Need industry standard router base hole pattern

[Doug Sams]

Hi,

I'm making a router table for use in model and high power rocketry, and I need to know the exact dimensions and locations for the holes so that it will accept most common routers.

It appears most router bases have 3 holes 120 degrees apart, approximately 2-11/16" from the center, but I'd like to verify that. Also, a 4-hole pattern pops up often, so its hole sizes and positions are needed, too. Any other common patterns would be helpful, too.

The table will be used to make centering rings for mounting the motor tubes in the airframes. A series of holes will be drilled into the table. A dowel is placed in one of the holes, then the wood is placed on the dowel, and rotated to form a circle. The table tops will be made using a CNC machine, so exact dimensions are needed.

Thanks in advance.

Regards, Doug

[George]

Sounds like it is time for a trip to Home Depot with a ruler, pencil, and pad of paper... AFAIK, there is no "industry standard".

need to know the exact dimensions and locations for the holes so that it will accept most common routers.

2-11/16" from the center, but I'd like to verify that. Also, a 4-hole pattern pops up often, so its hole sizes and positions are needed, too. Any other common patterns would be helpful, too.

tubes in the airframes. A series of holes will be drilled into the table. A dowel is placed in one of the holes, then the wood is placed on the dowel, and rotated to form a circle. The table tops will be made using a CNC machine, so exact dimensions are needed.

[J. Clarke]

There is no "standard pattern". Find a Woodcraft and look at their router baseplates and table inserts, and you'll see some with a bewildering array of holes that nonetheless fit only a few specific models of router. Your best bet would probably be to start with or copy one of those, but if you're making these for sale make sure it's not patented first.

To get an idea of what a commercial manufacturer specializing in such things has come up with, take a look at .

If high precision is required in this, then you may want to consider providing some kind of centering system that allows the user to drill his own aligned to the router that he has in his possession--the base-mounting holes on the router are not always perfectly concentric to the bit axis.

[Leon]

Go to

and select 1 of each of their router table plates that are specifically made for specific common routers.

[none]

You may want to consider purchasing this plate.

S.

need to know the exact dimensions and locations for the holes so that it will accept most common routers.

2-11/16" from the center, but I'd like to verify that. Also, a 4-hole pattern pops up often, so its hole sizes and positions are needed, too. Any other common patterns would be helpful, too.

tubes in the airframes. A series of holes will be drilled into the table. A dowel is placed in one of the holes, then the wood is placed on the dowel, and rotated to form a circle. The table tops will be made using a CNC machine, so exact dimensions are needed.

[George]

OR, this place has a "universal" for adaptation.

be infringement in either case, though.

[CW]

If you measure a Porter Cable base with a ruler, you will be off. They use odd measurements.