Sodick wire EDM machine retrofit

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05 Jan 2020 18:40 - 05 Jan 2020 18:41 #154104 by Henk
Hi all
I have a Sodick A320s with a mark ex controll that I basically got for nothing.

Has anyone here worked on these machines?

I would like to retrofit this machine but I can see that this is not going to be as simple as the lathes and mills that I have done before.

I was lucky to find similar wiring diagrams. They are for a machine some 2years younger but it seems to be very similar to my setup.

Henk
Last edit: 05 Jan 2020 18:41 by Henk. Reason: Typo in subject line

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05 Jan 2020 23:38 #154117 by Leon82
Our fanuc wires have XYZ, UV which are the head angles for angle cuts.

There is a wire tension sensor.

Also a motor that creates the tension on the wire spool.

As well as voltage, amperage and ionization sensors for the tank.

I'm not sure if this will help you but there would be a few things to figure out.

Each material has different settings also

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06 Jan 2020 06:44 #154127 by Henk
Thanks for your reply Leon82

Yes, there will indeed be a couple of things to figure out....

I studied the wiring diagrams in an attempt to figure out the control circuit of the power source. It seems that the voltage level is set by switching relays marked V0...V10, of which not all of them are used. The wiring diagrams suggest that there are a couple of settings (60, 80, 100, 150V) but my machine has only V0 and V1 connected, maybe my model only has 2 selectable voltage levels. Still checking that

The pulse frequency and length control is a bit more challenging. the wiring diagrams are a bit vague on that. I may have to strip out the hardware to figure that out. ...

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17 Mar 2020 09:07 #160524 by Henk
Update.

I managed to get most of the easy stuff sorted out and working. XY and UV axes working, Wire run and tension working the way it used to with speed and tension adjustable with the original hardware. I am using moion.spindle-enable to start the wire run.

Im happy with what i have so far. Now i have to move on to the more difficult part, the spark source. I have researched a lot on this topic and i have a prototype design that i want to start testing sometime this weekend.

For this i think i will need a custom bitfile for the 7i76E. I am using a cheap 5 axis LPT type BOB connected to one of the expansion ports on the 7i76E and i would like to use two PWM channels on pins 2 and 4. These will drive the MOSFET gate driver circuit to control the spark pulse length and frequency from LCNC.

Is there already a Bitfile that can do that? I tried finding one but there doesnt seem to be any PIN files that is human readable on the download from the Mesa site.

Maybe PCW can advise?

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19 Mar 2020 23:12 #160795 by andypugh
If you download the firmware pack from Mesa, then expand the source code section, you can try to find a .vhd file that contains a PWM that matches an available 7i76E bitfile name.

It's a bit of a performance, it has to be admitted.

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27 Jul 2020 19:07 #176129 by centreline
Hi Henk, following this with interest. I have a BF275 sodick with a similar era control but no AWT & is a dry tank machine, and while its currently working, I'd really like to add rotary axis/turn & burn and other more modern capabilities, and get away from the pc9801 gui control computer, and the even more weird and legacy main control computer.
I do have a set of the cutting condition tables detailing the original parameters to use with which material etc I can scan if that would help you at all?

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27 Jul 2020 20:08 #176144 by Henk
Hi!
Thanks for the help
At this stage any info is very welcome.

I have made some progress since my last post. Basically I have everything working on my machine but I had no option but to ditch the original spark generator. The original one is very complex and I could not find enough info on it to even try and get it integrated with linuxcnc. The multi layer PCBs in it makes it impossible to try and trace the circuits so that was a no go as well.

I have built my own spark generator and I have made some test cuts in steel up to 30mm thick. Im now starting to understand the enormity of the task that I have took on....it is not simple at all.

If you are prepared to spend money, buy the BAXedm spark generator. I don't have first hand experience on it but that will solve a lot of problems if what is advertised is true.

I am now playing with the adaptive control that is supposed to control the spark gap by adjusting the feed rate based on the gap voltage. I have not spent enough time on this to be able to comment on it but I will try and post here some details and my findings in the future.

My spark generator is a simple high side MOSFET switch with adjustable current limiting resistors and also adjustable on and off times for the pulse. I don't have any feedback that is capable of adjusting pulse parameters (current, voltage, on and off times etc) automatically but some friends over here offered to help develop such a system.

In short. I have cut material, bit painfully slow and not yet useable at this point. I have a lot of development still to do.

I will keep you posted.

Henk
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28 Jul 2020 00:00 #176175 by tommylight
You should look into external offsets and reverse run, both are included on LinuxCNC 2.8 and master, they are very useful for EDM.
Combined they should provide for speed adjustment during cutting and back off when the voltage goes to 0, although most probably only external offsets will do all the magic needed. Add to that a THCAD10 from Mesa for measuring the voltage and sending it to LinuxCNC.
PlasmaC should be a good starting point for that.

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29 Jul 2020 07:33 #176337 by centreline
I found the machining tables and Ive put it up on a host for you to download here, it might be useful if to get a grasp of how it was done OEM if nothing else :-
gallery.pipandphil.com/Vehicles/workshop...hiningConditions.pdf

Ive also added the manuals for the MK25 the MK21WT and a file called materials cross converting between JIS &AISI metals standards as referenced in the cutting tables book.
gallery.pipandphil.com/Vehicles/workshop/MK25Manual.pdf
gallery.pipandphil.com/Vehicles/workshop/MK21WTManual.pdf
gallery.pipandphil.com/Vehicles/workshop/material.pdf

I thought I had a repair manual with wiring schemas for a differetnt machine to mine, but when I offered it up a lot of circuits were similar, if I can find that again I'll post it here as that may still be of use to you. I have the servopack drive manuals if you have yaskawa servos fitted to your model also as I had to repair one of my axis as I got it as a broken machine also.

Also what I see as a slight issue is the original control was loaded with compensation settings for the ballscrews etc which are stored on floppy disk, or if you were really lucky (like me) also on a yellowed print out deep inside the machine cabinet. Without these the oem mapping of the screws etc will have to be redone of course.

Believe it or not, 3k is outside my budget for a part for this, I have less than 1000e in it in total (and its currently working condition). I'm just a hobbyist with big dreams. The converting it is a wish for now as I'm busy building a room to house a cinncinati sabre vmc after outgrowing a bridgeport interact :)

I'll have a dig round for the schematics/wiring manual, I'm sure I had one somewhere.

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29 Jul 2020 11:32 - 29 Jul 2020 13:04 #176359 by gerritv
I have been researching building my own small WEDM and so have been collecting info.
You might want to look here (
www.cnc.info.pl/drutowka-dk7725-na-linuxcnc-t92321-20.html) for hints on using LinuxCNC with WEDM. This particular retrofit does not use reverse run, they apparently don't find it necessary. The essense of their approach is to sense the voltage and stop moving when below a set threshold. It then 'sorts itself out' at least most of the time. Site is in Polish but easy enough to translate with the usual tools.
A few posts in there is a copy of the .hal file being used.
Last edit: 29 Jul 2020 13:04 by gerritv. Reason: spelling
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