Stuart Turner Launch engine con rod.

[rhitee93]

Thanks for posting the pics. That is some nice work you have done

 

[KBC]

After finishing the cylinder lagging and all the pipe work it was time to time the engine to fire it up on air I discovered that it was impossible to time the engine, so in speaking to a friend who had built a launch engine he suggested that I check the cylinder ports and to my horror they are way out.
Of all the Stuart engines and pumps that I have made, this being the first launch engine, I have always found the castings to be very good and accurate but the casting of the ports on this one is poor.

To over come this I am making plates from 1/16" thk gauge plate with accurate ports and will plant it between the cylinder face and the steam chest with a chemical filler paste to prevent leakage between the inlet and the exhaust.

Here is a pic of the cast ports which now that I have found out that they are wrong look enormous.

Any other suggestions would be appreciated.

George.

 

[KBC]

Engine now completed with the Gauge plate inserted between the steam chest and the cylinder casting.
The Stevenson gear now worked , although not very well in reverse and on further investigation it was found that one of the casting for the eccentric sheave was incorrectly cast so a new one was made from a piece of cast iron that I had in the scrap box so all is now well and it's a great running engine.
I must say that it's a sorry tale of very poor castings from Stuart and they would have been returned if I had bought them from Stuart but as they were bought on e-bay the mods had to be made, however it was a learning curve and a warning to check everything against the drawing.
This forum has been an inspiration to me as I am not a machinist and the quality of the work on view has been a great help in trying to emulate the workmanship on view.

I now only have to make an engine driven pump to finish the engine off.

George.

 

[vcutajar]

Well done George.

Vince

 

[Hilmar]

Georg,
on the launch engine, I wonder if the castings where original from Stuart Turner.
On the print from Stuart the valve cover shows only four screws for hold down ,also the cover
has no " S "cast into it. On my castings;" I bought from some one on the web not E Bay" they also lousy castings
and the dimensions are odd and the same just as yours and no 'S' also. They look like a copy.
What do You think.
Hilmar

 

[rhankey]

Georg,
on the launch engine, I wonder if the castings where original from Stuart Turner.
On the print from Stuart the valve cover shows only four screws for hold down ,also the cover
has no " S "cast into it. On my castings;" I bought from some one on the web not E Bay" they also lousy castings
and the dimensions are odd and the same just as yours and no 'S' also. They look like a copy.
What do You think.
Hilmar

Hilmar, I have a twin compound casting kit that I hope to start in the next few months that was cast around 1960, and it also lacks the ‘S’ in the valve covers. My old drawings show 4-corner bolts as you describe, but no 'S'. I wonder if/when Stuart ever did include the ‘S’ in the launch/compound engines?

George, I certainly can empathise with the challenges you had with building your twin launch. I’m about 75% along with a triple, being built from modern Stuart castings, and I am also dealing with the same very crude, sand encrusted blobs of metal as you had to. The cast iron has numerous cold spots, and the gunmetal is usually undersize in at least one dimension and I have uncovered a number of hidden holes. The cylinder heads which I’m working on currently, are giving me some challenges. With such poor quality castings I wish Stuart didn’t even bother including the valve ports in the castings, as I’m going tohave to spend much more effort trying to salvage their misaligned and sand filled ports rather than simply drilling/milling my own very precise ports.

I am not sure when Stuart started producing much poorer quality castings, but the difference between their current castings and their older castings is night and day. The castings to my old twin compound kit are gorgeous, crisp, smooth, highly detailed and accurate castings, none of which require any clean-up before they are machined. The same is the case with a Stuart/H.A.Taylor Undertype casting kit from around 1970 that I will be starting after the twin launch.

Robin

 

[jrogertaylor]

I just finished a beam engine from castings I bought from ST about 30 years ago when they were still in England. They were excellent. But they have moved at least twice and been sold since then.

 

[KBC]

Hi Vince,
Thanks for that.

Hilmar,

I think that one of the problems with Stuart is that they don't do their own castings but farm them out and over the years have tried a few foundries, some successful others not and this is why there can be a difference in cast iron quality.
On the Launch engine drawing it shows a 4- bolt fixing on the steam chest cover but on the drawing for machining the Stevenson reverse gear it show an 8- bolt fixing, this is why mine has the 8- bolt fixing.
The figure 'S' on the cover is only on the 10V, 10H, D10 and Score engines, whereas the Launch engine, Compound engine and the Triple Expansion has a plain cover, I think some of the bigger engines may have the 'S' cast in.

Robin,

I have over the years built many D10's, 10V's and steam pumps with no great complaint on the casting quality but this lot are quite frankly a disgrace and one can only hope that the new owners can get their act together and produce some better castings.

As an Ex design draughtsman/ engineer I can also comment on their drawings which are quite pathetic and in particular how you are supposed to machine the double eccentric sheaves for the reverse gear to the drawing beats me and for other machining there is not one Datum line to work from which I must add is common on all of their drawing for other models.
The drawing for the engine without reverse gear is dated 1972 and the one for the reverse gear is dated 1955 and they have the nerve to charge £20 for them.
Like you I wished that they had not cast in the ports which would allow you to mill them out correctly.

