View Full Version : What mill bits?

07-10-2011, 08:50 PM
Hi all

I am just about to purchase a kress 1050-1 FME for my cnc machine that I am constructing. However, one thing that I am confused about is what mill bit(s) do i need?

I will mainly be milling G10 fiber glass but also aluminum upto 10mm (possibly thicker - I don't mind doing many passes) - I will be creating bolt together frames for my multirotor hobby.

I have read that is best to purchase a collet of 1/8" as the milling bits are more plentiful - however, looking at https://www.damencnc.com/en/tools/cutting-tools/milling-cutter
it seems that these milling bits are what I need (?) but are not 1/8", so now I am confused.

Can anyone suggest the type of mill bits I should be purchasing for the milling i will be doing?



14-10-2011, 10:01 PM
Nobody have any ideas? would much appreciate some input now my frame has arrived.



blackburn mark
15-10-2011, 11:39 AM
search for "single flute carbide" on ebay, they are great for plastics and do pretty well on aluminium and are cheep enough to take a punt on (20 ish for 10 x 1/8" )

they have been talked about on this forum before, do a search for single flute :smile:


the ones you have linked seem a bit pricy, if i could only have one collet id go for 1/8" (cheep tooling) can you not buy a few collet sizes for the kress ?

15-10-2011, 12:03 PM
Thanks for that. I did not know that I had to search for the term 'single flute' - much appreciated. Looks like I will buy a 1/8" collet and the cutters you link to.

Are these good enough for actually cutting shapes out of the aluminum (assuming I do enough passes) as well as engraving type work? Sorry for the Noobie questions on this.



blackburn mark
15-10-2011, 12:30 PM
Sorry for the Noobie questions on this. behave yourself :smile: we are all here to learn :)

it can be slow and painful cutting aluminium on a router but that tends to be a machine limitation but theres nothing stopping you cutting posh shapes with these cutters

i mostly cut acetal on my machine without any lube/coolant and these cutters last a long time for me

iv cut aluminium when i have to and use WD40 for lube or the cutter will bog down re cutting the chips that havent cleared in tight slots, you need to get them chips cleared if you can... it can get pretty messy if your using lube and blowing the chips out with air, somtimes ill just lube and forgo the compressed air at the expence of tool life the tool can still bog down and snap in deep slots but the 1/8" single flute cutters are cheep enough to do some science and see what happens :smile:

EDIT: there are plenty of 1/8" engraving bits on ebay... iv used a few in alli and plastics with no problems

15-10-2011, 05:01 PM
There is a thread about these cutters and they seem to have a good review BUT they do take over three weeks to arrive



15-10-2011, 07:54 PM
Cheers for the info - I found the thread to which you are talking about, i think...is it this one:
The ebay link which you gave is to a different sized single flute cutter, is this specific to the Kress or does it require another collet size?



15-10-2011, 08:13 PM
The 6mm single flute cutters mentioned here will be excellent for the aluminium. Look at the parts I cut that are in luke11cnc's build log to see the finish...

However fiberglass is going to be much more difficult. Since it looks like you'll get some for aluminium anyway you might as well try it. I expect they will not last very long at all as glass is very hard and abrasive. I've cut some parts from carbon fiber and texalium sheet (so fairly similar stuff) and HSS tool lasted a few seconds and carbide a few minutes so both basically useless. You want diamond ... but that's expensive so I tried those cheap diamond burrs you get with rotary tool kits and it was excellent. 2mm diameter, highest spindle speed and something like 300-500mm/min (can't remember exactly but it was slow). The finish is good as you're grinding it. People who are fond of health and safety will mention at this point that the dust is very bad for you.


The second photo is before I washed the dust off, hence it looks a bit bad...

15-10-2011, 11:57 PM
@Jonathan - Which 6mm bits are you referring to? An item on the page in the link I posted or to the two ebay item links? I didn't think either of the ebay links were 6mm?? One is 0.125" (3.18mm) and the other 0.157"(3.9878mm)

I would also assume that I would need a 6mm collet to use 6mm bits with a Kress?



16-10-2011, 12:25 AM
@Jonathan - Which 6mm bits are you referring to?


I use them a lot... I've done anything up to 25mm thick with them.

I would also assume that I would need a 6mm collet to use 6mm bits with a Kress?

Yep, the bits don't squash that much :lol:

If you're cutting all the way through this 10mm aluminium then get the 6mm cutter as it's a huge amount more rigid than 1/8" and there's more space for the swarf to clear. That means you can cut faster (higher depth of cut and feedrate), and I guess the cutter will last longer too. I use mine on the router at 1.2mm depth of cut and 600mm/min @ 11000rpm, just putting coolant on with a pipette (so much easier than a brush) every so often. If you're using a rigid milling machine they will cut through 10mm in one pass, but on a router you need to use less as framework and spindle are not as strong.
A 1/8" wide slot 10mm deep is needlessly annoying if you can fit the 6mm cutter in.