Messages

11

General Mach Discussion / Re: 240v Router/Spindle

« on: January 11, 2009, 06:01:33 AM »

Nice one Bruce,

Could you tell me what you ordered from these guys??

Does the spindle need water cooling if so did you order a pump??

and did you go with the ER20 collets.

Also are you controling spindle speed via Mach through the inverter??

Sorry for all the questions

J

12

General Mach Discussion / Re: 240v Router/Spindle

« on: January 11, 2009, 12:57:19 AM »

Hi Bruce,

Did you end up ordering the spindle and other accessories??

If so how has it been running?

J

13

G-Code, CAD, and CAM discussions / Re: reset home with G code

« on: January 06, 2009, 09:54:02 PM »

Thanks Graham,

I like our idea. Wha are your thoughts on using a 0.9 deg stepper so that the step count/deg would be 4000/360 =11.1111111

Or are you thinking that a whole  number of steps/deg would reduce this error.

If this is the case do you think that a 3.6:1 would be better still with a higher step count.

I'm tossing up the amount of work required to do the reduction drive compared to sourcing a 0.9 deg stepper.

Thanks again

14

G-Code, CAD, and CAM discussions / Re: reset home with G code

« on: January 05, 2009, 09:49:43 PM »

Ok more testing today.

Happy New year to you all.

I still have the code pausing with the  M1099 A home command. I tried a dobutton (0) after this however it did not excute the A home. I tried adding a Code "G4 P5" after the A home and before the cycle start. Still it did not do the A home:)

I have run some simple 5 shape tests with F10000 and it is OK with refernce to A axis positionng.

I tried a 20 part cut in the CW direction and the error is exactly the same as the CCW being +15 degs out.

I switched my A axis stepper to Unipolar and change the current set resistor. Reduce A Axis motor tuning to V5000 A500 and run a test at F2500. The problem still exisits as if it was with high V and A setting and feedrates of F10000.

I am not sure where to go from here??

15

G-Code, CAD, and CAM discussions / Re: reset home with G code

« on: January 02, 2009, 05:10:13 AM »

I have been working on the machine today trying different things.

The macro continues to pause ater the a axis homes, I will read up tonight on a cycle start command to add to the macro.

Most of my code runs CCW and at the completion of one file the A was +20 deg out and another file it as +12deg, this was check by MDI'ing a A0 command then jogging backwards the axis until the homing limit is hit . I worked on reducing my step/deg number and found that 5.535/deg had the filet hat was + 20 out at the finish now finishing at 0 however the other gcode file is -7 deg when zeroed with these settings. These test were ran with the blade removed so no load on the stepper. I did another file wth 5 different shapes like a square, circle, pentagon and eclipse of varying sizes and at the completion the A axis was ok ie no lost steps. I tried running the problem files with reduce feed rates and vel and Acc settings on the A axis with similar gains of posttion as above. BTW I have I and J codes in these files. Meaning I have drawn the shapes using arcs and fillets between straight lines. I have done this as the speed of the machine is not compromised as the A axis runs in Exact stop mode even though I have a G64 in the code. This may have to do with the way the A axis code is outputed.

I may be wrong here but I thnk the A code is developed like this
A90
x100 y100


If it was done like this it may work better??
A90 X100 y100

My next process is to set the chains for the parts to run in the CW diection and see how the position ends up.

Thanks for the help and Happy New Year

16

General Mach Discussion / Re: Deeper into the 4th A Axis

« on: December 30, 2008, 04:26:41 PM »

I just had a look at you steps/deg calculation and I think there may be an error.

Wiith 1.8deg stepper it is 200 steps per 360 deg. With micro stepping it should be 2000 steps per 360 deg or 5.55555steps/deg

C

17

G-Code, CAD, and CAM discussions / Re: reset home with G code

« on: December 23, 2008, 04:24:36 AM »

Thanks for your info,

I have ran some tests today adjusting steps/mm etc.

Yes my machine is gaining deg on the A axis. On MDI A code tests like AO to A180 back to A0 etc the A axis works great. When I run different Gcode files the results at the end are varied when sending an A0 at the finish ie +3deg to +10 deg gains depending on code. Modifying steps/mm isnt the solution as I can adjust these to suit one file and then the A home is out after the completion of another

I did try the M code however it homes the A axs then pauses until cycle start is depressed

My thoughts is that the tangental A code that Mach outputs is where the problem lies.

Thanks
Jason

18

G-Code, CAD, and CAM discussions / Re: reset home with G code

« on: December 18, 2008, 08:51:50 PM »

Nice one TP,

I would be keen to give your macro a try

19

G-Code, CAD, and CAM discussions / Re: reset home with G code

« on: December 18, 2008, 12:35:51 AM »

I have just done some tests.

The MDI test with verify confirmed sucessfull?? Basically I ran A 180 to A360 approx 20 times and verified. It all looks Ok as far as position and DRO.

My Steps/mm on the A are 5.55555555555 calculate @ 200 x 10 micro step / 360 deg. I did change this to 5.5555 and ran one file with 70 parts. All was OK with this meaning the A DRO at zero  the knife position was at zero deg at the finish

I ran another file with 20 x parts and at the end set a A0 command and knife position was + 8 deg

Regarding noise the cables to the motor are not sheilded or the pairs from the SS to the G203V.

The question is why is it ok on some files and not on other files

Will a reference A macro that I can drop into the Gcode after each item do the trick. The G28.1 A0 command worked but would not continue running the file

Thanks again for the fault finding tips

20

G-Code, CAD, and CAM discussions / Re: reset home with G code

« on: December 17, 2008, 10:28:08 PM »

Hi Graham,

My machine is a CNC fabric Cutter using a rotary knife attached directly to an A axis. I'm running the machin in Tangential mode.

I'm using a Smooth Stepper with Gecko 203v for the Y + A  and a 320 for the X.

My problem is with some files my A axis gains steps  on One file it is +3 deg and on others is +10 deg on a dry run ie no load on the A axis. I have been adjusting feed rates and motor tuning etc with similar results on the same files. I have also tried DXF and Iges drawings to enhance the feedrates of F10000mm/min.

I'm now runing the machine in Plasma mode as it has the most smoothest and fastest movement at F10000.

My table size is X1500 x Y1200mm and we basically cut the same shapes continuously.

So towards the end of a file run as the A axis is getting out of position it starts to drag the knife. So I'm thinking that I can add a M code after each part is cut to realign the knife before the next cut.

I have tried the G28.1 A0 and what happens is Mach excutes the A axis home and re-zero's however it then haults until the cycle start is enable again.

I have tried adding a P command before and after the G28.1 A0 to allow for the knife to home in time before the next move and also to seperate it from the previuos lines G00 move. I read that as it is a Group 0 it can have confilcts with group 1 code. Still however the runing file pauses at the G28.1 A0.

if I type G28.1 A0 in the MDI all is oK, Just aproblem when implemented in the Gcode.
Attached is the gcode file where I have added the G28.1 A0 after the first part is cut.

C