HST and detph of cuts

[crazy^millman]

I am of the mind set it does me no good to rough at 150% for 2 passes to leave a 20% pass at the bottom. I will balance the depth of cuts to make them all even. What are others thoughts about this process?

[jeff]

I don't follow you.

What is at 150% ?

[gcode]

3 minutes ago, jeff said:

What is at 150% ?

1.5 length to diameter ratio

example ... 1/2" endmill 1.5" deep

[Guest]

I would push the DOC to get it to 2 passes and decrease the stepover a bit to compensate

[jeff]

1 minute ago, gcode said:

1.5 length to diameter ratio

example ... 1/2" endmill 1.5" deep

Ahh, I understand now. 

I try to balance the depth cuts also.

[huskermcdoogle]

The neurons floating around in the grey matter that were given to me by my ancestors usually steer me toward making them even so as to not wear out just the end of the tool.  But I have run into situations where it depends on the part geometry, and on how much more aggressively you can manually bump up the feed rates on the 20% pass to save cycle time, say if part workholding, or tool hangout is the limiting factor.  Theoretically, if you had say two 150% passses and a 20% pass, and your rigidity limit for elevated feeds and speeds is say 40% or 50% doc, and you can run at a 75% higher feed when below that DOC, you could in theory edit the toolpath to increase the feed by 75% for the last pass and end up with a shorter cycle time.  This is because if you split the doc's evenly you would be at roughly 100% DOC per pass.

Just my $.02, hope it makes sense.

[Newbeeee™]

I evened it up too and also did what JP does.

I'm not sure how a 7 year old would approach it though - probably too much thinking...

[crazy^millman]

4 hours ago, JParis said:

I would push the DOC to get it to 2 passes and decrease the stepover a bit to compensate

When you are hanging a tool out at 6X with only 110% flute length you do what you need to make it work. Then it is really nice when the tool is wore out and the customer only ordered one and you then have to reprogram everything to use what they have. You mean that cost extra?????

[lowcountrycamo]

For close tol. I like a small depth finish pass as it prevents the tool from deflecting thus cutting slightly deeper.  However, in most cases I try to cut to the first depth.

[RaiderX]

even depth of cut is knee jerk to meh but learned moons ago not good with hard materials. it puts a wear mark in the cutter and or does not use the full potential of flute length. so when hard I stagger depths, when soft fast and dirty even depths without adding depths.

 

[nickbe10]

If you start by getting 2 even cuts and then nudge the depth a bit positive you can usually get one slightly longer cut which helps with the depth of cut notching....if the material dictates

[Elmer Fudd]

On 4/18/2018 at 9:19 AM, gcode said:

1.5 length to diameter ratio

example ... 1/2" endmill 1.5" deep

LOL. That's all i'm gonna say.

[gcode]

2 hours ago, Elmer Fudd said:

LOL. That's all i'm gonna say.

1.5 L/D cuts are quit common in high speed dynamic mill toolpaths

150% DOC, 10% radial step over and 1 million ipm 

[Elmer Fudd]

150% of .500 is .750 is what I was LOLing about.