Knex Flux

Knex Community => Project Ideas and Help => Topic started by: Togofan on April 14, 2019, 04:21:44 am

Title: Ball Machine half pipe does not work well.
Post by: Togofan on April 14, 2019, 04:21:44 am
I am trying to make a half pipe for my new ball machine. 

(https://i.imgur.com/sWdDX6c.jpg) (https://i.imgur.com/HlmudOG.jpg) 

 The ball drops in at the top and should swing back and forth good until it nears the bottom of the halfpipe.  Then it should exit through the little hole.    The ball instead drops in and very lazily does two or so very small swings back and forth and then rolls straight to the exit.   I am using 2 layers of paper for the halfpipe. 
Title: Re: Ball Machine half pipe does not work well.
Post by: austron on April 14, 2019, 04:46:15 am
My theory is that the paper half pipe is not rigid enough. The ball is losing too much energy too quickly because it is all going into deforming the paper as it rolls over it. If you made your half pipe out of a slightly more rigid material, such as a sheet of thin plastic, or several sheets of think card stock glued together, I think it would perform much better.

Good luck!
Title: Re: Ball Machine half pipe does not work well.
Post by: Togofan on April 14, 2019, 04:50:11 am
Would using flexible cardboard from a spiral bound notebook work? 
Title: Re: Ball Machine half pipe does not work well.
Post by: austron on April 14, 2019, 04:55:01 am
It might, it's worth a try, but it would probably be helpful to find something a bit more rigid. The problem with cardboard is that it can crease and kink easily. You can get thin sheets of plastic at hardware or hobby stores for very cheap. A flexible plastic cutting board might work as well.
Title: Re: Ball Machine half pipe does not work well.
Post by: Togofan on April 14, 2019, 04:57:45 am
How about a cut in half PVC pipe?
Title: Re: Ball Machine half pipe does not work well.
Post by: austron on April 14, 2019, 05:00:15 am
That would probably work best of all! If you have a sufficient large PVC pipe, and the means to safely cut it in half, then definitely do that!
Title: Re: Ball Machine half pipe does not work well.
Post by: smunt93 on June 11, 2019, 01:15:26 pm
I have had good success using a folded up knex instruction manual!