The button
The spring under the cap returns the needle after each sample.
Palmo
A hand tool that takes micro-samples from paintings for scientific analysis. Designed on my own for a course at the University of Bologna, and 3D printed as a working prototype.
Team
Alessio Fontanelli
01 // THE BRIEF
Less than a millimetre
To study the pigments and layers of a painting, restorers take tiny cylinders of material from it. The brief came from the Materials and Processes for the Industrial Product course at the University of Bologna: a portable corer for paintings on canvas and wood, used with one hand, left or right, from the first push to the return.
- Needle bore, mm
- 2
- inner diameter of the hollow sampling needle.
- Coring depth, mm
- 0.8
- at most, so only a microscopic portion comes away.
- Rotation, degrees
- 180
- at least, while the needle moves forward.
Constraints from the course brief. Sampling from cultural property follows the general rules of EN 16085:2012.
02 // THE MOVEMENT
One press on the button
The needle has to move forward and turn at the same time, then come back on its own. Palmo does it with a screw constraint: pressing the top button drives the needle along the thread, and a spring brings it back when you let go. The body is open at the side, so you can watch the mechanism work, and it is easier to service.
The open body
The slot shows the mechanism as it moves.
03 // ERGONOMICS
Three ways to hold it
A restorer often works in tight spaces or awkward positions. The body takes three grips, so the hand stays steady wherever the painting is.
01
Full hand
A continuous volume for positioning and holding, with the weight spread across the palm.
02
Lower grip
Close to the needle, for precision while it goes in.
03
Upper grip
A second pair of wings near the button. It is a separate part: it snaps on when you need it and comes off for tight spaces.
04 // PRODUCTION
A printed prototype
The prototype is printed in FDM. Its geometry is drawn to need as few supports as possible, which saves printing time and material. The upper grip is printed on its own for the same reason, and that is also what makes it removable.
- Process
- FDM
- Supports
- Minimal
- Upper grip
- Separate
