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Polishing on a CNC

Nerdlinger

Stainless
Joined
Aug 10, 2013
Location
Chicago, IL
Hi Everyone! I have a steel plate, soft 1050, about the size of your hand and about .134" thick. It ultimately gets ground, polished (buffed), and nickel chrome plated. I have been hitting it with a face mill to give the guys in the grinding room a head start. I recently had success with an Ingersoll face mill using wiper inserts that get the part pretty darn smooth - 8Ra" maybe? I tried skipping the grinding belts and going straight to the buffing wheel and we were almost there (just a couple swirlies left over from the wiper) but I think if we got the part one "notch" smoother after the wiper inserts we would be good to go straight to the buffing wheel.

Sooooo I'm thinking either Brush Research Nam Power brush or XEBEC brush of some sort. Does anyone have any experience with either of these companies or, better yet, experience using them to polish steel parts? Or maybe there's another company I should be considering. Also, is it okay to have abrasive material in a VMC as long as coolant is there to flush away the spent grit??

Thank you for your help!
 
If you don't have them already, add filters to your coolant system. Shoot for a rough and fine filter setup, fine being in the 5 to 10 micron range.

You'll still have more wear on vises and anything else exposed to the coolant, so you'll have to balance efficiency improvements on one end with extra replacement costs on the other.
 
On those special occasions where I want a super spiffy finish on a facemilled part,
I just take out all the inserts but one and run it fly cutter style.

Its amazing how good of a finish you can get when EVERY insert (the ONLY insert) is
cutting at exactly the same height.

Problem is, its slow. I hear that "They" sell facemills where you can adjust insert heights
to get a perfect match.


I apologize for using the term "Exactly" and "perfect". Its one of my personal pet peeves, makes me
sound like a Fricken carpenter.
 
I also machine stone, quartz, and ceramic. With that experience, I DO NOT do abrasive machining on my VMC, NFW! I have had a 1 micron bag filter between my mill and coolant tank for years now with no issues so no need to do it different IME. If you do abrasive machining on your metal cutting machines keep a close eye on the way cover wipers, the abrasives will wear them quite quickly.
 
I bought a mill from Kyocera that spent it's entire life milling industrial ceramics. It was destroyed by 4 years old. I've also machined a lot of plastic composite material in a VMC and the glass fibers are brutal on way cover wipers.
 
To me its like changing the oil in your car along with a handful of sand.

If you think you'll finish and get all the fines out...When I first started with CNC I took just about any job I could get including cast iron. I used to start the job by cleaning and wiping the whole machine down to remove all oil traces so powder had nothing to stick to...machine with vacuum running and NO Coolant. Then when done...clean out machine wiping everything down. Still I'd find that black soot here and there after a weeks back to running.

I'm sure it will work for you, but at what cost.
 
Go with the Xebec. I've used them in VMCs to give a smooth (not polished, but smooth, uniform) finish to bone plates before anodize. The ceramic stones in the xebec tools hold up quite well, and though they're moderately pricey, they perform well enough to make them worth it.
 
Go with the Xebec. I've used them in VMCs to give a smooth (not polished, but smooth, uniform) finish to bone plates before anodize. The ceramic stones in the xebec tools hold up quite well, and though they're moderately pricey, they perform well enough to make them worth it.

Thanks! Have you used them enough to see any repercussions on your equipment from the errant grit whooshing around?
 
hmmmm, I'm hearing 1) fine filters and 2) spare way cover wipers. Thanks! Depending on how successful the process is, I may be able to deal with that. Any other votes for various tooling? So far there's one vote for Xebec...
 
Maybe Eric from Orange Vise will chime in, I know he uses the brush research brushes extensively in his HMC.

I second what Bob mentioned. Try a facemill with only a single insert in it, I think that will get rid of the swirls you're chasing.
 
Thanks! Have you used them enough to see any repercussions on your equipment from the errant grit whooshing around?

I have not... But my shop is the type with a maintenance department bigger than most shops, and PM and repair is just the cost of doing business, so I wouldn't know about it even if it was a problem, sorry.
 
Have not tried it myself, but Cogsdill makes a burnishing tool that looks like a facemill. Maybe that would do the trick? Quite expensive, I am sure.
 
Have not tried it myself, but Cogsdill makes a burnishing tool that looks like a facemill. Maybe that would do the trick? Quite expensive, I am sure.

Hmmmm, very interesting! Looks like the have a face mill with spring-loaded diamond-tipped burnishing pins. I’ve never done any real “burnishing” per se but I’ll be looking into this more, for sure! Thank you!
 
Hmmmm, very interesting! Looks like the have a face mill with spring-loaded diamond-tipped burnishing pins. I’ve never done any real “burnishing” per se but I’ll be looking into this more, for sure! Thank you!
Be aware that for roller burnishing you need a controlled bad finish. Their pamphlets will go into this but in essence, it's the opposite of thread rolling - they push the stickup material down into the valley material. It makes a dense shiny surface but not sure that is exactly what you want ? I tried it on bearing bores for a while and finally gave up, holding size was a bitch, it was not the cat's meow that cogsdill was promising :(
 








 
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