# Stuart Beam Engine



## Orrin (Nov 22, 2007)

Has anyone on this forum built the Stuart Beam Engine?  

http://www.stuartmodels.com/inprod_det.cfm/section/casting/mod_id/43

I just started one, yesterday, and after cleaning up the base painted the bosses with layout blue and I laid out the locations for the screw holes.  

I'm glad I did, because when starting at one end and doing the layout toward the flywheel end, the holes are not centered on the boss for the crankshaft bearing pedestal.  

That, of course, is not acceptable because the crank throw needs to be centered over the cavity for it that is cast into the base.  

Consequently, I'm going to shift the layout 0.057".  The net effect is the crankshaft, beam column and steam cylinder will be better centered but, the valve bearing pedestals will end up being off-center. 

Does anyone have any recommendations?  I could probably split the difference and only shift the layout 0.028".  

There is another option, however.  Seeing as how the only connections between the crankshaft and the rest of the engine is the connecting rod to the beam, and, the valve operating rod, why couldn't I merely center the crank on its boss?  The only thing I'd have to do to compensate would be to lengthen the valve operating rod by 0.057"

Are you still with me?  I realize that it is probably a remarkable achievement to produce a rough casting and have the length come out to within 0.057" in 8.5".  I'm just trying to figure out the best way of dealing with it, is all. 

Thanks.

Orrin


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## Orrin (Nov 22, 2007)

Thank you for your advice, John.  I appreciate it. 

Best regards, 

Orrin


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## Bogstandard (Nov 22, 2007)

This manufacturers reply in my estimation is a load of bullsh.
What they have most probably done, to save money, is use an original casting for the mold, and so produces a smaller casting because of shrinkage.
If a raw beginner bought one of these casting sets, and due to lack of experience didn't know about having to recalculate new dimensions , what is he to do?
Does he contact the manufacturer and ask them what to do, only to be told that he shouldn't be making one in the first place because he hasn't got the experience. Or finds out the hard way and partly machines the casting to drawings (maybe not doing a layout first, just using DRO settings) only to find that it ends up as a scrapper because the holes are all out, or nothing fits.
The onus is on the manufacturer to either supply castings that are fit for the purpose they were made (in the UK you can send them back and ask for a refund if they are found unfit for purpose) or produce a new set of plans (free of charge) to match the undersize castings.
DO NOT accept lame excuses from manufacturers, you have paid good money for their product. Just tell them where to stick their junk and demand your money back. If you don't do that they will just keep on making garbage and ripping people off.
How such a well established and respected manufacturer like Stuart could do such a thing is diabolical, their reputation in my opinion has just taken a nosedive, and I do hope they read this.

Go out and buy all the raw materials and make one from scratch, it will be about quarter of the price, and look better because things will fit right.

John


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## Orrin (Nov 22, 2007)

I agree with you, Bogstandard John.  So far, however, these Stuart castings are much better and closer to dimension than some I've received.  One such set had a pair of castings that were so undersized, I couldn't even fit the hole centers onto it.  One pair of holes was half off the casting!  

I salvaged it with a fabricated steel piece, fastened in place with JB-Weld.  Now, one would never know the difference; on the steel part I even duplicated the same draft angle as was used on the rest of it.  

In that same set, a connecting rod was far too short.  After splitting one end for a bearing, I had to sandwich in a piece of 1/8th-inch plate to make it long enough.  Actually, it should have been even longer.  But, it looks "factory," now.  

But, I look at it this way:  I have no way of casting iron, so it is better to deal with less-than-perfect castings than to do without. 

Best regards, 

Orrin


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## JimHs (Feb 21, 2008)

Orrin,
 I have a beam and entabulator that I believe came from a Stuart Beam kit. I'd like to verify that so if it is not too much to ask, can you tell me what the distance is between the holes at each end of the beam (center to center distance off the plans). Also, the basic dimensions shown for the entabulator. 

