Making a Part Look Pretty

It it's nothing but flat surfaces, lightly belt sand it to make it a bit flatter then jewel it. put a 3/8 wooden dowel in the mill, dab some lapping compound on the surface and spot it every 1/4 inch in each direction. Time consuming, yes, but you will have a beautiful finish.
 
Yes, too slow feed can be detrimental because it can't "bite" in and turn a chip, so it rubs.

The book "Manual of Lathe Operations", distributed by Atlas once upon a time, has the best explanation I've found for understanding how the tooling is working, regardless of the type of tool or machine, because they first get into metalworking theory. (The horrendously short version: every tool used to cut metal is a variation on a cold chisel.) There are also a number of old machining videos (like 1940s-1960s stuff) on YouTube that show what's happening very well. I'll try to find you some links. There are certain little lessons that just "click" when you see these concepts presented in just the right way, even though you had read explanations or seen videos of the tools used before.
 
In my opinion, the first step toward a good finish is to cut it clean in the first place. Use a fly cutter to square the part, not an end mill. Then rough your features with a roughing end mill before using a good finishing end mill. Your parts will need minimal clean up and final finishing will be much easier.
 
I don't know what mill you are using or just how much experience you have in milling, but a few things that I have learned either by listening to the guys here on The Hobby-Machinist or by hit and miss experimentation: What kid of a mill are you using. What kind of cutter are you using. Cutter RPM? Speed of feed? Lubricant? and possibly the most important that I have found is: are you firmly locking all axis that you are not using for the particular cut. Have you trammed your mill head and table?
SAs for final finish, I usually use 3M Scotchbrite pads which I have on hand in every conceivable size, form shape, and grit. I really like the ideas of the wooden dwell/lapping compound and lambs wool wheels mentioned above, as well as the tumbling and or vibration of the part in various media like walnut shells. Thanks for starting this discussion up, I'm picking up all sorts of new idea.
Let us know what you did up doing and show us some pictures of the before and after results.

CHuck the grumpy old guy
 
I have an older Grizzly 1004 I think it is. It came with a ton of end mills and other cutters, some where even new. It came with a fly cutter that cuts horrible. The cutting tool looks poor so my guess is it is the wrong geometry, sharp with no radius. I tried to hand grind some into it but didn't make much of a difference. It also came with what looks like a carbide fly cutter which has four cutting non removable inserts, at least they look non removable. This tool leaves a relatively smooth cut but lots of cutting marks which I'm learning is probably normal. Speeds were low. Anything more than a few thou DOC and my mill makes a horrible racket with those big cutters. The mill performs well with smaller end mills. I trammed it when I got it home. I should probably check it again though.
 
Here's that face mill. Those cutters are permanent or?thumbnail_IMG_20170121_123648933_HDR[1].jpg
 
Hi ddickey,
the cutters appear to be brazed in place by the manufacturer.
conceivably, they could be replaced if you had the need or inclination.
set up would need to be fairly precise to get the cutters in the same plane of height, but not too a big hurdle
 
Actually, with a bit of ingenuity, I'd be willing to bet you could modify that cutter to hold inserted tool bits!
 
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