What is proper way to program for multiple parts in fixture
I have a job upcoming that will require me to make a fixture plate that will hold (ideally) 24 parts at a time.
I have never really used a fixture with this many parts before.
In order to save me from selecting the same contours over and over again in my Cad/Cam software (solidcam) I know that it would be best to just select one peice and then use Macros to repeat the code at different locations.
My question is to you for advice as to what the BEST method is for doing this?
Without very little work in solidcam it generated the code but it used WHILE statements. Which I have found are not compatible with Mach software (DAMN THIS COULD HAVE BEEN EASY!!!)
Each part will need several operations with several tools.
is it best to set each part to have its own unique coordinate system?
(I assume I would hand code a bunch of G10's at the begining of the code for each of the parts location, then after running the first part in presumably g54 there would need to be a macro to increment the offset to g55 and so on and repeat the code???)
Is it best to use an incremental or absolute move after part 1 and then rerun the code?
(I worry that the gcode genereated by my cam software would have Absolute movements inside of it and it would end up back at part 1)
Is there another way that I am totally glazing over that i have yet to discover.
I would like to do this the best and most accurate way possible.
Also currently I am not concerned with having the CAM software/post processor automatically do this. I am seeking knowledge as to what the best method is and then I will go down that road with the Cam/Post processor
Thanks for your help
Re: What is proper way to program for multiple parts in fixture
I watched this last week: CNC Mill Soft Jaws How-To Tutorial - YouTube
He mostly deals with building the fixture/soft jaws but he does show some CAD screen shots. Some of the suggested videos also deal with multiple part fixturing.
I found this here. It describes a couple of ways of doing it: http://www.cnczone.com/forums/solidc...s-1-stock.html
I will be following this with interest. I have a small project in the design stage that could benefit from what you learn.
bob
Re: What is proper way to program for multiple parts in fixture
Quote:
Originally Posted by
rowbare
Thank you but he doesn't use offsets. He programs all the parts individual on the softjaws. Pretty much the opposite of what im looking for.
Re: What is proper way to program for multiple parts in fixture
Hi mioduz
I do a lot of this, 10 or 12 parts at a time. You have two ways to do it.
1) Put all the code for cutting out a single part in a subroutine, then call it a number of times (using the L parameter). The trick is to reset the origin at the end of the subroutine (ie last few lines). You start by zeroing a variable (say #10) at the start of your main calling program and then you move the origin to the 'new' X position contained in #10 at the start of the subroutine. Just before you exit from the subroutine you increment #10 by the distance between the parts. This works fine if you don't have too many layers of subroutine calls. However, Mach does not handle the relocation of the origin in the screen display, so it looks as though you are retracing the shape over and over again. Doesn't matter, but annoying.
2) Generate the code for the subroutine, then edit it so that EVERY (damn) call with X in it is changed from (say) X123.4 to X[#10+123.4]. Then you use #10 as a poor man's origin relocation. This can be painful if the code was generated by a CAM system and has 1000 lines for the part! However, Mach3 will correctly display the result.
I have used both methods, but I hand-code my programs in a very parametric manner. However, Mach3 cannot handle too many layers of subroutines before it gets its knickers in a twist. Roll on Mach4.
Cheers
Roger
Re: What is proper way to program for multiple parts in fixture
G52 shift as long as your not using more than one fixture offset(it moves all). Your current program becomes a sub program(remove any fixture offset calls), main program uses 1fixture offset,say G54 center off your plate.
Call G52 x?y? Where you 1st part is
Call sub
Call G52 x0y0
Call G52 x?y? 2nd part loc
Call sub etc.
Re: What is proper way to program for multiple parts in fixture
What cam are you using. I hate setting up multiple part offsets unless it's absolutely necessary. Your cam may have an array function. If so you would just program 1 part and then tell it how many and how far apart in x and y. If you just program 1 part and use offsets you will either get way to many tool changes or spend as much time adding offsets as you would just programming all of them to begin with.
Ben
Re: What is proper way to program for multiple parts in fixture
You can break up ea tool as a separate sub program if needed
Re: What is proper way to program for multiple parts in fixture
Quote:
You can break up ea tool as a separate sub program if needed
Of course!
Sorry - I assumed that part of the scheme. I load the tool, zero it, and then sit back as it wends its happy way from part to part. Can take a few hours.
Cheers
