Practical astronomy projects for every level of expertise

DIY Astronomy

How to build a sunbed binocular mount

Enjoy comfy, hands-free viewing with this attachment for your garden lounger

With this mount to hold a pair of binoculars to your sunbed, you’ll be able to relax your arms while looking at the sky and keep your target steady in the field of view. The design allows you to angle the binoculars up and down and side to side, and because it’s mounted on the lounger it doesn’t take up space on the ground. You can sit side by side with someone else too.

The parallelogram mechanism means binoculars can be brought close to the eyes of both taller and shorter observers. You can even swap places while retaining your aim towards the target area of sky.

The simple mounting ‘beam’ on which the mechanism is fixed can be modified to suit a variety of loungers. We added three short wooden pieces to ours. One has a nylon screw which presses against the back of our lounger to steady everything. By adding short lengths of wood in the right place it should be possible for the beam to be steadied against the frame of any design of lounger. For extra security and peace of mind, you may wish to use a clamp or bungees to fix the beam on tight.

We chose softwood strips to make our mechanism. Once you have used the downloadable plan to mark out the lengths and hole positions, it’s a simple task to cut and drill them. To maintain accuracy, we taped bundles of similar parts together before drilling so they came out identical. We rounded off the ends with a sanding machine for aesthetic reasons, but it is important to get the wooden elements smooth so they move freely. The length of the parts was worked out by trial and error and should apply to most situations. If your lounger differs greatly, however, you might need to adjust the length of the two arms which form the rear parallelogram (make them longer and drill several sets of holes to experiment with, then trim to length once you are happy).

There are washers between all the wooden strips and the nuts, which pivot on the threaded rod. We used Nylock locking nuts when making the final assembly as these can be tightened to give just the right amount of friction. You need your mechanism to move smoothly but stay in position once set. To overcome some of the weight of the binoculars, we made up some elastic straps, which stretch between hooks that are screwed into the wooden parts. In use, we found the mount worked perfectly once adjusted.

Observing without having to hold up even relatively light binoculars transformed our experience of a summer night’s observing session. You can even make notes or sketches with your free hands – or sip a glass of wine!

Step by step

Step 1

After marking out and cutting, you need to accurately drill the 6mm holes. Taping parts and drilling together ensures they come out identical (but only if your drill is held vertically). The length of the wood is less important than getting identical hole spacing.

Step 2

It is important to get the wood smooth. We used a plane to achieve this, but sandpaper is a good method as well. This is to help the pivots work freely. You now need to cut your threaded rods and make a metal bracket for the binoculars.

Step 3

A little experimentation is needed to fit the mounting beam to the lounger. We cut a 600mm strip of wood, and screwed/glued three smaller strips on it: two on the front, one on the back. You may need to modify this part of the design for your lounger.

Step 4

Carefully assemble the parts. We used normal nuts (not locking ones). Your binoculars should have a tripod mounting screw hole (usually under a cap) to which you can fix the metal bracket. Mount the assembly to the lounger and check.

Step 5

We disassembled at this stage and sprayed the wood with clear lacquer. This provides some protection and helps it to pivot. You may wish to paint yours. Reassemble when dry, including some glue/screws between mechanism uprights and mounting beam.

Step 6

To help resist some of the weight of the binoculars, we added elastic straps. We knotted these for the prototype, but once we got the lengths right, we made some loops with whipping twine. These fitted to cup hooks screwed into the wood.

Mark Parrish is a bespoke designer based in West Sussex