Cretors #1 Horizontal Steam Engine Build

[rstreift]

Time to clean up the sharp edges before I cut myself on them.  There are some high spots that need ground down while I’m at it to allow for the cylinder jacket.
S332-A-Cylinder-25.jpg

With the “under jacket” surfaces now under the diameter of the cylinder head surfaces, I can grip the cylinder in a vise.
The notes in the print says that I should indicate the cylinder mounting holes from the bases’ through holes.  I’m having a bit of a time following that advice when I believe I can measure to drill the cylinder’s mounting holes without locating them from the base holes.  As an aside, the notes also say the cylinder/frame is mounted to the base first and the bearing blocks’ holes are to be used to locate the holes in the base.  Give that errors add up, this seems reasonable and I’ll prolly do that as a reality check before I poke holes in the base for the bearing blocks.
So, I’m going to finish the cylinder and spot/drill/thread the mounting holes at this time.
S332-A-Cylinder-26.jpg, S332-A-Cylinder-27.jpg, S332-A-Cylinder-28.jpg, S332-A-Cylinder-29.jpg

The last hole to poke-n-thread is the exhaust port.  But before that the cylinder/frame/bearings were test fitted.  With that done, the cylinder was fixed in the vise, indicated for the centerlines and offset to drill/tap the exhaust port.
S332-A-Cylinder-30.jpg, S332-A-Cylinder-31.jpg

While the above was the last hole, the big hole needed the last little bits removed for the piston to fit.  Honing takes some patience and the ports need some care so the stones “just” cover the ends.
S332-A-Cylinder-32.jpg

[rstreift]

The Cylinder Head – Front End, #S331-G
This casting is specified to be machined all over, but I’m leaning to leaving the center curved section as cast finish.  After setup, I took cuts to remove the cast finish.
S331-G-CylinderHeadFront-1.jpg, S331-G-CylinderHeadFront-2.jpg

Unfortunately, I cast the internal softjaws many years ago and have not needed then until now.  There are other techniques that could be used, but I think it’s time to finish these jaws and use them.  The two pictures of this are the raw casting as it came out of the lost foam sand (decades ago) and the set of jaws after machining them.  Cutting them apart created another task as the when I changed the band on the saw, I noticed the drive wheel’s tire needed replaced.  Another order was placed. 😊
RndJaws-CastingBottom.jpg, RndJaws-Machined-1.jpg

Getting back to the head, with the surface as my datum plane, I remount it in the chuck using parallels.  Using a boring bit, the carving starts to bring the internal surfaces to size.  The remaining surface is the outer diameter where I’d like to hold the part by the internal surface.
I setup the softjaws for this internal holding and cut the jaws to fit the head’s internal diameter.
S331-G-CylinderHeadFront-3.jpg, S331-G-CylinderHeadFront-4.jpg

This holds the head nicely and the diameter is turned to size.  That is a bit of setup for a small bit of turning.  The part then goes to the mill where it’s centered, then spotted and holes poked for the bolt holes.
S331-G-CylinderHeadFront-5.jpg, S331-G-CylinderHeadFront-6.jpg

[rstreift]

The Cylinder Head – Crank End, #S331-H
This casting is similar to the front end head in that it is specified to be machined all over, difference is this one really does need machined all over.  The lump is reasonably symmetrical and thicker than the finished dimensions.  With a setup using parallels and an indicator to center, the part is ready to turn. 
This side has a gland nut and needs 5/8-18 threads.  The surfaces for the frame to nestle in as well as the major dimeter for the threads are turned, then the threads are cut using the upside down and rotating backward method.
To cut the diameter and opposite side surfaces for the cylinder, out comes another set of softjaws.

