Xrad's Stuart Triple

[xrad]

Bought this off ebay. The seller was super with fast shipping and great packing. The engine had many faults which probably happened ove time. Not to blame anyone, just describing them and the fixes.

Most of the original machining was excellent. Super smooth cylinder bores, perfectly fitting upper and lower covers, pistons and rods perfect. Base plate perfect. all cover holes and tapped block holes perfect.

Some issues included:
crank bent in more than one direction in more than one section.
Original parts stamped for position, but many in wrong positions
Mixing of BA and USA threads
Slide valves incorrect size and in wrong position
One broken piston ring (HP)
Missing many little parts
H2O pump scored internally
Pump holes drilled in wrong position
HP rod journal angled by 6 degrees from crank centerline, other two OK

Repairs included cutting out angled rod pin and drilling and brazing in a new 3/8th pin. Straightening crank which took about 3-4 hours and is now within 3 thou along the bearing length. 3-4 thou at crank end tip. Replacing all parts into appropriate positions and reaming the journals. Installed oil cups. All main components now function with just minimal drag. All slide valves now have smooth surfaces and slide very nicely.

will finish up over next few months for install into 60 inch trawler. Have a large chelston model boiler and large stuart boiler...will see which one works better. Chelston is coal fired and would need a big burner. Also have an external H20 pump and hand pump for boilers.

At one point I was considering a new crank . There is a gentleman in England who does cranks to order and was very fast to reply by email. If anyone needs one, he may be able to help you: type 'jim1kent ebay' into search bar. you will need ebay account to contact him.

 

[xrad]

Unfortunately, even though I have resized my pics to less thn 640x640 and have tried several different files extensions and types, I can get them to post. Maybe I need to have more than 10 posts or something..anyone know?

 

[xrad]

trying another pic. these work...don;t know why I can't load my jpg/jpegs

 

[Lawijt]

That boiler looks really great.

 

[xrad]

Thanks. I think they (Chelston Modelers) made them in the 80's of a limited run. Out of business now...
It is thick walled and of excellent quality. Whistle valve. Coal firing valve. cast Iron grates and door. Very heavy duty. All the seals were dried up and leaking..no big deal. Pops at about 90-95 psi.

I have 25 lbs of anthracite waiting for a cold day.....

The Stuart is a 1035 from a while back. It is not nearly as heavy duty in construction but steams in ~8-10 minutes with butane/propane mix.

 

[xrad]

Update:
The following was performed:
1) Fix crank pin , brazed and pinned in a new one...much effort
2) All valve surfaces were polished to 400-600 grit
3) all valves polished
4) slide valve face recut on all three to correct port size
5) IP to LP copper pipe and fittings made
6) tedious measuring of all eccentric straos and eccentrics and correctly positioned on crank
7) silver soldered all eccentric rods to straps after correctly lengthened
8) Set all valve rods to correct height (IP was not easy and probably is still off a little)
9) made thin gaskets for all sealed surfaces
10) packed all six rod holes
11) replaced and tapped countless holes and screws (BA and US as this engine is a mix)

The BIG ISSUE was that the whole head was canted by about 30thou throwing off the piston rods to crank alignment. It took a few hours of shimming to get everything aligned because the rod link control rod bushings were each milled a little differently. Now the head sits within 1-3 thou across its length in relation to the base. Of course, then all of the rod guides had to be repositioned with shims too.... fun, but tedious....

12) set timing as follows: On my engine, eccentric rods are crossed at BDC and open at TDC and all are in same order down the crank. Even though the LP valve is opposite the other two, this does not affect the eccentric or strap position. Then, all set screws are 90 degrees to the crank at TDC each corresponding cylinder. You will have to play with the set screws and add few degrees advance or retard as needed. These are set with the HP cylinder to the right and the LP to the left. Set screws face you. Look at the pic for strap/rod set up.

she runs OK on 30-40 PSI. There will be much fine tuning and more building to come.

SEE the first run on steam!
[ame]http://www.youtube.com/watch?v=1K-2Ob2kqvQ&list=UUYQskpmHyALB5hsentYB_6g&index=1[/ame]

at bottom is original ebay engine

 

[xrad]

Picked up my 60 inch hull form Carl of Microglass today. He was very nice. we met half way in Erie PA. Hull is beautiful...but...a hair too small for the triple expansion engine. Plus, I did not want to run engine as a single/double or single/single/single because the engine definately runs worse in these setups. It runs very smoothly as a triple the way it sits now. I plan to use a twin marine stuart engine for the job. pics to follow....

 

[xrad]

cut a new screw for the reach rod lever. Original was damaged and cut at 24 threads per in, new one per plan at 3/16 x 20. I added a few extra threads.....

Cutting these threads was not difficult, just change the cutting gears. I lost my thread dial so I had to eyeball the start point(using a magnifying glass and a mark on the part. The key on my machine was to realize that the travel mechanism had some play(about 1/2 a thread cut). I had to remove the play by cranking the travel handle opposite screw cut travel. Had to try this three times. One bad cut before I found the 'play,' one pretzel, and one good one.

Also mad a new HP to IP copper pipe as the original was a little crushed....

 

[xrad]

update: designe a surface condenser. Basics done......

I can get her to run great at 25 psi in one direction...not so well in the other. This will probably end up as a display model so one direction is fine for me.

Hard part is designing an oil seperator so I can run a closed loop system, or maybe I will use the heated water from the condenser chiller circuit as fresh boiler fill......

 

[xrad]

Stuart triple a little too big for my tramp steamer. FOund a nice replacement from station road steam. A stuart twin marine (not compound)...very nice people at Station Road Steam, FAST shipping.

