Hemingway 1/12 Ransomes and May horizontal engine

[samc88]

I bought this early last year as a present to myself and since the dividing head is nearly done awaiting a few bits in the post thought I would make a start, starting with the base. Similar to the S50 I did I wasn't keen on the cast in bosses for the mounting studs so I machined them flush and will replace them with washers. The hemingway castings are slightly undersized which will be an interesting challenge but they do machine nicely.

[samc88]

A little unconventional I guess but I started with the water pump, theory being I get the feeling for the kit and as it's only run on air it's a relatively unimportant part, plus if I can do the fiddly little."extras" then hopefully the engine itself.goes as well

I lost a few pictures on my old phone but basically I machined the bosses either side of the pump as well as skimming through base itself on the lathe. The lower suction fitting and the end plug have been made (no pictures I'm afraid) and the top cap has been made, I took pics of this, the threaded section was machined and then the bronze put in the 4 sided collet block to machine the square.

[samc88]

The Base was then machined square, the casting is lundersized but that's not really affected anything so far. No.43 holes drilled and fitted with temporary 8BA screws to check it fits. Still need to machine where the screws sit and the central rib needs thinning too.

That's where I'm up to so far

[Jasonb]

Off to a good start

Was it just teh base that came up undersize? I wonder if the pattern was originally meant for cast iron rather than Aluminium. You could think about adding new bosses for teh hold down bolts, just a shallow counterbore and then JB Weld in some rod an dmill flat when set, this would be truer to the original.

One other thing I noticed was how far back your ER collet is sitting in the nut. The way they should be used is to snap than into the offset ring within the nut first and then screw the nut/collet onto the thread. Not only does this hold the collet more concentric it will also pull it easily out of the taper when you undo the nut. You can also damage the collets by not clicking them in.

[samc88]

Thanks Jason, usually I do that with collet, not sure why I didn't this time, the end mill was fitted the way you say. I will probably do as you say as well in regards to the bosses, I only milled the cast ones off as there was quite a bit of excess material around them which wasn't the nicest looking  to say the least, not only was it excessive but it was all lumpy as well

Most of the castings are slightly undersized with the exception of the cylinder and steam chest, the water pump one at the minute is about 20 thou under in most dimensions, the base is about 40 thou smaller than it should be but Id rather it look right with clean edges, I did wonder if they had lost the patterns and used a casting as a pattern

[samc88]

Casting cleaned up, still need to thin the web but I'm waiting for a ball nosed end mill to blend it all in properly, same with the step on the top, the casting had quite a bad slant on it so I've brought it square. The casting is quite undersized but it needs to be machined to clean up the faces, hopefully it won't affect things too much down the line, it shouldn't do, it will just mean a little more of the ram coming through the gland, the other side just has a plug and a thread for a pipe fitting. Other than being undersized the casting machines really nicely. I am going to leave the chucking piece on until the last minute as it is very useful for holding in the collet.

[Dave Otto]

Off to a nice start, everything is looking good!

Dave

[ettingtonliam]

Have you told Hemmingway about the undersize issue? See what they say in the way of explanation.

[samc88]

Next up was the bore which was easily done in the mill using the collet block and DRO for the gland fixing holes. The bore has been reamed 4mm as I have a piece of 4mm stainless steel for the ram

[samc88]

Next I set up the rotary table to make up the pump gland from brass bar. I did make it from the casting but it wasn't symmetrical so wasn't too happy with how it looked. Did some trigonometry to work out the a goe needed to be 34⁰. I modified the indicator holder so I could hold it in the spindle which saves a lot of height when setting it up. Pretty happy with how it's come out

[samc88]

Started on the pump ram and fork. The ram is made from 4mm stainless and I modified the design slightly to incorporate O rings since that worked well on the other water pump I made for my Tich. The end was threaded 5/32 x 40 and screwed into some 3/8" bar. This was then held in a 4mm collet and machined to size and the slot put down the middle. It's slightly overlength at the minute so when I drill and tap it I have enough left to get a decent round on it

[crueby]

Great progress!   

[Admiral_dk]

Like your use of O-Rings - the rest is coming along nicely 

Per

[samc88]

Thanks both! Did a bit more pump progress today. The casting has been built up with JB weld to better match the shape of the gland as this area was a bit thin and wasnt looking the best, hopefully will look good once painted.l also finished off the pump ram. Just the lower part of the pump to machine now on this part and I can see if it will actually work! The articles that come with the kit have drawings for water outlet fittings which I can't find on the original drawings so will also make those up at some point

[samc88]

Made up a mandrel to hold the pump to finish turning the body. All that's left is to make a couple of fittings and studs for the gland packing. I did get tempted and tried it out and the pump pumps! Even with no sealant under the caps and no gland packing it works pretty well. Will try and upload a video in a bit