Router Speed VS Bit Diameter?

[macr0w]

Is there a rule of thumb for setting your router speed for different bits with different diameters?

I know that wide bits don't need to spin at 25000 rpms but is a rule of thumb for this?

Thanks

 

[Mike Davis]

It's not that easy to answer but generally larger bits do need to spin more slowly.

There are charts, calculators, and formulas on the web and especially on manufacturers sites that are worth checking out.

There are several factors that come into play and these may vary widely for each router, bit profile, wood species, feed rate, and number of flutes.

Some say start fast and slow down until the vibration stops, some say start slow and speed up till it starts to vibrate then back off.

Either too slow or too fast can burn the wood, burn the bit, dull the bit, or even cause a catastrophic failure of the bit.

I tend to err on the safe side by going a little slow since I'm not a high production shop. I want a good surface finish without burning or chatter.

 

[Joe Scharle]

http://www.rockler.com/how-to/router-bit-speed/
Many others on the net....

 

[JimD]

Joe's post from Rockler looks reasonable. A simpler rule of thumb is that if it's too big to use hand held it probably needs to be slowed down. Panel raising bits need to be slowed down. But nearly all round-over, chamfer bits and the like are OK at full rpm. Maybe slow the biggest a little.

 

[macr0w]

The main bit that I use is a 60 degree chamfer bit.

It is about 2.5" wide.

I would think it needs to spin slower.

I am slowly figuring out what works and what doesn't work with my router.

 

[CrealBilly]

I found slower is better than fast. To fast the bit heats up and burns the wood. To slow and it chips out the wood if you push to fast.

 

[SubGuy]

Bits have speed limits too. Experiment starting slow and move up to match your comfortable feed, ideal finish and lack of chatter.