A polar wedge is an accessory used in astronomy for mounting a telescope or a camera on an equatorial mount. It is designed to align the polar axis of the mount with the celestial pole, allowing for precise tracking of celestial objects as they move across the sky.

The polar wedge is typically made of sturdy material such as aluminum or steel, and it has an adjustable base that allows it to be leveled and aligned with the celestial pole. The telescope or camera is then attached to the wedge, which is in turn attached to the equatorial mount.

By using a polar wedge, the user can ensure that the mount’s polar axis is aligned with the Earth’s axis of rotation, allowing for accurate tracking of celestial objects as they move across the sky. This is particularly important for long-exposure astrophotography, where even small errors in tracking can result in blurry or distorted images.

My polar wedge is a Skywatcher Star Adventurer wedge. This is a cheap wedge which is, quite honestly, barely adequate for the job. Specifically, the Dec clamping mechanism is not fit for purpose. If you look at the wedge, it’s made of sturdy alloy with strengthening fins. It doesn’t look like it’s intended to flex yet that’s exactly what the standard clamping mechanism expects it to do! This mod is to install a bush so that we don’t rely on the chassis flexing to achieve clamping. The bush allows in-out movement to allow decent clamping force whilst also keeping everything rotationally aligned. I’ve also documented this on Cloudy Nights

1) Get a brass bush made, 14mm diameter, 6mm deep with a hole in the middle for an M6 bolt. I got mine made cheaply from a guy on ebay

2) Dismantle your wedge

3) Use a 4mm-20mm step drill to drill the hole out to 14mm. When you get to the 14mm cut, the step drill should now fit very conveniently into the hole on the opposite side & also into the recess to allow for an accurate cut

4) Put the brass bush in the hole

5) Reassemble with the plastic washer on the opposite side to the brass bush. I’ve replaced the standard lever here with a new one from eBay because my original broke long ago

You might notice my washer is red. I actually made a new one using the plastic lid from a confectionary container and a 44mm hole-saw

Enjoy a better clamped wedge