TAIG - Great surface finish with 4-flute EM + Scotchbrite

[tikka308]

Hey Folks,

I wanted to share a great experience last night. I was facing a piece of 0.75" square bar stock and wanted to get the best finish possible. I used a 4-flute 3/8" HSS End Mill at 5000 RPM, 7IPM, 0.030" DOC and was incredibly pleased with how smooth the surface turned out. While you could clearly see the toothpath, the part was very smooth.

I then used two different levels of 3M Scotchbrite and, after about 5 minutes, had a silky smooth finish completely devoid of any toolpaths. I think it's a great testament to how accurate & pleasant TAIG's can be when working with aluminum.

I've posted some more details and a youtube video of the part on my blog - check it out! http://www.nyccnc.com/Herbie/HERBIES..._Aluminum.html

Cheers.

[Gumby]

It's too bad taig can't use 1/2" end mills. I have these 6 flute end mills that leave a beautiful surface finish. I almost don't even have to polish the part after machining. Have you tried using a fly cutter?

[tikka308]

I have tried fly cutting and have definitely had good results, but can only remove a VERY small amount of materials - say 0.001". I need to remove about 0.030" for this part, so would prefer to do so without a tool change (i.e. an EM and then fly cut) since I have to make quite a few of these.

What kind of mill are you using with you 1/2"

[SpeedsCustom]

Tikka- When I cut my pieces I always then polish them with very fine grit. I don't polish what I cut, a 3mm thick piece is profiled and the top and bottom get sanded. It makes the aluminum look very nice. The Taig really does make great cuts in Al.

P.S. check the thread for the enclosure, think you will like it.


-Jason

[tikka308]

Speeds - just saw the new enclosure; checking it out now.

When you say "very fine grit", are you talking about sand paper? I didn't follow your comment re: 3mm piece...

[SpeedsCustom]

Right, I profile a piece that is already 3mm in thickness. But the aluminum I cut it from is rather dirty and scratched. So I use very very find sand paper and polish the top. It actually has no relevance too your topic because you polish away the mill marks. But I know what you mean, I do that sometimes too!

-Jason

[tikka308]

Jason - now I follow. What grit sandpaper do you use? What polish do you use after sanding?

[pzzamakr1980]

Tikka, you were talking about how to get the polisher and not have a circular motion. Tilt the head at a decent angle, use an polishing adaptor they sell for drills, chuck it, and just use the edge of it. I put a few dabs or superglue to hold the pads on, and just move the workpiece back and forth under the edge. I use this method with a homemade arbor, which was made on a lathe with scrap,to great effect. I have high density foam that I made into barrel shaped cutouts that go around the arbor, and with red and white turtle wax I can get a beautiful mirror finish on aluminum in a very short time. You can do the same with scotch brite pads, just cut in strips and glue together, then wrap them around something the same size as the arbor, and that way they are a bit cushy and conform better.

[tikka308]

Pzzamark - interesting idea. If I follow you correctly, you're basically putting a large-diameter cylinder in drill (for lack of a better example, think of a carousel wheel) and using the side? Obviously, although it's spinning, it's really a linear pattern on the side-contact point... great idea! Do you have a picture of your set up?

I have also been looking for a good polish for aluminum to get a mirror finish after I've scotch-brited everything. You use Red & White turtle wax? Is this it? http://www.amazon.com/Turtle-Wax-T37...9002036&sr=1-3

[pzzamakr1980]

Nope its the paste wax stuff that comes in a big shoe polish looking container. Im sorry, neither of them are actually wax, the red stuff is turtle wax rubbing compound, and the white stuff is polishing compound. Before I use those I use your regular green scotchbrite pads or 1500 grit sandpaper saturated with oil. Then I do the two turtle waxs and its a mirror finish. Actually, if you are not too anal, you can use 1500 than 2000+ sandpaper sprayed liberally with wd40 for a near mirror finish.

Yes, its basically just as you describe. By not using the whole round arbor and just using the edge, prevents swirls pretty well, and the finish doesnt look crappy. I will either move the piece back and forth by hand under the polisher, or use my mill to rapid back and forth. It works great, but I dont have any handy pictures.

[pzzamakr1980]

One last thing, if you want a polish that is chrome like, and looks like a car paint job, finish it off with a good auto wax and a polishing bonnet. I love meguires carnuba paste wax. I light it on fire, drip it on the part, and polish away. It takes some time but it is freaking amazing. On any part that can corrode, it also helps prevent the corrosion from happening in the first place. I coat my table before I mill with a good wax. Its not oily and it wont just wash away.

[tikka308]

Pzzamakr - where do you pick up your turtle wax? I have to order most of my stuff online due to location and would love to get your help with the specifics on the red wax rubbing compounding and the white polishing compound. It looks like this is the red rubbing: http://www.turtlewax.com/main.taf?p=2,1,4,13 and this is the white polishing: http://www.turtlewax.com/main.taf?p=2,1,4,14 ?

Also - don't laugh - but where do you buy 1500 and 2000 grit sandpaper? The highest I see on Enco is 1200...