Finding the correct feeds and speeds fast!

[Ukmiller]

Hi im new here.
Probably the oldest question in milling but im looking for advice on finding the correct feeds and speeds fast.
Im currently milling some en24t of which always seems to cause me issues.
I need to rough a profile out with a 12mm carbide end mill but it just doesnt seem to cut nice which ever way i do it.
Ive tried full depth cut and incrementing inwards 1mm per pass but the cutter isnt liking it.
Incrementing down 1mm per pass just wears the corners off after a few loops.
Is there something im missing when it comes to en24t?

[johngoodrich]

what type of endmill are you using. is it specifically designed for hard steels or just a standard endmill. I like using these for hard steel
http://www.cutwel.co.uk/milling/milling-cutters/v7-mill-variable-helix-steelstainlesshrsas/4-flute-standard-length-steel-geometry-v7-mill-variable-helix-coated-carbide-emd42-series
you need to look up your manufacturers cutting data

[magicniner]

I always fid HSM Advisor gets me in the ballpark straight away.
Are you sure that the corners are wearing off the carbide endmill and it's not another mechanical mode of failure?

[Ukmiller]

Im using ones designed for hard steels but o found a way to rough out by using a 16diameter two tipped tool but the tips are only lasting for two parts before i need to turn them round and ive 26 to make!

[Ukmiller]

I always fid HSM Advisor gets me in the ballpark straight away.
Are you sure that the corners are wearing off the carbide endmill and it's not another mechanical mode of failure?

I just looked at hsm.
Is it only available for pc or can i get it on my phone?
As for cutter wear im not sure what is going on other than i cannot get a good chip to come off the material.
All i can get is small hard chips which wear the cutting faces.
I tried full depth cut but im not getting my usual long thin chips off of it.
Its as if the en24t has work hardened in the turning stage