Thanks very much,
Jim


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## Orrin (Feb 21, 2008)

I read your post, Jim. I'm up to my eyeballs in chores, so there's a danger I may forget. If you don't hear from me by Monday, rattle my cage, again. 

I'll be away from home most of the time between now and Monday.

Best regards, 

Orrin


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## tel (Feb 24, 2008)

I probably hold some sort of record for building one of these. Did the base, column, flywheel, crank and entablature arms and then let it 'mature' for 17 years until I got around to finishing it. Don't recall any alignment problems like that, but I fitted things as I went along rather than to lay out the lot at once. It is a pretty forgiving engine for minor mistakes.

Personally I'd go with it 'as is' and look at the cranked rod if it's needed. Probably get away with the way you form the forked end - (central, one side or t'other)


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## tel (Feb 24, 2008)




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## JimHs (Mar 5, 2008)

Hi Orrin,
 Just rattling your cage as requested.  ;D
Jim


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## Orrin (Mar 5, 2008)

> Orrin,
> I have a beam and entabulator that I believe came from a Stuart Beam kit. I'd like to verify that so if it is not too much to ask, can you tell me what the distance is between the holes at each end of the beam (center to center distance off the plans). Also, the basic dimensions shown for the entabulator.
> 
> Thanks very much,
> Jim



Thank you for rattling my cage, Jim. I needed the reminder. I've been up to my ears in this:

http://users.moscow.com/oiseming/BBS/Hey_Look.htm

If you scroll down to the bottom of the page you'll see some links. If you keep exploring you might find my e-address at the bottom of one of my pages. If you have further questions you might want to e-mail me directly. 

"can you tell me what the distance is between the holes at each end of the beam (center to center distance off the plans)."

Let's see if I can give you what you need: 
The center-to-center distance between the pivot holes at each end of the beam is exactly 7-inches. They are 0.125" in diameter. 

The center hole for the main pivot is not dimensioned with respect to the end holes. Seeing as how the center of the hole is also shown as a centerline, person can only assume it is centered between the two end holes. At least that is where I put it, 3.5" from the end holes. It is 1/2" in diameter. 

The 0.125" hole for the Watt linkage is 1.75" from the end pivot hole. 

My beam was bowed. It apparently came that way from the foundry. Before I could do anything with it I had to heat it to red-hot and very gently press it until it was straight. 

"Also, the basic dimensions shown for the entabulator." 

Correct me if I am wrong, but I am assuming you are referring to items #75 on the Stewart exploded drawing and described as Entabulature . 

They consist of 3/16" X 3/8" mild steel stock, 5-3/32" long. 3/16" from one end is a hole large enough to accomodate a #2BA screw. At a center-to-center distance of 1-5/8" from that hole is another, same size. Both are on the centerline of the piece. 

At the opposite end on the 3/16" edge are two holes drilled and tapped for #7BA screws. Their center-to-center distance is 1.0" No dimension is given from the holes to the end of the piece. What I did was to place the bearing brackets flush with the end and locate the holes accordingly.

I hope this is what you need. Feel free to e-mail me if it isn't.

Best regards, 

Orrin


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## JimHs (Mar 6, 2008)

Orrin,
 Thanks for the info. I'll check tonight (if I get my chores done) and report back.  
Jim


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## Circlip (Mar 6, 2008)

Oh dear Orrin, you b*ggers appear all over the place :big: Daughter is one of the organisers for The White Rosettes, LABS on this side of the pond, they keep coming over there to try to teach you lot how to sing :bow: :big:
 Now on to serious stuff, while I totally agree with what our JohnB said about quality of Stuart castings and sending them back etc. Firstly I have no connection with either Stuarts or Vale Eng. but would ask how old are the castings and where were they supplied from over here? Were they from Stuarts and at what time? I ask cos Stuarts went under and the model engine side of the business was purchased by a company called Vale Engineering based in the Channel Islands. Judging by the improvements they are making to the original drawings to make sure that everything fits I can't see them compromising with c4ap castings. Could be that you've got some last run don't give a sh t products from the demise of the old company. It SHOULDN'T happen but a couple of companies I've worked for in the past, this has occurred and it says nothing for some of our previous product quality.


