Milling Advice

[M_R_205 5 1 Cars]

a very random topic, and not probably in the rong place, but im after a little advice please

 

We have a tool at work which cracked so i took it home and welded up the crack with the intention of milling it flat on my small diy style milling machine, (please bear in mind im an absolout beginner!!!) now your probably guessing that i couldnt cut the weld for love nor money, well your right, i just blunetd the tool, what sort of mill bit would i need to cut though the weld and what sort of speed would you recomend?

 

at the mo im just using (was just using) a 4 flute carbide mill bit 5mm at about 1500 rpm, so nothing spectacular, just basic, starting out tools

 

Anyadvice or tool recomendations would be ace

Paul.

[thirdtimelucky 3]

A carbide cutter cutter should be fine but weld is very hard and you need to push the cutter into it fairly hard so the cutting edge gets under the surface of the weld, you'll need a bigger cutter 12-20mm because a 5mm one will just break. you need a much slower rpm as well 700rpm or less. use plenty of coolant/cutting oil.

 

I would just use a grinder and file, much quicker and just as accurate if your good with a file.

[Rippthrough 98]

It depends on exactly what you are doing but try not to use the full width of the cutter - use about 60% at most, full width makes the cutter chatter (high frequency vibration), and they snap, unless you have tools designed to surpress it or special toolpaths that would take far too long on a manual mill.

 

And always use the biggest tool that'll do the job.