dcf.cymru stimulus sheet · Design and Technology · Year 11
Elin, her client, the lunch club, the users and every figure on this sheet are invented. This is a practice design project. It is not a WJEC contextual challenge.
Mrs Hughes, client interview: “I’ve given up on jars. I buy things in pots with ring pulls, or I wait for my son to visit. I don’t want something that looks like it came from the hospital. It has to go in the dishwasher, because I can’t scrub things any more. And keep it light: my wrists hurt when I hold anything heavy.”
An occupational therapist, by email: “A wide, soft handle means the hand does not have to close so far, which needs less grip force. Keep the aid under about 150 g. Many people with arthritis cannot scrub, so dishwasher-safe matters. Check 3D prints for sharp seams.”
| Point | The Gafael jar opener must… |
|---|---|
| S1 | open screw-top lids from 40 mm to 82 mm across. |
| S2 | have a handle grip 35 to 45 mm across. |
| S3 | have a mass of no more than 150 g. |
| S4 | let at least 8 out of 10 users open the test jar. |
| S5 | let users open a jar at least 30% faster than without it. |
| S6 | score an average comfort rating of at least 4.0 out of 5. |
| S7 | cost no more than £2.50 in materials per opener. |
| S8 | be safe to wash in a dishwasher. |
| S9 | look like a kitchen product, not a hospital aid, in a bright colour that is easy to find. |
| Test | Result |
|---|---|
| Lid sizes: three tries on each lid | 43 mm: the jaw slipped 3 times out of 3. 53 mm, 63 mm, 70 mm and 82 mm: opened every time. |
| Measure the handle grip with a vernier caliper | 38 mm across. |
| Weigh on kitchen scales | 168 g: PLA body 146 g, TPU liner 22 g. |
| Material prices | PLA filament £20.00 per kg. TPU filament £35.00 per kg. |
| One dishwasher cycle at 65 °C | The jaw warped by 2 mm and no longer closed evenly. PLA starts to soften at around 60 °C. |
| Run a finger along every edge | A ridge about 1 mm high along the print seam on the underside of the handle. |
How Elin ran it: 10 members of a lunch club that Elin’s grandmother goes to. Everyone knows Elin. Each user had two new, sealed 63 mm jars of the same jam. They opened the first without the opener, then the second with it. Elin timed each attempt with the stopwatch on her phone, stopped any attempt at 60 seconds and wrote “not opened”. Afterwards she asked each user two questions: “How comfortable is my opener, from 1 (very uncomfortable) to 5 (very comfortable)?” and “Do you like my opener?” All 10 said yes to the second question.
| User | Age | Arthritis | Time without (s) | Time with (s) | Comfort (1 to 5) | Comment |
|---|---|---|---|---|---|---|
| U1 | 81 | rheumatoid | not opened | 9 | 5 | “First jar I’ve opened on my own in months.” |
| U2 | 74 | osteoarthritis | 14 | 8 | 4 | “Looks like a proper kitchen gadget, not a hospital thing. A bit heavy.” |
| U3 | 69 | none | 6 | 7 | 3 | “Works, but I don’t really need it.” |
| U4 | 88 | rheumatoid | not opened | not opened | 2 | “My hands are too small to close it round the lid, and it’s heavy.” |
| U5 | 77 | osteoarthritis | 21 | 10 | 4 | “The soft grip is lovely.” |
| U6 | 72 | none | 8 | 7 | 3 | “Fine. Quicker to use a tea towel.” |
| U7 | 80 | osteoarthritis | 25 | 11 | 4 | “The yellow is easy to find in my drawer.” |
| U8 | 79 | rheumatoid | not opened | 13 | 5 | “Brilliant. Can it go in the dishwasher?” |
| U9 | 70 | osteoarthritis | 18 | 9 | 4 | “Much easier on my wrist.” |
| U10 | 83 | rheumatoid | 30 | 12 | 4 | “Works well, but the edge of the handle digs in a bit.” |
The same data is in gafael-user-trial.csv.
“My Gafael jar opener works for everyone and makes opening jars twice as fast. All 10 users liked it. It meets my specification.”