Ah, Mr De Waal strikes again!

If the flutes are a must I'd say splitting the part into two disk based shapes and a fluted drum between them would be easiest. If radii were allowable at the ends of the flutes they could be made with miniature ballnose endmills leaving the part one piece. The flutes could be made by EDM of course, with flat ends or radiused ends (or flat ends with 3-5 degree casting draft, for authenticity to real cast parts on the original engine).

But…

The easiest way by far to build the part would be to delete the flutes and say "the patternmakers was on strike M'Lord."

Edited By Jeff Dayman on 06/10/2022 03:13:02

A lot of models build up the bases and capitals for several parts, even the small simple entablature based on Muncaster's design that I made had two pieces top and bottom.

So ,ake from ,ore than one piece and either plunge as said or have a separate disc at the bottom then you could mill with a ball nose cutter or a single point tool much like cutting a gear

On a part like that I would make the components so the assembly is over height and without the two holes for the columns and once soldered bring to height and add the holes so there is not risk of problems if things move during soldering

I hope you won't be using the cap head screws he shows but leaving a spigot on the column to take a nut. There are other features that don't look right on Julius's version for example all that detail in the entablature and he sticks a simple big end on the conrod that would be more at home on a wobbler. I also feel that the large round top of the part in question should actually be square as you could not mount the governor that Muncaster shows on a round surface, infact most of that detail above the taper of the column should be square. Take a look at Muncaster's original illustrations and decide what you want to make.

Julius does not build any of hose engines. Do check for collisions as the grasshopped that he drew had a tight spot when motion was simulated due to the length of the linkages being wrong. I would not have been happy with his solution to just make one of the holes oversize, although it allowed the engine to be turned over on screen the CAD did not replicate the knocking that the oversize hole and small pin would cause.

Unusual for Julius to make an engine smaller than Muncaster originally drew it but he has on this one, probably trying to keep the flywheel so it fits on a few more lathes as 10" would have put it beyond Myford gap capacity.

Edited By JasonB on 06/10/2022 08:43:10