Greene Automatic Cutoff Steam Engine

[kvom]

I do have the exhaust valve clevises at opposite angles to the brackets so that the valves move in opposite directions.  I learned this from watching John's engine video. 

Earlier I calculated that to get valve to move .1" with the clevis 30 degrees above or below horizontal, the length of the conrod needed to be .9".  Since I had made the adjustable length conrods incorrectly that are unable to adjust that small, I made some fixed length ones that I've been testing with.  The motions do seem to be about right, but I think I need to redo the adjustable conrods if tuning is so sensitive.

That said, I picked up the wooden base today and next will machine the aluminum base that the engine will sit on.  As part of moving to this base, I'll do a partial disassembly and leak test the cylinder and valves again on the bench.

[kvom]

So another brain fart turned up.  I had ordered some aluminum plate to serve as the mount for the engine to fit onto the wooden base.  Unfortunately having order the plate a long while back I neglected to remember it is 12x24"  when designing the wooden base for ~13x21".     Had I remembered the plate size (I had left it in the shipping wrapper) I did have room to reduce the wood base by 1" in width.  So today I ordered some 18x24 plate, and I'll have to wait another week or so to get it.

I also ordered powder coat powder from Eastwood today in medium and dark green, and I'll do some tests to decide which shade I'll color the engine.

[crueby]

And will that plate fit in the powder coat oven? Asked by someone who has built lots of large projects and learned to measure the door...

[kvom]

Powder coat oven is a full-size kitchen double oven.

And just to double my daily quote of brain farts I find I have a piece of 1/4" aluminum plate that can be trimmed to fit the base.   

[kvom]

And will that plate fit in the powder coat oven? Asked by someone who has built lots of large projects and learned to measure the door...

Despite having a full size oven the plate will NOT fit.   

I spent the entire afternoon cutting the 1/4" plate down to fit the base.  Only way I could see to do it accurately was to take the vise off the Bridgeport and mill it on the table.  Luckily just enough X travel.

[crueby]

Not even diagonally?        Find a restaurant with a big oven and bad back door lock.... 

[kvom]

I had some difficulty getting the woodworker's base completed, and then fitting the base plate properly.  So as I had some loss of enthusiasm for the past month I didn't do much with the engine.  Finall I get the wooden base back:



And the 1/4" aluminum plate to fit.



I decided to powder coat all the parts that will need color before reassembling to try to get it running.  I also need to finish the governor and get it installed, as once everything else is in place it's hard to add on.  Here's the first batch of powder coated parts, with a number of smaller pieces still in process.  Seemed logical that the Greene engine would be green.



With the cutout for the flywheel, a test to see how it looks.

[Dennis]

Thanks for the link Kirk, for some reason I was not able to locate it.

I like the base you built.  The cut out for the flywheel is something I have never seen or noticed before.  It should make a great display.  Looking forward to seeing the assembly.

Dennis

[Craig DeShong]

Looking really sharp Kirk.  It’s going to be a real show stopper when you get it assembled.

 

[gbritnell]

Great job Kirk. It will look great when all assembled.
gbritnell

[kvom]

Almost done with the powder coating (other than the cylinder block), and am concentrating on getting the governor assembled.  I needed to remake the center shaft but a brain fart error means the day's work was wasted.

[kvom]

The governor center shaft consists of 4 sections. The top is a 5/16" diameter ball with a centered cross hole.  A shaft through this hole connects parts that secure the flyballs to the shaft.  The next section is 1/4" whose far end rests on the center section of the governor case and prevents the shaft from going down further.  The 3rd section is 3/16"diameter whose end can reach into the gearbox.  The final section is 1/8" diameter to which the pinion gear is attached.  Originally I made the top section from a ball bearing, but then attaching it to the second section proved problematic and eventually they broke apart.  So this time I formed the ball onto the end of some 5/16" drill rod using a 5/32" corner rounding mill held in a lathe holder.



A test to show the ball fits between the arms of the connecting brackets.



The other sections are drill rod with pockets drilled into them to accept the smaller size.



Fastened together with loctite



The final section length will depend on fitting the pinion gear.  It appears that the shaft of the gear needs to ride against the top of the gearbox to secure the shaft from pulling out.

One thing I've done throughout the build is to not finish every operation on a part for various reasons.  If I want to avoid many disassemblies of the engine I need to do these now.  One such op is drilling an tapping the grub screws into the hub of the flywheel.  Plans show a 10 degree slant to allow the mill to clear the rim, but I discovered I'll need more angle than that.  I decided the way to do this is to hold the flywheel vertical and tilt the head of the Bridgeport.  To secure that wheel I hauled out a very heavy drill press vise that I bought at a garage sale years ago from someone who had no idea what it is.  This allowed holding the wheel to the table.  However, with the wheel vertical I felt the heavy head needed to be tilted further than I was comfortable with.  So I added tilt to the vise using 2-3-6 and 1-2-3 block.  Even then I needed to use a small drill chuck sticking out from the collet to reach the hub.



Once I was ready to spot the first hole using an endmill, I found that the mill had locked up so that while the motor was turning, the belt sheaves would not.  So I'm now stuck with an inoperative mill waiting for a repair shop to return my call.   

[kvom]

With the mill out of order, I spent an afternoon powder coating the spokes and hub after grinding down the flashing.

[Kim]

Nice paint job! I always love a good powder coat
Kim

[kvom]

Since drilling the set screws into the flywheel hub is a no go, my alternative is to make two lock rings that are extensions of the hub on either side.  Starting with a piece of 1.5" diameter stressproof steel, I turned on end down to 1.125" for .3" allowing it to be held in the largest 5C collet.  I then faced, and then did successive through drilling up to 13/16", followed by 7/8" reamer.  Then marked the areas for parting.



Over to the CNC mill, use of a vise stop and hex collet block allowed 3 evenly spaced holes around each ring.



At my tapping station I was able to start the first three three threads of the 8-32 tap by finger pressure in each hole, then finished with a tap wrench/



Back at the lathe, I passed the 7/8" reamer again to remove the tapping burrs, then parted off the two rings.  Then after facing to clean up the parted side of each ring, I broached a 3/16" keyway in each to match the flywheel.  My #3 arbor press was able to do the broaching fairly easily as the rings are only .3" thick.



One of the holes passes into the keyway so that its set screw will keep the key from moving.  The other two will contact the flywheel shaft.  Hopefully the two rings will keep the flywheel from moving laterally.