[trialanderror]

I had a couple questions about making the most out of scrap 6061 aluminum.

1. Lets say I need to cut a 3" hole in the aluminum with a 1/2" endmill. Would it be more practical to machine a circle so I am left with a cylinder of material dropping out or should I just shave the hole inside of the circle leaving it all as chips?

2. When getting rid of the chips, does coolant mixed in with them drop the value? What do people usually do when coolant is in the mix?

[Jalapena]

Once the slug (cylinder of material) becomes free, it can wedge in the hole & break/chip the endmill. It is better to mill the hole to the desired diameter to prevent this from happening. Lastly, it will not affect the value of the chips as long as the majority of coolant has been drained.

[trialanderror]

Understand, the machining has to be done on both sides, would probably machine 75% of it on one side then flip it over to machine the other side. If I shave off 1/2" out of the inside circle and then mill around the edges of the circle from .5" to say 3" then flip it over and do the other 1" , will the newly formed cylinder just drop 1/2" onto the worktable and stay there as a shiny new cylinder to resell at full non scrap value or would it likely vibrate and cause issues?

[john robertson]

so you are going to extra trouble, an risk jamming slug which could break your cutter , just so you can get an extra few cents for the slug in swarf value ?????WTF

[keebler303]

Understand, the machining has to be done on both sides, would probably machine 75% of it on one side then flip it over to machine the other side. If I shave off 1/2" out of the inside circle and then mill around the edges of the circle from .5" to say 3" then flip it over and do the other 1" , will the newly formed cylinder just drop 1/2" onto the worktable and stay there as a shiny new cylinder to resell at full non scrap value or would it likely vibrate and cause issues?

At some point, your scrap may have actual value (maybe a 16" ring from2" MIC6 or something). Anything smallish should be turned into chips. You are risking the part you are cutting, a $30 endmill and your time to dig out the slug, replace the endmill, etc. for a little tiny chunk of metal. It WILL bite you.

[whateg01]

I've done almost that, except I left 3 tabs and broke the piece out afterward. I didn't do it for scrap value, though. I saved the slug for future projects.

Dave