delroy33 said:
hi:
where can i find a chart that shows what rpm. different dia. router bits should be safely run at.
does the bit configuration make a difference in the rpm to be used? i know that different wood requires rpm change. i have 1 3/4 hp. table mounted router.
thanks roy
Roy: Nice to hear from you. There are more to your question than is there a chart. All router bits should be designed to be run at the router's full speed. Having said that, not all router bits are created equal: some have the proper rake and sheer angle others don't, some have the proper carbide and others don't, some are balanced properly others are not. etc.
Cutting action is controled by two things feed speed and spindle speed. It is more important to understand the relationship between the spindle speed of router bit X, your feed speed and the cut.
Try cutting with your 1/4" round over bit at different feed rates then look at the cut. Faster feed rate will give you mill marks and slower will give you a cleaner cut. What is happening is the router bit at the faster feed rate has an increased chip load which produces the mill marks.
Slower spindle speed increases operator conidence (this is good) but will also increases the chip load on the cutter, which increases chatter and mill marks. This means that you need to slow down on the feed rate. Faster the cutter moves faster the feed rate. Practice with a variety of different router bits to get the feel of the relationship between feed and spindle speed.