Depth Cut Verses Feed Rate? 6 hr operation..

[Rich05]

A bit confused here.

MC program has the half inch 2 flute endmill speed rate suggested at 12 ipm, but this does not take into account the depth cut I have set at .125..

I am running 2hp Industrial Hobbies mill around 3,200 RPM. What depth cut should a 7/16 or 1/2 two flute endmill Tin Coated and HSS be doing? If the depth cut is .125 what feed rate should I be running at? Or is .125 too conservative for 6061 aluminum.

The part I am cutting is 25" long about .75 deep with pockets and so forth. Right now with 12ipm feed rate at .125 it is taking about 6 hours. Looking to reduce this time without wearing out stuff

Mill 3200 rpm 2hp Industrial hobbies, with Mist (NO FLOOD).
6061 Aluminum x=30" y=6" z=.75" stock

R.

[DSL PWR]

It is hard to suggest feeds for a mill that I'm not running. Just run the spindle as fast as the tool can take, and in aluminum bump up the feed rate until:

a: you run out of power
b: you can't clear the chips out,

[Rich05]

discovering optimum speed is quite an art.
Thanks much

[JDenyer232]

At 12 ipm you are feeding to conservativly. Your chip load is only .002, with a 1/2" mill I would run with a chip load of .003-.004 which would put your feed rate at 20-25 ipm. I would reduce the depth of cut to .100 and try it at 20 ipm for a start. According to my software you would be using a little over 1/2 a horsepower to achieve this. Of course I would also use a 3 flute mill in order to run at an even higher feedrate. Hope this is of some help.

[Rich05]

roger that I bumped it up to about 20imp now with no problems really. have gotten a couple chipped endmils no idea how that is happening the part is well ancored maybe larger chunks becoming lose during contouring operation.

R

[JDenyer232]

Originally Posted by Rich05 roger that I bumped it up to about 20imp now with no problems really. have gotten a couple chipped endmils no idea how that is happening the part is well ancored maybe larger chunks becoming lose during contouring operation. R

Are you cutting dry? You really will need coolant to achieve max feed rates and not chip the endmill or gouge the aluminum.

[Rich05]

using mist coolant only..

[JDenyer232]

Originally Posted by Rich05 using mist coolant only..

Mist is ok if that's all you got, flood is better as it gets the chips out of the way. A strong stream of air works well for chip removal as well, the idea is to not be recutting the chips. Try a 3 flute end mill, I think you will be impressed.

[Oldmanandhistoy]

Originally Posted by JDenyer232 According to my software you would be using a little over 1/2 a horsepower to achieve this.

Hi,

Do you mind me asking what software you are using?

John

[JDenyer232]

Originally Posted by Oldmanandhistoy Hi, Do you mind me asking what software you are using? John

Millworks, it's a free speed and feed utility that calculates feed, speed, horsepower, amount of material removed per minute, etc. Here's the link
http://lovejoytool.com/free.htm
I use this all the time when I program our VMC, works like a charm for getting you pretty close to where you need to be as far as feed and speed goes.

[Rich05]

just wanted to say thanks for the advise on this thread. I know the question was quite open ended, which is never a good thing, which takes some patience to answer. Cheers.

R

[Oldmanandhistoy]

Originally Posted by JDenyer232 Millworks, it's a free speed and feed utility that calculates feed, speed, horsepower, amount of material removed per minute, etc. Here's the link http://lovejoytool.com/free.htm I use this all the time when I program our VMC, works like a charm for getting you pretty close to where you need to be as far as feed and speed goes.

Thanks for that; I have an old copy of ME Consultant 2.0 which gives the same numbers as you did other than the power requirements which is 0.284 HP for a full width cut.

Looking back at the first post in this thread I noticed a Tin coated HSS EM was being used. From what I have read on the zone Tin is a bad choice for use with aluminium as the chips stick to it. Ticn coating is better but more difficult to find on HSS.

John