burrs when milling 304 stainless

[hodaken]

Hey guys,

I have kind of a unique problem I hope someone can help with... I'm side milling a small 304 ss part and the process breaks through into an id feature at one point. The problem is that when it breaks through it is laying a very thin burr (like a piece of shim stock) down into the id area. That is what i'm trying to remedy. Is there a special type of end mill/process I should me using that would prevent this?

 

[guythatbrews]

Kind of hard top see what exactly you are doing.

In general for an odd shaped burr take enough light finish passes so the burr is not stiff at the root. One might do, more may be needed. Arrange the direction of the passes to minimize the burr. Then you just gotta bite the bullet and file it off.

Use a good sharp carbide endmill with coolant.

 

[Matt@RFR]

Echoing "guythatbrews",

You might try conventional cutting to keep the flutes trying to cut the burr off, versus trying to drag the burr in to the new cavity.

Also, if you have the cycle time, rough the feature with whatever, then finish with an aluminum specific 3 flute. Tool life will be fine, and burrs will be minimal.

You should define "small". Given the lighting and the short focal plane of your picture, I'm thinking this part is MUCH smaller than people are going to assume.

 

[JasHarvey]

How many of these parts do you plan on making? Light cuts and sharp cutters will minimize the burr but won't completely eradicate it. That's a weirdly designed part if I say so myself. Looks to me like you're going to have to use an X-acto knife and some elbow grease to remove that burr. The only thing I see that might help is to have a reamer the size of the I.D. that you can hand turn into the bore to help get rid of the burr.

 

[TeachMePlease]

Can you index it and get another live tool on it? If so, I'd try to see if I could make one of these guys work, and save the manual deburring.

J.W. DONE ORBITOOL - CROSS HOLE DEBURRING TOOLS AND TECHNOLOGY

The NEXT TOOL AFTER DRILL, the only deburring tool capable of in-process deburring of cross-drilled holes. Removes burrs only at the hole intersection. Creates controlled radius or minimally broken edge.

www.jwdone.com

 

[Booze Daily]

Are you standing this on end to mill? Kinda looks like it.
Lay it down and use a rough and finish endmill.

 

[plastikdreams]

That's 304 for ya...nasty burrs nasty cutting just plain nasty.

 

[BT Fabrication]

That's 304 for ya...nasty burrs nasty cutting just plain nasty.

I like cutting and working with stainless. its easy.

 

[plastikdreams]

I like cutting and working with stainless. its easy.

I like stainless too...just not 304

 

[Mtndew]

Aside from finishing with a new sharp corner end mill, there's not much you can do on a 3 axis mill.
Maybe get a wire brush wheel that you can use with a Dremel or pencil grinder to remove the burrs.

 

[Mtndew]

Can you index it and get another live tool on it? If so, I'd try to see if I could make one of these guys work, and save the manual deburring.

J.W. DONE ORBITOOL - CROSS HOLE DEBURRING TOOLS AND TECHNOLOGY

The NEXT TOOL AFTER DRILL, the only deburring tool capable of in-process deburring of cross-drilled holes. Removes burrs only at the hole intersection. Creates controlled radius or minimally broken edge.

www.jwdone.com

Do you know roughly how much these are? We always have cross holes and angled holes that need deburring on the I.D. breakouts.

 

[Larry Dickman]

spring cut the i.d.

 

[TeachMePlease]

Do you know roughly how much these are? We always have cross holes and angled holes that need deburring on the I.D. breakouts.

I have not asked for a quote yet. I'm making some sample parts to send them to test a prototype tool they're developing for very, very small holes. But they're super responsive to the "contact us" form on their website. I had an email within an hour of using it.

 

[hodaken]

Sorry guys, I should have been more specific...This part is 6mm long by 8mm at the largest diameter. I'm running it on a swiss lathe holding it on the large diameter and have the endmill in a live drill position facing the spindle like so. for more reference, the endmill is 3/16

 

[JasHarvey]

I like cutting and working with stainless. its easy.

Tell us how?

 

[prime_mover]

Tell us how?

Use drills, taps, and cutting tools designed for stainless.

 

[prime_mover]

Sorry guys, I should have been more specific...This part is 6mm long by 8mm at the largest diameter. I'm running it on a swiss lathe holding it on the large diameter and have the endmill in a live drill position facing the spindle like so. for more reference, the endmill is 3/16

Usually breaking up the cut into multiple depths or multiple passes can do the trick. Even a strategy like a left hand spiral end mill coming from one side and a right hand spiral from the other is the kind of thing that could work. You might try a plunge cut on either side where the break thru starts, or a series of plunge cuts, then proceed with the side cut. But I think taking the cut in multiple depths will work in this case.

 

[Booze Daily]

If you can put your endmill 90 degrees from that I think that will help.

 

[guythatbrews]

So your doing this on a swiss in the pickoff spindle?

Move the milling to the front spindle. Back turn the small diameter then mill. Take dead passes, turning, boring, and milling as needed to debur.

 

[hodaken]

Thanks everyone! I think we have it figured out. I switched the end mill 90 degrees to what it was, and broke it up into 4 passes, going deeper in both axes with each pass.