50kg/110lbs load/force cell from cheap luggage scale

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What's this?

It's a cheap device for measuring weights/pushing forces up to 50kg or 110lbs.
Commercial force sensors which can do that are either really expensive or really big. Or both :)

Is this thing useful to you?

Don't hesitate to hit the ❤ and show some love. I'm always happy to hear from you in the 🗩 comment section. If you have problems printing my files: tell me in the comment section too!

Provided files

I do like to have real CAD-files, when downloading things from others. Most users don't provide files other than .STL-files. These are useless for further manipulation or quick changes. So I'll provide the following files to you:

What do I need?

• a cheap (10$) luggage scale, model: Etekcity EL11 or equivalent
• two 3D printed parts
• a few screws
• a few tools (M3 tap, soldering iron, glue, sticky tape)

How is the conversion done?

• use a pair of pliers to unscrew the (glued in) luggage-hook (counter-clockwise :) )
• open the scale (2 screws in the back)
• unscrew the PCB (3 screws)
• unscrew the load cell (2 screws)
• unsolder the load cells' 4 cables
• solder 4 wires as long as you need them (don't go too wild, maybe 50cm max or so) to the board. note colors and position!
• push wires through the opening in the case where the hook was
• put PCB back, secure with the 3 screws
• close case
• add heat shrink tubing to the individual wires and one bigger diameter tube to keep them all neatly together
• solder your extension wires (in the correct oder of course!) to the load cell wires and shrink heat shrink tubing
• cut M3 threads into the load cell case
• put load cell into the case (secure each corner with a dab of glue)
• put on lid, fasten with M3 screws
• add M8 screw, 8mm rod or what you like to act as a piston for the force sensor

If you want a different case, bigger screw holes, whatever: feel free to modify to your hearts content! ### Cheers, Jan

Print Settings

Rafts: no

Supports: no

Resolution: 0.15 … 0.2

Infill: Lid: 100%, case: 20-100%

Filament: PLA+, PETG, ABS, ASA