Trivet Engine?

[Tony Bird]

Hi,

Today I continued making the cylinder and fitting it to the engine. An aluminium plug with a hole the size of the piston rod was used to line the cylinder up with the beam. I hope the the photo graphs show how the cylinder was made. Any question please ask.

The Hexagonal brass tube was cut to make the base of the cylinder.







The base was soldered to the cylinder tube and machined.



Steam passageways were drilled.




The cylinder fitted to the engine.





As of 5.00 pm this evening. There is still quite a bit to do fit the K&S brass tube liner, cylinder covers and piston have to be made and the valve connected to its actuating rod. Some pipes will need to be fitted to the port block/cylinder support and some tidying up of screws etc.

Regards Tony.

 

[Tony Bird]

Hi,

A video of the part complete engine being turned over by an electric drill.

https://youtu.be/FT9Q4Gmv4N0

Regards Tony.

 

[Tony Bird]

Hi,
A lot of what I have achieved today is cosmetic.

The holes cut in the trivet were cleaned up.



The base of the cylinder/valve support was thinned a bit and was cut to match the trivet.



Steam and exhaust pipes were fitted.



A valve rod was made and fitted.



This is how the engine looks at the end of work today with all the screws cut to length and blackened.




Only the cylinder to finish with covers and piston. A liner still has to be fitted.

Regards Tony.

 

[Tony Bird]

Hi,

A video of testing the valve gear action.

https://youtu.be/7raw-igyICA

Regards Tony.

 

[Cymro77]

Tony,
How is the cylinder attached to its support? Is it free to move on the large central depression? If so what ensures that the steam ports remain aligned?
Thanks again for sharing, this is quite a project - fascinating how you fabricated the cylinder and its base.
David

 

[Tony Bird]

Hi David,

How is the cylinder attached to its support? Is it free to move on the large central depression? If so what ensures that the steam ports remain aligned?


The cylinder is an oscillating cylinder that doesn't move much and shares the same trunion as the oscillating valve. The cylinder has to move to allow for the shallow arc scribed by the beam, if it didn't move; parallel motion, a coupling rod or the like would need to be used to stop the piston rod jamming in the cylinder. As the cylinder moves very little the holes in the cylinder and port block don't really get out of line.


Today only had a few hours in the shed. The K&S brass tube liner was fitted in the cylinder and the steam/exhaust slot milled in the ends of the cylinder. An oil pot was fitted to the valve rod and the bottom cylinder cover made.

Milling steam/exhaust slots in the cylinder.



Lapping the cylinder bore.



Lapped bore.



Parting off the cylinder cover.



Cosmetic work on the cylinder cover.



Cylinder cover fitted.



Valve rod oil pot.



Regards Tony.

 

[Cymro77]

Tony,
Thanks for the cylinder attachment information. I thought the cylinder was moving a little on the video, just could not think why it would be an oscillator with a rotary valve. Now it is clear.
Once again thank you.....

 

[Tony Bird]

Hi,

I did a bit more cosmetic work on the engine. The cylinder looked a little plain so some bands have been fitted to it.





The top cylinder cover has been made.

First the inside was machined with a spigot to allow the other side to be machined.



With the other side machined the spigot was removed.



This is how the engine now looks.




Only the piston and gaskets to make and if the engine doesn't need to much tweaking it might get to run on air tomorrow.

Regards Tony.

 

[Cymro77]

I'll be waiting and watching!th_wwpDavid

 

[Tony Bird]

Hi David,

I'll be waiting and watching!


Not quite up to your Wild Life photographs but:

Here we are finished; text and video to follow when it has been down loaded.

Regards Tony.

 

[10K Pete]

Tony you're amazing! It's beautiful.

Pete

 

[Tony Bird]

Hi,

Well the Trivet engine is finished! It didn't need much tweaking after I had found that I had managed to fit the oscillating valve 90 degrees out!

Gaskets made and fitted



The piston was roughed out.



The piston was then fitted on its rod for finishing by hand turning.



Piston with its '0' ring fitted in cylinder.



The packing for the piston rod is PTFE plumbers tape wound up using a drill and fitted around the rod before twisting again. The twisted tape is then wound around the rod and compressed by the glad nut.





The finished product.



It will be a couple of weeks before the models steam test as I don't like heating the cylinders too soon after they have been painted.

Test the ‘0’ fitted to the piston.

https://youtu.be/sRgLuB-ljsk

The finished engine running on air.

https://youtu.be/2R-6Z4QnZ94

Well another project tomorrow.

Regards Tony.

 

[Cymro77]

Tony,
A triumph!th_wav
You also just gave me another new trick. I always have trouble with the valve and cylinder packing - the rolled up plumbers teflon tape is brilliant. Will be using it on the 10H I am currently restoring. Thanks once again for sharing not only your wonderful creativity but also your knowledge of machining and fettling.
David

p.s. Great pictures and Video - sound track is ot bad either. The 1812 might be a better conclusion.

 

[Tony Bird]

Hi,

Having given the paint on the Trivet engine a week or more to cure the engine had its first run on steam this morning.




A photograph I forgot to include earlier: because the oscillating valve is so large it was lapped to a near mirror finish to reduce friction.

I am quite pleased with the performance of the engine; to turn over slowly on air it requires about 5 psi and a steam boiler needs about 25 psi to give the same result as air. I have never made a Half Beam engine before and if I make another I will try and balance the weight of the beam and the connecting rod more accurately so the engine would work more slowly. The power required lifting the beam and its weight’s help on the down stroke means at low speed the action becomes lumpy, a bigger flywheel would help.

Regards Tony.

Forgot the video I made as the boiler ran out of gas! Video at:

https://youtu.be/p8zFU1iXWxQ

 

[Charles Lamont]

Next Project: you are wasting that vase as a chimney, it clearly wants to be a "bottle" engine:

http://myweb.tiscali.co.uk/remark/pages/Temp/images/bottleeng.jpg

 

[Tony Bird]

Hi Charles,

Next Project: you are wasting that vase as a chimney, it clearly wants to be a "bottle" engine:

A good idea! Very tempting.

Regards Tony.