Wal
14-02-2014, 07:36 PM
A bit of a general and elementary question here, but there's probably a 'right' way of doing this that I don't know about.
Consider this piece of 'free cutting' brass stock:
11608
11609
The way I'd approach this job would be to spot then drill the 4mm hole first, then pocket the 6.5mm - here come the dumb questions:
1. I take it I'm better off using a drill bit specifically for brass, but how about spindle rpm's and peck/depth settings? Where's a good place to start? I have one of the 2.2kw Chinese spindles - will dropping the rpm kill the torque enough to prevent it from drilling? Something tells me that I really don't want to send a drill in at 12000 rpm...
2. What end-mill would you recommend using to pocket the 6.5mm hole? A 6mm? Or stay small and go with a 4mm? 2 flute carbide intended for alu going to be okay?
Apologies for the basic nature of these questions, but I'd sooner start with half a chance of getting it right rather than waste stock/bits...
Cheers!
Wal.
Consider this piece of 'free cutting' brass stock:
11608
11609
The way I'd approach this job would be to spot then drill the 4mm hole first, then pocket the 6.5mm - here come the dumb questions:
1. I take it I'm better off using a drill bit specifically for brass, but how about spindle rpm's and peck/depth settings? Where's a good place to start? I have one of the 2.2kw Chinese spindles - will dropping the rpm kill the torque enough to prevent it from drilling? Something tells me that I really don't want to send a drill in at 12000 rpm...
2. What end-mill would you recommend using to pocket the 6.5mm hole? A 6mm? Or stay small and go with a 4mm? 2 flute carbide intended for alu going to be okay?
Apologies for the basic nature of these questions, but I'd sooner start with half a chance of getting it right rather than waste stock/bits...
Cheers!
Wal.