Monkey go round
Last Updated 9 November 2024
I made a Monkey go round as a Christmas gift for my wife.
She really wanted one of these.
She found it on www.palmastore.no. They were out of stock from the moment we first saw them, and I did not think it looked like it was very well built, so I decided to try to make her something similar for Christmas 2022.
It is made from brass, some 3D-printed parts and the wood from an old cutting board. Instead of heat from a candle it uses a small 12V fan to make it go round. Initially I wanted to use a candle, but with the curved trunk the construction is to heavy and out of balance to run with the heat from a candle (or even 3 candles). Luckily I can use the excuse that my wife has asthma and that a fan is better for her lungs than a candle.
If you want to make your own, you can find links to the 3D-printed parts and the drawings for cutting the palm leafs, the monkeys and the fan cover at the end of this post.
How I made monkeys spin
I used paper models to find the size of the palm leafs and monkeys and to make the very first proof of concept model.
Making the palm leafs
I started with cutting and engraving some palm leafs from 0.5mm brass plate. The way I usually do this is to print the design on to tracing paper and glue this to the brass using a glue stick. Then I cut the design with a jewelers saw and use a fine file to clean up if necessary. The engraving is done with a small ball nose milling cutter on my flexible shaft machine. In the center of all three pieces I drilled a 3mm hole. These holes will later be used to mount the leafs and a small ball bearing to a 3mm screw.
The leafs where then shaped with a ball-peen hammer on my wooden stump covered with a piece of leather as not to mar the brass while hammering.
Next I had to make something the monkeys could hang from. I filed a flat surface on some silver rings, made from 1mm wire, and soldered these to the underside of the brass leafs. I am using a propane torch, hard silver solder and a good quality yellow flux.
The extra ring on one of the leafs is because at first I wanted to have an extra monkey on one of the leafs, but I found it looked nicer without it.
Making the palm tree trunk
Then it was time to make the trunk of the palm tree. For this I used 10mm brass tubing with a wall thickness of 1mm. With a jewelers saw I cut 8 pieces of 20mm long tubing. I used a hammer and a conical punch with a larger diameter than the tubing to spread one end out enough to go over the next piece.
Then I soldered the pieces together one by one. For every piece I used the pliers and some hex nuts as a heat sink to minimize the risk of the previous solder joint detaching.
To the top of the trunk I soldered a 10mm long piece of tubing that has not been widened with the punch. This piece of tubing fits a small bearing with a outer diameter of 8mm. To make a shoulder for the bearing to rest on inside the 10mm tube, I made a small ring from 0.5mm brass plate and soldered this to the inside of the 10mm tube.
In the bottom end of the trunk I attached a M5x40mm screw with a washer and a hex nut before soldering this to the rest of the trunk.
The monkeys
After a rough polishing of the trunk I started cutting out the first of the four monkeys. Again I used a jewelers saw to cut the brass monkey and cleaned up the edges with a fine file.
Before making the base I just had to see what the monkey looked like on the palm tree.
The base
For the base I had this old 38mm thick cutting board that had been stored in a damp corner of the basement and was pretty cracked up in the glue joints. I managed to find a solid piece in the middle of the board with the dimensions 148mm x 88mm. To make room for the fan, this piece was then hollowed out with a handheld router and a hole for the fan cut out with a 38mm hole saw on the drill press. I also made a 5.5mm hole for the screw on the palm tree trunk.
To attach the fan I made a 3D-printed part that screws on to the base and the fan. The 12V fan is a silent NF-A4x20 FLX from Noctua.
Then everything was assembled and tested to see if the fan can spin the monkeys.
I then disassembled the whole ting in preparation for the last finish. With a handheld router I made a profile around the edge of the base. The groove for the fan cover was cut with a knife and with a small ball nose milling cutter on my flexible shaft machine. The base then got three coats of boiled linseed oil and the brass was polished. The fan-module was mounted with a 12V power supply, and the 3D-printed bottom cover and feet installed.
The monkeys was mounted to the palm leafs with silver rings made from 1mm wire. The bearing was installed on the 3mm screw.
The only thing missing now is the cover for the fan, but that means everything has to be disassembled again…
The fan cover
First I 3D-printed a few designs to test and get the airflow right. Then I made the cover from a 1mm thick brass sheet. The diameter of the cover is 41.5mm. The holes in the cover is made by drilling holes with a 4.5mm drill bit. First I drilled all 16 holes straight through on the drill press, and then I expanded the 8 oval holes using a handheld drill and tilting the drill bit to the right angle. If you do this do not try to hold the cover with your hand, but clamp it in a wise or a hand clamp.
I then soldered 3 pieces of 1mm silver wire to the bottom of the cover. Then I polished the visible side of the cover and installed it in the base by bending the silver wires into grooves that I had filed into the base with a small round file. The excess wire was just cut off with a wire cutter.
Reassembly and completion
Now everything was reassembled and the only thing left to do was to enjoy the result, and to write this way to comprehensive blog post about the build.
I do not have detailed drawings and measurements for this build. Most of it was done by using materials I had laying around, using the tools I have, and experiment my way to a final result. This is not a project that is easy to replicate unless you are willing to be creative and adapt it to what parts and tools you might have access to. If you want to build your own version of this I have included drawings for cutting out the palm leafs, the monkeys and the fan cover. A link to the 3D-design files for the 3D-printed parts are also included. If you make one please let me know, I would love to see the result.
You can find the 3D-design files on: Printables
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