachIII GCode Leadin questions

« on: April 23, 2013, 09:12:43 AM »

Rich,
   Thank yo for that.. There is a lot of great info there.
I still do not see where or how MachIII gets told what type of leadin is being used. There is nothing that jumps out at me inthe GCode that would indicate a circular, 45 deg or straight leadin as used by LC.

2

G-Code, CAD, and CAM discussions / Re: MachIII GCode Leadin questions

« on: April 22, 2013, 02:22:59 PM »

I used Lazycam to post the code
I tried to set all leadins to be straight, but have 2 parts on the layer that have a circular leadin, thats what promped me to start looking

3

G-Code, CAD, and CAM discussions / Re: MachIII GCode Leadin questions

« on: April 22, 2013, 12:56:41 PM »

Ok.. understood...
But would this not show up in the G-Code somewhere?


Here is a snippet of the code...

N825 G0  Z1.0000                                 Raise the tool to 1 unit                       
N830  X31.0187 Y22.8512                      Move to the start of the part cut   (this would be the beginning of the lead in) How does it know to do a lead in of straight or circular?
N835  Z0.1000                                      Lower the tool to the cut start depth   
N840 G1  Z0.0000 F1.00                        Lower the tool into the material at a slower speed
N845 G41                                             Set the offset           
N850  X31.0212  Y22.9374   F20.00        Start the cut with a feedrate of 20
N855  X29.0542  Y22.9945   
N860  X26.9885  Y23.0656   
N865  X24.5822  Y23.1224   

4

G-Code, CAD, and CAM discussions / Re: MachIII GCode Leadin questions

« on: April 22, 2013, 11:17:51 AM »

That is my point.
When I look at my G-Code, i see nothing to indicate a leadin (or how its defined as a circular, straight, 45deg...)
I see the machine move into place and beging the cut, but nothing before that other than the offset of G41.
Where does the leadin type and path get defined?

5

G-Code, CAD, and CAM discussions / MachIII GCode Leadin questions

« on: April 22, 2013, 08:44:58 AM »

I hope this is a quick question.
I am trying to learn and understand G-Code and have a bit of a sticking point...

If I look at the toolpath in MachIII, I can see that there are circular leadins for a part, I can zoom into the part and see in the toolpath that the leadin is a cricular leadin, but when i look at the G-Code for that same spot, there is nothing to tell me that there is a leadin (other than the tool starts at that point).
Where in G-Code can I see the leading definitions? I used LazyCam to post the code, selected "Straight" leadins and a tool offset of .125.
I cannot seem to locate how or where in the code the actaul leadin is defined. If I step through the code line by line, i see where the tool goes to the start point, makes the cut around the part then leaves.

Does MachIII make assumptions about the leadins or is it actually defined somewhere?
Any information here would be great.

6

General Mach Discussion / Re: Steppers chatter when running slow

« on: April 19, 2013, 08:41:58 AM »

Looks like it was the fact that my drivers were in full step mode.
I have now heard that this is common when running steppers at a slow speed and in full step.
I changed to 1/8 step and it seems to have clear up the issue.

7

General Mach Discussion / Re: Steppers chatter when running slow

« on: April 17, 2013, 12:14:16 PM »

I didn't realize the lack of info that i put here..
Here is a little more detail.

I can duplicate this with all 3 axis using the same procedure
On the MDI tab I enter g1 x20 f5 to start the movement at a feed rate of 5 (not sure I need the G1 in there but no matter).

As the axis is moving, I hit the override button to slow it down. As the axis gets to 1.3 the motor starts to reverse itself every couple of steps, I continue to drop the speed and at 1.2, the reversing stops and the motor continues to move along without issue.
I then start to increase the speed and at 1.26 the reversing every few steps process starts all over again, As the speed goes over 1.3, the movement gets smooth again and the issue goes away.

8

General Mach Discussion / Steppers chatter when running slow

« on: April 16, 2013, 06:39:27 PM »

Need a bit of advice here.. I have 3 "Japan Servo" Stepper motors with probostep drivers running a foam cutting table with a dremel router

KP56LM2-097 from JAPAN SERVO
Parameters:
Unipolar / 2 phases 6 Volts DC (nom) 1.2 Amps / Phase (nom) 2.4 Amps / Motor 1.8 Degree/Step

Each motor is driven by an independant power brick 18v @ 4.9amp the probostep driver are set to limit current to just at 1 amp (much higher and they get real hot)
they seem to run fine at higher speeds (cutting a straight line) but seem to chatter a bit when cutting a curved line.

I can duplicate this by running them individually from the MDI tab, when i slow the speed to about 1.26 to 1.3 they chatter in the same way when cutting parts. This is throwing the cuts WAY off. 

Above or below that they work fine.

Cna anyone sghed some light on this?