model boilers

[zeeprogrammer]

For my next project...way way in the future it seems by how fast Spinster is moving...I'm thinking I need a   boiler.

I'm not ready to consider a scratch build and instead would like to find a suitable kit if such a thing exists.

The engine it will drive is small. The flywheel probably along the lines of 3" diameter..maybe up to 5".

Does anyone have any experience with the PM Research vertical boiler? Or even horizontal?
Do you have suggestions for other vendors/manufacturers?
Detail in the model would be great.

If it helps any, the engine will drive a PM Dynamo that will in turn light up an LED.

Thanks for the help.

[mklotz]

I built the PM vertical boiler...





It should be more than adequate for the engine you describe.

Some things you should know...

It's not silver soldered.  The end pieces are riveted in place and silver-bearing solder is used to seal the joints.  The rivets provide the strength.  The firetubes are also soldered.  This approach is easier than the typical silver soldered approach but, being less traditional, may not satisfy you.

I fire mine with Sterno but it would be more convenient to build a gas burner.

You'll need to buy or make a lot of accessories... such as feed pump, valves, whistle, water gauge.

[zeeprogrammer]

Thanks Marv. And that's a nice looking job there.

You'll need to buy or make a lot of accesories... such as feed pump, valves, whistle, pressure gauge.

Sigh. Always something more isn't there? Don't you love it!

[b.lindsey]

Marv, would there be any benefit to to using true silver solder as opposed to the silver bearing solder supplied with the kit?  This is another kit I have had aging for some time and would like to get around to making it one of these days.

Bill

[mklotz]

I got interrupted yesterday by a herd of grandchildren so let me continue here.

There isn't a lot of machining to be done on the boiler and what there is is straightforward.  It's the riveting of the boiler shell that represents the biggest challenge.  The tools to set the rivets are not supplied with the kit.  You make those yourself.  They're not very complicated.

When you do the riveting be certain to wear hearing protectors.  I didn't and my ears rang for days afterward.

The PM dynamo will power something a lot more impressive than an LED.  Mine powers a 3 volt flashlight bulb more brightly than the flashlight batteries. 

Zee,

Yeah, there's always something else.  I forgot to mention that you'll need a displacement lubricator for your engine as well.  Oh, I checked the PMS site and the water gauge is included with the boiler.  I had forgotten that.  So, there's one less thing you have to buy/make.

Bill,

I see no real benefit to using silver solder.  As mentioned, the solder is used as sealant and does not provide the mechanical strength as in more conventional boilers.  If one were to run the boiler at very high pressures one might benefit from the higher melting point of the silver solder but this is a small boiler meant to be operated at low pressure.  The boiler is supplied with a safety valve set to blow at 60 psi.  At that pressure the water temperature is only 307 degF so the solder melting point isn't a big issue.

[zeeprogrammer]

Thanks Marv. I think I'll give it a try. As for those tools...do the instructions indicate what the tools look like or even how to make them? Mainly curious. I'll dive in anyway.

Thanks for asking that question Bill. I was wondering myself.

[mklotz]

Yes, it does show what the tools should look like.  When/if you get to that point, give me a shout and I'll take some photos of the ones I made.  There's really not much to them.  [Rivets are pretty simplistic fasteners.]

Incidentally, I built that boiler for exactly the same reasons that drive you towards it.  I wanted to get my feet wet boiler building but didn't want to go directly to the make-everything-from-scratch approach.  Also, I wanted something low pressure that had been designed by someone more boiler savvy than I.  My guess was that, if PMR was willing to sell it in our litigious society, there's a good chance I wouldn't end up building a bomb.

[zeeprogrammer]

Thanks Marv.

I went ahead and ordered it. Now I'll have the dynamo and boiler sitting on my desk staring at me and daring me to make them. Some extra motivation to finish the Spinster.

Yep...that's the plan. Finish the Spinster and then start on them. Yep...that's the plan.   
Well...I WILL finish the Spinster. But forgive me if I play with the other projects at the same time.

Won't be able to do much with them anyway. No engine. 

[b.lindsey]

Thanks Marv!!AS you say, the PMR folks have figured all this out so they must be comfortable with it in order to sell them.

Bill

[Jack]

I built the horizontal version to be able to run some of my little engines on steam.


It's very easy to build and everything is well thought out, it doesn't take that long to accomplish.


When you get it finished be sure to get their whistle a little pricy but what a hoot! Well worth the money! Then when you take your models to the local tractor shows you can blow your whistle at high noon just like the big boys.


Jack 

[zeeprogrammer]

Thanks Jack. I'd eyed that horizontal. But it's another $70. If the vertical works out for me, I may yet get that one too. For whatever reason, a horizontal boiler seems more traditional or 'real'. I suppose because that's what I came across first as a kid.

South of St. Louis eh? I was just in St. Louis visiting family. My old stomping grounds are down by Springfield.

[swilliams]

Carl - I'd sure like to see you build one of these. Then I can follow your lead

Steve

[mklotz]

I paired my PMR dynamo with Elmer's #44...

http://www.john-tom.com/ElmersEngines/44_openTwin.pdf






It's a good combination.  The engine is powerful enough, even on air, to run the dynamo at a good clip.  The engine is single acting so you only need to build one valve assembly to feed both cylinders.  I like it too because it has a much more "industrial" look than an oscillator to match the appearance of the generator.

