Tiny triple expansion steam engine

[gbritnell]

I almost have the rods finished. I just have to make an arbor to mount them and turn away some of the thickness of the big end leaving a circular boss around the journal.
I started making bolts! Awhile back I said that I really didn't like tapping lots of holes, well the next part of the build is making M1.2 x .25 hex head bolt of all different lengths and I guess that ranks up there with the hole tapping. Just the M1.2 bolts alone count is 84.
I put some of the pieces together just to see what it would look like and to keep my interest while I'm making bolts.
gbritnell
In the bolt picture that dimpled effect is the surface of the paper towel. Just to show the size.

[crueby]

Very nice! And thats a LOT of bolts to make.
 

[fumopuc]

Hi George, that is very nice.
I had to go back to the picture with the one cent or in front of the key board, to understand how tiny it is.

[b.lindsey]

The family shots are awesome and inspiring. Making all those boots is tedious work no south.

Bill

[gbritnell]

Finished up the crosshead guide/piston rod pieces with the wrist pin bolts and mounting plates and bolts. Assembled all the pieces to check the fit and everything seems to be good.
I put the quarter in there for comparison. It's .955 diameter, or about 1.00
gbritnell

[crueby]

Beautiful!

[Craig DeShong]

Exquisite work George.  You’re work is an inspiration for me to continually try to ‘up my game’. 

[Kim]

Wow, George!  You do some mighty fine work!
Kim

[gbritnell]

The final nail biting job to do on the cylinders is to drill the porting. I cleared the mill and set up my sine table with vise. The center hole was drilled with a #0 center drill that has some of the .125 shank ground away. The holes are drilled .039 diameter.

[derekwarner]

George...beautiful work.......I could be corrected, but re-reading the post thread suggests you have used a Loctited type construction for the crankshaft

We see from the earlier IMG_2090, there will be a very thin path width for the gaskets between the cylinder block & the cylinder covers .....I am guessing approx 3/16" wide max and this includes bolt holes...and that the IP & LP gasket will be one piece ... together the effective gasket width around the ports in the cylinders is extremely thin 

Will you use the traditional oiled [envelope thickness [~~0.006"] brown paper for the gaskets?...or have you been tempted to use one of these new fangeled liquid Teflon mediums?

Derek

[b.lindsey]

Awesome George!! Can't wait to see it running.

Bill

[Craig DeShong]

Some tedious setup work George.  Not much room for error.  Thanks for sharing.

[gbritnell]

To get the crank throws indexed properly I used v-blocks and protractor. I used a drop of Loctite just to hold everything in place and then drilled and pinned everything. The crank throws are turned as one piece, throws and both cheeks. This simplified construction rather than having 6 individual cheeks, 3 crank pins and the main shaft. As far as gaskets I'll probably use tissue paper or just some  motorcycle gasket sealant.
gbritnell

[derekwarner]

Thank you George...I saw one journal pin, but missed the others ............. Derek

[gbritnell]

Things are moving along steadily. I now have the valve straps, valve clevises, valve rods and valves made. Today I set up to make the reverse quadrants. The radius of the parts fit onto a piece of 2.50 diameter round stock so I set up my rotary table with an old 3 jaw chuck and indicated everything on center. Using my CAD drawing I put all the holes in for the slot corners, part corners and bolt holes.
The parts were sawed off with a 2 inch diameter slitting saw.