Chip Load and depth

[men8ifr]

Will I be OK to use the full depth of my endmill for roughing and finishing? 

FWIW it is a 4.5mm dia x 15mm (4) flute mill on a fairly rigid (for the endmill size) PM25 milling machine. 

I try to set the feed per tooth low at 0.03 but I don't know if the speeds/feeds in Fusion will account for lots of extra load using the full depth of the mill? 

I've not run a CNC program on this machine before so trying to use very conservative settings. 

Also I find it strange if I reduce spindle speed in the tool parameters fusion increases the feed per tooth unless I over-ride it. 

[DarthBane55]

You didn't say what material you are machining.

0.03 is metric or imperial?

Fusion outputs the feed that you input, it does not calculate any sort of compensation for tool engagement and whatnot, this is for you to calculate.

When you reduce the spindle speed, it maintains the feed per minute, that is why you see the feed per tooth increase.  To maintain it, I believe you need to look at it before changing your spindle speed, and re-input it as it was before...  if someone knows a way to keep the feed per tooth locked instead of feed per minute, please chime in!

[men8ifr]

0.03mm and aluminium 6061 with 4.5mmdia x 15mm flute length hss endmill. 

Thanks I sort of assumed (wrongly) when Fusion is changing parameters based on its calculations it would be doing in a safe way but instead it just recalculated stuff based on the feed then. 

I *think* like you said if I put feed per tooth back in it then calculates feeds based on this so gives the result I want (put in feed per tooth and rpm) 

[DarthBane55]

Yeah, don't assume that Fusion (or any other CAM software for that matter) would do things safely.  Better check, double check, and triple check for yourself before sending to machine.

The 15mm length, is that the flute length or the tool stick out or the cutting depth?

When unsure about speeds and feeds, you can mostly rely on the tool manufacturer to have some basic charts to guide you.  But it is basic.  When you tweak your cutting parameters outside of their rudimentary chart, experience will be useful, but you can also purchase a cheap software like HSMadvisor, and there is another one I can't remember the name of it though.  They basically are speeds and feeds calculators that give you a pretty **** close cutting data, for your exact cut, tool, and material.  I use it regularly, it helps optimize tool life and speeds and feeds for each single cut I do.  Then you can tweak on the machine to make it really perfect.

[jscott6SWZG]

I run 0.5mm step over, 6.3 mm doc, at 24000 rpm and 1500 mm/min. Must have good flood.

I can run up to 15 mm doc but that is close to the limit.

0.03 is step over for final pass and reducing cusps with a ballnose

definitely not a rigid machine

6061 aluminum

some where around .025mm per tooth, carbide, 6.35 mm dia