The original model is very detailed and looks to be quite accurate but there are some issues with it. It doesn't look like it was designed to be very serviceable, some of the models are broken, and some of the parts take a lot of filament to print.
I decided to tackle the hardest part first. The neutrino wand, in the 3d files, is complete but there are a number of issues with it. The original hand grips are too wide for a 7 year old kids hands and I need to make it a bit smaller. I've decided to use a 3/4 inch PVC pipe as my base for the front and rear hand grips. Those parts are blue in the image below. Everything else will be printed.
I've added a mount for the rear handle to the base, redid the front handle mount to work with the 3/4 inch pipe, and I cut out one of the sides to reduce print time/filament used. I added some mounts so I can glue the side in and make it strong but still allow me space to work. I made the base removable so I'll be able to get at the electronics using the existing 6 screw holes.
My plan for the electronics is to use 2 ardunio nano clones (I picked up 3 for $11) coordinated by the wand via a serial connection. The arduino in the wand will control all of the LED's in the wand and talk to the arduino in the pack. The arduino in the backpack will control a ton of LED's and also control an Adafruit audio fx sound board. I've just started playing with this sound board and it's really cool. I think I'll be able to do everything I want with it.
I have one of the cheap XYZ Printing Davinci Mini 3D printers and it's doing a pretty good job printing out the wand so far. The lighting in the pictures is pretty harsh but I will need to do some filling to clean up the parts. I am at about 80% of the parts printed at this point. I keep making changes to the models to make it print easier or be easier to take apart but it's coming along well. I hope to have the wand showing signs of life in the next week or so.