This side by side plate allows 2 small scopes or a scope and DSLR with large lens to be attached on my AP mount. Side by side has an advantage compared to "piggyback" - less counterweight is needed to balance the setup. One would argue that it essentially allows both the scope and DSLR to point only into one object at a time. This is right, but I found it just fine to shot with 450mm scope and APS-sized CCD as well as 200mm lens and DSLR - CCD would show the object wile DSLR an overall context in the same time. For situations where I would use much shorter lens and prefer to shot different object, I do have another piggyback attachment featured on other page here.

The plate was made in my workshop from 2 layers of 12mm thick waterproof plywood.

Although aluminum is much stiffer than plywood, the stiffness increases with a cube of material thickness. Comparison of material properties shows that 25mm thick plywood is stiffer than 10mm aluminum - which is just fine as a base for small telescopes. Yet, the plywood plate with some hollow areas and holes machined may be only 1/3 weight of the aluminum plate.

In practice, this plate was attached on top of AP400 GTO and was holding for imaging Takahashi FSQ85 with CCD camera, OAG and separate guider as well as Canon DSLR with 200mm f/2.8 lens. 10 min DSLR images guided through the main scope showed round stars, which is a nice proof of this setup.