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terry_g
05-10-2009, 11:13 AM
I recently purchased a small 8x30 1 1/2 HP knee mill a B048 from Busy Bee Tools.
http://busybeetools.ca/cgi-bin/picture10?NTITEM=B048
It came with a coolant system and power feed. I also bought a small selection of Niagara HSS end mills 2 and 4 flute in 1/4" 3/8" and 1/2" and some inexpensive fly cutters.
The max speed for a 1/2" HSS end mill should be around 700rpm. The belt drive has a gap in that speed range it goes from 490 to 950.

For heavy cutting in mild steel Will a slower speed make for longer tool life when running coolant?

How deep a cut can one safely make with an end mill?

Are carbide endmills good for the home shop?

What applications do 2 and 4 flute cutters work better for?

Can end mills be sharpened in the home shop?

Would this 2" carbide end mill be too much for this small mill?
http://busybeetools.ca/cgi-bin/picture10?NTITEM=B2136R8
http://www.busybeetools.com/pictures/b2136r8.jpg

I have run a lathe a fair amount but running milling machine
is a new experience for me so any advice would be greatly appreciated.



Thanks in advance! Terry

Davek0974
05-10-2009, 11:59 AM
Hi Terry, i'll try and answer what i can...


I recently purchased a small 8x30 1 1/2 HP knee mill a B048 from Busy Bee Tools.
http://busybeetools.ca/cgi-bin/picture10?NTITEM=B048
It came with a coolant system and power feed. I also bought a small selection of Niagara HSS end mills 2 and 4 flute in 1/4" 3/8" and 1/2" and some inexpensive fly cutters.

Looks ok to me.


The max speed for a 1/2" HSS end mill should be around 700rpm. The belt drive has a gap in that speed range it goes from 490 to 950.

My chart shows 800rpm, the question still remains higher or lower? I would probably go lower.


For heavy cutting in mild steel Will a slower speed make for longer tool life when running coolant?

Likely will but remember to lower the feedrate too.


How deep a cut can one safely make with an end mill?

I like to limit seriuos cuts to the same as the tool width.


What applications do 2 and 4 flute cutters work better for?

I would use two-fllute for plunge-cutting and closed-end slots, four flute tools for profiling and facing. Four-flute tools dont like cutting when bothe sides are in the cut, i like to limit width to half the tool width.


Can end mills be sharpened in the home shop?

Not very easily.


Would this 2" carbide end mill be too much for this small mill?

Should be ok for light cuts, i have best results with facecutter that have a high positive rake tip, much less strain on the mill.

Dave

danlb
05-10-2009, 12:53 PM
The max speed for a 1/2" HSS end mill should be around 700rpm. The belt drive has a gap in that speed range it goes from 490 to 950.

For heavy cutting in mild steel Will a slower speed make for longer tool life when running coolant?[/quote]

According to a bunch of charts, the range for mild steel is 80 to 140 sfm, so the RPM for a 1/2 inch endmill falls between 611 and 1069 rpm. My understanding is that If you run way too slow, the cutter will not bite in as well. The result is poor finish and dulled mills.



Are carbide endmills good for the home shop?

Sure. They allow deeper cuts without flexing.



Would this 2" carbide end mill be too much for this small mill?


I have a similar mill and a similar end mill. It works fine.

Dan