CriCri MC-15 in NZ

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Well-Known Member
May 16, 2009
Canterbury, New Zealand, Earth, Milky Way Galaxy.
Getting a few more jobs sorted,

First up I reassembled the second engine and am getting it ready to run. In the process I realized that I had lost the rotary valve for the second ZDZ engine, so I went about making a new one. I had ordered some of the 0.45mm thick spring steel sheet a long while back as I wanted to experiment with the valve timings.
Cutting out the spring steel I used a 1/8" cutter on the CNC with a really slow feed rate. It machined out okay although I really need to get some cutters with a geometry more suited to steel. The sharp edges of acrylic cutters don't hold up long on steel as the edge is so thin and sharp. Works in a pinch. The hub is some phenolic and riveted in place. While I had the CNC setup I cut an extra hub or two.
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Next up are some of the spark plug thermocouples I am working on assembling. I can buy these off the shelf for $35+ each and they still aren't quite what I need. I cut the 1.2mm thick copper on the CNC and will install some ebay thermocouples into them. I have attempted to spot weld the thermocouples themselves to the copper but so far have been unsuccessful. I will attempt to swage them in place instead.
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Active Member
Apr 5, 2021
Just want to share an update, as I too am building a Cri Cri, my engines, zdz 250’s arrived today!!! Dual spark heads like Shannon made and I will make electric starters that attach on the back!


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