Picture of Articulated M.C. Escher
I've been a fan of M.C. Escher's drawings since I was very young, and have always particularly loved his invented creature Curl-up (or Wentelteefje in Dutch).  I recently had the opportunity, as an Artist in Residence at Instructables, to build a model of it.  I have seen one or two previous attempts at the standing pose, but none that curled up, and I determined to make the attempt.
Remove these adsRemove these ads by Signing Up

Step 1: Analysis

Picture of Analysis
The first thing I did was to make some diagrams, expanding on Escher's creature as well as I could. Escher's published work containing the Curl-up constists of three drawings, Curl-up, House of Stairs, and House of Stairs II. These drawings are of course art, not a drafting diagram, so I had to make up some parts that were never shown clearly. I discovered that Escher cheated, too: the Curl-up's head is, in the standing posture, clearly the widest part of its body, but in the curled-up posture the smaller body segments encompass it, without any apparent stretching or bending. Although, with Escher's theme of realistically drawn but physically impossible objects, this isn't really surprising.

The Curl-up (in most cases I could observe) has a carapace with 18 body segments plus its head, with the last one, the tail, finishing in a rounded point instead of attaching to another segment. There is some inner flesh that protrudes a little from the head shell, but the underside of the body is never shown clearly. There are three pairs of legs, with a quite human knee and foot attached. I decided not to worry about the soft, squishy interior until I had the carapace working. I numbered the segments starting from the one just behind the head. The legs extend from segments 4, 9, and 14. The join between segments 1-2, 2-3, and 3-4 have a significant reverse bend in them when the Curl-up is standing normally, to keep its head raised. Some of the later segments also have a slighter reverse bend but this depends on the Curl-up's movement and activity.
Greasetattoo9 months ago
software used?
rachel (author)  Greasetattoo9 months ago
I used a CAD program called Moment of Inspiration ( I've been using it for a couple years now. It's not as full featured as something like Rhino or Inventor but it's an awful lot cheaper. There's a small but dedicated community and the program's author is extremely helpful and active in the forums, which is rare and awesome. I recommend it as a good beginner CAD program; these days I'd also look at FreeCAD (, which is actually free.
Thank you...
I use Sketchup!
DukeP9 months ago
Excellent! Where is the .stl files?
rachel (author)  DukeP9 months ago
I didn't think to post these originally but now I want to tweak them a little more first ... the neck bend in particular I am not happy with and want to improve. I will post the files once I've done some of these fixes!
dworley9 months ago
I see you have paid your tithe. It came out pretty cool!
Alpha_geek9 months ago
Stunning little project and a fantastic write-up of the design process. Many thanks for sharing ... :-)
graham6419 months ago
Gregbot9 months ago
Mr. Noack9 months ago
Awesome! I'm a huge Escher fan!
BadPuns9 months ago
I have loved Escher's work since I was six. He probably would've loved this.
ynze9 months ago
That is one lovely Wentelteefje!
angelgabriel9 months ago
Well done. You put a lot of thought into this. A large scale version would be interesting to make.
Motorized with a driver, for Burning Man?!
This is great!!!
Kiteman9 months ago
Oh, that's an amazing result, and an excellent write-up.

Are we going to see different-sized Curl-Ups appearing around Pier 9 now?
Toga_Dan9 months ago
Cool project. Love Escher.