I had both some ND filter gel sheet lying around, and also a set of ND + CPOL filters for the Mavic Air (I have never owned that drone, but I bought the filters to adapt for use with a different drone, and then I discovered they could be used with the Mini 3 Pro).
The filter attachment mechanism on the Mini 3 is really tiny, with small posts and locking tabs, but after many iterations of prototyping, I was able to arrive at a design that I could 3D-print on a FDM printer with a standard 0.4 mm nozzle. It does not have the locking tabs of the original, but there is still enough friction when twisting it in place that I don't think it will fall off. And if it does, that's not really a big problem, at least if the filter was made with ND filter gel, as the price for a filter will be almost nil. Here's a small portion of the prototype scraps I had before it went in the trash:
My ND filter cassette design is printed in two parts, and is just a snap fit (so no glue), where the ND filter gel (which must be carefully cut to size) is sandwhiched inside. The final ND filter then looks like this:
Here's also the adapter (where I even managed to print the threads, so the filter screws on properly:
Here's what the adapter looks like when rendered (those threads are really fine!):
And finally, here's the two part ND filter cassette (where layer(s) of ND filter gel can be placed inside):
I have no immediate plans to publish these designs, as it will be a fair bit of work creating good enough instructions, and there is a chance that people might try to force their printed parts onto the drone camera (despite good instructions), and could end up breaking those tiny locking/retaining posts.
The filter attachment mechanism on the Mini 3 is really tiny, with small posts and locking tabs, but after many iterations of prototyping, I was able to arrive at a design that I could 3D-print on a FDM printer with a standard 0.4 mm nozzle. It does not have the locking tabs of the original, but there is still enough friction when twisting it in place that I don't think it will fall off. And if it does, that's not really a big problem, at least if the filter was made with ND filter gel, as the price for a filter will be almost nil. Here's a small portion of the prototype scraps I had before it went in the trash:
My ND filter cassette design is printed in two parts, and is just a snap fit (so no glue), where the ND filter gel (which must be carefully cut to size) is sandwhiched inside. The final ND filter then looks like this:
Here's also the adapter (where I even managed to print the threads, so the filter screws on properly:
Here's what the adapter looks like when rendered (those threads are really fine!):
And finally, here's the two part ND filter cassette (where layer(s) of ND filter gel can be placed inside):
I have no immediate plans to publish these designs, as it will be a fair bit of work creating good enough instructions, and there is a chance that people might try to force their printed parts onto the drone camera (despite good instructions), and could end up breaking those tiny locking/retaining posts.
