Muncaster Joy Valve Steam Engine 1/2 scale

[raveney]

Hello all,
I am attempting to build a scale version of an interesting two cylinder steam engine that uses an unique valve train. Plans are available online. I found an archived copy of an antique model engineering magazine from 1905.
Here is the side elevation

I chose 0.6 scale to suit my propane forge and lathe capabilities. The full size engine was used to power a hobby size machine shop, and a bit large for my present collection.
As tradition, I started with the base and am attempting to cast it using lost foam aluminum rather than green sand. If I'm not fortunate after the first few attempts, I'll try a wooden pattern, but I haven't had much luck pulling the patterns out with hollow cavities like this.

 

[kvom]

I built this engine full size from casting 8 years ago. Here's the build thread. Joy's Valve Gear Horizontal Engine

I made a SolidWorks model of the engine as well.

Another user made a reduced model from bar stock and modeled it in Rhino.

There are several articles in ME provided by Muncaster. The one with your elevation is from March 9, 1905. Continued on March 23 and April 6.

Where are you finding other online plans?

 

[raveney]

Hi KVOM,
Beautiful craftsmanship! I really like the dual flywheels and will incorporate that in my rendition also. Thank you for sharing the link to your build and videos; it will certainly help.
I am basing the dimensions on Julius de Waal plans found online here
https://modelengineeringwebsite.com/Muncaster_Joy_valve_gear_engine.html

modeling in Fusion using metric dimensions, scaling 0.6, and converting to inch

 

[peterl95124]

Raveney, good choice !,
I too have a fondness for this engine, and am doing one in 2/3 scale, inspired by Simon Fraser's build, which I stumbled across while researching Joy's Valve Linkage as a result of seeing the Van Vleck triple expansion and Edison dynamo at Triple Expansion Steam Engine, 1891 - The Henry Ford which I'd also like to model some day.
Here's my progress, but I'll be watching you as this is on hold for me,
keep up the good work and keep us posted !

 

[raveney]

Hello Again,
Beautiful day in Florida to get some shop time in. Today I continued with the flywheel patterns, and made some linkage support patterns and the bearing cap patterns.
Started by carefully making a pie shaped jig out of plywood that will replicate the spoke cutouts. This can be used for either foam patterns, or split wood ones. I made this on the rotary table using my drawing. It indexes to two pins, center & six holes for this six spoke wheel. I typically place the outer holes in the center of the rim.

I then placed an MDF board on the mill, drilled and set a 1/8 pin and used a dremel 1/8 tile cutting bit to remove the foam for each feature of the pattern.

The plan was to slice the 1 inch thick foam blank later so I would have 3 patterns. Here is the glued up prototype.

I cut foam plugs where I had used drywall screws to anchor the foam while cutting. These were also smoothed out with beeswax. Not super happy with the effort to make just one foam pattern, and the dents in the spokes. 😒

I decided to save this pattern, but went ahead and made a split wood pattern and cast in green sand. I had some 1/4 and 1/2 MDF so the built up approach was used. First cut spokes and OD in the 1/4 MDF times two.

Then use the pin jig on the mill to contour the rim halves. After the parts were glued up, I still needed to put draft on the hub and OD. Used belt sander for OD, and a super sketchy setup on my mini lathe for the hub. Boring bar is upside down and sticking out way to far for metal. Good news that everything runs very true

MDF needs a lot of shellac unless one spray paints it first with a quick dry enamel. I had a can of white 15 minute dry and it barely raised the "grain". See below after letting cure and sanding with 220 grit. One on right is not sanded.

These will get two coats of shellac, and then get waxed before use. Should get much better results with the wood patterns.👍

 

[raveney]

Here is what the other parts should end up looking like....
Only needed the hot wire table for these simple parts. They got the beeswax treatment also for filleting and to hide the ugliness at the top. I only need two each, but made extras.
Group shot after dipping foam stuff in thinned drywall mud, and waxing the wood patterns. Hopefully the 6KG crucible will make it here this week, and next weekend will be casting day😬

 

[raveney]

Hello again,
Well it didn't work out as I had planned today.
I didn't have enough melt for the base even with the "bigger" crucible. Then my wooden flywheel patterns kept pulling the inner spoke sand out when attempting to remove them (twice).

I did have success with some small bearing caps, and standards I doubled down on these luckily. One standard didn't completely form at the top. The foam flywheel came out complete also (but I need two).


I measured the bigger 6KG crucible by filling my smaller 4 KG crucible with sand. Not much more melt (volume). I also weighed the casted base, flywheel, small parts, and some ingots. They weigh 1.1-1.2 kg and I'm supposed to yield 1.8 kg aluminum according to the data sheet. Back to Amazon and ordered a 8KG crucible from a different PRC company.

I don't think my forge will support the combustion with the bigger diameter though, and may have to fabricate a thinner wall steel pipe crucible if I can't get the flame to stay lit. Anyone here have success with welded steel pipe crucibles?

