I am new at CNC cutting, but what is the best order for CNC cutting Speaker fronts in MDF ?
1. Drilling (for speaker driver frame screwholes) - flat drill
2. Pocket (for lowering speaker driver frame into speaker front) - downcut drill
3. Contour (for penetrating speaker driver holes and speaker front outline) - downcut and upcut drill
I normally do the drilling first,with drill bits and then cut out pockets and other apertures before cutting the outline of the panel.it helps that I use a machine with vacuum hold down and an ATC.Without these features you will have to evolve a system that works for your machine.For MDF it isn't hugely important to use upcut,downcut or compression cutters.Straight will do the job and cost less.
Thank you for your answer. What RPMs are you using ? When I use straight drills with Shapeoko CNC at 18000 RPM it tears up the MDF. Downcut dont do that only on the underside.
Are you putting some material under the panel for cutting through ?
I normally use a spoilboard made of MDF on a vacuum hold down system and the presence of the spoilboard reduces tearout on the underside.I am a bit puzzled by your description of the material tearing with the cutter doing 18,000 RPM.I suggest you get hold of a cheap usb microscope and take a look at the cutting edge,sometimes there are abrasive particles in MDF and they very quickly ruin a sharp edge.Spindle speed,feed rate and depth of cut are things you may have to experiment with.The recommendations for commercial machines may exceed the ability of a Shapeoko.The most certain way to keep clean edges is to use a compression cutter and a single pass if your machine will hold the part in place.