Hone/Polish Technologies for interior EDM profiles

[FWPratEng]

Hello,

I am new to this forum and from reading past posts, there is a great deal of knowledge to be had from here.

I have come up dry though on how to finish the interior surface of a tool that has been cut with a wire EDM. The tool is used for ram extrusion of plastc. The small cross section of the profile makes it hard if not impossible to condition the surface. This has led us in the past to just be complacent with whatever finish the EDM was capable providing and I am trying to correct this. This finish was typically around a 32. If there is any other information that would be helpful, just let me know.

Any knowledge would be much appreciated.

Thanks,
Chris

 

[unclesyd]

One approach might be to use a vapor hone system to clean up your part. Look around as there are numerous variations of this process.
We use this approach on numerous die components used in Nylon production and molding

http://www.metalifeind.com/vaporprep.html

 

[FWPratEng]

Thanks unclesyd,

I will have to look into it. I have also sent samples out to have them extrude honed to see how this affects the surface.

- Chris

 

[is2634]

Current Wire EDM technology can achieve finishes < 6 microinch Ra. Have you investigated improving the wire EDM process? Extrude Hone will improve the finish but may compromise your geometry.

 

[FWPratEng]

I have read about shops able to hold that low of finish, but whenever I ask a shop in our area if they are capable of maintaining a 6 microinch Ra or less they just look at me like I am crazy. I did however receive a tool from Extrude Hone and was very impressed with the final result. On average it brought the finish from a .75 micrometer to a .16 micrometer. This is the best finish we have ever been able to achieve on our wire EDM tools. I am curious though what finish I would be able to achieve if I did find a tool shop with better EDM capabilities. If I do improve finish even more I will make sure to keep this thread updated.