Relativity Pen

[Mach4]

You may have seen my entry in the recent Kitless Contest - Relativity Pen. I indicated there that I would share the design parameters and technique once the contest was over....here is that process.

The technique involves creating a lithophane. A lithophane is piece that can show an image based on the thickness of material at any particular pixel...the thicker the material the darker it will show and the thinner the material the lighter it will show when illuminated from behind. With the advent of 3D printing, lithophanes can be easily be created at home with just a basic FDM 3D printer.

I decided to see if it was possible to create a pen lithophane. To do so I would need to see if it were possible to create a lithophane in a size reasonable for a pen. This problem was solved with an on-line lithophane generator called ItsLitho. I did many experiments to perfect the process based on the size and image parameters. Then I needed to find a suitable light source to illuminate the lithophane from behind within a pen. I then needed to find a way to provide for an ink refill that was small enough to not obstruct the light during operation. And finally I needed to design and print the various components and assemble them into a working pen.

Lastly I needed an image and a theme appropriate for a contest setting.

Theme

The theme I settled on was Relativity using an image of Einstein as the symbol. I thought that the whole "speed of light" constant in the equation and the use of light to reveal the man behind the theory was a nice hook.

Creating the Lithophane

I selected this image of Einstein because it was recognizable, relatively vertical and good contrast.

I brought that image into ItsLitho and created the body of the pen.

Here are the basic parameters I use for pen lithophanes within ItsLitho

Shape - Cylinder
Top Diameter - 12mm
Bottom Diameter - 18mm
Min Thickness - .8mm
Max Thickness - 3.2mm
Frame - ON
Thickness - 3mm
Depth - 3mm

Feel free to play with other parameters as you desire.

Lighting

I chose the Nightfox e1 flashlight (sourced from Amazon) for its small size, bright light and twist to illuminate operation. My design involved gluing the base of the flashlight into the base of the pen and the top of the flashlight into an insert in the main body. When the base is twisted right, the flashlight illuminates and when the base is twisted left it turns off. And when unscrewed all the way, the base comes off and the batteries can be replaced. The bottom of the flashlight is ground off to reduce the length as much as possible.

Other Pen Components

I designed the tip of the pen, the base and the insert in Fusion 360, exported them as .STL files and printed those out. The refill is glued into the tip. When a new refill is needed a new tip is printed and refill glued in. The tip is designed to be a firm press fit whereas the base is a slip fit.

Assembly

Here are the pen components shown ready for final assembly.

Finished Product

Here is the final result. The detail possible is truly remarkable.

The ItsLitho and 3D printing have pen applications beyond strict photograph lithophanes. I'll demonstrate those at a later date.

Hopefully this beginning foray into lithophane pens will encourage others to develop the tools, designs and creativity to make them even better.

 

[Cwalker935]

Very cool!

 

[MRDucks2]

I liked the effect you were able to generate. This how is likely Library worthy in my opinion.

 

[Penultimate]

Very cool.

 

[Jim15]

Amazing work.

 

[jttheclockman]

I believe your pen was the product of a new technology that has never been seen here before and not understood and thus for did not place in contest. I voted for this pen and now thank you for the explanation of how it was made. i believe this should be noted somewhere such as the library as to a new and profound method of blank making. I never seen this before and really like the concept. Thanks for showing.

 

[Dale Lynch]

Very creative use of 3D technology.

 

[Mach4]

I believe your pen was the product of a new technology that has never been seen here before and not understood and thus for did not place in contest.... a new and profound method of blank making.

One thing about lithophanes is the fact that the "outside" of the lithophane is "rough"....in fact it needs to be to have good resolution. One might think to just print it with the smooth side to the outside and the rough on the inside - in point of fact this will not work as this produces a very fuzzy image with no detail. What someone might try is to "cast" a lithophane in crystal clear resin and then turn it to a smooth polished surface. I believe this would give the "expected" surface of a pen and preserve the interest and detail of a lithophane image...and be the kind of product "expected" on a PenTurning forum.

Thanks for your comments.

 

[sorcerertd]

What someone might try is to "cast" a lithophane in crystal clear resin and then turn it to a smooth polished surface.

I was just thinking this. Brilliant work! Truly remarkable and innovative!

 

[TDahl]

Very innovative.

 

[Roly]

Thank you so much for this. Most fascinating and I will give it a bit of a go.