S331-H-CylinderHeadCrank-1.jpg, S331-H-CylinderHeadCrank-2.jpg

The part is mounted in the “precise” fit of the softjaws and the diameter and cylinder surfaces are turned.  Like the front end head, over to the mill to center it up and spot/drill the bolt holes.
S331-H-CylinderHeadCrank-3.jpg, S331-H-CylinderHeadCrank-4.jpg

[rstreift]

The Cylinder Head Bolts
The S-332 print has a hardware table of “fastenings”. The cylinder heads are listed as “hex head cap screw”.  Comparing the lengths with the total required length, I found them to be 1/8” longer than necessary even considering a generous 3/8” engagement for the threads.  I made them an 1/8” shorter.
S331-GH-CylinderHeadBolts-1.jpg, S331-GH-CylinderHeadBolts-2.jpg


The Gland Nut, #S331-J
A gland nut is not usually a challenge, most of them are smaller and within my range of taps.  With a 5/8-18 thread, it required single point threading as using a tap is not an option.  I have a nicely ground 60-degree lathe bit for internal threading, but ground for the right-hand thread in the usual manner for the lathe to be in the forward direction and carriage running right to left.  Running up to a should that I cannot see is outside my skill set. 😊
While I was looking for a 60-degree bit, I also looked for a bit ground square with enough relief to cut the undercut at the end of the thread.  No such luck, so off to grind the two bits.
With those bits completed, I started with some 3/4” hex stock and turned the truncated minor diameter, undercut for the thread, and the outside diameter feature.
S331-J-GlandNut-1.jpg, S331-J-GlandNut-2.jpg

Mounting the newly minted 60-degree bit in a holder, setup the gearbox for 18 TPI, and engage the feed screw to feed right to left with the spindle in reverse; the thread is completed using the crank-end head as the thread gage.
A little finishing work and the cut-off, this part is functional.
S331-J-GlandNut-3.jpg, S331-J-GlandNut-4.jpg

[rstreift]

The Wrist Pin, #S331-C
The wrist pin and nut seem like another quick part to complete.  I start with a piece of SS hex stock and turn down the bearing surface, then the major diameter reduced for the thread “flat”.  A die is used for the thread and the minor diameter is turned to finish the thread then parted off.
S331-C-WristPin-1.jpg, S331-C-WristPin-2.jpg

Changing to a 5/16” round collet, the bolt head is faced to spec and radiused to finish. The collet is changed back to a ½” hex because I didn’t plan ahead and do the nut after the bolt was parted off. 😊 Drill, tap, face, radius, and I have a nut.
S331-C-WristPin-3.jpg, S331-C-WristPin-4.jpg

The final assembled wrist pin and nut.
S331-C-WristPin-5-Asy.jpg

[rstreift]

The Crosshead, #S331-D

The crosshead is another casting that is spec’ed to be machined 100%.  I suspect that by the time the machining is done, I’m going to call it finished and there will be some areas that will be left “as cast”.  This is a pretty good casting in that there is ample metal to carve away, I marked out the thickness before beginning.
S331-D-Crosshead-1.jpg, S331-D-Crosshead-3.jpg

The boss was used to align the casting in the chuck as it was found to be well placed.  I turned it down my “thickness  mark” and turned the boss to spec.  I drilled a 1/4” pilot hole to use to align it in the chuck when I flip it over to do the other side.
S331-D-Crosshead-5.jpg, S331-D-Crosshead-6.jpg

The casting is flipped over, aligned on the pilot hole, and finished the turning. 
S331-D-Crosshead-7.jpg, S331-D-Crosshead-8.jpg

[rstreift]

Moving to the mill, the pilot hole and a square are used to align the casting so I can carve out the cavity to accept the connecting rod end. 
S331-D-Crosshead-9.jpg, S331-D-Crosshead-10.jpg

The piston rod’s hole is drilled and reamed.  By now, I’ve decided to leave the area around the taper pin “as is”, set the taper pin and use the rod to hold the part for the final machining.
S331-D-Crosshead-13.jpg, S331-D-Crosshead-14.jpg

I drilled the pilot for the tapered reamer.  Unfortunately, the reamer I purchased was dull and simply would not cut.  It was time consuming to find this reamer and I was out of patience.  Time to use the backup plan.  I drilled/reamed for a 9/64” dowel pin and loctite’ed the “taper” pin in place.  If anyone ever wants to take it apart, measuring the ends of the pin will inform them it is a straight pin.
After a day for curing, on to the lathe and finish the turning.
S331-D-Crosshead-15.jpg, S331-D-Crosshead-17.jpg

The finished crosshead with the print.  Well, almost finished.  I had not test fit the wrist pin and when I did, it was a no-go.  I failed to finish the drilling/reaming to 5/16”.  A quick setup/machining, and the wrist pin was fitted.
S331-D-Crosshead-16.jpg

[crueby]

Excellent! A classic style crosshead.   