All in all it has been a challenge but I was determined not to be beaten and made a few mods along the way, i.e. the bearing blocks, steel con rods and the drag links for the reverse gear, did away with the grooves to hold the eccentric sheaves in place by making then plain with a flanged end and the main thing being the gauge plate with new ports, now just a boiler feed pump, will post some pics when completed.

Thanks to all who helped in my early en devours.
George.

 

[Hilmar]

George,
You said that you made a cover over the valve ports, did you glued it
in or just let it be loose and how thick did you made it?
Hilmar

 

[KBC]

George,
You said that you made a cover over the valve ports, did you glued it
in or just let it be loose and how thick did you made it?
Hilmar

Hilmar,

I used a piece of gauge plate 1/16" thk but didn't harden it, just polished it with very fine emery paper.
I smeared the back of the plate with Hermetite green gasket sealer, which goes hard when cured, put the plate onto the old face with the out of line ports and bolted it up with the steam chest casting without the cover on and with the point of my scriber cleaned out the excess sealant, repeat to other end and leave for 24 hrs.
When I undid the nuts and removed the steam chest casting the plate was very firmly stuck on, to date there has been no leakage between the steam inlets and the exhaust out let.

The green Hermetite sealant is very high temp, I use it on my Flash Steam engines to great effect, it can be purchased from some Auto shops or Engineering supply companies.

George.
Pic of the sealant.

 

[KBC]

After all of the trials and tribulations on the Launch engine its almost there.

I have made a boiler feed pump from the scrap box and mounted it on the side of the base plate but I am not too happy with it as its difficult to get a good screw fixing and the long reach of the pump ram from the Scotch crank isn't too good so I am about to change the drive system to a cam on an eccentric with a stronger bracket fixed to the Ali base for stability, I will post pics when the big FINAL day arrives.
The engine now runs very well on forward and reverse, still a bit stiff to turn over by hand but runs well on 20 p.s.i of air.
Next thing is to make a new boiler as at present I don't have a test boiler but can run a feed from my steam tug boiler for a trial.

George.

 

[vcutajar]

Wow George that looks awesome. Hang in there.

Vince

 

[compspecial]

Its great to have you with us George! and may I say you have had such an interesting life, I am fascinated by the millwright part, does that mean wind and water mills?
Stew.

 

[KBC]

Its great to have you with us George! and may I say you have had such an interesting life, I am fascinated by the millwright part, does that mean wind and water mills?
Stew.

Hi Stew,
Thanks for the welcome, Millwrights were the guys who maintained flour mills where all the local crop growers brought there grain to be milled and they had to be Jack of all trades as they were the only maintenance men employed.
I served my time in the largest Flour and Provender mill in Scotland at the time which was situated on the Clyde near the city center, just as I had started Clydeside dictated " one man for one job " so the mill employed joiners and electricians as well as us maintenance fitters but the original Millwrights did the joinery, electrical and engineering work.
I was trained in the maintenance of flour milling machines and cattle food machines, it was a dirty oily flour covered business and in those days there were no showers so at the end of the day it was a quick wash at the cold tap, a change into my cycling gear and a 30 mile training ride back home ( we were bred tough in those days )
As far as I am aware today Millwrights are employed in the large machine shops to strip down and repair any type of manufacturing machinery, Lathes, Mills e.t.c. not sure about the car industry with all of the Robotics.

I hope this fills you in a little bit on Millwrights.

George.

 

[KBC]

I think that I started this engine some time late Jan this year and has it been a trial !!
However at last I can say FINISHED and I am pleased with it's running performance.
I have changed the boiler feed pump arrangement from Scotch crank to eccentric drive as I wasn't quite happy with the drive, now it works to my satisfaction.
Pump is 1/4" dia ram x 1/2" stroke to 5/8" stroke adjustable via the pitched holes on the drive disc.

I will now need to think about my next project which certainly will not be another Stuart Launch engine.

Thank you for all of your help and comments along the way.

George.

 

[Alec Ryals]

Hello,
Beautiful work. im building one also but my drawing of the reverse fwd brass bracket for the cross head slider got destroyed and was wondering if you could post a photo of it
Thank You
Alec Ryals

 

[KBC]

Hi Alex,
If you would send me your mail address I can take pics of what you require, I am afraid that the drawing is of such poor quality and being so large I can't scan it but I can take pics for you, please don't post your e-mail address on the open forum.
I see that you are also enquiring on R/Cgroup forum and you mention eccentrics I will do them for you as well,
Regards
George.

 

[David Shealey]

This is a pretty old thread, but glad it is here. I am picking up with one my Dad started decades ago, but he never got past the base and main bearing caps. He machined the bores larger and put Babbitt in for the bearing surfaces. He did not get the bores centered well, and the babbitt is off center. The crank bores are centered though. It is only a cosmetic issue. I was toying with machine it out even larger, but centered and re-casting the babbitt, but the bearing surfaces are good, so I will probably just leave it that way. I do like your flanged eccentrics better than the Stuart design, so am doing that. Using 303 stainless for them. The casting kit my Dad had did not include the Reversing assembly, so I am doing all those parts from bar stock.