Making a Part Look Pretty

[ddickey]

Especially milled parts. I have milling marks everywhere. Not sure if this is normal but what would be the process of making parts look nice. File, sanding, polishing. How do I decided how to go about this?

 

[Ulma Doctor]

different materials will machine differently and the leftover marks will vary
some materials you need to intentionally leave a little large and grind or otherwise finish to final dimension
softer materials can use cutters spinning at higher speeds with an end finish that will appear less flawed
sometimes tool geometry is critical to a good finish as is feed rate and RPM

a lot of production parts are tumbled in vibratory finishers for brilliant finishes
perhaps a homebrew tumbler may be something to consider.
walnut hulls, almond hulls, ceramic media, and sand/gravel could be used to different levels of polish
then there is always sanding and polishing with elbow grease and polishing compounds too

 

[Wreck™Wreck]

Handwork, polish until the desired results are achieved.

Electro polishing is an option but I suspect that you would not like the cost, a timesaver is also helpful before starting the work, otherwise the tooling marks are part of the game.

 

[chips&more]

Maybe do the last pass with only a few thousandths of material removal and a higher spindle speed. Also, you should always conventional mill. But, on that last pass maybe return with a climb cut with no cut intended. Just return the cutter to the beginning in a climb cut...Dave

 

[jlsmithseven]

If you really want it shiny, go take it to the surface grinder. Make sure you leave a couple extra thousandths to take off after your done milling.

 

[intjonmiller]

It depends ENTIRELY on what you're doing. As Ulma Doctor said, the tool geometry matters. The feeds and speeds matter (higher speed and slower feed, for instance, will generally produce a finer finish, all else being equal). The materials matter. The shape you're producing matters. A well-tuned surface grinder can make your parts incredibly smooth and shiny when done right...if your part involves all flat surfaces to allow it to be surface ground.

Generally hand finishing is an excellent option for most projects. Not always the most efficient, if resources were unlimited, but always effective. Check out Tom Lipton's (Oxtoolco on YouTube) completed Baby Bullet Vise series for an excellent demonstration of all the different aspects of producing an incredible finished part. His ongoing series on building an intaglio printing press is also very good. Many other such projects out there. But the absolute best I am aware of is Clickspring's recently completed clock project. It took him almost two years to make it, and every minute of every one of his videos is enjoyable and educational.

See you next week.

 

[ddickey]

I believe I'm using the correct speed not sure about the feed. My mill is manual so I normally feed slowly no matter what the speed. Can to slow a feed with the correct speed contribute to a poor finish?
Thanks for the tips guys.

 

[Chipper5783]

Practice, try again, read about material properties/tool geometry/speeds/feeds, practice, talk to machinists, practice, ask questions here - try, try again. I don't think there is any magic recipe to getting a good surface finish as machined. All the above ideas are good - but you need to simply keep at it.

 

[tq60]

If a mill then depth of cut and speed of feed as well as consistency of feed meaning power feed will be much better than manual.

Good sharp tools and a perfectly trimmed head.

If it is not perfectly straight then the cutter will not cut flat and will never De good in less you are cutting a cove.

Sent from my SAMSUNG-SGH-I337Z using Tapatalk

 

[Subwayrocket]

I often use the first few passes to get the speed dialed in . Feeding by hand would make it more difficult to be consistent . Too slow feed or too shallow cut and it rubs , too fast and you get lines . I usually have an idea where i wana be , then tweak it as the first pass is feeding across . Scotch brite wheels and Roloc discs work well in steels and the lambs wool wheels do good in Alum . I've put them in a hand drill .