RFQ: Need (3) Electrodes - 4 Axis?

[Jim Estes]

I am in need of getting (3) electrodes machined of this part. I have a solid model for it and I have a source to burn it but I am not confident about my source for making the electrodes. I would need the electrode to create the spiral fluted portion that is tapered 60 degrees. This would most likely be a 4 axis job or possible a cnc lathe with powered milling cutter job.

If you are interested, please e-mail me a cost and leadtime to machine (3) electrodes, that will be mounted on 20 mm System 3R tool holders.

Thank you,

Jim Estes

[DareBee]

I am curious as to why you wouldn't machine this auger in a lathe and/or a mill instead of burning it?

Maybe I am not understanding what you are asking for.

[Jim Estes]

Maybe I didn't make it clear, I am building a mold, and I need a mold cavity burned. I need electrodes of this shape so that they can be used to burn a mold cavity.

Jim

[DareBee]

So...you will burn this in with a 4 axis EDM (like threading a hole)?

If you are going to side sink it into a piece I am fairly sure that it will not match the 'trode because the angles lead of the screw will pass through material that is not to be cut to get to its final position.

If you are "threading" it in all you will need is a single point 'trode that looks like a threading tool only sized to your valley shape. Much much simpler and economical.

[Jim Estes]

I hadn't thought about using just a single point electrode, I'll have to see if we can program the taper into the burn.

Thanks Darebee.

Jim

[DareBee]

I figure if my old FineSodick would burn it that way that others should be able to as well.

[tjones]

Copper or graphite (grade)?


Also do you wish to have the full part as electrode or just the helical? What undersizes will be needed? Do you wish to have a full round or 3 each of a half form for Z axis burning?

Sorry for all the questions but wish to get it right the first time.

Is the mold extracting the part from a parting line or is it screw ejected? If parting line then it must be able to burn in side or Z for the extraction from the mold.

[Jim Estes]

Graphite, I can mount them on 20 mm 3R holders and UPS them.
We would be burning this cavity by CNC EDM by "screwing" them into the steel. I don't need anything but the tapered flute.

Our shrink factor is 0.003"/inch and overburn is typically 0.003"/side.

The mold will have four slides creating the flute around a center core, the ejection will be sleeve ejection, after the slides pull back.

Jim

[tjones]

Will you have a solid model of the electrode, part, or none? (engineering time)

Also will you be able to helical thread edm this with the taper going smaller near the back of the part? It appears from the pdf file the part actually gets smaller in diameter during the last pitch. If this is true then making the part as a single piece and doing a side burn may be a better option.

The electrode can still be made even if you decide to burn from a side instead.

[Jim Estes]

Yes, I have a solid model, I can add the shrink factor and subtract the overburn. The upper flute is actually tapered the opposite direction on a 50 degree taper. I will be creating this upper portion using a sprially contoured parting line and a angled step at the point where the upper and lower flute meet.

This part cannot be burned from the side, since the pitch of the flute is so large (19mm) and the angle of the flute is so small (8 degrees), the flute actually gets undercut, so if I tried to burn it from the side, I would be burning away too much steel.

This needs to be burned by rotating the electrode through the pitch.

I would not need the upper portion of the flute on the electrodes, just the 60 degree portion .

Jim