This thing is a "Cannon" to lift Gravitrax steel marbles up 15cm, giving them more potential energy to spend along the track that follows.
If you have played Gravitrax you know that the most recurring question you will be asking yourself is "How do I gain more height?"
Height is important because it all works on gravity pulling the marbles down and spending their potential energy doing tricks and gaining speed.
I know there are solutions out there, Gravitrax stock lift, for example, but the idea of designing an actual shooting cannon was too tempting to resist!
The principle is very simple... A percussor held in a "loaded" position by a trigger that gets freed when the marble falls into the cannon. The percussor is loaded by 2 rubber bands. The rubber bands I personally used are the replacement ones you will find in the stock Gravitrax "Catapult" expansion. There are plenty of replacements, the Catapult only needs 1, so the Cannon can use another 2. I believe any small rubber band will do, though, you will just have to calibrate the force to avoid having your marble either punch a hole in the ceiling or not make it past the cannon mouth... :)
You will need to print one each of the parts you will find in this Thing's files, except for the part named "MarbleGuide", which you will need 5 of.
The project also makes use of a few parts I have designed and already shared here on Thingiverse.
Besides the files you will find listed for this thing, you will also need to print the following parts from my other designs:
Please note that the top "Exit" part has 4 beds for 4 marbles to act as stabilization weights, a bit like they do in the Catapult base. It is important that you "sacrifice" 4 marbles for this purpose, as they ensure that the top doesn't go flying off if the rubber bands are too strong.
Please also read the Print Settings and Post Printing sections for more info on how to print and assemble the Cannon.
Don't forget to take a look at the Post Printing section to see it in action!
If you make this, it would be awesome to see pics of your makes!
Note: I am in no way associated with Ravensburger or Gravitrax, this is just a design that is compatible with the Gravitrax system that provides functionality the stock parts do not.
I do this just for mere fun, but if you find my projects useful to enhance your Gravitrax experience, consider the idea of tipping me, I'd really appreciate it! :)
bq, Sienoc PLA
White, Grey, Yellow, Black
Remove supports carefully, especially from the cannon barrel, and sand any irregularities that might be left in it after removing supports.
It is important that the barrel is as smooth as possible, both to ensure the trigger mechanism works well and to prevent the marble from bouncing along it rather than sliding.
Be very careful with the "hooks" for the rubber bands, both on the cannon mouth and the percussor. They are tiny. The orientation I am providing the parts in ensures the maximum sturdiness of these little parts, so I suggest you print them just as you downloaded them, without re-orienting them.
During assembly, pay special attention as some parts are small and fragile, at least until they are all put together.
The 5 MarbleGuide rails that go into the MarbleEntrance need to be pressed fully into the holes, but do it gently, as they could snap.
It is much easier to first assemble the trigger, cannon mouth and barrel together, fit the rubber bands, and only after that slide the percussor in the slots and fix the barrel to the bottom base tile. Rubber bands are very hard to place if you do it once the whole cannon is assembled.
Detail of the marble flying up to the top in slow motion
All my custom designed parts in one track!
This image shows a cross-section of the assembled Cannon. Besides providing help on how to assemble it, it also shows the path the marble takes from entrance through the mouth to exit through the top guide