I just tried my first cut on aluminum using the 200W CNC. I tried a simple contour cut on a small piece using the suggested settings (100mm/min, 0.1mm depth). I was going around the outside of the piece so there was only ~0.5mm of material being removed.
I secured the aluminum using the 2-sided tape method. This came loose. The aluminum was spray painted and it looks like the paint/tape didn’t hold well as the piece heated up.
This leads to two questions:
Is it normal for the aluminum to get quite hot under these conditions. It was very noticeably hot to the touch, but not quite painful. Is this normal, or is my endmill dull maybe? It is the 2-flute 3mm endmill that came with the machine so it is pretty old now and has had quite a bit of use on wood.
Should I expect painters tape to hold down a piece of aluminum? I’ve been doing this with wood for years. I’d love to continue with aluminum.
ZERO chance tape is going to hold down alu block for CNC (maybe a large flat sheet with a LOT of double sided gorilla tape). I’ve never heard of 2 sided painters tape, the whole point of painters tape is low adhesion. Not a great idea.
Of course the block will heat up. I’m guessing you’re not using cutting oil?
In metalworking, cutting tools use formulas to calculate machining conditions based on parameters such as number of revolutions, number of blades, cutting speed, and depth of cut in line with the material to be machined.
Sandvik, Iskal, and other metalworking cutting tool manufacturers have calculation formulas.
Calculate the optimum values for end mills, drills, etc., as each has its own calculation formula.
The machining heat is air-cooled because oil or water cooling is not possible with Snapmaker.
The higher the machining heat, the higher the machining high load.
High load machining will damage or wear the cutter.
To machine a metal with an end mill, it is necessary to obtain the machining conditions, a world that is difficult for the layman to understand.
Painters tape works quite fine for me on small and larger pieces. Make sure the surface is super clean. I use contact spray from Home Depot to glue the two pieces of tape together.
As for heat, if it is getting hot, you have a problem. It should heat up a little but not much. Could be several things. Dull bit (as you mentioned) I suggest a single flute for ALU. Moving too fast. I generally find most ‘calculated’ speeds are too fast. Cutting too deep or too wide. Try to remain below 50% of the cutting bits width. Shallower cuts also help. Remember, you only have 200 watts. Might sound like a lot but it isn’t. When the bit is cutting, there should be no reduction in speed of the motor.
I used the standard fusion profile of the bits but adapted to 0.1mm stepdown.
It depends on your material and cnc router how fast you can go.
Personally I would not cut with a router of 1.5mm diameter again.
Here is the 3.175mm single flute for aluminium which worked pretty fine for me:
