Steam engine (Tiny vertical w/reverse)

[gbritnell]

The part was removed from the mill and put back in the 3 jaw chuck in the lathe to turn the upper valve stem boss. A tool with a small radius was mounted and I slowly cut the material away given the extra loading of the radius tool and the fragileness of the part. Once I was close to the proper diameter I took the final side cut to establish the height of the part (.400) and finished the boss.
The part was then cut off of the bar.

[gbritnell]

The final operation was to remove the 3 jaw chuck and mount the 4 jaw chuck so that I could form the radius on the end of the valve boss. The part was clamped lightly so as to not mark the finished surfaces of the chest and was adjusted to center with an indicator. The radius was filed onto the boss and then polished with emery paper.
gbritnell

[zeeprogrammer]

I don't post much in your threads...but I always read them.
Excellent work for me to learn from.

[Don1966]

George you are a man of few words, but dog gone up do excellent work.

Don

[steamer]

Beautiful George......George showed me some of his art work he's working on at the moment yesterday.....it's everything you could possibly imagine!

 

Dave
 

[tvoght]

I like to print out the drawing pages and hold the relevant one in my non-mouse hand as I follow along with the pictorials here.

--Tim

[Jo]

My hat is off to you George  I have just followed this thread through and your work is stunning.

Jo

[sbwhart]

That realy is a master class of maching small parts George

 

I've learnt a lot by following your thread, thanks for showing.

Stew

[b.lindsey]

Might have to have a go at this one George, once I get the Ericsson finished. Its the small size and reversing gear that really sets it off i think...good project for the Sherline equipment too!!  Now if only I can find the stronger diopter lens for my magnifying hood  .  Great work and documentation as always !!

Bill

[gbritnell]

With the cylinders bored and machined to shape it was time to put in all the ports and bolt holes. The ports were done with the cylinder clamped in the mill vise. They (intake ports) were too small for any cutter that I have (.025 wide) so a series of holes were drilled and then with a sharp utility knife I cut away the steps between the drilled holes. The same was done for the exhaust port but I was able to get a small file in to clean up the edge.
Now it was time to put in all the holes for the cylinder heads and cut the recess for the ports at the cylinder ends. I found a fixture plate in my stash of plates and turned up a boss to locate the cylinder. With the cylinder mounted on the boss I then used one of my tiny clamps as a stop so that the subsequent operations would all be square and true. The holes were drilled and the notch was milled.

[gbritnell]

The next part would be the crankshaft. For this part I used some 1144 steel. Normally I use this material for it's non warping properties but in this small size it's not really an issue. The O.D. of the discs is .375. I started by facing and center drilling the stock. The next step was to turn the main shaft to .089 diameter. With this done on 2 pieces of stock it was time to make a fixture block to hold the blank for offset turning of the throw journal. I squared up a piece of aluminum and then centered it in my 4 jaw chuck. I put an -X- as register mark to locate the block to the #1 jaw in the chuck so that the bored hole would always be square to it's original setup.
With the block made and a tapped hole put in to hold the crank I put it back in the chuck and offset it with a dial indicator to get a reading of .250. With this done I cut the throw journal by plunging in with a necking tool. The tool was a little wider than 1/2 of the slot so once the first cut was made I could take the remaining stock from the chuck side with no worry about the crank twisting off. To finish off the crank I put the it into a collet and turned the other main down leaving .010. I thought I took pics but apparently not. The second main shaft was made .25 longer than the required length so I could clamp to it while supporting the outboard shaft with a live center. The remaining stock was removed and the crank was cut off to length. The bearing blocks had been made in another operation that I didn't document, just milling and reaming to the proper dimensions.
 

[gbritnell]

The next part is the connecting rod. This was all basic machining but in a much smaller scale.
I started by facing a piece of .25 square brass rod. The next step was to cut the yoke end with a slitting saw. Now I could center drill and drill the hole for the crosshead screw. I did this next so that the stock would still be heavy enough not to flex while drilling.
Now I cut the yoke area to size.

[gbritnell]

With that part of the milling finished the stock went back into the 4 jaw chuck to cut the shaft. This is .062 diameter with small fillets at each end.
From the lathe it was back into the mill to cut the area for the big end of the rod.

[gbritnell]

I then cut the rod blank from the stock. It was too hard to square the rod in my big mill vise so I used my small Sherline vise for this operation. I squared it up on my layout plate with an indicator and then clamped the small vise into the large one. The end was milled flat and then the screw holes (1.0x.025mm) were drilled.
The cap was then cut off with a jewelers saw and it and the rod were milled square and cut to size.

[gbritnell]

I have some screws on order but not wanting to wait for them I made up 4 screws to hold the caps to the rods so that I could finish the crank holes.