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I believe this design is called a "barrel engine" or "axial engine". https://en.m.wikipedia.org/wiki/Axial_engine I seem to remember OS produced a single cylinder axial at some point.

Induction from the carburettor passes through the hollow crankshaft, which has a port cut into one side. As the engine rotates around the shaft, the port in the crankshaft aligns with the ports leading to each cylinders pump chamber, below the piston. In this respect, induction timing is similar...

A little more on the porting and valve timing: As with the original Gnome engines, the exhaust valve opens directly to atmosphere. With the engine spinning, the airflow velocity past the exhaust port creates low pressure and effectively extracts the exhaust from the cylinder, allowing for full...

Yes, I saw that when I was researching for my design. It seems a pity that they went to all the trouble to do that, but didn't make it a uniflow. The designer focuses heavily on not burning 2 stroke oil, but makes no mention of how the piston and bush are lubricated.

kf2, I have described the induction system in some detail above.

Hi John, At this stage, I am going with a flat topped piston and concical combustion chamber. I'm not looking to optimise performance yet. I anticipate that the engine will need to run at relatively low RPM in order to limit the radial acceleration forces on the components and the gyroscopic...

The piston runs in a cylinder which has 4 transfer ports like a conventional 2 stroke. The piston is still supported between the transfer ports, although that is not clear because of the way the section is cut across the ports. The piston will have a ring, with a locating dowel to prevent the...

Hi John, Not sure what you mean by charge cutoff. The port in the crankshaft will control the timing of intake to the 'pump chamber', opening the intake passage after BDC when the transfer ports close and closing off the intake passage as the piston arrives at TDC. I have four transfer ports in...

Hi Petertha, This is what an individual rod looks like at the moment. The whole set of rods will be made as a turned 'disc' to get the curvature of the 'foot' to properly match the crankpin. When assembled to the crankpin, two rings fit over the 'feet' of the rods - for clarity, I have not...

It is my intention to first build a single cylinder non-rotary prototype with a conventional big end arrangement. This approach will allow me to develop the 'top end' design before building the whole engine.

A section through one cylinder shows the induction chamber below the piston and the port from the crankshaft. The exhaust valve is operated by a cam which is fixed to the forward part of the crankshaft. The piston needs no skirt, as it is supported by the crosshead. It need only be thick enough...

Having built the Whittle V8, I have developed a taste for scale (ish) engines for flying models. I am attracted to early aircraft, so inevitably a rotary will happen sooner or later. I have looked at designs for 'true' scale rotaries, such as the Bently BR2 and the Gnome. However, I would like...

Another option for creating complex thin walled parts is electroforming. I wrote a post on it on this group a year or so ago. The part would be in copper, but could of course be painted to give the desired appearance. Pete.

Thanks. The video shows a simplified prop with a flat section. I used a similar method, but with a series of aerofoil sections of reducing thickness. I then cut the model into slices, which I used as patterns to make wood laminations.

What method did you use to model the prop? I have recently done a 4 blade prop, by creating a series of sections and lofting between them.

How do you intend to arrange the servo operated lock? You don't want the servo to be under load in either the locked or unlocked condition - it will draw a lot of current and quickly overheat. I would suggest an over-centre cam of some kind and code to drive the servo to desired position, then...

Sidevalve radial! Two of my favourite design elements on one engine. I'll be watching...

Another factor is the expansion of the gas as it loses pressure. As the gas moves from the outside to the inside of the discs, it's pressure falls. As it's pressure falls, the gas expands and must travel at greater velocity so that the same mass of gas can pass through the space between the...

I have used a 2 pack pourable material (as opposed to putty): https://www.mbfg.co.uk/pt-flex-20-rubber.html?gad_source=1&gclid=Cj0KCQjwudexBhDKARIsAI-GWYV5Gai-7aE1RvyYSm8nZqLsgs1PhOJpUq-eoh0vr9qdm_XVOvzo1_AaAptIEALw_wcB