A note from the ROC-TECH team, since running aluminum on a router comes up often.
We went through this with a customer last month: 6061 plate on a 3 kW router, 2-flute carbide, dry with an air blast. Chip welding right at the flute tips after a few minutes of cut. They had been running the feed conservatively to be safe, which is backwards on aluminum — a thin chip rubs and galls instead of shearing, and once the tip galls it keeps getting worse.
What we recommend:
More feed per tooth, so the cutter makes a real chip.
Spindle speed matched to the chip load, not left at the nameplate figure.
A mist instead of dry air. Air moves chips; it does not pull heat out of the cutting edge.
The ceiling is set by spindle power and frame rigidity, and that differs from machine to machine, so we do not publish figures meant to carry over between routers. For the starting point on a specific model, send us the model and the spindle and we will point you at the right sheet.
Is the customer cutting pockets or profiles? And is their air blast actually pointed at the cutting zone, or just blowing somewhere in the general area? I misaimed a blast on a 6061 cut once and got welds almost immediately, so both of those seem like they’d matter here.
Get a tach on the spindle before you change anything else. The speed on the nameplate is not the speed you cut at — under load a router spindle will sag ten to fifteen percent, and that moves your chip load more than any tweak you make at the control.
The rest comes down to reading the chip, not a chart. A clean curl with a little color is close. Dust means you are rubbing. Blue means you are cooking it. Numbers off someone else’s spindle will not transfer — yours sags differently than theirs.
Mist is worth it. Air clears chips but barely pulls heat out of the edge. And check the nozzle is aimed at the flute tip, not the chip pile. Single-flute is a band-aid; the finish suffers.
Adding our service view, because the measurement matters more than the numbers.
Before changing any figure, measure the actual RPM at the tool under load. A router spindle sags under load, and the nameplate figure is not what the cutting edge sees.
On aluminum, chip welding at the tip almost always means the chip is too thin: a thin chip rubs, and rubbing galls. So more feed per tooth, not less. Air blast clears chips but does not cool the edge, so a mist helps.
How far you can push the feed depends on spindle power and frame rigidity, and that varies from machine to machine — there is no chart that carries over. Read the chip instead: a clean curl with a little colour is close, dust means rubbing, blue means cooking.
Single-flute is not something we would recommend as a fix. The finish suffers, and the real problem is chip load and cooling.
One thing worth checking before any parameter change: that the air is aimed at the flute tip, and not just blowing across the table.
I disagree with calling single-flute a band-aid. I’ve used it for small aluminum offcuts on my 3-axis router when I couldn’t get mist set up fast enough. The finish was rough, but it stopped chip welding on good material that would’ve otherwise been scrap. It’s not a long-term fix, but it’s a valid stopgap for small runs. Don’t write it off entirely.