Free Plans: How to Make a Large Harmongraph

how to make a
Large Harmonograph

Basic Description

A harmonograph is a pendulum-based drawing board that produces beautiful curvaceous drawings. After you give the large hanging platform a gentle push, gravity works its magic while a pen records the results. Each swing is almost identical to its predecessor: the minute discrepancies are responsible for the remarkably sinuous curves. The version that we have detailed in the plan below allows you to make drawings on paper or on an erasable whiteboard. You can set up the harmonograph in a garage or basement and hoist it out of the way when not in use; it ends up taking virtually no space at all. We love to enjoy the mesmerizing action, but it makes a great conservation piece at a party and kids absolutely love it! It takes some patience to get everything working right, but it is definitely worth the fine tuning that this project requires; as always, we will walk you through all of the steps.

Design Considerations

ideas

The drawing board itself doesn't need to be a dry erase board, you can use regular plywood, but you will be required to use paper. On the dry erase board, we just tape large sheets of paper from a roll with masking tape when we want paper drawings. The dry-erase board also allows you to erase parts of the drawing with a finger or cloth to embellish the designs. We tried using a chalkboard but, of course, the friction needed drains the swinging energy and the effect was not as dramatic. You can use several different colors and draw curves on different sections of the whiteboard or paper. You can also redirect the pendulum midswing to see what happens. Other things to experiment with include, waiting a few swings before engaging the pen, and disengaging the pen before it comes to a stop. We also love to grab the taut string between thumb and forefinger at varying locations and plucking it to play one-string bass.

size

The size can be altered as desired, but it would be wise to maintain the ratio of dimensions we have shown in the plan. The best alternative is to design your version with adjustability so you can try all sorts of arrangements.

friction

Keep in mind that friction and disruption is the enemy to the harmonograph. As long as you are free from wind, earthquakes (the harmonograph acts as a great seismograph) and other disturbances, friction is the primary consideration. As we described, if you use narrow cord strung through holes, as opposed to eyebolts, friction is reduced. The only other culprit then, becomes the tip of the pen against the drawing surface. Adjust the counterweight on the pen holder so that just enough pressure is applied for the pen to write. Excessive pressure slows down the swinging action. A pen tip sliding along a dry erase marker has minimal friction and that is critical to the success of the design. If you are using paper, glossier paper and smooth writing pens are the best option.

location

The harmonograph can be located anywhere as long is shielded from the wind. Indoors is best, but an outdoor area protected from the wind will work fine too. We found that 6' (1.8m) strings worked well, but you can experiment with longer ones if your ceiling is higher. If there isn't a ceiling where you are placing your harmonograph, you will have to build a structure to hold it up. You could attach some tarp or canvas around this structure to block the wind.

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clear answers to common questions

storage

Unfortunately, few of us have enough room to keep the harmonograph set up at all times. The pen holder has been designed so that when you raise it to the highest point, the arm can be tilted downwards. This angled surface acts as a perfect rest for the drawing board. You can tuck the whole thing away up against a wall. Its best to mark your string locations and counterweight locations before dismantling the setup; that way, you will be ready to go right away when you set up again

notes

Many strings stretch and knots may slowly give, so you may have to change your settings after periods of heavy use or disuse. Check your knots occasionally to ensure that they are firm. It is also critical for the pen holder to be stable: if you notice any rocking during the drawing process, you can stack a few bricks on the base.


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