How Fast is too fast?

[lgalla]

Don't really know where to post this.Here goes.
Ihad parts cut on a commercial machine[Thermwood 10hp].The material was 18mm birch plywood cut at 600ipm.The chatter on the cuts was so bad it added 5 hrs to the unit being assembled as all edges had extreme sanding to be done.If we reduce the IPM to 300IPM the machining cost is double to $160/hr.This is way above the cost of doing the job manually on the table saw.Anyone else find the old traditional way is cost effective compared to CNC?
Larry

[nwrepair1]

Yes. I have CNC routers and one sliding tablesaw. When I make rectangle shaped cuttingboards for restaurants out of solid phenolic material it is faster and cheaper to do it on the saw. I can get clean no sand edges with the proper blade. Now, if the part list has cut outs or odd shaping, it goes on the router. But you shouldn't be getting bad edges with the CNC router. There should be little or no sanding required. Bad edges are caused by many factors in CNC machining. Improper tooling, bad bearings in spindle , worn collets, and not enough vacuum to hold parts down. If this is not your machine, you need to find another CNC operator. You shouldn.t accept the poor edge quality

[ger21]

As the previous poster mentioned, CNC is not always the answer in woodworking. He's also correct that you should be getting clean edges. I'd look at hold down and tooling, perhaps spindle speed as well.