looking to Wire EDM any current users

More
03 Nov 2015 22:37 #64702 by toolmaker69
I just saw this thread and am posting even though it is a late bump.

From my experience with wire edm, I don't believe that it is just an issue of backing up. Just backing up would only require keeping an array of the last motions in memory (or a file) and reading it in reverse.

It is also an issue of sensing the spark and moving away from it, creating a new local tool path. Sometimes the wire needs to back up because of a flushing problem and would short if returning along exactly the same path. Of course then the power also needs to be reduced to prevent overburning. It's sort-of-like adaptive control, but with intelligence based on burning. It also needs to make decisions if it "sees" it has moved more than a minimum distance with the spark reduced, which could mean a sliver has shorted the wire and it hasn't cut for a while.

Other times material can spring or a slug can twist at the end of a cut and the wire needs to back up. But if it repeats the same path, again it can ruin the part.

I'll look around here a little more on the subject, but meanwhile it seems to me that you'll definitely need a PLC to handle the spark control with IO lines between the PLC(PMC) and CNC portions. Some PLC memory would also needed to hold the local tool path in order for the adaptive path to be acted upon and sent back to the CNC.

4 axis wire would not be so difficult, but to implement 2 axis with angle and wire offset simultaneously would also need PLC intervention, I think.

If I were to start the project, I would see if I could pick up an old wire edm where the iron and wire adaptive feedback electronics wire still good. Then I would hook up the axis motors, get the wire mechanism controllable, and then work on interfacing linuxcnc and the feedback box. This assumes that the feedback box is separate or can be addressed without affecting any other electronics in the unit.

Please Log in or Create an account to join the conversation.

More
03 Nov 2015 22:48 #64705 by andypugh

I'll look around here a little more on the subject, but meanwhile it seems to me that you'll definitely need a PLC to handle the spark control with IO lines between the PLC(PMC) and CNC portions. Some PLC memory would also needed to hold the local tool path in order for the adaptive path to be acted upon and sent back to the CNC.


Since this thread was last active there has been a significant development:
git.linuxcnc.org/gitweb?p=linuxcnc.git;a...ture/reverse-run-2.7


The following user(s) said Thank You: toolmaker69, andgs1

Please Log in or Create an account to join the conversation.

More
04 Nov 2015 02:22 #64733 by cncbasher
linuxcnc has a plc built in , due to the way linuxcnc works and with the updates done as mentioned , this makes a much better
way of putting a edm to use , using linuxcnc .

at the moment i have a pulse generator seperate to linuxcnc , but controlled from hal , i hope to pick this back up probably next month , when time becomes more available
The following user(s) said Thank You: toolmaker69

Please Log in or Create an account to join the conversation.

More
21 Oct 2016 15:44 #81915 by 10K
I'm considering building a wire EDM. Based on this post, I see that LinuxCNC seems to have all of the functionality to control EDM. I'm wondering if anyone has actually built or retrofitted a wire EDM machine? If so, could you post your HAL / INI?

I've seen projects where people have used Arduino or PLCs for spark control, but none that went all LinuxCNC. The systems I've seen either pause/resume the feed or control the feed rate percentage. None have backed up the toolpath.

Thanks!
The following user(s) said Thank You: andgs1

Please Log in or Create an account to join the conversation.

More
21 Oct 2016 19:12 #81926 by andypugh
I don't think reverse-run has been implement in a released branch yet.

Please Log in or Create an account to join the conversation.

More
23 Oct 2016 09:42 #81953 by octopus80
Hello, I got the link from Thomas to contact you I have build 5 EDM wire machines but it runs on mach3 if you have any quistions you can ask it for people that have intrest in it on the Yahoo groups Plasmaboog you can find photo of the projects
Greetings Benny

Please Log in or Create an account to join the conversation.

More
23 Oct 2016 09:52 #81954 by andypugh
You might also want to look at the mailing list archives. There was a long discussion on the subject of EDM gap control on the developers list recently:

sourceforge.net/p/emc/mailman/search/?q=...rol%22&mail_list=all

You might also want to try different search terms to find other threads. For example, the "coffee cup EDM" thread.

Please Log in or Create an account to join the conversation.

More
23 Oct 2016 17:30 #81968 by octopus80
I have read the topic about the GAP control this a discusion have I done before so you have to understand first what the parameters are doing in you cutting process for what is use the voltage 80, 100, 150, 200 volt, what is doing the freqence from 40 till 250Khz are doing on the surface but also the conductivity of the water in µsiemens. so the quistion when do you gone masseur your GAP voltage? But the major quistion you have to ask what do I like to cut what material what quailty of surface do I wont and what may the machine cost me. so if you have quistion you can ask it but don't ask me everytime the same quistion.

Please Log in or Create an account to join the conversation.

More
27 Oct 2016 17:55 #82153 by Fang
I'm also interested in building or retrofitting a wire edm, so be interested to know how others get on

Thanks

Please Log in or Create an account to join the conversation.

Time to create page: 0.242 seconds
Powered by Kunena Forum