Gravitrax Compatible Ballista

cults3d

After trying many different Gravitrax Gauss Cannon prints on here, I found all of them to be finnicky and somewhat unrealiable. To solve this, I decided to tackle the problem from a different angle. I present you the Ballista! It uses small rubber bands in a sling-shot type mechanism to launch a ball with seriously impressive force. For real, this thing will blast marbles straight across the room so use it with caution. It works much more consistently than printed gauss cannons and doesnt require any magnets. All you need is 2 small rubber bands (I use size #8) and an M3x20mm screw. Depending on how you choose to loop the rubber bands, you can adjust the power up or down. If the power is too strong (which ive found to be the case for most applications), you can print the Trigger_Long part instead of the regular trigger which reduces the draw length and therefore power. No supports required, prints in about 1h40m Enjoy! UPDATE: Added new files for the Base and the TriggerFrames that have interlocking tabs / slots to allow for easier assembly. These variants have the "_SnapFit" suffix. Assembly Instructions Once all of the parts are printed, gather 2 small rubber bands and an M3x20mm screw. First, place the Sled into the channel on the Base with the rectangular notch in the Sled facing up. Loop your rubber bands around the "wings" of the sled and into the small notches in them. Loop the other end of the rubber bands around the raised pegs on the front end of the Base and into the small triangular notches. Next, take the TriggerFrame and TriggerFrame_Right and apply some glue to the flat plates, then glue them to the Base such that the back ends of the TriggerFrames are flush with the back end of the Base. The long thin rails should be on top of the wings of the Sled and hold it in place while allowing it slide along the channel. Next glue the far ends of the TriggerFrame's rails to the front end of the Base. Next, insert the M3x20mm screw through the hole in one of the TriggerFrames and screw it until its about halfway between the Frames. Insert the Trigger onto the screw, then finish screwing until its secured into the other TriggerFrame. Ensure that the trigger is roughly in the middle. Finally, take the TileBase_BottomInsert and glue it into the small hexagonal space in the bottom of the Base. To load the Ballista, pull the Sled all the way back and then lift the trigger and insert its hook into the small notch in the Sled. Place a ball in the small divot in the channel of the Base. Once a ball is rolled into the rear end, it should release the trigger and send the ball in the channel flying!