How to get polished look when milling pocket

[originator]

I have been using some good end mills by Micro100, the edges of the parts are always nice, even the milled down pocket using aluminum feels smooth but has the path showing. Is there a technique to polish the inside of a pocket to make it completely smooth?

Thanks

[dertsap]

600 grit and some eagle one aluminum wheel polish , it will give you a mirror shine ,its an incredible polish

[STATEMENT]

^its hard to get a peice of sand paper or use a polish wheel to get the right finnish inside a pocket, I would suggest doing a small finnished at a low rpm all the way around the pocket

[tobyaxis]

Originator,

Rough your pocket and leave about .005 on the walls and .005 on the floor.
When finishing do the floor first. Do Not Cut the Walls. Feeds and Speeds will be low as already suggested by Statement. Then Finish the Walls. As a rule of thumb and if given a choice I Never Finish Walls and Floors at the same time. The finishes won't be perfect because your milling. If you where turning you would you would be able to get a 32 micro finish or better depending on the condition of the lathe and rigidity of the setup (tools, part, chuck/collet).

[STATEMENT]

yeah, its definitly harder to get the floor with a real good finnish than the walls, another way of solving the problem would be to get a fresh end mill

[dertsap]

Originally Posted by STATEMENT ^its hard to get a peice of sand paper or use a polish wheel to get the right finnish inside a pocket, I would suggest doing a small finnished at a low rpm all the way around the pocket

you d be surprised what a rag with some of that polish can do

high rpm with a light cut is best to get a decent finish in aluminum , aluminum tears at low rpm , too high of an rmp will produce chatter

[STATEMENT]

Originally Posted by dertsap you d be surprised what a rag with some of that polish can do

im sure it would work, but in my situation im making over 500 parts and im running 3 different machines at the same time. So im trying to make less hand work for myself by taking advantage of finnishing cuts on the machine. Also I use a tumbler with small rocks and that also help smooth out the finnish on the entire part.

[tobyaxis]

In that case, play with your Speeds and Feeds on the Roughing tool. What you might be getting is Tool Flex that makes a slight concave in the tool path. Let the tool cut to a degree, but don't lose too much production with increased cycle time. Do the same with the Finish Tool. Do the best you can. One part at a time, one tool at a time.

[widgitmaster]

One of the most important tricks that has not been mentioned so far is to take the new endmill and carefully put a fine radius on the points with a small hard stone, or diamond file if carbide! The Radius will produce smoother peaks and valleys as the cutter moves! Don't forget to check the print to see what the maximum allowable fillit radius is!

Finer finishes are easier to polish too!

[STATEMENT]

^interesting

[dertsap]

Originally Posted by STATEMENT im sure it would work, but in my situation im making over 500 parts and im running 3 different machines at the same time. So im trying to make less hand work for myself by taking advantage of finnishing cuts on the machine. Also I use a tumbler with small rocks and that also help smooth out the finnish on the entire part.

im not sure what your situation is but i was only answering to the original question posted asking how to get a POLISHED finish

also i agree with widgetmaster in adding a rad on the corner , if the tool wants to chatter a trick i use on new carb endmills is to lightly stone the flute to dull down the sharp edge ever so slightly, sharp isn t always best

[all around]

you could also leave .0005 for another pass that is offset in the "z" axis by .003-.010, approximately. There are also some auto polishing solutions to mount right in your toolholder that have replacable drums of scotch- brite material.

good luck