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## Orrin (Mar 6, 2008)

I ordered my castings from Coles Power Models. They didn't have the beam engine in stock so they ordered it from England. They didn't say anything about who they got it from. All the packaging was labeled "Stuart" and I didn't see anything that would hint of a new owner. 

For sure, the Stuart castings are barely large enough. The finished width of the beam is supposed to be 3/8" but in places it wasn't that thick. 

I hadn't heard that Stuart had gone under. Thank you for the news. 

Best regards, 

Orrin


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## HS93 (Mar 6, 2008)

I may be wrong but I don't think they ever went under , 1980 saw the business being split the model engine side from the pumps , In 1990 it split again and part became Cheddar and the other half moved to Guernsey then a year or two back cheddar models closed its doors and sold the rights to Stuarts for the model marine side.

peter


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## JimHs (Mar 6, 2008)

The beam is definitely from the Stuart beam. The entabulator is not from that engine. 
Thanks.
Jim


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## HS93 (Mar 6, 2008)

Just out of interest , where all the parts shrunk wrapped on to cardboard ?

Peter


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## Orrin (Mar 7, 2008)

> Just out of interest , where all the parts shrunk wrapped on to cardboard ?
> 
> Peter



Yes. The very elaborate Stuart artwork was on the outside of the box, too.

Best regards, 

Orrin


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## Kludge (Aug 19, 2008)

Orrin  said:
			
		

> Correct me if I am wrong, but I am assuming you are referring to items #75 on the Stewart exploded drawing and described as Entabulature .



For my gnu-bee question of the moment, is that the mechanism attached to the connecting rod, the beam and the pair of fixed arms extending toward the cylinder end of the beam? If so, what does it do? I've been straining my already misfiring neuron trying to figure it out.

Best regards,

Kludge


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## Bogstandard (Aug 19, 2008)

Kludge,

That is called a parallel motion link, a Stevenson's patent I think.

It allows the linear motion of the cylinder stroke to join onto the rotary motion of the beam end, without putting any bending force onto the cylinder piston rod.

John


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## mklotz (Aug 19, 2008)

Where the devil is the "entabulator" on an engine? Or is this the British spelling of "entablature"?


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## Orrin (Aug 19, 2008)

I suspect it is a matter of spelling. I assumed "entablature" was what was intended. 

Orrin


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## Kludge (Aug 19, 2008)

Bogstandard  said:
			
		

> That is called a parallel motion link, a Stevenson's patent I think.



Cool. Thanks, John. I'd never seen it before and it truly did puzzle me.

Another reason I love this place!

Best regards,

Kludge


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## mklotz (Aug 19, 2008)

Orrin  said:
			
		

> I suspect it is a matter of spelling. I assumed "entablature" was what was intended.
> 
> Orrin



I thought they were referring to this...

[ame]http://www.youtube.com/watch?v=lBp5ag6SJH4&mode=related&search=[/ame]

or, perhaps, due to a single letter misspelling, the world famous turbo encabulator... 

http://en.wikipedia.org/wiki/Turboencabulator


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## chuck foster (Aug 19, 2008)

and he said all that with a straight face........ :big:    ;D   ??? : 

chuck :-[ :-X :-\ :-* :'( :bow:


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## Bogstandard (Aug 19, 2008)

Marv,

Sounds a little like what your country's leader would come out with, when he forgets his lines.

John


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## mklotz (Aug 19, 2008)

Now, Bogs, you stop making fun of our Prez. How can one not be proud of someone who makes such insightful statements as:

We look forward to hearing your vision, so we can more better do our job. That's what I'm telling you.

One of the common denominators I have found is that expectations rise above that which is expected.