[mklotz]

Here are the riveting tools you need to make...



The long bucking bar [experienced riveteers are encouraged to correct my terminology] goes in the bench vise and holds a removable form that supports the head of the rivet inside the boiler cylinder.  The setter (?) with the simple hole then fits over the projecting rivet shank and forces the plates to be riveted together.  Then the remaining setter with the hemispherical depression is used to form the head of the rivet, securing all in place.

All the tools are made from drill rod/silver steel and their working ends are hardened.  Very straightforward stuff.

I annealed all the (copper) rivets before using them.  I don't know if that was necessary but it can't have hurt.

Ok, Zee, I've hijacked your thread enough.  I'll go sit in my corner now.

[zeeprogrammer]

Thanks very much Marv. That will be helpful.

Ok, Zee, I've hijacked your thread enough.

No hijack here. This thread has exceeded my hopes.

I'll go sit in my corner now.

Sure sure. We all believe that. You? Sit in a corner?
That'd be a shame. Come out come out wherever you are.

[zeeprogrammer]

I received the PMR Boiler today.
Looks like a very fun project.
It's much bigger than I had thought. The boiler pipe alone is 6.5".
You read the dimensions...but seeing it in real life is different.

Here's a shot of the box and contents.



Here's a shot of the separate parts. The baggie at top right was stuff in the boiler tube.



Inside the baggie were 4 more baggies.
One containing a pre-made safety valve.
One containing the parts for the water level tube.
One containing some solder and liquid flux (zinc chloride and hydrochloric acid).
One containing the rivets and many other odds and ends (including a finishing nail).



Two large sheets of instructions.

I won't start on this for a while. Too much of a distraction from Spinster. (The Dynamo on the other hand looks fun and quick.)

When I do start this, I'll start a thread and repost the pictures.

I do worry a bit about the size of the parts. I just have a mini-lathe. But I suspect others have done this on a similar lathe. Should be okay.

Looks like a great beginner's project and to Marv's point reduces the anxiety of building something that's certainly much more than a toy.

I also got the PMR Dynamo the other day. I won't post the pictures of it yet. There's not that much to it and Marv's shot below pretty much tells the story. I'll have pictures of the contents when I start that thread.

[smfr]

Looks like a great project! I might have to do one of these; I wonder if it's big enough to drive my Stuart No. 4.

Simon

[zeeprogrammer]

I remember Stuart Models since I was a kid. I think seeing their kits and models was part of the reason I got interested in machining (along with Opi, science museums in Europe, and scads of English model magazines I read during my wonder years).

But I'm not that familiar with specific Stuart model types and wanted to see a No.4. I came across this...

http://www.modelstationarysteamengine.com/Stuart%20engines.html

It shows a No.4. 10" tall with a 5" flywheel. Quite large in my world!

The boiler comes with a 60 PSI safety valve. I have no experience with boilers and hence no idea how long it would run or any other operational specs.

I hope some others can pop in to answer your question and provide any other bits of information.

BTW As Marv mentioned, the instructions show how to make the riveting tools and how to use them.

The kit is about $150. A bargain for me as it saves a lot of time gathering the needed (I suspect, difficult to get) material and includes a pre-made safety valve.

I worry a little about screwing up a part but if I recall correctly, other people have reported being able to order the odd replacement part from PMR. I don't remember if it was because the original part was bad or if the part was made unusable in machining it. I'm hoping it's possible to get individual parts if needed. A look at my 'wall of learning' and I'm praying it's possible.

[b.lindsey]

Simon, the PRM website gives some guidelines on their models which are appropriate for each of the two boilers they offer. In your case which according to Zee's link has a 1.5x1.5 bore and stroke, it would require the larger of the two pmr boilers (the horizontal one). Note however that they say that even the larger boiler will not run their #4 or #6 engines which have a 1.5"bore x2.5" stroke. I'm sure if you contact them they can advise if the stuart #4 is within the range of the larger  (#2) boiler, or if it would be marginal.  Hope that helps.

Bill

[Bearcar1]

Hi Zeepster,


 You are going to be pleased with that boiler kit I think. The quality of the parts are excellent and the drawings are very clear as well. PMR will sell/provide  replacement pieces, whether it is due to a defect or the result of one of those "oh crap" moments hat we all seem to encounter from time to time. I've had many dealings with PMR since they began selling model engines and such and have nothing but good things to say about them. There were no hassles or BS, just friendly, good customer service. 


BC1
Jim

[mklotz]

The dynamo is indeed a quick build but one caution...

The two endbells provide the bearings for the armature.  Each endbell is bolted separately to the body of the dynamo.  It's important that the bearings are properly aligned so that the armature will turn freely once assembled.

There are numerous techniques by which this alignment can be accomplished.  Be sure to carefully think through your machining sequence before making chips.

[rleete]

Dammit Zee!  I see you posting here, but no updates to the Spinster.  This is NOT acceptable!   


Put the boiler aside, get back in the shop and get the spinning wheel project back underway. 

[zeeprogrammer]

Thanks Jim. I had gotten that impression of PMR. Good to know I have more economical means to replace my mistakes.

Thanks for the caution Marv. Well worthwhile for me.

rleete! I'm lucky to get some machine time once a week. Last night all I managed was hacking two pieces of aluminum stock and trimming the end of one. The boiler is in the box. I'll admit I've opened it three times to peer in. Can't start the boiler until the Spinster is done.