Carpe Mundum - grabber/gripper tool system

Carpe Mundum – Seize the World!

Additional hardware needed for this project!

Carpe Mundum is a system designed for quadriplegic individuals who have retained gross arm movement but have lost the use of their fingers. The goal of the device is to help pick up various objects off the floor, including small items like coins and pens, flat items like cell phones, tablets, and books, and oddly shaped items like toys, cups, silverware, clothes, etc. The system includes different tool heads depending on the required task. Items up to a few pounds can also be picked up with some of the tool heads. 

The system includes:

A base unit, which contains an air pump, a solenoid valve and a rechargeable 12V NiMH battery pack. The unit straps onto the users forearm with an accessible ratchet crank, and the users wrist movement up or down can then turn on the pump to apply either negative or positive pressure to the tool head to grab or release an item. 

A charging unit, which holds the base unit and charges the battery.

A large freeform gripper, which is simply a 24" latex balloon filled with ground coffee. This gripper can be useful for picking up objects that are large-ish, hard, and oddly shaped like tools, children's toys, etc. I say large-ish because items still need to be small enough to fit in one hand. This tool can hold several pounds of weight as long as it has enough lumps and bumps for the balloon to wrap around and grip onto.

A small freeform gripper, which is simply a 6" latex balloon filled with ground coffee. This gripper is useful for picking up small objects such as coins, pens and pencils, screws, etc. The balloon material is thinner than the large freeform gripper, and can pick up small items that would require more dexterity.

A suction grabber, which is a medium silicone cup from a cupping therapy set. This gripper is useful for picking up items with wide flat surfaces, like phones, tablets, and glossy hardcover books. It can also pickup magazines, envelopes and some softcover books with some technique and persistence. 

A pincher grabber (separate model), which is composed of two semi-circle fingers that pinch toward each other to grip, wrap around, or hook onto an item. This gripper is useful for picking up items with handles like mugs or jugs, wrapping around wide cylinders like cups, or picking up lightweight soft items like clothes or small stuffed animals. This current design is a remix of an existing grabbing, and I've loaded that as a separate model so I can properly attribute it ( https://www.printables.com/model/1383984-carpe-mundum-pincher-grabber ). I plan to design a better functioning pincher grabber in the future.

A tool changer, which allows the user to easily swap out tool heads using only arm movements. It is meant to be clamped down onto a table top. Users can to load and unload tool heads into the tool changer by hooking their thumb into an attached handle.

Materials list

In this build, wherever possible, I use common materials for easy home repairs. However, some parts require special components.  The total cost for the project is ~$460 USD, though that includes extra materials (it's not possible to buy a pack of one for many items). Cost of materials for a single complete build is ~$370 USD (excluding the cost of extra materials). You will find a complete materials list below. In a future update, I will link to full instructions on how to build.
 

Print info:

0.4mm Nozzle, 0.2 strength preset unless otherwise noted

coffee gripper

• flat plate: 4 hr 46 min, $3.79, 148g filament, uses supports
• cupped: 5 hr 11 min, $3.98, 155.43g filament, uses supports

coffee gripper mini print: 1 hr 29 min, $0.77, 30.68g PLA

connector: 

• Plate 1: 1 hr 53 min, $1.35, 52.37g PLA filament, uses supports
• Plate 2: 2 hr 43 min, $2.26, 89.20g PLA filament, uses supports

crank

• Plate 1: 2 hr 19 min, $1.90, 75.89g PLA filament
• Plate 2: 1 hr 51 min, $2.50, 64.07g TPU filament
• Plate 3: 12 min 18 sec, $0.03, 1.35g PETG filament

housing and charger

• Plate 1: 3 hr 47 min, $4.35, 174.25g PLA
• Plate 2: 6 hr 3 min, $6.35, 254.01g PLA filament, uses supports

lever: 1 hr 38 min, $1.30, 52g PLA filament

suction cup hardware print: 1 hr 17 min, $0.74, 29.78g PLA

Toolhead Changer

• Plate 1: 3 hr 40 min, $3.54, 141.82g PLA
• Plate 2: 2 hr 45 min, $2.17, 86.80g PLA
• Plate 3: 4 hr 57 min, $4.87, 194.76g PLA
• Plate 4: 59 min 18 sec, $0.75, 30.08g PLA
• Plate 5: 3 hr 46 min, $2.62, 103.74g PLA