Hemingway 1/12 Ransomes and May horizontal engine

[samc88]

Thanks Per!

I got the port face finished tonight, the slots were milled out first and then the 10BA clearance holes were drilled and 5 were countersunk for mounting the plate to the block. It does call for the lower ones to be countersunk but as you will be able to see these I will use studs and nuts rather than countersunk screws. To make the countersink I first tried using a centre drill but it didn't work very well due to it being a little too small so I used a drill and carefully pecked down until the screw head was just flush. The ports then had the corners filed square as per the drawing.I then lapped both faces with 600 grit wet and dry to take off the machining marks. The DRO is again proving to be an excellent investment, all the bolt holes lined up perfectly, quite pleased with how this has come out

[samc88]

Some progress has been made on the steam chest . Was first milled to dimension (the top surface I will do later as it has a circular boss in it, I will do that feature on the rotary table). The slot was then opened up and filed to final.size to be a good fit with the previous port face part. Once that was done I marked out the hole locations, will hopefully drill these tomorrow night 10Ba clearance

[Michael S.]

That was good work with the file. 👍

Michael

[samc88]

Thanks Michael!

Bit more done tonight, drilled the mounting holes and then machined away the top surface leaving enough for the boss to be machined circular later. I did put a centre in there though after edge finding so I can use it to centre up on the rotary table. I then worked on the gland end, drilling 3/32 through the centre and following with a 1/4" end mill. The 2 mounting holes were then drilled and tapped 10BA. This was then flipped upside down and the 3/16" x 40 thread put in for the tail piece to support the valve rod.

[modelsteam]

Excellent progress, keep up the good work.
      Chris

[Charles Lamont]

A little suggestion for a small detail. Portface wear is often uneven. As the valve only covers the ends of the travel momentarily it tends to wear the portface more in the middle and less at the ends, making a hollow depression in the portface. This tendency can be much reduced by relieving the portface at the ends of the valve stroke, so that the valve overlaps the edge by a small amount at each end. As you have a raised portface this would by quite easy to do. The red bits show where I mean.

[samc88]

Thanks both! Interesting detail to know Charles thank you, I think I'll keep it as it is on this one just because I cant see it getting run that much to cause much wear.

Another part made this afternoon was the valve chest cover. The kit gives you 6mm steel to machine down but since I had aa piece of 4mm I started with that instead. I used a slot drill to machine the boss on both sides, one side is decorative and the other goes into the steam chest.

Once that was done and since it was still set up in the vice I drilled the holes 10BA clearance. Next I cut the part out and then milled it down to final dimensions. Its quite a nice fit into the steam chest and all of the holes line up which is a relief! Going to have a look and see which part to make next

[crueby]

great progress!   

[samc88]

Thanks Chris!

Little bit more progress this afternoon. I worked out the position of the holes for the governer bracket as this wasnt on the drawing and drilled and tapped them 12BA after opening up the pocket a little to make some clearance. The only thing left on the cylinder really is the drain cocks but Im not sure which to go for as there are a couple of options, I'll sort those at a later date

Next I thought I would make the tail guide for the steam chest. On the plans there are 2 flats but I prefer the look of the fully round version like on Stuart engines so thats what I have done, I had a mandrel so used that to hold it and then did the acorn shape with a file and some wet and dry

[samc88]

I have been experimenting with making 10BA studs tonight until I ran out of material. They look a lot better in real life than in the photos (the photos make them look like they have no thread on them but in actual fact the die cut them quite nicely). I need to redoio a couple, the first few were a bit inconsistent until I found a good method of setting the length.

[samc88]

Back to it, was feeling motivated and picked up the cylinder cover casting. It was held in the chuck and then the chucking piece machined to 14mm to fit in a collet. This was then held in the chuck and the OD turned and faced. The guide bar supports were then machined to diameter (the drawing has them milled square but it was an easy job in the lathe and looks quite good)  and length from the cylinder surface.

This was then set up in the rotary table (this was already on the mill with the collet chuck fitted which was why I turned the spigot to fit a collet). It was indicated square and then the centre gap milled and the gland surface cleaned up before drilling and tapping the gland fixing holes. Whilst everyrhubg was set up square I drilled the mounting holes which should mean the guide bars will be aligned correctly.

I will finish this later on, it needs the holes in the guidebar supports putting in and this will be easy in the collet block. I want to make up the piston and valve rod glands next whilst the rotary table is set up

[samc88]

Starting on the piston and valve rod glands this evening as Im making the most of having the rotary table set up. The casting supplied isnt quite symmetrical so I will be making these from bar and machining the angles on the rotary table which worked really well when I did the water pump one

[Admiral_dk]

You are really productive Sam - many new parts done in the last days 

Are you a bit like me, were better weather improves the motivation 

Per         

[samc88]

Thanks Per! Been off work this week and got a lot of stuff done which gives me a free weekend.

I got the glands finished this afternoon, machined to width and then set the angle on the rotary table and milled 2 sides at a time. I then parted them off on the lathe and faced the back side, just needed a little clean up with a file. Pretty pleased with these small parts!

Since I still had the rotary table on the mill I set up the small vice and finished the steam chest, centering on the centre drill mark I had put in previously to locate the inlet. This was then drilled and tapped 1/4" x 40 and then machined round using the rotary table

[samc88]

A little progress tonight, drillled the mounting holes for the guide bars on the front cylinder cover.
I then thought I would do the valve rod, a nice simple job I thought! Took a few attempts and finding a good tool to turn the thin end down, found a good HSS tool which worked well for doijg it and turning a small section at a time, drawing it out of the collet each time. When test fitted with the gland in the chest, it slides freely enough.