A Full Size Weighshaft

The crowds were down at this year’s Truck Show at the Geelong Showgrounds.  Maybe the  38c weather prediction had something to do with that.

But those hardy souls who did turn up were treated to a feast of steam engines working on steam, and other antique engines popping away, as well as the magnificent trucks, tactors, and military vehicles.  There was a superb display of radio controlled trucks and excavators, and unbelievable machinery created with Meccano.

My interest was mainly focussed, for some reason, on the full sized triple expansion steam engine, which is the prize display in the vintage machinery shed.  it once powered a tug boat, and later a dredge on Port Phillip Bay.   And the following photos and video, if it will upload, show the bits which were of particular interest.

triple-expansion-engine-1-37

The red control handle top right is the main steam control valve.  The one on the left is the reversing control handle.  Note the big steam piston centre bottom.  It is a steam powered reversing control piston.   This engine was made in 1951, so is just about the last gasp in triple expansion steam engine development.

triple-expansion-engine-2-8

and the rod at top is about 5″ diameter.  It is the weighshaft, which carries the reversing levers for each cylinder.  On my model it is 5mm diameter.

triple-expansion-engine-3-6

Another view of the weighshaft and the levers.   Massive.

triple-expansion-engine-4-5

And note the drag links in the adjustable block.   That would have been set at intitial installation, and probably never altered since then.

Video of the big triple expansion engine working.  Maybe not.

For those following my triple expansion steam model engine build, I have put it aside again.  It is at the final assembly stage now.

Meanwhile, I am making some extra tool holders for the CNC lathe, and another ER40 chuck for the CNC lathe.

The ER40 chuck which I am currently using has an M5 shaft which is held with a drawbar, so I cannot feed work through the lathe spindle.  Plus it sticks out of the headstock a bit excessively.  So I have drawn up plans for a new chuck which I will fit to the lathe spindle and use the CNC to make the ER40 taper and threads.  Pics will follow.

And I really need some extra tool holders for the CNC lathe.  I have 5, but have material to make another 10.   The material is high quality cast iron off a scrapped T&C grinder.  I bought the grinder table cheaply (($AUD20 from memory) and have been gradually canibalising it over the last couple of years.   I have cut up the remains into rectangular 30x80x40mm chunks and will make the tool holders in the next couple of days, SWMBO and weather permitting.  Unfortunately there was insufficient material to make a long section, machine it, then cut it up, so each tool holder will have to be made separately.