I have been cutting .0625 canvas reinforced phenolic sheet, decent volume of parts that have a number of 1/8th inch holes that need to be drilled and then profiled out of the sheets. Since the relationship between the holes and the edges of the pieces isn't particularly critical (.025-.030 would be all but unnoticeable) I have been stacking them up 12 high and drilling all the holes and then using some aluminum plates and bolts through the holes to hold 8 at a time to inserts in my spoil board for the profile operations. This works pretty well, I just can't seem to find a bit that my machine can use make use of that will give me a decent top edge along the cuts. I have been using a
46092 Solid Carbide Spiral 3/16 Dia x 5/8 x 1/4 Shank x 2-1/2 Inch Long Composite, Fiberglass & Phenolic Cutting ZrN Coated Up-Cut Router Bit since one of the parts I can only fit 3/16 between them without losing a ton of material to waste.
Today I tried a
48052-E High Performance Solid Carbide Fiberglass and Composite Cutting 1/4 Dia x 1 x 1/4 Shank AlTiN Coated End Mill Router Bit after reading that they are supposed to produce a nice edge finish top and bottom, but I don't think my machine can push this thing fast enough. I am limited to 16000 rpm at the low end, and about 150 ipm with even .134 doc before I start having problems losing steps. At these speeds the bit produces a nasty high pitch squeal that I assume is from chatter that would only go away if I brought the feed down to like 10-15 ipm. It also produced a terrible edge, even worse than the upcut on most of the pieces. I am having trouble figuring out how to calculate a good starting feed rate for the bit as I don't know how many flutes to use in the calculation. I have posted to Amana's support forums but haven't heard anything back yet, and haven't been able to get away during the business day to call them, but I am pretty sure my problem is not being able to drive the bit fast enough.
Does anyone have any suggestions on another type of bit that might work better for me, I have thought about grabbing the 1/4 inch down cut version of the 46092 even though I couldn't use it on all the parts, it would save me a good bit of sanding time if it worked better. I just don't really see how it wouldn't just move the bad edge to the bottom instead of the top.