[Lab] first try at cutting aluminum

[bentfork at gmail.com]

Sounds like you're on the right track.

Here are a few formulas to help you calculate the speed.

http://www.endmill.com/pages/training/spdfeed.html

You need to also find the cutting speed of the material itself. Milling
metal ain't easy ;)

Good luck


On 29 May 2011 11:40, Darcy Whyte <darcy at siteware.com> wrote:

>
> okay, here's the plan:
>
> Yes, I'm using brand new endmills.
>
> Okay, it's a 4 flute so I guess 7640/2 rpm for 76.4 inches per minute?  Or
> 7640 rpm for 76.4 * 2 inches per minute?
>
> I'm going to chock up the endmill in the chuck so it only sticks out
> enough.
>
> I'm going to install the vacuum and lord over it to make sure there are not
> chips.
>
> I'n my test run, I threw some water on the cutting and it made aluminum
> soup.
>
>
> On Sun, May 29, 2011 at 11:35 AM, <aaron at ottawarobotics.org> wrote:
>
>>  First things to check is whether or not you have a nice sharp bit. That
>> can cause troubles.
>>
>> The next is to make sure you have the right feed and rpm for what you are
>> up to. That is all related to your milling bit diameter and the number of
>> flutes.
>>
>> For instance, a 1/8th endmill with 2 flutes should be around 7640rpm and
>> you can run at 76.4 inches per minute. A 4 flute can run twice the speed
>> (152.8 inches per minute) because the flute can carry twice the number of
>> chips out of the cutting area. As you move up in endmill size, the rpm and
>> ipm drop in half, so a 1/4" mill can run 3820rpm and 38.2ipm. That is all
>> assuming that you can enough torque and speed in the steppers and the
>> milling head.
>>
>> The next thing to worry about is removing the chips. If you leave alot of
>> chips in the channel that you are cutting, the milling bit ends up having to
>> 'recut' those and that can cause everything to gum up. Vacuum or blow the
>> chips out of the way as you are running is the best bet.
>>
>> The final thing you need to worry about is your cutting tool flexing. Once
>> you start to flex it, not only does your cutting path go wrong but you'll
>> likely end up breaking it. Bigger diameter tools are stiffer so they can
>> take deeper cuts. If you are using a skinny tool and have a couple inches
>> hanging out under your milling head, it will flex and cause troubles.
>>
>> All that being said, I run at 15 IPM for aluminum with a 1/4" mill and
>> 25mil cuts. Works ok. When I go to smaller milling bits, I actually reduce
>> the speed down to around 5ipm just to make sure that poor thing isn't
>> flexing.
>>
>> Aaron
>>
>>
>>
>> On Sun, 29 May 2011 11:14:21 -0400, Darcy Whyte wrote:
>>
>>  I tried to cut aluminum for the first time last night. Pictures of the
>> results here
>> http://mambohead.com/2011/05/first-try-at-aluminum-with-cnc-mill/
>> I think I had the feed rates wrong. Anybody have any idea why the endmill
>> gummed up?
>>
>>
>>
>> _______________________________________________
>> Lab mailing list
>> Lab at artengine.ca
>> http://artengine.ca/mailman/listinfo/lab
>>
>>
>
> _______________________________________________
> Lab mailing list
> Lab at artengine.ca
> http://artengine.ca/mailman/listinfo/lab
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://artengine.ca/pipermail/lab/attachments/20110529/6c59b097/attachment.htm>