Recognize this extrusion?

[Firstram]

I didnt figure out why it was always one gullet, but i do think it was always the same location. It did seem chip welded, but why that sarted is a mystery to me. For a single part it was tolerable. I think had it been a through cut it may not have been as bad. The part itself got very hot from the number of passes required; i had to stop a couple time so the piece could cool enough to handle.

I meant to say, a slight chip or flaw in one of the blades teeth would cause that gullet to pack up!

 

[woodchucker]

no mystery to me. first AL likes to transfer heat very well. So even before you cut an area it's heated by where it was already cut. Second, the blade is not able to cool or release the chips above the piece, so it holds on to the metal longer, and it cause melting and galling.

all this plus the blade speed.

 

[borges1]

no mystery to me. first AL likes to transfer heat very well. So even before you cut an area it's heated by where it was already cut. Second, the blade is not able to cool or release the chips above the piece, so it holds on to the metal longer, and it cause melting and galling.

That all makes sense. I know how wood chips work in machines, but every metal project im learning about metal chips. I knew the non-through cut would be an issue, but galling wasn't what i expected. Given the heat buildup next time i'll know. Really its very similar to why you want to make slots in metal on a mill with an undersized end mill, then widen. Just didn't occur to me given the different situation

 

[brino]

I may have started half-depth cuts to full width, and then done full-depth.
Obviously your method worked.

1) you did not get hurt (most important)
2) you learned a some more about metal working, and
3) you got the job done

......also, you have now left a trail for others to learn from your experiences.

That's a win all around!

Brian