26th Nov 2015
So for the skittle challenge we did some thinking and testing and figured that just “nudging” the ball in the direction of the pins wouldnt cut the mustard so to speak. We needed something a tad more energetic. Resident ingenious person Mark quickly rustled up a 3d printed contra-rotating mechanism to give the bowling ball a spot more oomph!
Here are some tests
The first couple of tests used the small ramp but the ball was getting too much air so we swapped things around for the subsequent tests.
Here is another video
Things we learned from these tests:-
- Lose the ramp. In this case getting air is not good.
- Balance is your friend. 3D hubs and spindles are not well balanced and cause huge vibration.
It is difficult to see but the rig was difficult to hang on to once the wheels got up to speed. So we went back to the drawing board and Mike took on the task of fashioning Mk2. This time we would have steel shafts and a metal chassis. First models for the Mk2
The second version tidied up a bit…
Cutting some metal
A revised hub was printed without the built in spindles to try and make it less out of balance to reduce vibration.
The Mk2 flywheel assemblies are finished and look like this.
There is still quite a lot to do to make the assembly on which the flywheels will be mounted and which will be attached to the front of our robot. Here are some views of the cad of the rest of the assembly.
Some laser cutting for the main support arms, 3d printing for the smaller arms and a bit of metal bashing for mounting brackets. Finished off with a bit of wiring. More updates as the assembly comes together.