Avril Griessbach


Industrial designer with several years of experience in the tool industry / consumer products / design leadership / corporate branding strategy.

Passionate about user-centric processes and creating satisfying solutions.



Email
CV
Linkedin




Design
Redesign


Misc.











OX Pro Precision Chalk Reel

An award winning compact chalk reel with an innovative braking mechanism and an integrated karuko pin.


RedDot Design Award, Patent Pending

concept-to-production, innovation, user research, brand language
















One of seven chalk reels developed for a new range for OX Tools. This piece primarily details the process behind the precision chalk reel.










Project start -> prototype in less than 3 months for a successful pitch to Lowe’s (the US’s second largest home improvement retailer)











User Research
Depending on the trade, users have many different preferences for their chalk reel. 

The precision chalk reel is designed for
tradies for whom precision is vital (primarily finish carpenters and woodworkers) who value:
  • a compact chalk reel
  • a precise yet durable line
  • keeping their hands free of chalk
photography by Dominic Florio











Key Issues Identified in Motion Studies

1. The string is often pulled out without using the push button* and often the hook won’t hold onto the edge (and no nail can be placed to fix the hook), turning the task into a two-person job.

*A button which acts as a clutch release by disengaging the gears which connect the crank to the string spool, meant to be used to preserve the longevity of the gears.


2. Many people pull the line taught by wrapping the string around their finger.



3. Snapping line leaves chalk on hands (which depending on the grade ranges from brush-off to permanent and then gets transferred to tools, clothes, etc.).
4. Finally the line is rewinded by spinning the crank.











Ideation

Problem #1: Many people pull the line taught by wrapping the string around their finger.





The Solution: A tip which acts as a brake and using the stored handle as a lock











Problem #2: Standard hooks are limited








The Solution: A Hook/Pin Combo
(the #1 most requrested feature from a survey to OX Tools’ Tuff Club)

This allows the user to:
  • set the hook into a soft surface without any additional tools
  • fasten the hook away from an edge without leaving significant damage
  • snap lines more easily at any angle 


Pin is able to snap onto the hook, whereby the tooling for the hook is only slightly modified by changing the shape of the slot in the center.



 The pin can either be left on the hook or be stored in chalk reel when not in use.

(Small Sumitubo. Dieter Schmid Fine Tools, https://www.fine-tools.com/ba1.html. Accessed 31 Jan. 2025.)




This feature is inspired by the karuko pin from the sumitsubo, a tool dating back to the 8th century which was, and still is, used for marking ink lines in woodworking. 








Problem/Solution #3: Creating a visually cohesive range  













Manufacturing Challenges



Chalk reels are usually manufactured with a housing that consists of two halves in plastic, metal, or overmolded plastic (which provides the best balance between durability and weight). 

94% of survey respondents said it was essential that their chalk reel be ‘durable’.
47% said it was essential that it also be ‘lightweight’.






















Due to the squishable tip, standard overmolding wouldn’t work.  

The rubber grip had to be manufactured as a seperate component which is held fast between the two halves of the shell. 


‘An eco ‘friendlier’ solution’ 

Components of this chalk reel’s case can be recycled if disassembled, whereas usually, overmolded plastics cannot be recycled. 












Educational Social Media

https://www.instagram.com/reel/DDiKrBTB0s1/

Promoting use via industry professionals. 
https://www.instagram.com/reel/DCdBeeXixBv/

Promoting the use of the clutch release and how the handle storage can be used as a built-in lock.
https://www.instagram.com/reel/DC_otQKo_F3/

Showing how the tip as an alternative to wrapping the string around your finger

Social Media Content by Evan Clark












Final Design/Features
















The Complete Range

















Timeline













Video created for Lowe’s innovation event

Video shot and edited by Dominic Florio 
















Publications


Red Dot Award 2025
https://www.red-dot.org/project/ox-pro-precision-chalk-reel-80656
Pro Tool Innovation Award 2024
https://protoolinnovationawards.com/winners/2024-pro-tool-innovation-awards/hand-tools/
Patent Pending – Chalk box with a flexible tip 
WO2025233924A1 
https://patents.google.com/patent/WO2025233924A1US20250346066A1
https://patents.google.com/patent/US20250346066A1








   
©2026 Avril Griessbach