From Wood to Metal

[toolznthings]

Hi All,

This build comes from a very unusual approach by John W. Reichart to build a ALL wood oscillating engine. The write up is in "Steam & Stirling" Engines You Can Build Book # 2 from The Village Press. Everything is made from wood with good instructions and a very nice set of drawings. I liked the style of the engine and decided to make this engine from metal.

Using the basic overall sizes and dimensions I made several changes. The main frame and outboard bearing support was modified to accept ball bearings for the crankshaft.
Overall height of the main frame was adjusted to allow for tapped holes to plug the air passages. I resized the air passages and added a bronze bearing for the cylinder pivot.The flywheel is a complete redesign and I did some special additions to make the cylinder pivot with little friction.

The materials used are 6061 aluminum for the cylinder and engine base plate, cast tooling plate for the frame and outboard bearing support, brass piston and cylinder ends,
and ground 12L14 round stock for all shafts. Shielded 1/2" bore x 1 1/8" O.D. ball bearings for the crankshaft.

A cad drawing of the main frame was positioned on the aluminum stock as guide. The very bottom of the frame was machined first and a series of rough drilling for the bearing bore was next. Using a boring head the bearing bore was completed. The bore for the bronze pivot bearing was also finished in the setup.

At the CNC mill the frame was set up on a sacrificial aluminum plate with holes taped at the bearing bore locations for mounting. Indicating the bottom first and indicating the bore set zero.

The beginning of the milling ...... 

[yogi]

Nice, another build underway... 
I’ll be following along. 

[toolznthings]

Finish machining the main frame .....

More milling on the CNC mill to do the pocket cut out and the outside contour.

Next setup at the manual mill is the bottom taped holes for mounting the frame to the base plate.

The air passages are drilled from the top of the frame. Two more setups drilled the air passages for the cylinder and the input and exhaust ports.
The side ports were tapped 5/16-24.

[b.lindsey]

Making good progress so far. This is going to be a good sized engine!!

Bill

[toolznthings]

Machining the outboard bearing support,base plate and a trial assembly.

Roughing the bearing bore and and using a end mill to finish the bottom arch cut out. Boring to 1.125 " for the ball bearing. Sized for a lite press fit. ( The bottom mounting surface was machined first. )

Set up on the CNC to mill the outside contour. Made a setup at the manual mill to add the tapped holes to the bottom.

After milling the base plate to a flat surface the mounting holes for the frame and outboard support were drilled and counter bored from the back side.

Trial assembly.

[toolznthings]

Machining the cylinder ..........

Made from 6061-T6 aluminum. I machined the overall size of the cylinder first. The cylinder is 2.125" from front to back, 2.000" wide and 3.125" overall long.
The finished bore will be 1.500" diameter.

Rough drilling thru the block at the mill and boring a undersized short bore on location. I will use this bore to indicate the cylinder at the lathe in the four jaw chuck. Being careful to make sure the milling operation produced a parallel and square blank I can indicate the face and indicator bore and be sure the finished cylinder bore will be true to the outside.

After boring I added the air inlet holes using a end mill, produces less of a burr where it breaks thru into the bore.

The next operation is to bore a .3125 blind hole for the cylinder pivot shaft.

[b.lindsey]

What sized flywheel will you use on this beast ?

Bill

[toolznthings]

What sized flywheel will you use on this beast ?

Bill

The flywheel will be 4 1/4" in diameter and 7/8" thick at the rim.

[J.L.]

This is a very interesting project.

I went the other way -  paper to wood . Like you, someday I'd like to make that paper engine a metal one.

Tidy work here.

Cheers...John

[toolznthings]

Finishing the cylinder, machining the crankshaft throw and the piston rod end .........

I set up the cylinder on the mill and located the pivot shaft bore. Using a 5/16" collet I held the pivot shaft. Using Loctite the shaft was held in place with the mill to insure the best possible alignment to the cylinder. After the Loctite cured the ends of the cylinder were drilled and tapped for the cylinder ends.

A test fit to the main frame.

At the CNC mill the crank throw profile was machined. The blank had the two bores finished first and these holes were used to secure the stock to a sacrificial plate. Using a shoulder bolt and socket head screw. I left the stock long and added a mill clamp to the far end.

The piston rod end was machined in two setups. One half of the profile done at a time. Did not have any brass thick enough to mill in one setup and then face to thickness.
Set up at the mill to drill and tap the end, 1/4-28 thread. Used a wiggler and scribed line to pickup center left to right.

The crank throw was Loctited to the crank.

[toolznthings]

This is a very interesting project.

I went the other way -  paper to wood . Like you, someday I'd like to make that paper engine a metal one.

Tidy work here.

Cheers...John

Thanks John ! 

[Plani]

Great progress and lots of nice looking parts 
And great pictures too 

Plani

[b.lindsey]

Coming together very nicely!!  I really like the bearing stands on this one too.

Bill

[toolznthings]

Thanks Plani and Bill !

Piston assembly and cylinder top and bottom ...........

Single point chasing the 1/4-28 threads on the end of the piston rod first after cutting the overall length. This end is for the brass rod end.
Boring a piece of brass for the piston rod to be Loctited to the rod. There is stock left for final machining.

Machining the bottom side of the piston first. Re positioned in the chuck to face to thickness and turn the O.D. plus adding a couple of grooves for oil.
Completed assembly.

Some turning operations to machine the cylinder head and cylinder bottom / rod guide. Used some soft jaws to finish the cylinder head. At the mill set up for drilling the mounting holes.

 

[toolznthings]

Machining the flywheel ...........

The flywheel is 4 1/2" in diameter and 7/8" thick at the rim. The center hub is 1" in diameter with a overall length of 1 1/4".

Setup at the lathe to machine the O.D. , face  / dished center , and bore. All finished in one setup. Held in soft jaws the opposite side was finished.

A 1/8" key way was broached and a 10-32 set screw hole drilled and taped over the key way.

Not shown are the 5/8" holes drilled thru for " spokes " to finish the machining.