A variation of the Grab Toy ++ (https://www.thingiverse.com/thing:2750749) where the number of expansion frames is a parameter; this way you can make the thing as large as you want.
I guess there is a limit of how large you can make it before hinge friction and mass of the thing prevents proper opening and closing but I have no idea what this limit may be. Also, depending on the material, a huge thing may snap under its own weight!
The PLA print in the photos is 6 frames long, which still kind of works although the grip at the jaw end is not very strong.
Please note that the STL file with the 10-frame GrabToy has only been included to show the OpenSCAD code can generate things as large as you want. I haven't printed it, so I cannot confirm it will function properly. In fact, having seen the 6-frames print I very much doubt the 10-frame version will be even able to fully close the jaws. In any case, if you do print it please tell us how it went!
GrabToyInfinite(N): generates a grab toy with N expansion frames. The corresponding number of hinges is 3*N+1.
Set global variable N to the desired value and press F6 to render. Keep in mind that more frames means longer time to render. Some indications: for N=10 it takes 12 minutes for my rusty i7-920 to render the thing at moderate quality and 42 minutes at high quality; for N=6 it takes 26 minutes at high quality).
Enjoy!
Update 22/03/2018: EviGL managed to print the 10-frame version and it actually seems to function! So I thought, well, I guess now it's time to render a 15-frame version? Took 1h10min for OpenSCAD to generate the STL!
GrabToyInfinite.scad | 12.9KB | |
GrabToyInfinite_10frames_slack05.stl | 49.8MB | |
GrabToyInfinite_15frames_slack05.stl | 69.6MB | |
GrabToyInfinite_2015compatible.scad | 13.7KB | |
GrabToyInfinite_2frames_slack05.stl | 17.6MB | |
GrabToyInfinite_4frames_slack05.stl | 25.9MB | |
GrabToyInfinite_5frames_slack05.stl | 30.0MB | |
GrabToyInfinite_6frames_slack05.stl | 33.9MB | |
GrabToyInfinite_8frames_slack05.stl | 41.8MB |