[impact]

I am milling out the exhaust manifold for my nissan 200sx as the divider is a weak point and is already practically destroyed.



Currently taking 0.01 passes at 2IPM with a 0.25" TiCN Endmill.

Am I noob?

Discuss.

[impact]

http://purecomponents.ca//Media/MOV01133.MPG

Video.

[levelzero]

What rpm are you running it at? Sounds like your surface speed is too high in the video.

[9 1/2]

Cast iron is very brittle and has a high carbon content. What cutter are you using? If it is HSS have you checked your numbers?

Check the MHB for cutting speed, d.o.c., and RPM values for milling grey cast iron with HSS

fm = ft*nt*N
Where:
fm =milling machine table feed rate in inches per minute (ipm)
ft =feed in inch per tooth (ipt)
nt =number of teeth in the milling cutter
N=spindle speed of the milling machine in revolutions per minute (rpm)

and RPM would be calculated as follows ->
RPM=12*V/(3.14*D)
Where:
V= cutting speed
D= diameter of your cutter.

Look Table 14. Cutting Feeds and Speeds for Milling Ferrous Cast Metals for the variables.

Nice looking rig you got there.