We are ready for any unforeseen event which may or may not happen.

Natural gas is hemispheric. I like to call it hemispheric in nature because it is a product that we can find in our neighborhoods.

Saw a bumper sticker the other day that read, "Somewhere in Texas, a village is missing its idiot."


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## Kludge (Aug 19, 2008)

Bogstandard  said:
			
		

> Sounds a little like what your country's leader would come out with, when he forgets his lines.



He doesn't even have to forget them, just "explain" them. ;D

Kludge


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## tel (Aug 19, 2008)

Bogstandard  said:
			
		

> Kludge,
> 
> That is called a parallel motion link, a Stevenson's patent I think.
> 
> ...



Watts Boggy - them fluffy bunnies getting at yer memory banks?


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## Bogstandard (Aug 20, 2008)

Tel,

Notice the disclaimer.

Stevenson's patent I think.

The reason is, I forget to think most times.

Thanks for the correction.

Bogs


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## tel (Aug 20, 2008)

Noted mate, and thanks for not picking up on the 'Watts' rather than the 'Watt's'


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## NickG (Nov 13, 2008)

I'd agree with Bogs re the comment on stuart castings. I have been considering doing a stuart engine purely because the castings and drawings (I assumed) would be very good, clear and concise. As Bogs said, a company such as stuart turner should be producing excellent stuff, and I'm shocked by there response that the drawings are there as a guide only. In my opinion I think a company like Stuart should be thinking of going a step further and actually putting tolerances on their drawings.

This thread has now put me right off buying very expensive Stuart castings as a fill in project. I'd rather spend the time designing something myself and making it from bar stock, then I know it will fit together, I'll have more satisfaction making it and if it didn't work I'd only have myself to blame!

Nick


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## tel (Nov 13, 2008)

Unless they have improved in recent times, Stuarts aren't what they used to be. In 1979 I built a 10V and the castings were a delight, the castings for the Beam I built several years later ranged from OK to, frankly, 'orrible. And the prices? Nowadays I can buy a 5hp Briggs engine for what the 10V castings cost.


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## Orrin (Nov 13, 2008)

The quality of the Stuart castings is very good; but, many are undersized, not allowing enough meat for cleanup. Take the beam, for instance, in places the flange width was less than the finished width called for on the drawings. Granted, it is not a critical dimension; but, it from a cosmetic point of view it is huge. 

IMHO, here in the USA a person can get more bang for the buck by buying US products. Granted, some types of engine castings cannot be found on this side of the pond; but, it pays to shop around, anyhow. I heartily recommend this site to you your browsing for supplies:

http://www.antiquengines.com/Davis_Model_Suppliers_List_.htm

Here's another supplier. I've not checked to see if Davis lists it, yet, so forgive me if this is redundant:

http://www.lonestarengineworks.com/Products.html

Best regards, 

Orrin


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## Mcgyver (Nov 13, 2008)

> I'd agree with Bogs re the comment on stuart castings. I have been considering doing a stuart engine purely because the castings and drawings (I assumed) would be very good, clear and concise.



I've built a couple of stuarts and imo the castings were in a word excellent. I haven't seen bette and that is 99% of it, drawings 1%. imo Stuart drawings are technically there but leave a lot to be desired in usability - they're from the school that says if there any conceivable way the builder can calculate a dimension from upteen others, lets not print it on the drawing. Other drawings i've worked have been much nicer, but end of the day they do give you what you need.



> As Bogs said, a company such as stuart turner should be producing excellent stuff, and I'm shocked by there response that the drawings are there as a guide only. In my opinion I think a company like Stuart should be thinking of going a step further and actually putting tolerances on their drawings.



On this I completely disagree with you. I'll rant a bit, not so much at you .but at the notion someone familiar with industrial practice comes to the hobby and in ignorance is critical of things they haven't fully thought though....

