Compound Condensing Engine

[Helder22]

Thanks Paul,
I'm not really sure how long it took me to get this far with them. Probably too many lol. They aren't finished yet actually. lots of bits and pieces are still missing.

Helder

 

[Rivergypsy]

Trust me, a lot!

 

[Rivergypsy]

Hi Helder,

Just out of interest, how had you planned on constructing your engine - castings or fabrication?

Dave

 

[Helder22]

I actually wasn't sure yet. I was thinking about it as I was drawing. I was pending towards fabricating the columns/condenser I think. Maybe CNCing the condenser and attaching it to the columns. I knew the cylinders would have to be cast because of the the steam passageways. The majority of the other parts I could probably CNC.

So are the castings that you guys are making (I'm assuming its you who is selling these : http://www.steamlaunch.com/engines/engineers.html) ready to ship out or is everything still in the testing phase? Its not really clear on the website.
Fantastic work by the way!

 

[Rivergypsy]

When I started drawing this up, I had a start at fabricating the bedplate from stainless steel, with upper and lower plates, with columns between them that were slotted to accept the webs. I gave up on that idea pretty swiftly as it was a complete pain in the proverbial and would take an serious amount of heat to even start to solder, not to mention the distortion. that's why the project never really took off until Pete put me in touch with Dennis of Historic Models and Reproductions.

The website you've quoted is who a lot of us tried to obtain castings from but struggled to even get a reply from. It is based on the same engine, but with some differences, such as the split cylinder block you can see in their photos.

Dennis email address is :- http://www.historicmodelsandreproductions.com/

I would like to stress again that I've no financial interest in this; we're just working together to get this model back to life. And he's a top bloke too

Here's some more progress on mine - the rods have been bored and profiled in line with the bores, and then turned through 90 and the slot for the piston rod profiled. The first roughing op on the piston rods is underway from some 25x50 316 stainless, to bring the rod down to 11mm initially, plus I'm pushing on with a design for a thrust box for them, which Dennis is going to cast, and may even be of use to owners of Stuart & similar marine engines to help put them into full marine use.

 

[Rivergypsy]

Well the 'rods aren't too far from completion now, with just fettling, cap profiling and the 2nd half of the oil drilling to do, and to be honest I'm very happy with them.

I also found some hex stainless on EBay for reasonable money to save the tedium of milling hexes (life's just too short for some jobs!), so here's the first fasteners - the nuts for the front columns, with M8x0.5 threads, domed tops, and a lower relief to the hex so they don't rip up any paintwork.

Next job - finishing the crank...

 

[Rivergypsy]

And some more connecting rod and piston rod progress ;D

The piston rods are currently +1mm on all faces, but once they're totally roughed I'll dump them in a corner for a week or so for any stresses to (hopefully!) come out before final machining.

Next job should be finishing the nuts & bolts before fitting the main bearings...

 

[Philjoe5]

Really beautiful work. It's a joy to see this kind of workmanship.

Cheers,
Phil

 

[Rivergypsy]

Many thanks, Phil! Dave

 

[Brian Rupnow]

You do beautiful work, even if you do set yourself on fire occasionally!!!---Brian

 

[Rivergypsy]

LOL!! Thanks Brian!

So far, so good on the flammability thankfully

Dennis is nearly ready for another foundry trip, so more progress soon...

 

[Rivergypsy]

Ok, well I've not got a lot of machining done lately, but that because we've come up with a cunning plan for this model - we've got a copy of some Filer-Stowell engine plans, and these include the thrust block (plus a lot more!) so we've decided to model it in SW and then scale it down for the compound engine model. I'll be doing the drawings, and then Dennis the castings.

Here's the near complete block as modelled, and then a scaled version sat behind the compound ;D

 

[Rivergypsy]

Oh, and I forgot to say - we're going to be doing our best to implement the full water cooled, Babbitt faced horseshoes and the oil cooling on this one

 

[Rivergypsy]

Well, the material was there, the lathe was free, so I thought 'what the hell!' - here's the thrust shaft roughed to 1mm all over to get an idea of how it looks next to the crankshaft. By the time the turning gear is in between them we should have quite a beast here ;D

 

[Rivergypsy]

Here's a job I've been putting off for too long - finishing the crankshaft. There's a lot more castings coming back from the foundry soon, so I thought it was time to get this one out of the way. An hours machining has got the big ends roughed, so next week it's time to make a fixture to throw it 1" off centre...

 

[Rivergypsy]

And here's the latest condenser castings which Dennis is shipping today - a lovely bit of work that I can't wait to get my grubby little hands on! woohoo1woohoo1woohoo1

 

[Rivergypsy]

Well, what can I say? Dennis has really excelled on this casting – I couldn’t help but run down to the machine shop with it after it arrived this morning, and it cuts like an absolute dream. The squareness of the casting is beautiful too, as when I referenced from the flat rear face I only needed to take 0.3mm off of the crosshead guide faces to clean them up completely. There’s going to be a fair few hours’ work in this, but if the rest is as good as this then bring it on ;D

 

[Rivergypsy]

And the last two pairs of reference faces cleaned up, so now time to take some accurate measurements and work out how best to start finishing this to size. I know I keep banging on about it, but this is such a pleasure to machine

 

[Rivergypsy]

And more machining on the condenser casting - 5 out of six faces are now to size and have cleaned beautifully. Just the face carrying the crossheads to go, then we'll be thinking about some drilling

 

[TimTaylor]

Awesome project and beautiful work! I'm looking forward to seeing more as this project progresses.

If I recall correctly, there is a full size 2 stage condensing steam engine similar to this in one of the Smithsonian museums in DC.