[rstreift]

The Steam Chest, #S332-H

The steam chest casting is drawn to be machined-n-finished on all surfaces.  After taking measurements, it is unlikely a completely machined finish will be possible on the interior.  At the very least, the 1/4" ‘shelf’ that is part of the guide for the slide valve will remain as cast.  It measures 0.300” thick as opposed to 0.250” per the print.  That might be fine except that the center of the boss for the gland appears to be more than 0.050” above the surface plate.  However, the boss has about an 1/8” greater diameter than finished diameter, so I’ll take off what is needed from the side resting on the surface plate and go from there.
S332-H-SteamChest-1.jpg, S332-H-SteamChest-2.jpg

With the bottom of the steam chest cleaned up, there will be ample thickness for the slide guide feature.  After a few measurements, I know what to take off each side so the boss and the interior slide guide space will be centered.
S332-H-SteamChest-4.jpg, S332-H-SteamChest-5.jpg

Now to flip it over and bring the top down to spec.  Now that four sides are square and on spec, time to address the ends.  The gland end will be turned, so the other end will be milled.  A bit of math and playing on the surface plate places the lines about where they need to be.  The lines indicate the hole centers and the edges as a reality check.
S332-H-SteamChest-6.jpg, S332-H-SteamChest-7.jpg

[rstreift]

I used a square to get close and then the DTI to clock it in.  It is milled to the line and now 5 sides are square.
S332-H-SteamChest-8.jpg, S332-H-SteamChest-9.jpg

I redye’d the boss and marked the center.  Then clock it into the lathe chuck.  Giving it a spin, it was wrong.  The boss’s center was off.  I didn’t see where the error was, so I took out the part and examined the packing.  One of the steel packing pieces was slightly warped and I replaced it, but that wouldn’t be the problem.  I didn’t need the thickness of the wood packing and replaced it with thin cardboard since the surfaces are machined.  The part was returned to the surface plate to check the center lines of the boss, it was fine.  I then looked at the chuck and re indicated in the part, then I noticed the previous error.  The DT has a tenths’ hand marked in half-tenths.  When I was spinning the chuck and checking the sides of the part to center it, I missed seeing the tenths hand was 0.100 different between two opposite sides. 
I suspect if I have omitted marking the center lines on the boss, I’d be looking for a solution to fix the off-set hole. 
S332-H-SteamChest-10.jpg, S332-H-SteamChest-11.jpg

I also ran a DTI along sides on the Z-axis to triple check the part was parallel to it.  Turned it to the marked line (ended up +0.005, but I’m ok with that as my tolerance) and drilled/threaded it.
S332-H-SteamChest-13.jpg, S332-H-SteamChest-14.jpg

[rstreift]

The through holes for the studs are next.  The steam chest is dropped into the vise and the center located.  Armed with the correct offsets from the center, the holes are spotted/drilled
S332-H-SteamChest-15.jpg, S332-H-SteamChest-16.jpg

The final feature is the threaded hole for the governor.  This took a bit of setup to mount-n-hold without marring it.  The wooden block has a hole for the sliding valve’s rod’s boss.  For the DT to clear the jaws, the small “gage” block is providing the extension to clock it in.  After that, it is drill/bore/chase to finish the steam chest.
S332-H-SteamChest-17.jpg, S332-H-SteamChest-18, S332-H-SteamChest-19.jpg

[rstreift]

Thanks.  Cretors designed a nice looking engine.

[rstreift]

The Steam Chest Cover, #S332-G

The steam chest cover is a nice slab of bronze.  It is as square as one can expect a cast object to be.  I decided to square off the thin edges first, then the bottom and top.  Once that was done, the center lines were located and the holes poked for the studs.
S332-G-SteamChestcover-1.jpg, S332-G-SteamChestcover-2.jpg, S332-G-SteamChestcover-3.jpg

[Dave Otto]

Lots of nice work there!

Dave

[Sanjay F]

I agree, looking really nice and following along