We are preparing to engrave brass, what do I need to know before I start? We will be be engraving a design onto a 1" diameter flat top knob for a cabinet door? What is the best way to secure the knob to the board so it does not start unscrewing from the mount if the machine starts moving counter clockwise? What would be good feed rates for a 10, 30, and 60 degree engraving bits, what is the max depth you would recommend for each of those bits? What about feed rates for 1/32, 1/16, 1/8, and 1/4 inch bits? What speed should I set the DeWalt? Do we need any special protection do do this? Do we need to close the hole on the DeWalt 611 that blows air to clear dust?
I have been doing tons of brass engraving. For delicate engraving bits with .001" tips, I use .001" per pass and do two passes at 50 inches per minute and 20k rpms. The same settings can be used for all of your bits - but more robust bits like a 60 or 90 v=bit can go .005" doc. But you probably don’t want your engravings that deep unless you are planning to flood them with paint. Even then, for a knob, .004" total DOC would be more than sufficient for engraving and then flooding.
But I use v-carve software and choose the POCKET option, NOT the V-CARVE or ENGRAVE option. Engrave is meaningless on an (stock) x-carve and V-Carve will carve too deep a pocket on thick vectors. You want a pocket and the depth of that pocket should be between .002 and .004". Also, you better make sure you are really good at zeroiing that bit - or that you have a touch probe.
For securing it, I would screw it down and then put a clamp around it. Put a screw in to the waste board to prevent your clamp from spinning. Do one knob at a time and re-zero your bit every time. After, 100 brass engravings, my engraving bit was no longer .001". In fact, it was more than .002". So you should have plenty of spares.