machining a small deep slot

[Richl]

Hi,
I have a 5.5mm closed slot x 32mm deep to machine in mild steel using a long series 3-flute carbide cutter. Does anybody have any reccomendations for feeds & speeds d.o.c etc. I would be grateful for any suggestions as my background is turning but this job has been landed on me.
Thanks

[txcncman]

Try 1/2 cutter diameter for DOC. 125 for your SFM. 0.002 chip per tooth.

[Richl]

Thanks for the reply , do you think 1/2 cutter dia d.o.c will be ok with the long series cutter ?

[DMF_TomB]

carbide end mill
3 flute
5.5 mm / 0.216" diameter
Stickout / Flute Length 32 mm / 1.3"
milling mild steel machinability rating 0.8 cubic inches per hp per min
.
max parameters at
125 sfpm
2211 rpm
max depth of cut 0.039" (about 1 mm)
max Feed 9.4 ipm
chip thickness 0.0014"
End force on end mill tip comes out at 22 pounds at max parameters with 0.10 horsepower needed
an end mill 32mm long by 5.5mm diameter is a 5.82 length to dia ratio
...... in general end mills with higher than a 5 length to diameter ratio flex a large amount for harder materials like steel. you will probably have vibration problems and the milled finish will probably be rough

[Dyad1]

How long is the slot? You might try a series of drilled holes say 3/16 dia. along the length of the slot spaced next to each other. Then setup your end mill to plunge the webs out. offset the end mill center line so you don't run the center of the end mill down the center of the web. This gets most of the material out of the way. Does the slot go through? This would be great because it is so much easier to flush out the chips.

[Richl]

Thanks for all the replies, got something to work with now
Thanks.