Lady Stephanie Pumping Engine

[springcrocus]

Probably. 
Regards, Steve

[springcrocus]

Crankshaft Bearings

There are a few different parts that make each of the crankshaft bearings but the two assemblies are identical.

The first parts I made were the crankshaft bearing block bases, cut from some 1/2" x 3/16" ground flat stock. The centre section needed to be reduced to 1.5mm thick and one of my mill fixtures came into play again. After milling, three 4.1 diameter holes were drilled and the centre one countersunk to accept an M4 screw to just below the surface.



Next I made the bearing blocks from some 30 x 12 black bar, a bit large but giving me a substantial section to hold in the vice. After skimming them to 10mm thick, the sides and centre  were roughed out with a 10mm slot drill then finished to size with a 12mm one. All holes were drilled and tapped in the same setup. Then they were flipped over, the base milled to finished size and the end trimmed to length, too.



The two bearings were made from some bronze offcuts. Milled all round first, drilled, bored and reamed 10mm on the lathe using a s/c 4-jaw chuck, them back to the mill to put the 10mm slots in all round.



Two top plates were made along with a couple of simple oil cups. These are all the parts that go to make the bearing assembly except for a pair of oval wedges that fit each end of the bearing blocks and seem a bit of a nonsense to me.



And this is how they are mounted on the platform. Different fasteners will be used at final assembly depending on what looks most authentic.



Regards, Steve

[springcrocus]

Cylinder Mounting Frame

This part I have fabricated from various sections of brass bar. The first part made was the bottom of the assembly, a cylindrical section that locates in the platform.



The base ring was machined first, drilled and bored through, a locating spigot turned on the front, then parted off.



The base plate was milled all roumd to size, then the centre removed with a 38mm hole saw before finishing with the boring head.



The upper face of the base plate was thinned to leave locating faces for the two side pieces.



Hard-soldered together with 55% silver solder.



After cleaning up, the base was returned to the lathe and the inside of the boss bored out to size. Then the two sides and top piece were silver-soldered into place. Easy to say but much juggling with clamps to get it all to hold together.



The rest of the holes were drilled and tapped to suit.



The drawing shows a full-length cast-in section which carries the pivot rod for the lower valve link rods but I have fabricated something a little different and soft-soldered it into place but with a pair of M3 screws for additional support.



And, finally, a picture of it mounted in place on the platform.



Regards, Steve

[crueby]

Quite a complex frame, came out great!

[uuu]

I like the text on the drawing "Hidden lines removed for clarity" - if they were hidden then you wouldn't need to remove them!

Wilf

[PaulR]

I like the text on the drawing "Hidden lines removed for clarity" - if they were hidden then you wouldn't need to remove them!

[Jo]

Mike Coles and I said thank you Steve for the ice cream  Jason did not get one because he left too early   

Jo

P.S. Yes Surus now has a full set of Score Castings to replace the flywheel 

[Jasonb]

Wouldn't have been able to hold it anyway as I stocked up on Brass and Ali on my way out. Though I think I should have bought that Score off you before it got hidden away. I've a compound version drawn up that it could have been sacrificed for.

[springcrocus]

Glad you all had a good time at Guildford. 
Cylinder

I found a lump of cast iron in the scrap box so decided to make the cylinder from that. Wish I hadn't, tough as old boots but should be OK. After roughing out, I finished the billet to length, then drilled and bored to just below 25mm diameter. I was planning on using a between-centres boring bar to get to finished size but the parallelism was so good, I just finished to size instead. Obviously. it will be honed later.



Before finishing the outside, I moved over to the mill and drilled and tapped the holes for the two end caps, centering off the bore and using the DRO to position the holes. The holes break out at the back of the flanges so better to do now and save on broken drills.



Back on the lathe, a mandrel was machined from some 1.1/4" diameter stock, turned 25mm diameter and tapped M8, the work being clamped on with a 6mm thick end cap and Allen bolt.



Then the outer form was machined using a freehand-ground 6mm radius tool. Julius shows the cylinder undercut to 34mm diameter but I have left mine at 35mm to thicken the wall - less chance of the steam ports breaking out if the small drill wanders off-line a little.