[ame]http://www.youtube.com/watch?v=ny_MEHWgLDg&feature=c4-overview&list=UUYQskpmHyALB5hsentYB_6g[/ame]

 

[xrad]

Hi everyone, had some time last evening to make a sil soldered condenser for the triple. 21 3/16 tubes giving a surface are of about 40sq in. Had to redesign the Stuart vac/water pump because the piston and the ports as designed di not work well. Solved by drilling four holes through the piston and adding a thin brass disc on the rod side a valve. held down with just enougn play by a silicone band cut from model fuel line. There is a second valve up higher. So now the pump really does work well.

tap cold water in to BOTTOM of condenser (so that you know it fills completely) and drains out top. Still in mock up but really functions well. the engine definately runs better with the comdenser. Also, I can maintain 50 psi in the boiler while running the engine at about 120 rpms(using very little steam compared to the stuart double); it will run for hours at about 10-15 psi

deflector on top of condenser pipes distributes steam. clean out ports at each end. Can't really clean out the steam side, but it would take such a long time to build up enough goo so I don;t worry about it.

The incomming cooling water probably about 50degrees, and outging coolant is mild to moderately hot at low speeds. High speeds, it gets hot...so condenser seems to be designed at about the right surface area. Also, when running full on, the pump is really pushing out condensed steam, and only spitting at low speed.

the condenser ends and inside braces are machined 2 inch bronze water pipe fittings. not made for any significant pressure, but I don't have to worry about that.

some Utube vids:

[ame]http://www.youtube.com/watch?v=9TlwleHfXdE[/ame]

[ame]http://www.youtube.com/watch?v=AUlyQP11JYI[/ame]

 

[Rivergypsy]

Very nice work - I like it!

You're making me want to get moving with my compound too

Dave

 

[xrad]

Thanks Dave,

I don't have the proper stock to make nice brass end rings for the condenser so I had to use what was available. I am more of a build to function first and form second......

Gentle sloped exhaust pipe, .25ID into condenser and .1ID outlet to pump. Uses about 1.5L/~20min of water at full gravity flow, which can be adjusted with addition of a valve. May use heated coolant water as boiler fill. Condensate to waste container. Maybe an oil separator down the road? maybe a radiator and pump to cycle the cooling water...will see......

 

[xrad]

Built a simpling valve for the triple. Basically a branch off the HP line after the lubricator. Runs straight into the LP chest. Can control pressure/flow with the needle valve. Works GREAT to start the engine. As soon as she warms up, it becomes counterproductive and will actually slow the engine. It seems that valve timing is pretty good for triple expansion and not so good for triple double action. May be timing, may be that the pressure is now against the lower pressure IP cylinder.

The real benefit is that I hardly have to turn over the flywheel by hand to get her going. As soon as the water squirts out of the cylinder, tighten up the cocks and the simpling valve and away she goes. I was reading a marine steam book last night about condensers and triple expansion engines. Although this triple runs well at 10-15 psi, it runs really well at 50 psi with the main throttle valve just cracked. Seems that ~50psi is nearer to what a triple expansion needs in terms of steam expansion...rather than 10-20. Makes sense.

 

[xrad]

Building a Tramp steamer model. As the triple is more difficult to run, I am going with this ST twin launch engine. Did some work to her to get her in better shape. Before and after pics top and bottom. More to do....

Also have a better and bigger burner for the stuart boiler. Uses a touch more gas...maybe has a big #8 or small #9 jet...maintains 60psi longer and better with the low effeciency twin....

 

[xrad]

New drip oiler manifold with preheating by exhaust pipe.

 

[xrad]

Finished the oiler. Works very well for mains, not so much for the straps and crosshead pin. These get a startup oil shot anyway so no big deal. Fun to build.

[ame]http://www.youtube.com/watch?v=8vS_iotWU24[/ame]

 

[xrad]

repaired a water pump. Bought from a nice guy named Vern who lives in northern plains area. Pump needed some repairs including removing all the expanded gasket goo, and repairing of a valve rod. Ball valve surfaces needed some cleaning.....

It is a steam hog and may be better on my 3/4 Northern rather than the trawler....

http://www.youtube.com/watch?v=HfBsafxi12k&feature=youtu.be

 

[xrad]

Well.......the Sweden burner was a flop. I got it to burn well but it jumped from the end to the jet and would then cycle with a popping sound. And then I added the smoke stack and it ran like crap....so....time to build my own burner.
It is 1.5 in wide and about 4 inches long. Solid brass base and thick brass tube. Screen mesh just inside of the stainless perforated end. This keeps the flame from jumping to the base port. The base port flares 20 degrees for mixing gas and air in the brass tube before burning. Lights easily hot or cold. uses number 8 jet(and uses no more gas than my smaller 3/4 in burner also a #8..hmmm...maybe I need a smaller jet on the smaller burner). 4-40 set screw.
Might have to build a surrounding guard so as not to draw too much cool air into boiler when firing. about 1/4 inch gap around the burner.

see vid:
http://www.youtube.com/watch?v=Z09Bvdtlmu0&feature=youtu.be

 

[xrad]

Did some lagging today. Used 3/4 character hickory left over from flooring, ripped down to a 1/4 plank and then ripped to smaller pieces. Honed a curve on the backside but was too lazy to bevel all the edges. Went with a thicker cut for strength and looks. Brass straps.
The wood has a very tight grain and is strong and cheap. A few drops of CA glue to hold position while the bands were applied. Blue mark applied to inside of curve so that I stained the correct side.

stained and oiled...no poly or anything on top...just let a natural aging occur..

I was just looking at micromark's nickle plating kit. I should have plated the cylinder head and valve chests to avoid the rust back when it was all apart. I will have to make an air compressor valve attachment to blow out the engine after running. Anyone else do this?