Dovetail Adaptor for Old EQ3-2 Mounts

My EQ3-2 is one of the older models that has fittings for scope rings, but doesn’t have any form of dovetail clamp. The new models have both. I prefer to use dovetails as it makes swapping scopes around between mounts easier, so I decided to modify my mount to add a suitable saddle. I’ve seen this done by mounting a saddle on a section of dovetail that is then bolted to the mount using the holes for the rings, but I wanted something with a little more lateral stability.

I bought a new saddle from Sky’s the Limit and after some hunting around discovered that it’s possible to buy small sheets of aluminium on ebay for very little money. I bought some 5mm sheet and cut out a piece that would support the entire base of the saddle as well as resting on the sides of the mount head. The plate extends out far enough to reach the holes for mounting scope rings. I drilled out matching holes in the plate and tapped them to accept an M6 thread. When fitted to the mount the bolts then hold the plate tight to the top of the mount without it being able to rock or twist.

Four more holes tapped to M6 take the screws that hold the saddle to the plate. Tapping M6 holes squarely in 5mm plate is tricky. I discovered the way to do it is to put the tap into the chuck of a pillar drill with the plate clamped to the table and then turn the chuck by hand. This keeps the tap square to the face of the plate. Doubtless there’s some clever way to do this, but it worked for me.

Here’s what it looks like when assembled:

I’ve not had a chance to try it out properly yet as it’s rained for the last three months. Hopefully things will change some time soon. If they don’t change soon though I’ll be making a similar adaptor for my AZ3 to take a dovetail.

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