All I need to do now is find a way to make and attach a steam chest, should be fun since I can't  silver-solder it. Otherwise, I've just made a pencil-holder for the workbench.

Regards, Steve

[springcrocus]

Cylinder cont.

I thought I would put the steam ports in before making the steam chest and used a pair of drills in the end-cap holes to get the cylinder correctly aligned. The wall thickness is 5mm so I drilled three holes 2.5mm diameter x 4mm deep for each port, then opened them up with a 3mm slot drill, again being very careful not to go below 4mm deep.



I set the mandrel up on the mill table so that I could drill the steam passages, here just clocking it out the easy way.



Then I centre-drilled and drilled three 2.4mm diameter holes from each end until they met the ports. Because the ports are offset, the longer side was just beyond the flute-length of the drill so very small pecks were taken near the ends.



The ends were also recessed by 4mm to clear the end caps using a 4mm slot drill.

Regards, Steve

[springcrocus]

Steam Chest Base

I started making this by milling up a block of bronze to 47mm x 28mm x 15mm and then needed to form the underside shape to fit the cylinder. I found this easiest to do on the lathe and swapped over my cross-slides to allow mounting of an angle plate. I am lucky because this takes just a few minutes because of how the lathe is constructed.





I already have a between-centres boring bar suitable for the job and this was set to 35mm diameter and loaded to the lathe. A small vice was then nipped onto the bar with packing pieces to set the height correctly and an angle plate loosely clamped to the cross-slide.



The vice was then clamped to the angle plate and the angle plate tightened down. A bit Heath-Robinson but accurate enough and strong enough to do the job.



The workpiece was loaded to the vice and cuts taken until the thinnest part measured 8mm.





Test-fitted to the cylinder and all appears fine.



Regards, Steve

[Jo]

 

Jo

[springcrocus]

Steam Chest Base cont.

The underside of one end was milled away to clear the cylinder flange. It would look better if it were shaped to fit properly but it will be hidden beneath the cylinder cladding so I decided not to bother.



The steam ports were milled out next, the two inlet ports going all the way through and the exhaust port for a depth of 6mm, leaving a 2mm wall at the bottom of the port. A 2.6mm hole was then drilled through the exhaust port to provide the first fixing point. After that, twelve holes were drilled and tapped to take the fixing bolts. The top was then lapped on some fine emery cloth on a surface table to remove the burrs but keep the nice, crisp edges of the ports.



With the ports visible on the underside, I was able to mark where I wanted four clamping screws to go but I want them square to the cylinder, not the top of the steam chest base. Also, the holes should miss the steam passages if I'm careful. I set my tilt-plate visually and four holes were drilled through at 2.6mm diameter.



Then the workpiece was flipped over and a 3/16" diameter slot drill used to counterbore the four holes to take the heads of 2.5mm cap screws.



Now I need to spot through to drill and tap the cylinder body. Just waiting on some M2.5 taps to arrive.

Regards, Steve

[uuu]

That answers your own question of how to fix the valve block to the cylinder.  Neat.

Wilf

[springcrocus]

Lower Cylinder End Cap

I have some plates that I thought were brass but it turns out they are a bronze of some sort, a bit chewy like phosphor bronze but light yellow in colour. 'Twill suffice.



After cleaning up all round to 48 x 48 x 6, I then set up to drill all the holes including reaming the 10mm diameter centre hole. I nearly messed up though, just remembering in time that the four inner holes are blind, tapped M3 x 4 deep.



I turned up a 10mm mandrel in the lathe and used this to machine the spigots on either side to ensure concentricity. The spigot for the cylinder was made bang-on size but the platform one was made a few thou sloppy.



Then it was held in a normal chuck and the "O" ring recess bored out. I also made the cap but adapted it so that it closes fully on the "O" ring; the drawing dimensions leave it protruding by 2mm.



And, finally, fitted to the base of the cylinder with M3 countersunk screws complete with end cap and "O" ring in place



Regards, Steve