Spindle Mount Reducer Shim – Router & Spindle Diameter Adapters

Made to order – ships in 3–5 days depending on inventory.

Spindle Mount Reducer Shims

Adapt a larger spindle mount to fit a smaller router or spindle body.

These reducer shims are designed to fit inside compatible spindle mounts and reduce the clamping diameter so you can securely install a smaller router or spindle. They are especially useful when upgrading in stages—for example, using a 65mm trim router in an 80mm spindle mount while you save for a full spindle system.

Available Sizes

80mm to 65mm – 42mm tall
69mm to 65mm – 25mm tall
69mm to 65mm – 75mm tall
89mm to 80mm – 44mm tall
108mm to 80mm – 44mm tall
80mm to 65mm – 90mm tall
86mm to 80mm – 60mm tall
89mm to 80mm – 65mm tall

Common Uses

Install a 65mm Makita-style trim router in an 80mm spindle mount
Install a 65mm Carbide 3D router in a compatible larger mount
Adapt 69mm, 80mm, 86mm, 89mm, or 108mm mounts to smaller motor diameters
Reuse an existing mount while transitioning to a different router or spindle size

Compatibility

These shims were designed primarily around PwnCNC spindle mounts, but they may also work with other mounts that use the same nominal inside diameter and provide suitable clamping support.

Measure before ordering. Confirm the inside diameter and usable clamp height of your mount, along with the outside diameter of your router or spindle body. Select the reducer size and height that best match your installation.

Installation Notes

Insert the shim fully into the spindle mount before installing the router or spindle.
Make sure the shim sits evenly and does not overlap a split, bolt, or internal obstruction in the mount.
Tighten the mount evenly and only enough to hold the motor securely.
Do not overtighten, crush the shim, or deform the router or spindle body.
Verify that the motor cannot rotate or slide before operating the machine.

What’s Included

One spindle mount reducer shim in the selected size.

Perfect Fit

Ordered two of these shims and they were exactly as advertised. I’m using them in a Rockler SL lift where I’m replacing a Dewalt router (3.5” OD) with the PWNCNC water cooled 1.5 kw spindle (80mm OD) system.

Sent several questions to PWNCNC Support and they were helpful.

RTL Custom Woodworking

Spindle Reducer Shim

The Spindle Reducer Shim fit perfectly on Elite Foreman from Onefinity. I got the 80 mm and reduced it to 65 mm for my Makita router so I can upgrade to a bigger spindle in the future.

Spindle Reducer Shim

PWN is everything to do with customer satisfaction, because of supplier problems not within their control, they saw to it that a 65-80mm shim was sent to keep me in business. PWN is sincere when they want their customers to dominate there CNC.