Cutting a part hardened to Rc60 with Dynamic Milling (feedback welcomed)

[crazy^millman]

Once again thank you for all the input on here.  The project is finished and the only casualty was the end mill that was broke the first go around.  We were able to cut the part with no problems with the following adjustments made.

 

 

 

Macgyver'd up an air blast system to clear the chips.

 

Used a shorter Kennametal (cxer0500nn4-f) endmill to remove all the material in the pocket down to the 3/4" depth.

 

Used different feeds and speeds

 

Inserted a plate jack In between the fixture and the table to reduce vibration.

 

 

Below is the finished product.

 

 

 

 

IMG_3530.JPG

IMG_3531.JPG

 

Thank you for the feedback. Looks great.

[?Mark]

Looks like I'm a little late to the party, lol.

 

I can't seem to find my library that I set up years ago for materials HT'ed to 60-65 Rc,  but...here are some tips:

-run dry, make sure there is no coolant anywhere near... even on the spindle housing . Drips of coolant will kill any tool very fast when cutting 60+rc material

-I used Niagara 6+ fl and hanita Javelin series end mills. There should be plenty more choices available now

-make sure there is no runout as mentioned previously

-on a weaker machine the smaller diameter is better

-don't be afraid of red/orange glow when cutting. Those end mills LOVE the heat at high sfm and chipload. The chips should be falling far from the part forming a fine, hair like pile

-you'll now when time comes to swap for a new end mill

-the part will eventually get hot, but you should be able to touch it

-again, NO COOLANT

-I'll post the speeds and feeds when I find my library...

[MrFish]

Once again thank you for all the input on here.  The project is finished and the only casualty was the end mill that was broke the first go around.  We were able to cut the part with no problems with the following adjustments made.

 

 

 

Macgyver'd up an air blast system to clear the chips.

 

Used a shorter Kennametal (cxer0500nn4-f) endmill to remove all the material in the pocket down to the 3/4" depth.

 

Used different feeds and speeds

 

Inserted a plate jack In between the fixture and the table to reduce vibration.

 

 

Below is the finished product.

 

 

 

 

IMG_3530.JPG

IMG_3531.JPG

Good stuff, probably learnt lots too which is what makes our work interesting ;-)

 

and all done on a weak Haas (cough) all you nay sayers !

[Bachmakinoman]

... +1 Didn't know Kennametal had such an array of hardmilling. 

 

Always a lil skeptical of some of their :starting: parameters for surface speed