The Submarine Door Box by Odrivous February 15 2019
A young father, skilled designer, and what's more, even an experienced printer – that's our ex-employee who now works at Prusa Research as the Head of Testing – Jindrich Benes aka Odrivous. Let’s read about one of his newest projects which he made in his free time – The Submarine Door Box.
Hello : )
When I've seen the first photos of this project, they amazed me. I know you're highly skilled at modelling, I'd already seen that form your ongoing project of the modelling and printing of characters from Terry Pratchett's Discworld. Now, this is a thing! How did you get to this idea?
It all started last January when I knew what I would like to give to my father and brother for Christmas. I made for myself a 3D-printed metal belt buckle and decided to make matching belts for them as well. Now, since we have the technology, why not make a fancy box for the gift?
They are guys and into mechanics, so let's make it technical – that's what I was thinking. And lo, the idea of a box with gears, bars, transmissions, and rivets came to be.
Now that’s a unique “wrapping paper”! How did your father and brother react?
They didn't expect anything like it at all. At first, they both thought it must be an intricate puzzle but then found out the opening of the box is rather straightforward. But that gave me some new ideas ...
Oh, and they did like the belt as well.
You've made something that looks fantastic, what comes first for you, a form or function?
Mostly, a form is the reason I create (while keeping the technical side of things – printability – in mind). Here, I sort of made an exception, I knew I wanted a working mechanism as intricate as I can create while referencing the submarine door aesthetics.
So you could say the form and form of motion were the leading aspects here as well.
This is not a simple model at all. When I was asking you about this interview, you immediately answered saying you don’t have all those prototypes anymore. How many of them did you have?
This project took about 10 months from the first prototype to the final product.
There were about 6 major prototype versions of which the first three were just experiments with gear kinematics. I am no engineer, so the whole mechanism is a result of trial and error. This gave me some idea of how the gears actually work and provided a base for the mechanism's final composition. Lastly came the fine-tuning of the prototypes in the components' dimensions and tolerances.
What modelling software did you use and what was the biggest challenge you needed to solve?
I used Autodesk Fusion 360 – great software for home use with 3D printing – to design the whole model.
I would consider myself a fluent user of Fusion 360, so the design process was quite smooth. The time-consuming part, though, was the kinematics of the mechanism itself. Luckily, with 3D-printing, I can make some design changes in that one hour I have for modelling in the evening and check the results in the morning.
For printing, you used the Prusa printer, of course. Did you use some special settings to get such great results?
If you want to rivet a door using no glue, you might want to experiment with rivet sizes and increase or decrease them a little. Each printer might need a specific size multiplier to make it fit just right. Alternatively, you can just glue in the outer rivets.
The Slicer PE which I mostly use does have this handy “elephant foot compensation” setting – it battles a sharp squeeze to bed on objects by offsetting the first layer inside. I used it with great success on the gears and thus ensured they move smoothly.
Some of the parts require supports; namely: wheel, rivets, hinges, and single-piece version of the main box. The rivets can benefit from larger “XY separation” in the Slicer PE support settings – say 80%.
Can you share some post-processing and assembling tips with makers? Where did you get the plexiglass on the top from?
The hinges are connected with a piece of 1.75 filament which should go in with a small resistance under slight force.
Correct bars are indicated by a corresponding number of notches on both bars and the base plate.
The plexiglass cover on the door is optional. There is a .DXF amongst the print files which you can use to cut the lid from plexiglass at your local maker-space or provider of laser-cutting. In my case, I used the Prusa Lab – an open maker-space at Prusa Research HQ.
But since the box is intended primarily for the FDM 3D-printing, the main version of the cover is printable with holes to reveal the cogs.
Is there anything you want to say to the makers reading this? : )
Thank you for reading this interview.
Enjoy the free time you have when you have it.
If you'd like to contact me, feel free to use one of the channels below.
In the interview: Odrivous & Laila