Moved as best I can to the What is Model Engineering thread as it seems to be more related to that.

Some of the old inboard single cylinder marine engines would be a good candidate for the water cooled option

Old tether engines for air cooled

You just need to find a scrap ride on lawn mower or mobility scooter and graft the steamy bit onto that.

I mentioned the need for a wow-factor project in the “Traditional Model Engineering” topic, so Diogenes starting this thread is helpful!

Here’s one I’ve put a little effort into.   Not got far because I’ve already got a long to-do list, and am poorly in a way that intermittently destroys my concentration.   Not allowed to operate machinery whilst ill, and even armchair engineering is takes forever because I can only work in short bursts.  Been a bit better recently, but being unwell has left me even less productive than normal.   Hats off to everyone on the forum who has to cope with illness – it’s hard!

Done some work in Solid Edge, but no developed plans yet, so this calls for original design work.   To speed production, I  intend to 3D-print most of the machine, only making  metal parts as necessary to stiffen it up or reduce friction etc.  I also expect it to be driven by electric motors and solenoids controlled by a microcontroller.   None of this is required:  a purely mechanical system worked by cams and made in metal is fine.   As this for public display, lots of shiny brass and polished steel would be good, even better if the device is powered by steam rather than electricity!

Anyway, here’s the requirement.

• A table top machine that loads and unloads marbles from matchboxes.
• The machine should rotate a small number of matchboxes, say 5, through the following cycle:
  1. Empty closed box arrives at station 1 and is pushed open.
  2. Open box moves to station 2 where a marble is dropped in.
  3. Open box with marble moves to station 3 where the box is closed.
  4. Closed box is moved to the station 4, where it is opened and the marble removed.
  5. Empty, but open box is moved to the 5 station where it is closed.
  6. Next move is to station 1, and the cycle restarts.
• When a marble is removed, the machine should return it to a magazine for re-use.   Moving the marble is an opportunity for bling, perhaps lifting the marble out and high with a rotating helix and running it back to the magazine via a Heath Robinson arrangement.
• Desirable to extract marbles from the magazine and deliver them to Station 2 with another Heath Robinson affair.   I think it’s harder to add bling to this than lifting marbles into the magazine.

This type of matchbox, home-made allowed:

My first attempt in Solid Edge carries the matchboxes on a rotating carousel, with the marble magazine and lift in the centre, main motor underneath.  The matchboxes are opened and closed by solenoids, and CAD suggests the geometry requires them to move levers rather than push/pull on the boxes directly.  The question is still open.

As the design got more complicated, especially planning the way marbles are removed, which requires boxes to be lifted and turned vertically, I started to favour a conveyor belt, in which Stations 4 and 5 receive the matchboxes held upside down.  Gravity drops the marble out at station 4, very simple, but hidden and not exciting.   To maintain symmetry a conveyor belt using top and bottom would need 6 stations, where one does nothing.   Other configurations are allowed.

Any takers?  Be warned, could be a lot of work.   Though CAD breaks the back of the design by ensuring parts fit together and will move without interfering, CAD won’t spot all the practical gotchas.  Like as not, the prototype won’t work first time and it will be necessary to fettle and adapt.   Not much to do if the design is well thought through, but start again from scratch if something major is missed!

Dave

Keeping it to the “Models that I might aspire to”, these are a few that are closer to the top of my “Future Projects” folder. In no particular order except the first two have the majority of the CAD work done and the first I have the metal for.

The one on the left

Had better stop there but hopefully if I post one or two of these builds it may inspire others to have a go at something a bit different. Even old and rarely visited designs can be made with a modern twist or just as originally designed rather then the same old.

Looks like it was almost designed with the model engineer in mind.

Nothing there that would be too hard to fabricate – parallel column, plain twin beams, simple flywheel, no Watt fiddly linkage, etc.

Cylinder is an easy fabrication and the round valve chest is a bit different but should present no problems.

Nice to have the two ram pumps and their four non return valves working. There is some hidden plumbing within the base and I assume that one has the water inlet on the far side, the outlet is the flange on the bottom of the column. This one has them both on the same side so you have the option to model it either way.

So what is the biggest flywheel you can turn?