Project Logs

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• Feedback

  infiniter4506 • 05/20/2025 at 19:18 • 0 comments

  Today was presentation day. We were given a lot of positive feedback, we were told that it would have been better if we had used a triangle instead of the T-shaped part. And include a mechanism the fork directly, rather than gluing the fork. Additionally, it would have been better if we had sent previous prototypes to be printed in one go, instead of one at a time.

• 13. Final Documentation (Yousef, Jahed, Jihoon)

  infiniter4506 • 05/20/2025 at 19:16 • 0 comments

  <Adjustable Hand Strap Project for Diego>

  Team Members:

  • Yousef Abouturkia
  • Zahed Al-Kassous
  • Jihoon Choe

  Project Timeline and Development

  February 11: Initial Brainstorming

  • Discussed Diego's challenges and possible solutions.
  • Decided to focus on creating an adjustable hand strap to aid with gripping.

  February 25: First Prototype (Cardboard)

  • Created an initial prototype using cardboard.
  • Main issue: Size adjustment.
  • Solution: Adopted a method where the strap ends are inserted into holes to secure the fit.
  • Design considerations:
    • Hole size: 2 cm
    • Fixing method: Initially considered an arrow-shaped hook, but changed to a T-shaped end for stability.

  March 4: Digital Design (Autodesk Fusion and version 1 of strap)

  • Transitioned from cardboard to digital modelling using Autodesk Fusion.
  • Initial theoretical models: 

  •  (Version 1):

     Initial design to use as foundation to work from:

  March 11: Learning 3D Printing

  • Explored 3D printing techniques.
  • Learned the printing process, material loading, and safety precautions.
  • Decided to attach T-shaped end. (Version 2).

  March 18: First 3D Printed Prototype (Version 2)

  • Features:
    • Small, thick strap for the hand.
    • Simple, one-piece structure.
  • Feedback:

  1. Rigid structure caused discomfort, especially for children.
  2. Material was too thick, reducing flexibility.

  • Improvements:

  • Decided to fillet the edges to reduce the risk of tearing (avoid right angles). (Version 3)

  April 1: Improved Versions (3 & 4)

  • Adjustments:
    • Fillet edges between the T-shaped part  so lowered the risk of tearing. (Version 3)
    • Reduced thickness for comfort. (Version 4)
    • Enlarged holes. (Version 4)

  • Feedback:
    • Thickness still felt excessive.
    • Enlarged hole diameter from 2 cm to 2.5 cm but found it unnecessary.
  • Next Steps:
    • Further reduce thickness and maintain the original hole size

  April 8: Version 5 - Enhanced Usability

  • Major improvements:
    1. Reduced thickness (0.5 cm to 0.2 cm) and width (7 cm to 5 cm).
    2. Increased gap between the two holes.
    3. Reduced T-shaped size

  • Benefits:
    • Easier to wear and manipulate.
    • Improved holding power due to natural tension.

  April 22: Second 3D Print (Version 5)

  • Feedback:
    • Insufficient flexibility despite reduced thickness.

  April 29th: (Version 6)

  • Adjustments:
    • Only one circular hole, added three rounded-rectangular holes for the fork in the middle section. (Three holes for stability)
    • Further reduced the thickness. (1.2 mm)

  • Feedback:

  • Corners not filleted enough, leading us to add quarter circles on each corner.

  • Expected Outcome:
    • Improved comfort and usability for Diego.

  May 6th: (Version  7 and version 1 of clip)

  • Adjustments:

  • Added another circular hole for better fit.
  • Changed material to softer TPU.
  • Smooth and filleted edges for comfort. (Round instead of angular)

  • Feedback:

  • Make the edges of the T-shaped circular rather than angular for ease.

  • Clip:

         - Initial model for the clip with no fillets to work around obstacles.

         - 20 mm width intended for the fork’s handle to fit in.

  May 13th: (Version 8 strap, versions 2&3 of clip)

  • Adjustments for strap:

  • Enlarged the circular holes. (Version 8 strap)
  • Circular edges on the T-shaped tip. (Version 8 strap)

  • Adjustments for clip:

     -  Added fillets to print prototype. (Version 2 clip)

     -  24 mm diameter circle for the fork head to fit. (Version 3 clip)

     -  Added a hook at the tip of the clip for possible stability. (Version 3 clip)

  May 18th: (Version 9 strap and version 4 of clip)

  • Adjustments for strap:

  • Increased the gap between two circular holes (Version 9 strap)
  • Reduced the hole size as the softer TPU was too weak to have a small distance between the edge of the circle and the end of the strap (horizontally). (Version 9 strap)

  • Adjustments for clip:

  • Made the clip longer. (Version...

