Here is how I magnetised the new Games Workshop plastic Deimos Rhino kit so that the hatches could be interchangeable.
You just need the sprues that came with it and some magnets. I used 5x1mm magnets but 4x1mm, 3x1mm or even 2x1mm would work as well – they don’t need to be strong magnets as they’re not really fighting gravity here.
On the underside of the top section, cut a section of sprue and glue it in place. You can do this after it’s been assembled if you are careful and use tweezers/small pliers to guide the sprue in and pull it against the underside. Then just turn the tank upside down to let gravity keep it against the underside.
Alternately, do it before you assemble…
I used four pieces of sprue – you really only need one, but since the sprue was being chucked anyway I figured why not.
From the top:
Add a magnet at the front:
The front is easiest for the hatches since the lowest point of the hatches is located there. On the underside of the hatches:
You can see that the 5mm magnet overhangs the area it’s glued to – that’s not strictly an issue, but if I had smaller diameter magnets it would have been a good opportunity to use them. The 1mm depth is important here – two 1mm deep magnets align perfectly with the gap available.
The missile launcher hatch requires a single piece of sprue to be glued under it to achieve the same gap – photos to come.
The gunner/commander will require something across the gap at the front – I used this with a 3x1mm magnet underneath:
For his gun mount I used a 2x1mm magnet on the gun end and a 3x1mm on the handle end – it would be easier to use 2×1 on both ends.
Will need more of part #15 – the arm that the gun mounts to – but something compatible shouldn’t be hard to come up with. More on that to come…