I included a picture of the 1500W heat treat oven that I built which I used to preheat the 6KG crucible before use.
I relieved the hard edges on the wooden flywheel spokes and coated again with shellac. I will try again next week

 

[peterl95124]

yes, as a hobbyist its all about the learning curve !!!
I'm also admiring your electric kiln, I have a commercial made one that needs a new element, but its cemented in so I'll have to figure out a way to deal with that, maybe an angle grinder

 

[Steamchick]

Hi Raveney. I am very impressed with the results you have achieved so far. Keep up the good work, you are obviously on a steep learning curve and I am sure you'll have more successes in future. Foundry work is something I started to do - just on small bits using simple plaster moulds. I soon came to realise the investment in time money and equipment was way beyond me, so I am very impressed with the size and scope of your work.
K2.

 

[raveney]

yes, as a hobbyist its all about the learning curve !!!
I'm also admiring your electric kiln, I have a commercial made one that needs a new element, but its cemented in so I'll have to figure out a way to deal with that, maybe an angle grinder

Thank you for the encouragement Peter,
This is the first real work for the oven. I have only test fired for temperature and cured the fire brick cement up until now. I have read that elements do burn out after use, and that's too bad that the commercial oven doesn't have a way to replace them. I considered this during this oven build and made the rear panel replaceable by welding tabs to the back plate and drilling tapping #6 button head screws thru to secure it. Also used two ceramic junction blocks and routed high temperature wire to the PID. Drilling and tapping SS 304 is really difficult, but I had sufficient 3 mm SS panel that I salvaged and it doesn't need paint so that is what was used here. Super easy to weld also. Good luck with the replacement

 

[raveney]

Hi Raveney. I am very impressed with the results you have achieved so far. Keep up the good work, you are obviously on a steep learning curve and I am sure you'll have more successes in future. Foundry work is something I started to do - just on small bits using simple plaster moulds. I soon came to realise the investment in time money and equipment was way beyond me, so I am very impressed with the size and scope of your work.
K2.

Thank you for the compliments Mr Chick,
This is the largest casting that I have attempted, and I am learning a lot. I have been fortunate with both lost foam and sand casting in the past, but not without setbacks. To me it's a lot like fishing.... A bad day casting is still better than a good day at work etc.
On Sunday I re-radiused the flywheel rims and used some graphite powder I had to burnish the finish. Also the sand had dried a little, so a practice run shows that this may be acceptable in a future casting day.

I remade a new base and gated in a different position placing the heavy pedestal part at the top. After it dries I will weigh/and calculate the volume so I can compare to the new 8KG crucible before trying another pour

This pattern has the bearing supports incorporated into the sides so the seam is avoided like the original Muncaster plans. The last one patterned after the De-Wall plans where the standard was a separate part.

We will see how it goes once the new larger crucible arrives

 

[Steamchick]

I owned a very old (c1960s) Kiln that had channels along the 3 inside walls with electric elements in them. It had been re-wired by an electrician with new elements (that he wound from resistance wire), before he sold it to me. It had a kiln-sitter - used for pottery up to around 1300C. The Kiln-sitter uses bars of clay prepared to soften at specific temperatures (relating to firing temperatures for clays and glazes). When the clay stick softens, the kiln sitter switches of the power to the elements. Seems that some sort of simple control could be used for the Foundry kiln or heat-treatment kiln?
I also inherited a muffle furnace that needed an external temperature control and temp sensors.... but I didn't have those and burnt out the element as a result. The resistance wire was wound around the outside of central hollow brick so got much hotter than the inside until it reached a balanced temperature....
Replacement elements not available, but element plates (firebrick plates with elements embedded inside) were available - but at a price beyond my needs. Maybe these plates are the replacement for Peter's kiln?
https://www.google.com/aclk?sa=l&ai...&&ctype=5&q=&nb=0&nm=9&nx=75&ny=13&is=650x304or:
https://duralite.com/shop/kiln-replacement-elements/replacement-heating-elements-forkilns/
K2

 

[peterl95124]

Raveney, since you're going from the original 1905 plans, there's one critical part that isn't dimensioned, Fig 15 shows the "lower link" (which you can see in Fig 14 is pinned to the main Con Rod) but also in Fig 14 there's a "radius link" (which is pinned to the lower link) and there's no drawing for the radius link. Simon Fraser ran into this issue and wrote a software simulation to verify his guesstimate for its dimensions, for the original full size engine its longer lever arm should be 2.40" and its shorter lever arm 0.45".

for my 2:3 scale engine the lower link arms are 1" and 0.5", the upper link arms are 1.625" and 0.312" but these dims are critically dependent on the valve stem height and my engine is not exactly scale in this respect, I didn't like how the original slide valve has this huge obstruction in the exhaust cavity, so I raised the valve stem to avoid this obstruction to have a large clean exhaust cavity.

