Remake of a 100 year old patented toy. It is intended for kids learning to learn multiplication of small numbers. I've also added some photos of historic instructions for entertainment.
The original name was 'Consul' - The Educated Monkey
This version is for 3mm birch plywood. The svg has multiple layers to structure the construction. The 'laser' layer has all parts thrown together in a 200mm x 280mm rectangle. Enable one of the sub-layers 'english text' or 'german text'.
There are far too many copies of the small pieces. The little rectangles server as axis in the joints. They are available in multiple widths, 3.8mm up to 4.2mm -- choose the one that gives a good pressfit and discard the rest. For best strength, make sure to orient the wood grain lengthwise.
Some glue is needed to add the supports on the back of the base and to fix the top layer of the window. Everything else is supposed to work with press-fits but some minimal glue here and there would not hurt.
The original patent is long since expired. I assume I am free to publish this remake here as a non-commercial item.
The four files SVG files each contain all exactly the same drawings. The difference is only in the visible layers, for ease of use.
The photos after the SVG file show some details of the assembly steps -- read these instructions first before you start.
All joints consist of 3 layers and a rectangular pin. The material in the top and bottom layer has a rectangular hole where the pin should sit strong. Choose the pin size that fits best.
The middle layer has a circular hole and the pin is supposed to rotate in there.
ATTENTION: The two joints behind the head are different. They are for 3.2 or 3.4 mm pins while all other joints use thicker pins (3.8 .. 4.2 mm). The two joints behind the head mount the upper ends of the two large body parts. These joints are secured with rectangular counterpieses, while all other joints are secured with round counterpieces.
The pin should slide into the middle hole with only a little force. Do not worry if it does not turn nicely after first assembly. If you can turn it at all, it is good. It will turn easily after the first few movements.
The first photos show pins pressed into 4 round buttons, (and into the rectangular counterpieces for the head). Do that first to reduce the number of small pieces you have to handle.
[More detailled instructions left as an exercise to the reader. Please add hints to the comments below.]
After assembly: If the feet do not slide smoothly, apply some wax from a candle to the slot.
Overview and Background
Learn to multiply small numbers up to 12
Use the monkey to check your results. compute 5 * 7 first in your head, and if you think you got the result move the monkey feet to 5 and 7. Then check if his fingers really point at 35. Assuming you got 35 as the result, did you?
Lesson Plan and Activity
Assembly and use
Prepare a sufficient number of lasercut sets.
Pep up a dry math lesson by some manual exercise.
Allow one or two hours for assembly and test.
When the first monkey is assembled bring the class together and let them call out numbers and operate the monkey. Ask if the result shown by the monkey is correct.
When all monkeys are assembled, tell them to consult the monkey as an expert whenever unsure.
3mm Birch plywood or 3mm MDF.
Tools needed: Some white glue, sanding paper, an old candle (and a small hammer for emergencies).