Stuart Triple new build

[anday1]

thanks for that andy
i am looking to make the ip eccentrics and crankshaft out of solid bar using 2 separate throw pieces which i will align each end and help with jacking the crank to support it through making it. would you know the co-ordinances from the 120 degrees throw as i will center drill on the mill the 6 centers (each clamp) out of round bar and clamp both ends to the crank and turn between centers. hope this makes sence!!!
Regards
Andrew

 

[anday1]

Hi Bob
If you start this build I am happy to help any way I can
Cheers
John

Hi john not sure you could help with the measurement on the crank for the ceters machined the mill

 

[Steamingandy]

would you know the co-ordinances from the 120 degrees throw as i will center drill on the mill the 6 centers (each clamp) out of round bar and clamp both ends to the crank and turn between centers. hope this makes sence!!!

The crank throw is 1/2” at 120 Deg and the IP cams are 5/32” throw at +- 105 Deg from the IP crank, it will certainly complicate the manufacture of the crank shaft good luck with that not for the faint hearted.

 

[Emers]

I have a question for everybody. Has anyone had a Stewart Triple running on steam

 

[Steamchick]

No. But I have run a compound twin on Steam. MUCH better then air.
Procedure,
Turn ON steam supply slightly, and turn engine over so it gurgles and pumps condensate out... There is a lot of metal to heat before this will run so a lot of condensate ,,,,, I start when the boiler is below running pressure - e.g. ~5psi on gauge.

When the exhaust is not producing a lot of water (An hydraulic lock can seriously damage engine components! - So must be avoided!) you can open the supply a little more and the engine will kick - stroke by stroke - showing you it will not hydraulically lock - IF you have warmed it adequately. Maybe the boiler has reached 10 to 15 psi by now....
When if feeels ready to run open the valve a crack more until it runs SLOWLY on the HP cylinder.... at ~15~20psi.
After running for maybe 5 to 10 minutes, (~15~20 psi) the engine will pick-up speed - a step-up, not gradual increase - showing a LP stage is hot enough to start doing some work.
I can then open the valve further if required - and notice the (LP) wet exhaust is just a spray of water. (Unless the exhaust is connected to an oil-water trap or separator),
ANy use?
K2

 

[Jens Eirik Skogstad]

Here is the picture who tell more than I can write here. How to machine the excenter in 2 parts.

 

[Jens Eirik Skogstad]

Still more..

 

[steamedlou]

I've only run my triple on steam. Never could get it to run on air. Takes me a long time to get it going using about 20 psi. Before the condenser gauge quit, it actually registered 15" of Hg when running cooling water. Mine only runs well in one direction no matter how many hours I've spent making adjustments. Tired of fooling with it! Going on the shelf for display only now that it's pretty and mounted on a board.

 

[Jens Eirik Skogstad]

Discovered that the photos are not in the same order, but you will probably find it eventually..

 

[anday1]

Discovered that the photos are not in the same order, but you will probably find it eventually..

View attachment 155360View attachment 155361View attachment 155362View attachment 155363View attachment 155364View attachment 155365View attachment 155366View attachment 155367

Thank you for taking the time to show these much appreciated. i am assuming that you would not try to make the IP eccentrics with the crankshaft?

 

[Mechanicboy]

Thank you for taking the time to show these much appreciated. i am assuming that you would not try to make the IP eccentrics with the crankshaft?

Much better to have the 2 part IP eccentric sheave instead the IP sheave with crankshaft in case there is faults with the crankshaft in case bend or twisted. The crankshaft is not so easy to machine straight from the steel bar. My crankshaft is build up of a lot parts and silver steel shaft. Build with locktite 648 and steel pins with locktite 648 applied and mounted in the holes without force. The 2 part IP eccentric sheave can adjust in degree to get correct centered and sideways. Use jig to produce the eccentric sheave in right degrees in both ways. Save much time.

