For a person that only has one functional arm some daily actions could sometimes be difficult. The action of squeezing a rag is an example of this phenomenal. The typical wring motion used to dry a rag requires two functional hands. An option to dry the rag with only one hand is to just squeeze it with one hand or push it against the sink. A disadvantage of these methods is that it's nearly impossible to get the rag dry enough and the squeezing motion with one hand can be painful or even cause convulsions. Trying to find a solution for this problem we came up with the idea to modify a tin can crusher and we have had some great results with it.
Step 1: Materials Needed
- A tin can crusher (we used one branded 'Cosy and Trendy' which we found in a local supermarket)
- Steel profile, 4x30 mm length 74 mm (approx. 1 3/16 x 5⁄32 in, length 30 in)
- Steel profile, 3x40 mm length 170 mm (approx. 1/8 x 1 1/2 in, length 6 3/4 in)
- Galvanised steel plate, thickness 1,2 mm (approx. 1/16 in) 300 x 200 mm (approx. 12 x 8 in)
- 2x countersink screw M6 x 12
- 2x countersink screw M6 x 16
- 10x M6 (nylon) washer
- 6x M6 locknut
- 1x threaded rod M6 100 mm
- 1x threaded rod M8 100 mm
- 2x M8 washer
- 2x M8 locknut
- 2x M8 spacer
- 2x M6 spacer
- nylon plate thickness 10 mm, 100 x 100 mm
- water container box
Step 2: Tools Needed
- a drill
- a bending machine
- a welding machine
- a metal saw
- a grinder
Step 3: Finding a Tin Can Crusher
By using a lever it's possible to increase the strength of a small motion. We went and bought a cheap tin can crusher in a local supermarket. Because it wasn't really heavy duty and the force needed to squeeze a rag is pretty big we did some modifications to it to make it stronger. If you decide to buy a heavy duty one you can skip the next step and go straight to step 5.
Step 4: Reinforcing the Can Crusher
While doing some of the first tests with the can crusher in an attempt to squeeze a moist rag it became clear pretty fast that it wasn't going to be strong enough. The big metal parts of the lever started to bend when the crusher was forced a bit and the rivets used for the hinges came loose. The metal parts in the lever were made of thin steel with a small bend in it in attempt to reinforce it. I guess that squeezing a rag requires a bit more strength then crushing a can. We modified our can crusher to make it stronger, the following instructions are written to modify a can crusher of the type we used, when using another can crusher, sizes and systems may vary. We grinded off the rivets and removed the metal arms and replaced it with new arms. The steel we used is blank steel with a thickness of 4 mm (approx. 5⁄32 in) and a width of 30 mm (approx.1 3⁄16 in). A total of 74 cm (approx. 30 in) is needed and has to be cut it in 4 pieces using a steel saw. Cut two pieces of 25 cm (approx. 10 in) each and two pieces of 12 cm (approx. 5 in) each. Drill two 6mm (1/4 in) holes in the short pieces both 15 mm (19/32 in) from each side. The rivets we replaced with M6 (1/4 in) countersunk screws, some (nylon) washers and locknuts. The foam handle which was also attached with a rivet system we re-used but we replaced the rivet system with an M8 wire rod and added some washers and bolts to attach it to the arms.
Step 5: Moddifying the Slider Bed
One of the problems we came across while testing was that some parts of the rag were hanging outside the bed and were not getting dry. At the same time the bended walls where the arms were attached started to bend back because of excessive force. We decided to grind them off and added a u-shaped piece which we welded onto the bed. By adding this piece 'walls' are added so the rag can't hang outside the bed and the arms can be attached without the walls bending back. We used a blank metal plate with a thickness of 3 mm (approx. 1/8 in) and a width of 40 mm (approx. 1 1/2 in). The length we used was 170 mm (approx. 6 3/4 in). It was bended using a bending machine in a U with a 70 mm (approx. 2 3/4 in) back and 50 mm (approx. 2 in) legs (see picture). The U was welded on the bed with it's legs facing the other way (see picture). Afterwords holes were adde through the bended plate and through the bed so the water can flow away. We drilled 5 mm (approx. 7/32 in) wide holes (4 sets of 5 holes). We then added two holes in the side walls were the arms can be reconnected.
Step 6: Give It a Nice Color
Because we used blank steel and the purpose of the design is to use it with fluids it has to be protected against corrosion. The cheapest way to do this is by painting. We painted our model using spray paint. We sprayed one layer of primer and three layers of black paint.
Step 7: Creating a Draining System
To drain the water that's pressed out of the rag we added a bended plate that's attached behind the crusher. We used a galvanized plate we had laying around in the workshop with a thickness of 1,2 mm (approx. 1/16 in). The plate we used was 300 x 200 mm (approx. 12 x 8 in). We rounded the corners for safety reasons and added some bends to drain the water to the drain container box. We also drilled some holes (the same as the crusher) to attach it.
Step 8: Adding a Container to Cath the Water
If it's possible, you could just hang the aid above the sink so the excessive water drains into it. When it's not possible to hang above your sink an option is to add a tray underneath the aid that catches the waten. Make sure the tray is detachable so it's easy to empty it.
Step 9: Assembly
After al the parts are adjusted and sprayed the last step is to assemble all the pars and tighten the bolts. Just make sure that all moveable parts can still move. You can hang the aid above your sink or at any other place using a tray. If you make sure a tin still fits in it, it's still possible to use the aid as a tin crusher. Also a handy tool to have.
Step 10: Final Prototype
This rag squeezing aid was made for Bart who has only one functional arm. This helps him to clean up his house in a more efficient en less painfull way. The product is shown in the video above.
This aid was designed by Sander Klomp & Pieter Vanoverberghe with support from 2 occupational therapists : Sharon Dejaeghere & Emiel Tanghe.