Crazy Idea: Offset Router

Every once in awhile, I post a crazy idea, just to get it out of my brain and let it haunt others’. :crazy_face: So here’s my latest: what if you attached the router to an offset gearbox so the router body doesn’t have to be at the cutting location? Why, you ask? Because the axis of the bit is the center of the Maslow universe. We build complicated assemblies like the ring and the pantograph just to make the chains “think” they are connected to the sled at the bit axis.

Potential complications with this approach I can think of are keeping this assembly from torquing the sled, and possibly added complexity in the z-axis.

Potential benefits include moving the router lower on the sled, where I think it might serve as a weight, reducing the load of bricks needed.

Do they make such a thing at a reasonable price that is designed to work with a router?

I like the idea in theory :slight_smile: The lower the center of balance the better IMHO. But routers spin pretty fast so any offset might be very noise and maintenance prone.

I’m guessing there’s something out there. The key question is at what price.

Two other options:

1.) Replace the heavy AC router with a more torquey DC brushless, can reduce overall weight this way. Depending on your material, this should also reduce overall RPM making it more feasible.

2.) Use a flexible shaft instead of some crazy gearbox… someone’s gotta make this in a 1/4 inch version.

note that all of these options will add a fairly significant amount of cost and

switching from a router to a CNC spindle would be an improvement and if you have
a separate Z axis already may be close in cost.

the key advantge of the maslow is it’s low cost and relatively easy
construction, if you make it too much more expensive, you may as well get a
‘normal’ CNC instead.

David Lang

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How so? Spindle at $150 and flexible shaft at $50, still well under the $3-4k that a normal CNC runs.

how do you mount the flexible shaft (including the Z axis), how durable is that
shaft after hundreds of hours of operation, lots of other problems start showing

but working equipment trumps theory, build it and let’s see.

David Lang

Here is a flexible shaft rig that is rated for continuous duty and handles a 1/4" collet. At ~$420 it’s more expensive than a standard router, but it is capable of running at lower rpms than a woodworking router.

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This is just straight out a bad idea. having a spining motor off axis of the router bit will cause it to torque when its under load. With the current designs when that happens the sled may rotate slightly but maintains center. In an off axis router situation the center of rotation for the main mass (the motor) is away from the bit so it will tend to want to rotatate around some other point than the router bit causing poor cuts and reduced accuracy. Weight is not an issue as we are adding balast to the sled in any case and using a lighter but more powerful motor only changes the amount of balast required. Using a flexible shaft will just add load to the motor with little benefit.