  Read more »

• 12. <Performance Report>

  infiniter4506 • 05/18/2025 at 10:14 • 0 comments

  1. Intent: hand strap with adjustable length to assist a user (Diego) who has difficulty gripping objects.

  2. Summary of progress

   0) version 0 : outline

   1) version 1~2

  : deciding the way of wearing

   (inserting tips of body with scratches => insering “T-shaped” into holes)

   2) first outcome : too thick

   3) version 3~5

  : reduce thickness twice and make distance between body and “T-shaped” longer

   4) second outcome

  : Thinner thickness and overall smaller size

   => It is more flexible and easy to wear compared to last outcome

   => But, there is many remaining issues due to structural limitations.

   5) version 6 : there is big change in structure of strap

     => transforming simple structure into main and supporting bodies

   6) third outcome : increased ease of weaing compared to last versions

     => but, still nees adjustment of components (length of body, size of holes, etc)

   7) version 9~10 (skip version 7~8 because there are no major changes)

   : maintain basic structure, but reduce size of holes and make a little bit more angle in supporting body

   8) fourth outcome (Final outcome) : Our end result of this project

  3. good points

   1) easy to understand the way of wearing : insert into holes

   2) reduced overall size, length and thickness : low load on the wrist of wearer

  4. Problems (need to improve)

   1) There is only two holes : The length can be adjusted, but the range is small.

   2) There are no noticeable differences when compared to existing straps.

  5. Final opinion

   This hand strap project achieved some success in designing a compact structure to reduce the burden on the user's hand and length adjustment function , but we conflicted lack of range of adjustment limitations and problem of absence of uniqueness. We will continuously try to improve these problems. Thank you.

• 11. May 13 (13 mars)

  infiniter4506 • 05/18/2025 at 10:07 • 0 comments

  This is the documentation of final week.

  1) We increased the vertical length of the hand strap a little bit from version 6 because we thought it would be too short for DIEGO's hands.

  => length change: 19cm -> 21cm

  (they temporarily became Version7,8, but I don't upload the files because there were no major changes).

  2) Due to lack of time, we decided not to touch the big structures like body anymore. Instead, we spent the rest of the time checking if there was any danger that diego (the user) could get hurt.

  => We rounded the end of the supporting body where the “holes” are, and angled the square a bit more on the opposite “T-shaped” side of the supporting body to make it almost octagonal.

  (file : Version9,10)

  3) Based on version 10, we printed the fourth and final 3D printed result in . Compared to the 3rd printout (based on version6), it was easier to fit both diego's actual hand and the model of his hand. 

   While there are still improvements to be made, this is the final product of our semester-long effort towards our initial goal of “a hand strap that assists diego's (the user's) grip”.

• 10. May 6 (6 mars)

  infiniter4506 • 05/18/2025 at 10:04 • 0 comments

   We started to make a modeling (file : version6) with length of “shape2” that we made last week and quickly printed third outcome. As we mentioned in the last documentation, we needed a new design. So, as you can see in pictures below, there were big improvements from this version. Moving away from the simple structure of version5, it becomes a more watch-like design that is more comfortable to wear.

  1) The part that meets the palm of hand is the “main body”, which is not significantly different in length of width from version 5.

  2) However, the “supporting bodies” that extend out from the main body on either side are about 1.5 centimeters, shorter width than the main body.

  3) The way of wearing is the same, with putting “T-shaped” in the “holes”. These two elements are attached to each end of the secondary body.

   Next week is the last week of work for this semester, so we'll keep this basic structure and adjust details such as the size of the holes, the size of the “T-shaped”, and the vertical length of the main body and supporting bodies, etc.

• 9. April 29 (29 avril)

  infiniter4506 • 05/18/2025 at 10:02 • 0 comments

  Before making complete structure of new type of our hand strap, we needed to make a new shape which becomes basic structure. At first, we tried to design shape with much longer length than second outcome (file : shape), but it was too long. (Almost 32cm) So, we redesigned something with reduced length of body and it becomes a little bit longer than outcome. (file : shape2, change in length from second outcome to shape2 : 15cm -> 19cm)

  Using this completely different-shaped design, we will test third 3D outcome next week. We expect that this new strap become more comfortable.