Simon's software is javascript so it runs in any browser window and you can probably still find it on the internet. Since I am additionally interested in the Van Vleck engine that also uses Joy's Valve Gear, I did a bit of software enhancement, and my version of the software is on BAEM-Club website if you want to play with that too.

I did a huge amount of web research about Joy's Valve design, and found that just about everything that's ever been written about it is incorrect, and have come up with my own rule-of-thumb design, let me know if you'd like me to try to make a drawing and explanation.

 

[Steamchick]

Hi Raveny, this may be a complete red herring, (I catch many when fishing!) but I tried making a plaster mould of an existing flywheel by pre-dipping the existing machined flywheel in wax. It produced a reasonable extra 1 mm of thickness, rounded corners, etc. to make a pattern that easily removed from the plaster when cast. But my plaster-casting technique was worse than my fishing casts!
K2

 

[raveney]

Raveney, since you're going from the original 1905 plans, there's one critical part that isn't dimensioned, Fig 15 shows the "lower link" (which you can see in Fig 14 is pinned to the main Con Rod) but also in Fig 14 there's a "radius link" (which is pinned to the lower link) and there's no drawing for the radius link. Simon Fraser ran into this issue and wrote a software simulation to verify his guesstimate for its dimensions, for the original full size engine its longer lever arm should be 2.40" and its shorter lever arm 0.45".

for my 2:3 scale engine the lower link arms are 1" and 0.5", the upper link arms are 1.625" and 0.312" but these dims are critically dependent on the valve stem height and my engine is not exactly scale in this respect, I didn't like how the original slide valve has this huge obstruction in the exhaust cavity, so I raised the valve stem to avoid this obstruction to have a large clean exhaust cavity.

Simon's software is javascript so it runs in any browser window and you can probably still find it on the internet. Since I am additionally interested in the Van Vleck engine that also uses Joy's Valve Gear, I did a bit of software enhancement, and my version of the software is on BAEM-Club website if you want to play with that too.

I did a huge amount of web research about Joy's Valve design, and found that just about everything that's ever been written about it is incorrect, and have come up with my own rule-of-thumb design, let me know if you'd like me to try to make a drawing and explanation.

Peter,
I am greatly intrigued by the Joy valve linkage, and see it as a challenge to successfully model in scale. I believe the measure of success will be not only aesthetics, that the engine runs on steam, but also that the engine will reverse when changing the valve "radius cams".
My model will very likely have an accumulation of error, but also be affected by changes made based on materials on hand. I am seriously contemplating fabricating/welding the cylinders rather then purchasing an expensive lump of cast iron, so this will alter the valve stem centers above cylinder centers. Appreciate the note about the valve stem boss impeding on the slide valve passageway.
I certainly could learn a lot from your research, drawing, and explanation. Please share

 

[raveney]

Hi Raveny, this may be a complete red herring, (I catch many when fishing!) but I tried making a plaster mould of an existing flywheel by pre-dipping the existing machined flywheel in wax. It produced a reasonable extra 1 mm of thickness, rounded corners, etc. to make a pattern that easily removed from the plaster when cast. But my plaster-casting technique was worse than my fishing casts!
K2

Hi Steamchick,
I haven't attempted any plaster casting yet. Do you have a picture of the part you cast?

 

[peterl95124]

Peter,
I am greatly intrigued by the Joy valve linkage, and see it as a challenge to successfully model in scale. I believe the measure of success will be not only aesthetics, that the engine runs on steam, but also that the engine will reverse when changing the valve "radius cams".
My model will very likely have an accumulation of error, but also be affected by changes made based on materials on hand. I am seriously contemplating fabricating/welding the cylinders rather then purchasing an expensive lump of cast iron, so this will alter the valve stem centers above cylinder centers. Appreciate the note about the valve stem boss impeding on the slide valve passageway.
I certainly could learn a lot from your research, drawing, and explanation. Please share

Raveney,
I started a new thread in Uploads

Joy's Valve Simulation, by Simon Fraser, enhanced by Peter Lawrence


let me know if you have any problems with it, I'm a Linux guy ("I don't do Windows") so its possible...

 

[raveney]

Good morning,
The base casted reasonably well with one noticeable exception. I inverted the part so the rear cavities would fill, but the step down on top didn't completely fill. I'll run a ball end mill down the corner to replicate the filleted corner. Ran very close to running out of aluminum on this pour. The 8 KG crucible is smaller than described on Amazon, just like the 6 KG was. The part with gates and pouring basin only weighs 1.9 KG, and should be a calculated 2.5 KG.
I also cast both flywheels using green sand method. Had difficulties pulling the patterns again, so lots of flash and poor surface finish. Hopefully they clean up well.

 

[raveney]

Here is a short video of the pour

Video

 

[peterl95124]

Awesome, if only we were doing the same scale I'd ask you to pour a frame for me too !!!
(am currently planning on a bar stock frame bolted, and maybe tig-welded, together)