Scale it however you like and use screws to assemble. The spring on the top head can be either 3D printed or from a kit. Entirely up to you. The transformation from Blaster Mode to Saber Mode is manual with a collapsible blade. The base blade is snug to fit in the compartment, however, a touch of glue wouldn't hurt. I printed my blade in vase [spiral mode]. I didn't get a chance to check in normal mode, I'm sure it will work. The internal gear system is embedded on the parts so make sure you print the Main Head parts accordingly. I printed mines standing up with tree supports [I'll post a time-lapse later] and it came out fine. The mouth does lock into place when going from blaster mode to saber mode, however, you can insert magnets to make the lock more secure if you want. The mouth is a snug fit already and should be just fine. Magnets used are 10mmx2mm.