[n1k86]

I have a standard X3 that I recently converted to CNC with a CNC Fusion deluxe kit. I have to mill the outside profile of some parts out of a 1/4" bar of 360 brass so I will need to make full width cuts. I will be making a couple of hundred parts a year most likely and they will be setup in a production fixture to hold multiples at a time. My questions are what size endmill will work best to minimize waste while still being able to move reasonably quick and should I bother with a rougher? I would like to take a full depth pass but realize that it may be unrealistic with a machine this size. Also, does anyone have a suggestion for a chipload in brass? Thanks for any help.

[pete from TN]

Brass is an easy material to machine usually altho it does have some funny chip problems sometimes and I would probably check into Bob Warfields cutter feeds and speeds program G wizard. It would help a lot if you could tell us how deep you need to go and if there are any radiuses that will require a smaller endmill to get inside them. On most of my parts that are gonna be deep milled I use a step machining to get to depth and then a full depth finish pass of around 10 thousandths. This is of course assuming you are using some kinda air blower, mister, or coolant to remove the chips from the deep cavities. The X3 looks to be a decent machine for its size and is kinda the little brother to my Rf45 in a lot of ways so I would imagine it can take some decent cuts. For most things I have seen the shape of the cut and the depth of the cut will dictate the cutter size and then I just try to optimize it as much as I can if I have to make more than a few items at a time. So far the biggest part run I have done is like twenty parts at a time so nothing too major just yet. The twenty part run I made is probably gonna be an at least occasional run and I am hoping next time to setup a larger fixture to run many of them at once as they are machined from a 1/4 inch angle aluminum. I would think a nice two or three flute cutter would be great for the brass stock and a similar high helix to aluminum would be probably your best bet. I have a 3/8 inch three flute high helix I bought recently that I am finding is my go to tool for a lot of cuts. The three flute seems to give a great finish, can hog really well, yet has enough flute clearance to evacuate chips rapidly. The flood coolant sure helps too now that I have a decent pump on it.... Good luck with your parts run and congratulations on finding a product that you need to make over the long run. That is the best way to make cash I think is the small niche market part that people need often and are willing to pay a little more for since they are not available in a lot of places. At least on machines like our small platform ones high production is just not in the cards.... peace

[ViperTX]

Well, I also have an X3 with the CNC fusion Deluxe Kit and I'm milling 360 brass.

At 2000 RPM, using a 1/8 inch diameter high speed uncoated end mill (2 or 4 flute) my depth of cut is 0.040 at 5 IPM. Any faster then 5 IPM breaks end mills.

Go to niagaracutter.com and use thier speed/feed calculator.

Paul

[Enraged]

it may be best to use a band saw to cut up your blanks prior to machining, to minimize waste. for rigidity, you want to use the largest cutter possible that will fit your geometry.