Airfix manufacture educational construction kits for both combustion and jet engines. The combustion engine is set A42509 and the jet engine is set A20005. My son was very keen to receive a jet engine for Christmas and he very quickly set to work building it.
I can’t recommend the kit because the instructions are poor (the black and white images don’t exactly help) but we got it working – sort of – in that it would whir and puff but the fans wouldn’t turn.
My son didn’t seem to mind, but it annoyed me that his new toy didn’t work. So, this afternoon, I set to work with my favourite search engine and found some really useful advice. Firstly, making sure the compressor turned freely (thanks to Phil Parker):
“By taking the red cone off the back and shoving the spindle back and forth once everything is in place you can put enough lash in to get really free turning.”
After following Phil’s advice I could blow on the blades and turn the compressor but it didn’t work under its own power. So, I found some more advice on the Unofficial Airfix Modellers Forum:
“[…] clean up the parts where you’ve removed them from the sprues […]”
My son set to work with a knife to remove a couple of bits of plastic on the main fans that were snagging. After this, we were able to run the engine with a “twist start” and after it had run for a while and loosened up some more, we were able to start it using the controls in the kit.
Looking at the reviews on Amazon, there are a lot of people struggling with this kit (we wouldn’t have bought it if my son hadn’t been so keen) but hopefully, this post will come up in someone’s searches and help them out…