If you are in industry, tolerances are critical and the drawing defines everything leaving nothing to chance. Parts suppliers on different sides of the globe make their respective bits and pieces, the all come together, fit and the assembly works. yippy.

BUT, parts suppliers are only chosen who can satisfy the tolerance requirements of the drawing. They don't redesign the whole thing because some bidder says "hey, I don't have a thread grinder, can we come at this a different way". No, they get guys with thread grinders (or whatever) to bid.

This isn't how model engineering works. We don't by rote follow plans and tolerances; we take them as a guide to interpret in the context of our abilities and machines. There are big difference between us and industry, is 1) the variance in available equipment, 2) that everything included final assembly is done by one participant, 4) were not mass producing and 3) the objective is to make it accessible for as many as possible- not just a couple of bidders who have specialized equipment.

Let me give you an example. Lets say were making an internal combustion engine where the nominal bore is 1". Industry would spec a tolerance, say .0005 +- on the cylinder and say the piston .998 +- .0005. The cylinder will be a maximum of 2 thou and a minimum of 1 thou larger than the piston. Well, maybe I don't have a micrometer. I can still build that engine and have it work perfectly with the piston 1.5 thou smaller than the bore because i know how to fit a piston to a bore. However the bore may be 1.010" because I don't have a micrometer. Specifying a tolerance wouldnt accomplish anything because for one of's made and assembled by the same person there is no need. The hobby is model engineering - the builder has to develop engineer skills to figure out how to make it in the context of what they have available - if the hobby was by rote machining to drawings it would be rather dull.

Youre critical of Stuart  but take a broader perspective - I've got 1000's of model engineers going back to the 30's. In these or Live Steam or Engineering in Miniature or Home Shop Machinists I cant remember ever seeing drawings presented as they are in industry with tolerances are they all wrong? Anyone familiar with the content that has graced the pages of ME for last 70 years would hardly categorize those brilliant engineers as not knowing what they are doing; no the omission of tolerances is intentional and logical in the context of how they are used by us hobbyist and comparison to industrial drawings practice is not warranted or sensible.

End of the day, I have to agree with Stuart; drawings for ME's are a guide and its up to us as amateur engineers to determine fits and tolerance and construction techniques in the context of our abilities and resources. Now wether there is value is a personal decision, they are getting bloody expensive.


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## tel (Nov 13, 2008)

I agree with what you say McG, my bone(s) of contention are with the declining quality of the castings, and the price.


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## NickG (Nov 14, 2008)

I'd go along with all of what you have said Mcgyver, I wasn't suggesting that all model engineering drawings should have tolerances, as you said, it would be dull and would take most of the fun out of the hobby for the majority. However, I was picking up on something that Bogs said and just thought it would be a nice option for the beginner, he / she wouldn't have to follow them, but it would be a good guide and it would also get the beginner thinking about limits and fits.

As John said, without a good set of drawings a beginner could easily mess up a set of expensive castings (S50, 10V, 10H etc) that they say are for the beginner purely because their drawings are sub-standard, this could leave a beginner quite upset and they would have no comeback if that's the sort of reply stuart are giving.

So I just think a company like stuart should be putting out top notch drawings and a comprehensive set of building instructions if they want to charge the prices they do. The tolerancing comment was a bit of a throw away one, nevertheless, I still think it would be a big improvement to have that option.

Perhaps though, I should try a set of stuart castings before I comment any further.


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## Mcgyver (Nov 14, 2008)

hey Nick, like i said wasn't directed at you but I've heard this lack of tolerance criticism a few times and while its not like i'm hot about it, the reasons this criticism is unfounded takes a bit of explaining so it takes the form of a rant 

I do agree the drawings are far from the the nicest i've worked from, but they are i think technically competent


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## compound driver 2 (Nov 14, 2008)

Im in the middle of machining two sets of S50 castings for a customer that were bought last month and the drawings and castings are fine. Irons nice and clean to machine with no hard spots and all the dimms on the drawings are ok.


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