Re: [CAD_CAM_EDM_DRO] EDM

Jan,
I have mastered the WireEDM at our VoTech School.
This is a 1993 model Hitachi-Seiko H-CUT 230.
We use .25mm (.010") brass wire only. The wire cannot be reused. Used wire
is heavily pitted and would soon break if reused.
It is pulled thru the guides and dumped into a box below to be discarded.
Wire EDMs use water for an electrolyte pumped into the kerf from both sides
to flush out the dirt.
Atlanta water is very mineral free and clean. No special processing is
used other than filtering to reuse it here.
Cutting aluminum is VERY dirty and clogs the filter very quickly. Not cheap
to replace. I washed it last week on cleanup day. I'll see if that helped in Jan.
Al cuts pretty quickly on the order of .25-.30 in/min. depending on thickness.
Steel cuts at about .025-.100"/min depending. Brass about between the two.
Any conductive metal can be cut, I am told.
The wire can be thought of as a micro milling cutter of very long length.
It is positioned at the edge of the material where appropriate, typically at
right angles. The computer is zeroed to the set coordinates and the program
is then run with flush, feed and power on. Any out of bounds, continuous short
or broken wire stops the machine.
I made a bearing bronze spindle drive "nut" for a Dyna Myte 2400CNC 4" long to be
parted up into several nuts as replacements on my mill. This is a cut 4" long
thru a drilled hole in the bronze in the shape of a circle with two inward
facing keys. Then a cut 1" diameter to finish the blank. Very difficult by any
other means.
The clock makers have made tons of gears with it. For any weird straight cut,
its a natural.
I want one for Christmas :-). I bought Dan's book, but that's for another day.
RichD


JanRwl@... wrote:

>
> In a message dated 12/14/2002 12:28:17 PM Central Standard Time,
> xmas4lites@... writes:
>
> > There has been so little content on EDM on this and other lists that I think
> > any useful information on the subject is helpful.
>
> I mostly kinda agree with this letter. But directly relating to CAM, say I
> was gonna EDM-cut some, oh, 3/8" or 1/2" 6061 plate, using (brass?) EDM wire
> (what, 0.015" or 0.02" dia?), how FAST (inches/per minute or mm/second, or
> however whoever knows) would the material move "across the wire"? How fast
> should the wire "dive" into the electrolyte? Why is BRASS wire used rather
> than, oh, copper-plated steel, or copper, etc.? In properly-built EDM rigs,
> does the "used" wire go straight down below the work-piece, through the
> container-bottom, to the take-up reel, or can it go around nylon (?) pullies
> and then UP, say, "over in a distant corner of the container", or would this
> exposure-length in the electrolyte be "too much" for the worn wire???
> Discuss.
>
> Can someone who HAS done EDM give us dummies a grasp of the "mechanics" of
> it?
>
> Thanks! Jan Rowland
>
> [Non-text portions of this message have been removed]
>
> Addresses:
> FAQ: http://www.ktmarketing.com/faq.html
> FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
> Post Messages: CAD_CAM_EDM_DRO@yahoogroups.com
>
> Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@...
> Moderator: jmelson@... timg@... [Moderator]
> URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
>
> OFF Topic POSTS: General Machining
> If you wish to post on unlimited OT subjects goto: aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if you have trouble.
> http://www.metalworking.com/news_servers.html
>
> http://groups.yahoo.com/group/jobshophomeshop I consider this to be a sister site to the CCED group, as many of the same members are there, for OT subjects, that are not allowed on the CCED list.
>
> NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
> bill
> List Mom
> List Owner
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

--
=-=Rich=-=Colorado Midland Railway=-=
<http://cmsteamer.homestead.com/>
*******Happy Holidays*******