>>pillar+(OP)
Some Model Engineering related resources:

1. Engineering drawings of small model engines used for model aircrafts. They are designed for manufacturing and working, not not like showcase item. We can actually build them.

https://outerzone.co.uk/plans.asp?cat=Engines&Xcardsperpage=...

2. https://modelenginenews.org/midge/index.html

>>pillar+(OP)
I went down a rabbit hole lately and found this article on tiny diesel engines built throughout the past decades, most of them model engines: https://modelenginenews.org/techniques/minid.html

> I've seen collectors turn a greenish blue and stammer out crazy offers on sight of my 0.1cc Nano, pictured here. But as the size goes down, construction difficulty and criticality of "fits" goes up exponentially.

>>pillar+M
I still have a Cox .049 engine in the basement somewhere.

>>pillar+(OP)
I just noticed that this channel has 2 million views and only four videos, all from about a year ago!

>>pillar+(OP)
This is great. If you enjoyed it you should check https://www.youtube.com/watch?v=8IEGmD_aV3w . Next to that it’s child’s play. That’s a whole trasatlantic’s engine room from scratch.

>>wcross+vXi
Wait but the one you linked seems to be pneumatically driven, while the op one is an actual combustion engine, right?

>>Wander+g0j
That’s true! Sorry for not mentioning that.

>>pillar+(OP)
I skipped some bits of the video so probably missed this, but: in the beginning he mentioned no spark or glow plugs and said “similar to a diesel”, but in the end that didn’t work and he had to resort to a glow plug.

Did he mention what fuel he was using for the compression-only attempts? If not actual diesel, it seems like he would have had to use ether or something like that.

>>Walter+IUi
Of course that's .049 cubic inches (~ 0.82 cc), huge compared to the one in the article.

>>antonv+Q9j
He did: It was just warm enough for the ether in the mix to evaporate long before it reached the engine, so it couldn't run.

>>pillar+(OP)
If you want to see the engine running it's at 30:12

>>antonv+Q9j
It was a mixture of ether, castor oil, and something else. He theorised that the ether was boiling off in the tank before it made it to the engine.

>>pillar+(OP)
Last century I was gifted a gas powered model helicopter with one of these small gas engines. It had a propeller would fly up, run out of gas and fall back down (it had some larger blades to slow its decent).

You started by spinning the propeller and letting it spring back.

How I didn’t loose a finger…

They’re remarkable little devices.

>>RossBe+0gj
Ah thanks - I was imagining that perhaps the engine didn’t have high enough compression to achieve ignition.

>>pillar+(OP)
The second I heard that engine fire it was 1986 in my brain again. I could smell the fuel and feel the finger damage from repeatedly trying to get the darned thing to start. Followed by damage on the other side of the finger when it actually did. Ouch.

>>jakeda+Omj
Cox 0.049?

>>pillar+M
Outerzone is a great site for (mostly vintage) model aircraft plans.

Cut my fingers up many times as a kid trying to start Cox model airplane engines…

>>jakeda+Omj
Me too, brother.

>>pillar+(OP)
Related? Blondihacks [1] has been working through machining a live-steam powered scale locomotive.

Has it been three years now? She easily has another year of work ahead of her before she has live, rolling stock. Wild dedication to a project that could perhaps consume half a decade of your life.

[1] https://www.youtube.com/@Blondihacks

>>jakeda+Omj
Flick a pen on it instead.

>>pillar+(OP)
Sorry for offtopic, I want to share,

Some Machining related channels on youtube:

this old tony, Chronova engineering, cylo's garage, inheritance machining, breaking taps, blondie hacks, tarkka, dan gelbert, Jonesey Makes, Eric(with a K), Clough42, Alec steele, NBR Works, Not An engineer, Stefan Gotteswinter, oxtoolco, ROBRENZ, MrCrispin, Clickspring, Artisan Makes, MH Anything, Jellyfish machine,Maker B,

And also there is great course on precision engineering by Alex slocum:

https://m.youtube.com/playlist?list=PLksE8LDXGXl_MQHKr2DqhfD...

>>pillar+Xuj
https://www.youtube.com/@thisoldtony

https://www.youtube.com/@Chronovaengineering

https://www.youtube.com/@cylosgarage

https://www.youtube.com/@inheritancemachining

https://www.youtube.com/@breakingtaps

https://www.youtube.com/@blondihacks

https://www.youtube.com/@tarkka

https://www.youtube.com/@dgelbart

https://www.youtube.com/@JoneseyMakes

https://www.youtube.com/@Erik-not-Eric

https://www.youtube.com/@Clough42

https://www.youtube.com/@Alecsteele

https://www.youtube.com/@NBRWorks

https://www.youtube.com/@NoEngineerHere

https://www.youtube.com/@StefanGotteswinter

https://www.youtube.com/@oxtoolco

https://www.youtube.com/@ROBRENZ

https://www.youtube.com/@MrCrispin

https://www.youtube.com/@Clickspring

https://www.youtube.com/@ArtisanMakes

https://www.youtube.com/@MHAnything

https://www.youtube.com/@Jellyfishmachine

https://www.youtube.com/@MakerB

>>echelo+Pwj
Thank you!

>>pillar+Xuj
Have to recommend TryAlly. He makes it look easy and straightforward. It's not.

https://www.youtube.com/@tryally

>>acomje+fjj
Brings back memories from childhood. I used to build and fly model airplanes (by wire not rc). Starting those engines was also a challenge. I still have a scar on one finger from an engine kicking back when trying to flip the propeller.

>>antonv+Q9j
https://modelenginenews.org/techniques/minid.html Mentions that this engine needs a spring start and 50% ether and it runs up to 40k rpm(!) seems like it’s finicky, which makes sense given its size

>>acomje+fjj
I would love to couple one of these mini-engines to an electric motor and... build a cursed USB-C "generator"... ;)

>>pillar+Xuj
Thank you for the Alex Slocum link. I was aware of a lot of those other machinist channels but the engineering course is new to me. This looks incredible. Alex is a fantastic teacher!

>>pillar+(OP)
As someone who always thought that it'd be cool to create my own parts and components by milling, but who never actually had access to a milling workshop, I find this video extremely satisfying to watch. Thank you!

>>Walter+IUi
Used to see adverts for those in magazines and even (iirc) comic books

>>mycall+ouj
Ah, the classic "chicken stick" approach. No shame in that!

>>vessen+UMj
The spring start makes a lot of sense, thanks.

>>tlb+0bj
I also had an .020 engine, but it never ran very well, and I don't know what happened to it.

I had a lot of fun designing my own airplanes and flying them with the .049. Modern electric airplanes are too easy.

>>antonv+Dkj
I would think there would be some interaction between the carburetor air intake and the propeller right next to it. Intentional feedback, maybe, to change the mixture as the RPM goes up? If not intentional, then it sounds like a potential showstopper.

>>kotaKa+aOj
I would also like to try that some day, but theres little information on efficiency.

I'd also like to see one running on laughing gas (N2O), as the autodecomposition reaction is nitrogen and oxygen gas, in similar proportions to atmosphere. But the reaction efficiency would have to be high enough or I'd feel bad about the GWP.