[Adam] over at Makefast Workshop writes about some of the tests they’ve been running on their 3D printer. They experimented with pausing a 3D print midway and inserting various materials into the print. In this case, sand, water, and metal BBs.
The first experiment was a mixture of salt and water used to make a can chiller for soda or beer (the blue thing in the upper right). It took some experimentation to get a print that didn’t leak and was strong. For example, if the water was too cold the print could come off the plate or delaminate. If there was too much water it would splash up while the printer was running and cause bad layer adhesion.
They used what they learned to build on their next experiment, which was filling the print with sand to give it more heft. This is actually a common manufacturing process — for instance, hollow-handled cutlery often has clay, sand, or cement for heft. They eventually found that they had to preheat the sand to get the results they wanted and managed to produce a fairly passable maraca.
The final experiment was a variation on the popular ball bearing prints. Rather than printing plastic balls they designed the print to be paused midway and then placed warmed copper BBs in the print. The printer finished its work and then they spun the BB. It worked pretty well! All in all an interesting read.
I believe that beyond testing, is better to use cylindrical metal bearings to widen the contact area.
With spherical metal bearings the load is transferred to the plastic housing in it’s weakest point (thinnest zone) and there are big chances to split it in two halves.
Try this one. http://www.thingiverse.com/thing:1769802
This could be very useful for inserting solid parts like the BB’s which you couldn’t easily add later. For pourable contents like water or sand it’s probably still easier to add it through a hole after printing.
Maybe Cura or Slic3r just need a new infill setting, change the acceleration profile to reduce jerk based on the fluid viscosity?
I’ve been tempted to install mounting hardware, like square 1/4-20 nuts, into my prints this way, but have not wanted to manually pause my print to do so, i would love if there were a software route for these pauses, but I don’t expect one any time soon
Yes software support would be helpful, then one could embed objects like a bracket or something that the head needs to know to avoid.
For the solid stuff (BBs, nuts, magnets, etc) you could make a solid case for combining a pick and place head with the 3D printer. The print doesn’t need to pause if the print head places the filled-in parts.
You could try adding a ferrofluid to create a magnetoreactive hydraulic logic device.
I made some weighted dice by just pausing and hot gluing a bolt on one side