Replies

1. 
   ScottWhiting | Oct 02, 2002 10:53pm | #1

   Generaly you can run any bit up to 2" ( yours should be 1-7/8 - 2")in diameter at the full rpm of most routers (usually 20-24,000). Higher end bits that should be run slower will have instructions packed with them. The largest bits out there, 3-1/2 to 4", need to be run at 10,000. Everything else runs in between. I know Amana has rpm limits right in their catalog but I am not sure everyone else does. Maybe Charles will chime in here.

   Scott

   Scott's Sharpening Service

   Glendale, Az.

2. 
   pors912 | Oct 02, 2002 11:04pm | #2

   Kell,

   Thanks for the tip.  That sounds very similar to the article I read.  I am not afraid of a little work to give me the best finish. 

3. 
   DonaldCBrown | Oct 02, 2002 11:13pm | #3

   It's an issue of rim speed.  With the modern bits of up to 4" in diameter, you can get rim speeds of nearly Mach 0.5 with a 24,000rpm router. Ideally, the cutter (rim) speed of any bit should be some constant number, but for anything over 1.5" in diameter, you really should slow the thing down.

   So assume that 24,000 rpm is o.k. for a 1.5" diameter bit. Circumfrence, and hence rim speed, scales with diameter. So for a 2" bit, slow down to  18,000 rpm. For a 3" bit, cut the speed in half to 12,000 rpm. For something larger, use the slowest speed your router has (probably around 10,000 rpm).

4. 
   eddiefromaustralia | Oct 02, 2002 11:40pm | #4

   Attached file scanned directly from 2001 CMT catalogue.

   Basic speeds for routing vs diameter and safe working tips.

   Trust that this may help guide you. I wouldn't run it full speed.

   Cheers, eddie

   edit: Sorry Don, missed your reply while fighting with my scanner

   
   

   ---

   Edited 10/2/2002 4:44:39 PM ET by eddie (aust)

   
5. 
   charlesm | Oct 03, 2002 08:03pm | #5

   PNut,

   The rule of thumb for cutter speed is to start at 100mph rim speed and adjust as necessary to acheive the desired safety level, feed rate and finish. For a 2" diameter slot cutter this would translate to to app. 17000RPM.

   The formula to calculate this is:

   RPM=MPH/Diameter/pi*1056

   So for a 2" bit:

   RPM=100/2/3.14*1056

   RPM=16815.28662

   Charles M

   Freud, Inc.

1. 
   eddiefromaustralia | Oct 07, 2002 02:29am | #6

   Thanks for this info Charles. It will be very useful and much appreciated.

   Cheers,

   eddie

6. 
   smijal | Oct 07, 2002 09:14pm | #7

   One word of warning---be carefull!   Last week my cousins husband was using a buscuit cutter in his router and had a lapse on concentration, lost 1.25" of his middle finger. Cut right through the bone! They werent able to reattach , so he is now able to express his anger in full and abbrivated forms.

7. 
   Pnut | Oct 07, 2002 11:12pm | #8

   Thanks to all for the great information--I learned a lot.