Slot cutter speed and feed?

[Greg_J]

What would you run a 10" dia x .625 wide, .125 tip rad slot cutter. Cat 50 taper, 25hp spindle motor, very rigid setup in 4140 steel.

 

I presently I am making a flange have a 10.62 dia stock and I need to make it 5.6 dia x 4.25 leaving the flange 2.3 thick.

 

I have it set to run at 250rpm at 6ipm at .75 depth per pass, the first cut is full width so I have to slow it down in the feed. I have depth cuts of .5 and multi pass step at .75

 

What do you think?

[Tony35]

how many inserts on the cutter? are they coated? are they a tool steel grade?

[Greg_J]

Ingersoll grade IN2030, 18 inserts.

In their book it says 250-400 sfpm and .005-.01 feed per insert for 4140, it's quite the range.

 

For my first cut full width I had to slow my rpm down to 150.

[Hardmill]

150 RPM is at the high end (400sfm)

250 sfm is 95 rpm.

 

Even at the low end chip load your still at

8ipm (18inserts)

95*.005*18 = 8.55ipm

 

And dont be afraid to let it cut, most ppl tend

to slow it down at the first sound and end up

breaking inserts due to chatter.

 

 

PEACE

[Tony35]

for the first cut go with what sounds good and what the machine likes(spindle load ect.)

cut 1 (full) 124 RPM @ 6.696 (6.7)IPM

325 sfm .003 chip

cut 2 on up 152 RPM @ 19.152 (19.) IPM

400 sfm .007 chip

this would be a start. tweak as the machine,cutter wants it. i would try to get that heat into the chips. you may have to give it more feed if it starts to chatter or slow the rpm down(bring the chipload up).

HTH and good luck

[G Caputo]

Just making a stab in the dark here, but if the cutter has 18 inserts and it is 5/8" wide, you have 9 effective inserts per side when figuring out the feedrate going off of their recommended chip load. Sounds to me like you are doubling the recommended chip load. JM2C.

[G Caputo]

oops, double post

[Greg_J]

I'm through the full width cuts now I am in to the second .5 depth cut and .75 multipass, 200rpm @ 8.0 ipm spindle load is 15% and not much on the X or Z the Y is about 25% but the machine is a horizontal.

[Tony35]

looks like it could take more. how do the chips look(blue)? how do the inserts look? are you using coolant or dry?

[Greg_J]

I'm using coolant, they are blue some are silver the inserts are doing okay, I think one or two are getting worn. There is runout so they are getting it worse, there is a rythmic noise when I am cutting.

[Tony35]

try giving it more feed. put more heat into the chip. spindle load 30-40% see if that helps

[Greg_J]

Just a pic so you can visualize what I'm doing better.

 

[Greg_J]

Would you climb or conventional cut this?

[Tony35]

climb (less load) from the pic the chips look good. let err eat!

[Tony35]

well how did it go? what are the final results?

[Greg_J]

It went well I was cutting at 10 ipm at 170 rpm.

 

The next problem I have is that I need to create a large radius on the underside of the flange and a 45 deg on the side that meets the body.

 

I've cut the 45 part but I'm still working on the radius undercut. I am using surface finish flowline and it takes forever to calculate.

[Tony35]

can you do a surface finish contour, 2d swept?

good to hear it went well

[Greg_J]

I'll give it a try when I get back, I'm off till monday.

 

Thanks for the input.