Question about bits


(Ivan Pedruzzi) #1

Am I a complete fool thinking that I could use these micro bits (0.5, 1.0 mm) with the DeWalt router?

My goal is to create the following object which is 20 mm across and 3 mm thick, out of aluminum 6061 stock
There is also an hexagonal slot for a M3 nut.

These in gold are the bit which I am blowing to peaces even slowing down the feed rate to a crawl

Any suggestion?


(Mad Hatter) #2

What are you feeds and speeds? Are those diamond cut carbide burrs? I have not used those for metal. I use mine only for cutting FR1 and FR4 circuit boards.

EDIT: I don’t cut aluminum, but I use bits from 0.2500" down to 0.0110" in exotic hard woods and plastics. I know, not the same as aluminum, but it’s the only info I can give you.


(Ivan Pedruzzi) #3

I tried 3000 rpm feed rate 1 mm/min, plunge speed 1 mm/min

The seller claims <<" solid carbide micro PCB Drill Cutter,TiN Coated pcb router bit,corn tungsten Milling Cutter">>


(William Adams) #4

Yes, you should be able to use such delicate endmills (EDIT: if they’re good quality) — but possibly not with the stock collet, and rather than our precision collet — see:

http://www.precisebits.com/gateways/ColletsNutsHome.htm#paneThree1


(mikep) #5

depth of cut matters a lot too - they just can’t take a lot of side force


(Richard Cournoyer) #6

If you use proper end mills suited for the metal (not just some cheap Chinese generic), and follow their recommended speeds and feeds, AND use a proper coolant to clear, cool and lube the cutter, you will be fine. I use small cutters/drills all the time.


(Adam X) #7

Those “gold” mills on the left look suspiciously like the sets they sell on AMZ for $15 or so… spoiler: they’re garbage (ask how I know this). You should be able to get quality 1/32" solid carbide end mills with a 1/8" shank from C3D. “Drillman1” is a seller on ebay who I (and others) have had excellent luck with.


(Daniel Loughmiller) #8

Big thing we seem to be missing unless I missed it is depth of cut.


(Ivan Pedruzzi) #9

I need to mill 3 mm which is thickness of the stock


(Ivan Pedruzzi) #10

Thank you, I ordered this https://www.amazon.com/gp/product/B00X78AYL2/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1


(Daniel Loughmiller) #11

Can you do it in multiple passes? I’ve been keeping my 1/8" bits to milling 3mm each pass in wood so, smaller bit in metal I’d keep it shallow and do multiple passes if possible.


(Ivan Pedruzzi) #12

I think my step down was 0.5 mm per pass


(mikep) #13

I would start at .005-.008" and work up from there with a .125" end mill on aluminum, .5mm (.019") seems pretty deep for a .5mm end mill.


(Ivan Pedruzzi) #14

You are absolutely right even with a mediocre cutter I am making progress, thanks Mike


(Ivan Pedruzzi) #15

Success!

These will replace 3D printed plate adjuster wheels.

I did the bolt trap and the M3 hole using a 0.5 mm bit and the contour with a 1/8 with a very conservative 0.05 mm plunge rate

Shapeoko 3 rocks!


(system) #16

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