Best practise for repeating / duplicating parts

[dolby]

Hi all,

it's been quite a handy forum so far but I could not find a ideal solution for repeating / duplicating parts. I know I can use the work offsets (e.g. G54, G56), but what if I want to do 20 equal / identical parts in a pattern of 5 colums and 4 rows for example it would take me quite some time programming it.

I saw another option doing workshifts for groups, but I could not find out how to use that propery to generate one file in the end with multiple groups.

I have OneCNC XR2 and Mach3 as programs and am trying to prevent doing anything manually (like copy and paste complete my g-code and edit g54 to g55 in the beginning) to reduce the risk of making mistakes.

Thanks averyone and ...happy holidays !-)

[BMG]

I asked the exact same question n the EMC2 email list last friday. One of the developers shared code that allows just what you are looking to do. I posted his solution to the WIKI there and the link is below. I know it works with EMC2, but your mileage may vary with other programs due to slight differences in gcode implementation.


http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Oword

[HuFlungDung]

Can you use the G52 work offset in Mach? On Haas, this is possible, and I think this would be the least painful way to make the program.

There are different methods of machining: some guys would prefer to use one tool at a time at all 20 locations, then change to the next tool and do all 20 locations.

You could opt for either method, but the programming details would vary.

Basically each machining operation is put into a subroutine. If Mach can handle local subs, so much the better.

Your main program would consist of custom code, and would be a list of G52 Xx.xxx Y.yyy where the X and Y are datum locations for each part in your grid. G52 is a local coordinate system shift, so it is able to run absolute code (which is what you would normally post out of OneCNC) almost as if it were incremental subs, at each location.

I've not done this yet, but I keep the idea in the back of my mind

Some guys would just post the whole program longhand, if this doesn't make it too excessive, and provided that they actually have enough work offsets to call. G52 circumvents the problem of not having enough work offsets.

[dolby]

thanks for the reply so far, but I think I should be more specific.
I would like to able to program that in OneCNC directly in order to simulate my routings there as well.

Unfortunately G52 does not work in Mach3 and I could not get the G92 to work either. (Using the OneCNC custom coding insert)

I am probably a little bit spoiled from SolidWorks but I can't understand that there is not an easy way to do that in OneCNC, with the mentionied option of using one tool at a time for all parts and move to the next tool/operation.

I assume if I can get the multiple groups working with the workshift offsets - that's an option but it only works for seperate files right now.

[tminnig]

Can you use additional work offsets? Like G54 P1, P2, P3,...?

Another option could be to use G10's throughout the code to reposition the work coordinate. I don't know much about the machine or software you are talking about, so I don't know about your posts, I'm just offering possible solutions to make your idea a reality.

With G10's, you can have a program that writes the G10 values and then goes into a subroutine to cut the part, then goes back and writes the new G10 values and back to the subroutine. This will not work well if you want to run one tool on all parts, then the next tool and so on. However, if you can utilize the extended offsets (P1, P2,..) then you can write all the offsets for each P-value and then move on to the subroutine that will simply call the offsets as it moves the tools from one part to the next.

Travis

[HuFlungDung]

Dolby,
If you want full simulation, then there is no shortcut but to do the operations on the complete grid of parts. Anything less than that would be based on assumptions about grid spacing and so on. Lots of us (machinists) are comfortable with using workshifts without literally seeing it all on the screen: if we see it simulates okay in one position, then it will be okay in all the rest ( which is a mental assumption about the care taken to do the part setup, and setting the work shifts).

You can opt to duplicate all the operations (many times!) and change the work offset in each one. This is very tedious and if you need to alter one operation, then you need to alter all the duplicates.

Since the grid pattern is most likely well defined (if the cutouts are all done in one large piece of material, it would likely make more sense to just machine it as if it were 1 large part, with many pockets in it (or whatever the features look like).

I primarily use workshifts whenever there are several parts in several vises, or some sort of fixture arrangement that might possibly require minute adjustments between positions, from one setup to the next.