Advanced Engine Building Projects

[GWRdriver]

If anyone is building or contemplates building any of the following engines I would like to correspond. One thing I am interested in doing is compiling a list of drawing errors for each design. I already have a list of errors started for the ME Beam Engine.

Stuart Major Beam (Castings: Stuart)
Stuart Compound Launch Engine (Stuart)
Model Engineer Beam Engine (Reeves)
Sanderson Beam Engine (Clarkson)
Henry Coventry 1/3hp Compound Marine (H.Coventry)
James Coombs Table Engine (Stuart)
Southworth Lincoln Mill Engine (Peter Southworth)
Murdock-Aitken Table Engine (Clarkson)
Charles Hanson Corliss Engine (Model Craftsman)
Southworth (or Fleet) Corliss (Peter Southworth)
The ME Compound Undertype (Stuart/Reeves)

 

[kellswaterri]

HHarry, how's it going, I have been out of circulation and off the planet for a year and am just now starting to get back into the sheds...I have currently the James Coombes about 50% stage and the Southworth corliss single at about 20% Build...I do not remember any problems with the coombes but the corliss presented trouble from the start as the castings were smaller than drawing size the hole dimensions had to be juggled a bit...what I will meet up with when I start to finish these engines remains to be seen... the Chester Conquest mill is now acting as a Jig borer and is replaced with a PROPER mill...a Cowells...a weee bit smaller , but it will be well capable of finishing the engine work...currently having an enclosed verenda built between the two shops so I can commute between in wet weather and keep things dry...once finished I can get mucked in and do some engine building.
All the best for now,
John.

 

[GWRdriver]

...I have currently the James Coombes about 50% stage and the Southworth corliss single at about 20% Build...I do not remember any problems with the Coombes - John

Hi John,
That's good to hear as the Coombs may be the first one of the list I tackle (if I live so long.) I know about the problems with the Corliss engine, which is a shame, given the quality of the other Southworth engines.
Regards,
Harry

 

[cfellows]

I have the castings for the Sanderson Beam but the drawings have faded to the point where they aren't really readable. Any idea where I can get a fresh set of drawings?

Chuck

 

[GWRdriver]

Chuck,
I'll be sending you a PM.
Harry

 

[Jasonb]

I know someone who has just done the Stuart Major Beam, said every casting was chilled and went through about £200 worth of tooling in the process of machining.

Video of it in this post on Traction Talk

Jason

 

[GWRdriver]

Jason,
I'm sorry to hear that because as most of us know Stuarts was always known for the machinability of their castings, but I'm not surprised because I hear similar treports from all over. The Major is a very large investment to make in castings which turn out to be that difficult to machine. I started a Double Ten a while back and the box-bed was chilled, but everything else seemed to be OK.

 

[BAH101]

Could you please explain what you mean by "chilled"? Thanks

 

[zeeprogrammer]

I'd like to know a little more about chilled casting too. I looked it up and it seems to be a process where the iron is chilled (cooled) when cast. The article says this results in a hard exterior and tougher interior. I'm not sure how that happens - in particular how you get a tougher interior. But I'm also interested in what this means to the model engineer. Is it something to look for? Or to look out for? And why? Thanks.

 

[GWRdriver]

Bah,
"Chilled" is a condition that occurs when cast iron has cooled too quickly in the mold and is left in a hard, brittle state. I will spare you the chemistry involved but it involves the unequal distribution of carbon within the metal. Chilling most often occurs locally, rather than throughout a casting, and the result is the dreaded "hard spot" which can be glass hard. When the condition is spread throughout the casting this is said to be "white iron" and can be intentional in industrial usage depending upon need.

Since model castings typically have relatively thin sections in places they are especially proned to chilling since the thin sections will cool faster than thicker areas, and to Zee's question will cool on the skin faster than on the interior. Sometimes this doesn't affect the machinability, such as if the chill occurs in the spokes of a flywheel or other surfaces to be left as-cast, but if it occurs say on or in the rim it can make getting a good finish very difficult. Stuart used to trade on their claim that their casting were soft and easy to machine (and they were), and was a welcome attribute because the castings of other suppliers were often not so soft. As I heard it Clarksons (R.I.P.) had a very poor reputation for casting quality.

Most times the solution to a chilled casting is to anneal it by heating the casting slowly to critical (red?) temperature and bring it down slowly, which is what should have been done in the first place. This takes time however, and costs money for the manufacturers, which they would pass along to us, and very few model engineers have heat-treating gear. Occasionally the wife might have a ceramics kiln which could do the job.

 

[bearcar1]

I own a set of the James Coombes engine castings and drawings and have not found any problems in the dimensions or the the castings, of course I am far from completion, but at this stage, all seems to be OK. This particular set of castings has some age on them, the grain seems to be just a bit finer than some of the 'newer' items that is currently being sold by Stuart.

BC1
Jim

 

[kellswaterri]

Yes ''Chilled'' is what I forgot to mention with regard to the corliss fly wheel...comes in two halves and when machined and bolted together finishes at 10'' diam. doing the two mateing faces was a starter for ten warning as I had to take about 1/16'' off each face...I then had to make a packer to bring the two halves to round when bolted together [funny thing the full size corliss has a packer just the same]...cutting the outside diam. to size wrecked a couple of carbide tipped tools before we decided to spin the flywheel with the added attention of an angle grinder to break the very heavy skin, once through that every thing was fine...the machining of the three parts of the bed frame for the engine went well only cutting where needed and ''fettling'' elsewhere due to very low tolerances.
John.

 

[BAH101]

Thanks, learned another new thing today. Better slow down the learning, don't want to learn everything too fast

 

[Chris W]

I have a set of Coventry compound castings and prints that I picked up from Cole's several years ago. It will be a few more years until I get around to starting on them so I can't vouch for the accuracy of the prints. I would be interested in hearing what you come up with for errors.

On another note, I had a Stuart twin launch cylinder casting that gave me fits due to hard spots. I had to scrap it but was lucky enough to find a good raw casting on ebay for a reasonable price.

Cheers, Chris

 

[GWRdriver]

I have a set of Coventry compound castings and prints that I picked up from Cole's several years ago. It will be a few more years until I get around to starting on them - Cheers, Chris

Chris,
Same here. I've not yet built an H.Coventry project but my guess is that problems will be minimal. He had years to proof his designs and revise his drawings but I've heard virtually nothing about recurring errors. I met Mr Coventry at a steam meet in Florida the late 1960's and we subsequently corresponded. He was a gentleman in every sense of the word and treated everyone just the same whether you were a grizzled veteran live steamer or a green kid.

 

[DougLanum]

Harry,

I too have built the Stuart James Coombes Table engine.
As I recall, there were no issues and it is a nice running model.
It always draws attention at a show.

Doug