This week’s selection are the 3D printed Vise Grips by Adam Cook.
I always fall for print-in-place models, and this is certainly one of those. What is it? It’s exactly as billed, a set of vise grips, one of the most useful items in anyone’s hardware toolbox.
Here we have a relatively complex mechanical system that has been carefully designed by Cook to be printed in one piece, ready for use as soon as it’s lifted off the print plate.
There is a very interesting approach used in this model to achieve print-in-place. One of the trickier elements of the design is the need for a threaded rod to move the jaws wider or narrower. Printing a rod of that type would typically have to be done in vertical form in order to build threads on the entire surface.
If you were to print the rod shape laying down, then you’d need a pile of support structures that would absolutely mess up the smoothness of the threads.
How does Cook overcome this? The approach was to flatten one side of the threaded rod, as you can see in the images above if you look closely. Mechanically, this still works: the threaded rod can still rotate and drive the mechanism, even if a portion of the rod is flat. Even better, this means no support material is required for the rod. Brilliant!
There’s one caution here: you will be printing a tool in plastic, not metal, so there is no way this will have anything close to the strength of an actual vise grip.
I’ve printed many tools similar to this, including a vice, and found that they tend to crack relatively easily due to the brittleness of PLA. Cook recommends adding perimeters to the print job, perhaps up to ten. That could make the object very close to fully solid.
Another approach would be to print the vise grips in a material other than PLA. ABS and ASA come to mind, as they are viewed as stronger than PLA. However, they are “stronger” in that they have a bit of “give” when impacted. But that’s not what you want in a precision tool; bending is not desired.
Instead you want a material that is strong but also very hard. PLA is like that, but it is too brittle. It will also soften if left in the sun too long.
The ideal material for this might be a PETG-CF material, where the embedded carbon fiber would make the grips very hard and resistant to cracking. I’ve printed many CF objects, and it is shocking how hard and strong they can be.
My recommendation: print the vise grips using a CF material and you may end up with a tool you can practically use in many situations.