Small part machining R.004"

[Jabberwocky]

Ok, I have a potential part which is pretty small, although not microscopic. I need to get a 2d shape cut with corner radii on the order of .004". I'm working in titanium with a part thickness around .050"

Should I be looking into laser-cutting, waterjet, or EDM?

 

[mfgenggear]

need more info!!!!!
part sketch maybe

 

[Jabberwocky]

What other info do you need? .050" thickness, so like a heavy gauge sheet metal, and a 2d shape I need to produce with internal corners around R.004" (Or less if possible) The lowest wall-thickness of the shape itself goes to around .020"

It is metal so EDM is possible but my shop is saying our smallest EDM wire is .004" - can waterjet or laser cut smaller shapes than that?

 

[ajack1]

I would very much doubt it although technology moves along fast so I would not give a definitive no, try speaking to different companies that offer this service.

You can certainly get wire down to 0.05mm diameter (possibly even smaller) so you could go below .004” rads, however this would probably require special guides, wire and settings so cost would increase, unless you find a company that specialises in this type of thing.

 

[mfgenggear]

Jabber

"What other info do you need? .050" thickness, so like a heavy gauge sheet metal, and a 2d shape I need to produce with internal corners around R.004" (Or less if possible) The lowest wall-thickness of the shape itself goes to around .020"

What does your geometry look like?
is it a flat piece with cut outs?
is it bent 90 deg or what?
You know what you want we don't have a clue.

to my experience wire cut is the best method to use for
precise machining very small lots. +/_ .0001

blank & pierce for large lots/production.
+/_ .0005

cnc punch for semi small large runs.
+/_.005

laser is very good for cosmetic designs with very liberal
dimensions. +/_.030 or more.

water jet works great for thick large jobs
also very liberal dimensioning is required.
+/_ .030 or more

so these tolerances can be subjective to the expertise of the shop & the personnel.

MfgEngGear

 

[Jabberwocky]

Thanks all, I'm not trying to be furtive just not at liberty to divulge the particulars.

I guess you could imagine the shape as a flat, lowercase 'e' - although the fully enclosed boundary could be drilled and I'm more interested in the thin arm across the bottom of the 'e'. No bends.

It sounds like wire is the best assuming we can find some that small, although I'm kind of surprised the laser is so (relatively) inaccurate.

 

[MikeHalloran]

I've had good luck with self-conjugate parts lasercut from 12ga stainless, laid out for a .007" diameter kerf. Bigger photon cannons leave bigger tracks. Ti must behave differently.

If you need a bunch of parts, the tooling for powdermetal might be affordable.




Mike Halloran
Pembroke Pines, FL, USA

 

[TVP]

Jabberwocky,

Your requirement is getting close to the limits of wire EDM, but it is possible. Some shops use wire as fine as 0.002 inches in diameter (0.05 mm), so you should probably contact some other EDM vendors, or have your shop investigate finer wire. Personally, I worked with Nitro EDM in Shelby Township, MI (suburban Detroit) to machine tiny grooves into die-cast Mg specimens (2-6 mm thick), where the groove width was 0.34-0.42 mm and the end radius was 0.13-0.18 mm. I agree with the others that laser and water jet will not be capable of meeting this requirement.

 

[tomwalz]

Might try posting on practicalmachinist.com as well.

Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

Good engineering starts with a Grainger Catalog.

 

[EVERFABCHAD]

Is it a pocket with .004 corner rads? If so how deep is the pocket? We mill things like this all the time. You can buy toole that are .020 DOC that could cut this.