And Now for the Twin

A special section just for steam engines and boilers, as without these you may as well fit a sail.
Mike Rometer
Full Steam Ahead
Full Steam Ahead
Posts: 673
Joined: Sat Aug 13, 2011 6:41 pm
Boat Name: B.N.Y.S.
Location: Middle Earth

Re: And Now for the Twin

Post by Mike Rometer » Sun May 20, 2018 3:13 pm

Not that I've actually done any more, except I have now acquired a copy of the drawings (I don't intend to follow them at all closely).

They show 5 fixings per head with one on the centre-line. That very neatly steps the outer four well away from the port area. As I said above "Too late" they are already drilled. Hmm, must get round to tapping them!
Retirement is about doing what floats your boat!

A BODGE : - A Bit Of Damn Good Engineering.
Mike Rometer
Full Steam Ahead
Full Steam Ahead
Posts: 673
Joined: Sat Aug 13, 2011 6:41 pm
Boat Name: B.N.Y.S.
Location: Middle Earth

Re: And Now for the Twin

Post by Mike Rometer » Sat Jul 28, 2018 8:11 pm

Progress is slow and sporadic, but : -

The ali pistons are finished and fitted to the rods, which aren't yet cut to length. I've gone with two rings in one groove to maintain the 3.25" stroke that I wanted.

I acquired a large chunk of cast iron from which I've fashioned the valve chest blanks. Lot of metal still to remove from the middles.
Steam Chests (7) (600 x 450).jpg
Steam Chests (7) (600 x 450).jpg (70.61 KiB) Viewed 150 times
The crankshaft webs have been reduced to an overall thickness 0.750" with main bosses left at 1" for stiffness. I then made a fixture for the mill bed and bored the crankpin holes. They may just need a smidgeon more removing (reamer) before the pins are pressed in, after the shape of the weights has been machined.
Crankshaft (12) (600 x 450).jpg
Crankshaft (12) (600 x 450).jpg (62.57 KiB) Viewed 150 times
Lots of metal to come off yet!
Retirement is about doing what floats your boat!

A BODGE : - A Bit Of Damn Good Engineering.
Post Reply