By far the most challenging parts are ones involving thin ( < 0.125" ) aluminum sheets. I keep a healthy stock of 1/8 inch bits single flute carbide bits because I break them so often. I tried multiple feeds and speeds combo, and go through WD40 like crazy. My suspicion is that my hold down is not sufficient to prevent the material from pulling and vibrating during cutting leading to quickly dulled tools, chip welding, and eventually breakage within seconds.... Getting a good setup for doing sheet metal 1 offs would be great. I started noodling on a hold down system tied to the spindle head. Then I found these.

CNC Pressure Foot Clamping

CNC Pressure Foot Clamping Attachment for CNC Router Spindle

Factory Supply Spindle Diameter 80mm Auto Pressure Foot Fixture Holder for CNC Router DIY Accessories CNC Plate Clamp-in Wood Router from Industry & Business on Aliexpress.com | Alibaba Group

I am leaning towards the Chinese style ones, since the using ball bearings instead of a teflon block seems like it would work better skimming over metal chips.

Anyone have experience with this type of device?