Randco Meatball-o-Matic 2000

I struggle making round meataballs. My paws are too big, I'm clumsy and I get ground meat stuck to everything. Many commercial meataball presses suffer from the meat getting stuck inside the hollows, and require you to pick out and reshape by hand which becomes a frustrating cycle. And I like nice, round, same-sized meatballs that look pleasing to the eye. I haven't tried it yet, but I'm thinking this might work making onigiri (Japanese round rice balls). With a little work you also might be able to insert some sort of ‘stuffing’ like cheese.

The secrets to using the Randco Meatball-o-Matic

1. I use a blend of hamburger or lamb and ground pork. The pork helps as a binder without adding sloppy egg. I also add toasted bread crumbs and whatever seasoning I like at the moment
2. When you spoon the meat into each half of the MoM, leave the surface ‘ragged’. This helps each half bond better
3. When you're pressing the meat together, press on both ‘shells’, not the ‘extraction plungers’. If you also press on the extractor ends they will leave dimples in the meataball
4. Rotating the tools in opposite directions, while maintaining pressure, sometimes helps to cut through any residual excess meat and help with bonding
5. After the meat is pressed together, use the fingers of both hands to pull the shells apart without moving the extraction plungers (see inserted .gif)
6. After the shells are apart, and have exposed that nice, round meataball, then pull both tools apart and let the meataball fall onto your plate
7. I use a mini-muffin pan to roast the meataballs to maintain shape (not flatten one side) and contain the inevitable grease
8. YMMV

For printing/assembling

1. The main model is print in place as there are 2 parts to each tool side, in addition to the separate screw-in cap
2. The .3mf is from Prusa slicer for printing multi-material, but you can print with single filament if desired
3. I use PolyMaker PETG for safety and durability
4. I used .4 nozzles and .15 layer height
5. There is a single support for the bottom face of the shells
6. Before screwing the end cap into the assembly, I inserted a Mardatt 0.024x0.37x0.79 spring into the assembly base. This helps pop the shells back out after pressing.
7. The tolerances are fairly tight, so some cleanup work around the shell holes may be necessary with a dental pick. In addition, slight pulling of the shell to its outer extreme (and letting it set for a moment) helps to eliminate any burrs and make sliding easier
8. Cleanup is easy with some swirling in warm, soapy water