Milling the best possible finish on this aluminum surface

[Peroni]

I've been tasked with trying to find some sort of cutter to mill the red surface pictured. I have about .175 square between the outer islands. Material is 7075 aluminum. This is all about surface finish, customer would like something around a 2ra. Thoughts?

 

[Finegrain]

I've been tasked with trying to find some sort of cutter to mill the red surface pictured. I have about .175 square between the outer islands. Material is 7075 aluminum. This is all about surface finish, customer would like something around a 2ra. Thoughts?

View attachment 330511

2ra what units? If μin, then this is at the limits of lapping, so I think milling is not possible. If μm, then no problem, any good new sharp endmill should work.

Regards.

Mike

 

[Ianagos]

2 ra sounds to me very very smooth.

If you want to do it on the mill mcd inserts are probably going to achieve about the best finish possible. Surface will look like a mirror but like above poster said may still not be that smooth. Pcd will also look good but I believe mcd(never used it myself) will be even better

 

[MaxPrairie]

You also need to have very clean coolant.

 

[Conrad Hoffman]

The geometry of the part makes it very difficult. You can't use anything like a fly cutter. I don't think you can chuck it up and turn it. If you could, diamond turning would get you anything you needed. I'm assuming 2 microinch Ra because 2 micrometer Ra would be cake.

 

[Ianagos]

The geometry of the part makes it very difficult. You can't use anything like a fly cutter. I don't think you can chuck it up and turn it. If you could, diamond turning would get you anything you needed. I'm assuming 2 microinch Ra because 2 micrometer Ra would be cake.

Not sure on part size but he could use a small fly cutter or insert mill and go diagonal corner to corner

 

[TeachMePlease]

Diamond Burnish Face Mill Tools by Cogsdill

 

[Mark P.]

I used to machine torpedo vanes. I got great results when I used mist coolant system. Machine had a 900 rpm max on the 50 taper side but the finishes were close to spec. It was just a small 2 1/2 Seco cutter with APKT inserts too.

 

[BROTHERFRANK]

As Ian mentioned, check into MCD (mono crystalline diamond) it's pretty amazing

 

[Houndogforever]

I've been tasked with trying to find some sort of cutter to mill the red surface pictured. I have about .175 square between the outer islands. Material is 7075 aluminum. This is all about surface finish, customer would like something around a 2ra. Thoughts?

View attachment 330511

Well, I'd like to be about 100lbs smaller and have a better memory, but what are the functional requirements for that surface?

 

[precisionmetal]

MCD Diamond Tip Radius 2 Flutes by VAN_HOORN | MISUMI online shop - Select, configure, order

PM

 

[Milland]

Any process is going to be compromised unless the spindle and axis control is in top shape. If the customer really wants/needs such a surface finish, it may require an air bearing spindle and linear travel machine to take advantage of even the best diamond cutter.

 

[Bogie83]

Houndogforever

Hey there. So I tried responding to you the following 3 days or so after you messaged me. But it kept saying your inbox was full. Just tried again, and still says the same thing

 

[Mechanola]

What a stupid design! Typical CNC trap. The four outer studs should be made separately and added. That way you had free access to the central plane. Then, of course, you’d put the part(s) on a lapping plate and have any desired smoothness.

 

[trochoidalpath]

I've been tasked with trying to find some sort of cutter to mill the red surface pictured. I have about .175 square between the outer islands. Material is 7075 aluminum. This is all about surface finish, customer would like something around a 2ra. Thoughts?

Try a Fraisa NX. I believe they can produce 0.1um Ra and come in tiny (3mm?) sizes. For sure when I tried them for floor finishing I was astonished.

 

[Houndogforever]

Hey there. So I tried responding to you the following 3 days or so after you messaged me. But it kept saying your inbox was full. Just tried again, and still says the same thing

oops. Sorry, emptied out now.

 

[Mtndew]

You might have to polish it by hand given the geometry of the part. How flat does it have to be?

 

[PHANG]

You can try to use a carbide bullnose endmill to facing it. if possible going to higher rpm with low feed rate.
after out from machine, direct use dish wash liquid to wash your part and blow it dry and keep it in close container with put in the silica gel pack together.
it to make sure the container inside low humidity. it prevent the part surface oxidation. cause the material aluminium 7075 easy to oxidized.