• 8. April 22 (22 avril)

  infiniter4506 • 05/18/2025 at 10:00 • 0 comments

   We made a 2^nd outcome of 3D printer based on version 5 and received feedback from professor. In conclusion, we also found several problems of this outcome.

  1. Lack of flexibility in the T-shaped fixed structure

  Although the overall thickness has been reduced and elasticity has increased compared to the previous 3D outcome (based on version2), the overall structure remains too simple, making it unsuitable for mounting on the human wrist.

  => Short of stability

  2. No anti-slip design after fixation

  Even after inserting the T-shaped structure into the hole, there are no elements to restrict movement(=ensure fixation), which may cause it to come off the wrist.

  3. The spacing between the holes is fixed and cannot be adjusted

  There are only two holes with a fixed spacing, making it difficult to adjust flexibly according to length of wrist circumfence and limiting the adjustment range.

   => insufficient length adjustment

• 7. April 8 (8 avril)

  infiniter4506 • 05/18/2025 at 09:57 • 0 comments

   We made a new design (file : Version5) based on direction that made in last week. There are two big improvements.

  1. We reduced the thickness and length of the short side of the wristband body.

  => At first, we tried to only reduce the thickness as we originally planned. But, we need more decrease of load. So, we also reduce the width of the wristband.

  (thickness from version 4 to version 5 : 0.5cm -> 0.2cm)

  (width from version 4 to version 5 : 7cm -> 5cm)

  2. We made the distance between body and “T-shaped” longer.

  1) Easier to wear

  As the distance increases, the user has more space to hold and manipulate

  "T-shaped", making it easier to insert the strap into the hole or pull it.

  => This is especially helpful for children with weak hand strength or caregiver

  thanks to easy manipulation even with small hands.

  2) Improved holding power

  As “T-shaped” moves further away from the main body, a natural tension (pulling force) is generated after passing through the hole, providing a loose-prevention effect. As a result, the strap is secured more firmly.

  Thanks to these intentions, shape of version 5 looks quite different from version 2(first outcome of 3D printer). So, we will check problem of actual use by printing second outcome in next week.

• 6. April 1 (1 avril)

  infiniter4506 • 05/18/2025 at 09:55 • 0 comments

   Based on feed-back about our first 3D outcomes, we designed another modelings (File : Version3 and Version4) to reduce thickness and make “T-shaped” softer as we mentioned last documentation.

   In version 3, we tried to make the inner corners of the band softer. And then, in version 4, we tired to make the rest of corners same shape as inner corners and reduce the band’s entire thickness by almost half. (1cm – 0.5cm)

   But, confirming design of version 4, we felt two problems below.

  1) Compared to the 3D printout of diego's hand, thickness of version 4 (0.5cm) still felt thick. So, we decided to reduce it once again in next version.

  2) We made holes in the body of band bigger to test the ease of band’s equip. 

  (diameter : 2cm -> 2.5cm) But, it doesn’t seem to have the much influence on it. So, we will reduce width to original value again in next version.

   Conslusively, we decided to make the direction of our next step based on our discussed solution of these problems.

• 5. March 18 (18 mars)

  infiniter4506 • 05/18/2025 at 09:48 • 0 comments

  Using second version, we made a first printed outcome and checked it.

  There is ouline below.

  1. Intent: A small, thin, semi-circular band designed to fit children's wrists well

  2. Design Features:

  • Reduced overall size to fit children's wrists
  • Simple, one-piece structure without hinges or rings

  3. Issues

  1) Insufficient holding power : When the strap ends (“T-shaped”) are inserted into the holes, there is no additional securing mechanism, causing them to easily come loose

  2) Material thickness issue : Although we designed thickness which we thought is thin (50mm), the actual printed result is still too thick. It result in almost no flexibility and inability to bend like a strap.

  3) Lack of flexibility : The rigid structure prevents it from softly wrapping around the wrist, potentially causing discomfort when worn. If we, as adults, feel discomfort, diego will feel it even more because he is more sensitive because of lower age than us. So, we decided to decrease the thickness.

  4. Improvement directions

  1) Since the target user(Diego) is young children, it is necessary to reduce the overall size to minimize wrist strain.

  2) significantly reduce the thickness to enhance flexibility and ensure the wrist is comfortably wrapped during actual use.

  3) Smooth the edges of “T-shaped” to ensure it fits properly into the hole.

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