 

[anday1]

Much better to have the 2 part IP eccentric sheave instead the IP sheave with crankshaft in case there is faults with the crankshaft in case bend or twisted. The crankshaft is not so easy to machine straight from the steel bar. My crankshaft is build up of a lot parts and silver steel shaft. Build with locktite 648 and steel pins with locktite 648 applied and mounted in the holes without force. The 2 part IP eccentric sheave can adjust in degree to get correct centered and sideways. Use jig to produce the eccentric sheave in right degrees in both ways. Save much time.

have a look at one i made..this was cut in half for a center bearing

 

[oldengineguy]

Never had mine running on steam as I do not have a boiler. Found that making the IP eccentric with30 degree separation worked much better than the 15 degrees called out by Stuart. The only way I could get this engine to run in reverse was to make separate eccentrics for the LP cylinder and time them individually for the best performance. After a lot of "fiddle and fart" the engine runs fine forward or reverse on about 15 psi. I made my crankshaft from pieces loc-tite and pinned . Seems to work O.K. Will look for pictures.
Colin

 

[Steamingandy]

I have a question for everybody. Has anyone had a Stewart Triple running on steam

I am going to run these on steam, they run fine on air but I need to sort the pipe work out.




https://youtu.be/LwgAAgHrEyU?si=TP0ubB9r2y_ebRWD

 

[anday1]

This is the method I used on the three I have done and they all ran first time, hopefully it makes sense.
Assumptions: The cams are machined to the correct throw and angles, check HP 30deg IP, LP 15deg and the cylinder ports are machined to the drawing and if not possible compensated in the valve.
set the cams to sit equally to the appropriate crank (pictures)

HP cylinder, with the exhaust/transfer pipes removed and drain cocks open feed a few pounds of air to the inlet of the valve chest.
Determine what direction the engine is turning with the expansion link in current position by turning to TDC and find the direction the valve rod drops (direction of rotation)
Turning in that direction only listen when the air just starts to enter the cylinder and make a note of the position of the crank compared to TDC now continue to turn (in direction of rotation) and note the position at BDC, these positions need to be equal, set by adjusting the length of the valve rod, just the one driving the valve.
Now move the expansion link to use the other cam, turning in the OPPOSITE direction repeat the process.

IP cylinder, attach air to chest inlet without moving the expansion link turning in the direction of rotation at TDC check the valve is DROPPING if not swap the valve rods at the link end, now equalise as before move the expansion link and repeat equalisation.

LP cylinder, attach air to chest inlet as before but remember you have now turned the engine round and last direction of rotation is reversed.

Hopefully this makes sense if not maybe I can take more pictures

HP cam setting

hi
is the drawn picture the relation of the HP crank to the IP eccentrics? if you can show some more pics that would be really helpful

Andy

 

[Steamingandy]

hi
is the drawn picture the relation of the HP crank to the IP eccentrics? if you can show some more pics that would be really helpful

It is the relationship between the journal and their respective eccentrics, because the eccentrics are made together and the engine is reversible the eccentrics need to be set equal to the respective journal. I have found that as long as you have machined to the drawings and any irregularities in the ports have been compensated in the valve they will run in both directions happily.
I have actually keyed them in this position.

 

[anday1]

It is the relationship between the journal and their respective eccentrics, because the eccentrics are made together and the engine is reversible the eccentrics need to be set equal to the respective journal. I have found that as long as you have machined to the drawings and any irregularities in the ports have been compensated in the valve they will run in both directions happily.
I have actually keyed them in this position.

Penny has dropped as you show its the same for each crank....many thanks ..build starts next week so it will be some time before i get to crank but i will keep an update coming through
all the best
andrew

 

[Steamingandy]

Penny has dropped as you show its the same for each crank....many thanks ..build starts next week so it will be some time before i get to crank but i will keep an update coming through
all the best

This was my build might give you some ideas

 

[anday1]

This was my build might give you some ideas

wow there are some great tips there ....i may lean on you in the future if thats ok
many thanks
andy

 

[paulrayner]

This was my build might give you some ideas

Fantastic