Bicycle seismographs
Album

The bicycle seismograph is a mechanical device - no electronics involved - which records the bumpiness of the ride on a paper roll when bicycling. / CC BY Kati Hyyppä

The ingredients of the seismograph come mainly from hardware store (wood, metal rods, pipes etc.). Few special parts were also used, such as mechanical speedometer parts and gears from the German construction toy called Fischertechnik. / CC BY Kati Hyyppä

In the workshop we had a factory-like set up and divided into smaller teams, which produced different parts. Here the wood team is preparing the wooden parts. The pieces had to be carefully measured and outlined first using a pre-made list of parts as a guide. / CC BY Kati Hyyppä

Sawing the wooden parts was the next task. / CC BY Kati Hyyppä

Several holes were needed for the wooden parts where rods and pipes were later to be attached. Paper templates taped on wood pieces were used as drilling guides. / CC BY Kati Hyyppä

Once the wood pieces were ready, assembling started. / CC BY Kati Hyyppä

While the wood group was producing the wood pieces, another team prepared all the numerous metal rods and pipes, cutting and filing them. / CC BY Kati Hyyppä

The pens were also prepared by taking the inside part of a ballpoint pen and heating it up with a lighter, so it could be bent. The idea was to keep the end of the pen pointing upwards, so that ink would keep flowing. / CC BY Kati Hyyppä

The pens were attached with tape to small rubber band holders bent from welding rod. The idea of the rubber band was to press the pen against the paper. / CC BY Kati Hyyppä

Attaching the worm gear for the reduction gear mechanism required detailed work. First, small aluminum pipe pieces were filed so that they would have little dents, which would lock with the worm gear. Here the sections to be filed are being marked. / CC BY Kati Hyyppä

Next, the worm gear axis was placed on the seismograph, and one of the locking aluminum pieces was taped to the axis, so that the worm gear would rotate as the axis rotates. Each rotation of the worm gear rotated the bigger, black, spur gear one tooth and hence the paper roll minimally. The worm gear was connected ultimately to the front wheel of the bike via the speedometer parts, so pedaling the bike was winding the paper slowly. / CC BY Kati Hyyppä

The pen holder was made such that it contained a pipe in the middle for the pen and large washers as a weight. The weight enables the pen to stay steady while the bike shakes. / CC BY Kati Hyyppä

An additional part for the pen holder mechanism was bent from welding rod. / CC BY Kati Hyyppä

The pen holder was placed on rails made of steel rod so that it was hanging on a rubber band and could slide up and down, responding to the road bumps. / CC BY Kati Hyyppä

At this point all the participants were working in parallel on the fine-mechanical tasks in deep concentration. / CC BY Kati Hyyppä

Paper rolls of two different sizes were available for seismographic recordings. The rolls are meant for cash registers and some of them were of thermal paper and some of regular paper. / CC BY Kati Hyyppä

The paper roll was first attached to the holder stick on the left side of the seismograph. Then the paper was slid under two metal rods, which kept the paper close to the back plate of the device. Lastly, the end of the roll was taped on the rotating axis on the right, so it would wind nicely as the gear mechanism rotates. / CC BY Kati Hyyppä

The mechanical speedometers from which parts were re-purposed for the seismographs. Just the cable and the grey plastic part were needed. / CC BY Kati Hyyppä

One end of the speedometer cable was attached to the seismograph's worm gear axis with a screw terminal and tie-wraps. / CC BY Kati Hyyppä

The plastic part of the speedometer was attached to the front wheel of the bike, between the fork and the wheel. This way a small metal stick is positioned in between the spokes and rotates 360 degrees as the wheel turns. The plastic part contains gears and is attached to the other end of the speedometer cable (taped part in the photo), so that the movement of the wheel is conveyed to the seismograph. / CC BY Kati Hyyppä

Attaching the speedometer parts to the front wheels. / CC BY Kati Hyyppä

The seismograph itself was attached to the bike with thick tie-wraps. / CC BY Kati Hyyppä

We made short test rides in order to check that all works well. There was a perfect cobblestone street next to the Fab Lab for this purpose. Here the recordings are being investigated. / CC BY Kati Hyyppä

As we were good in time, there was also time for building some GoPro mounts for filming the seismograph from cool angles. / CC BY Kati Hyyppä

One participant made a numbered list of the streets where he rode, so he could check the data points later on his paper roll. / CC BY Kati Hyyppä

Here is one such data point marked with a number on the seismographic paper roll. / CC BY Kati Hyyppä

As a next step the participant made a more advanced recording together with two other people, which consisted of a route drawn on a map. The route was in the St. Pauli area near the Fab Lab. / CC BY Kati Hyyppä

In addition to the seismographic recordings, the route was documented further with photos of the road surfaces, each of which corresponded to the points numbered on the map. / CC BY Kati Hyyppä

Furthermore, frottage technique was used for visualizing the road surfaces at the numbered points. For this coal found in the grill was used in combination with hairspray. / CC BY Kati Hyyppä

The route and the associated visual recordings were presented after the workshop in the A/D/A exhibition. / CC BY Kati Hyyppä

Close-up of the route in the exhibition. The visitors could follow the route with a map handout and discover interesting topographic details. / CC BY Kati Hyyppä

One participant made also systematic recordings on the Fab Lab yard by measuring what kinds of seismographic recordings result from obstacles of different heights. / CC BY Kati Hyyppä

Here are the results of the recordings in a nutshell. / CC BY Kati Hyyppä

Another participant modified his seismograph so that the pen was moving wildly in all directions. He was new in Hamburg and related his recordings to his experiences of drifting in a new place, a kind of drawn diary of a new city. / CC BY Kati Hyyppä

The bicycle seismograph team after a common ride and ice cream. / CC BY Kati Hyyppä

The nicest thing happened also the day after the workshop. Jan, one of the participants came to show how he had improved already his seismograph by attaching a second pen mechanism, which drew small, horizontal lines on the bottom of the paper. The lines served as scaling lines, which gave an idea of the distance travelled. Thankfully Jan had also Fischertechnik parts at his disposal, so he could keep the style of the seismograph consistent. / Photo by Jan