Stuart Beam Engine in Diorama

[J.L.]

I have a greater appreciation for the need to keep governor design suitable to the space where it will have to work. On Victoria, the tight 'L' shaped arms have arcs cut into them to keep the balls in a tight rotation circle (Photo 1). The governor in my hand (Photo 2) really makes the point of keeping the design' tight'. Centrifugal force will throw them all out but keep them from hitting flywheels, columns, etc.

I chose to use the Mount design for my governor (last post), but it was designed for open space. That's not the case with this beam engine.

In these sequential photos that follow, you can see that the base of my governor is being remade to draw the balls in tighter and make room for the gear below.

[J.L.]

The lad who made the follower or shoe for this governor did a great job. He even curved the end to ride the radius the groove. I found it wrapped tighjtly to its lever and rod with  a little piece of masking tape.

It makes me sad a bit when I discover things like this. The fellow lovingly made that part and carefully wrapped it safely away for a day that never came.

Hopefully Tom and I can bring his dream to life.

The planning stage begins now to design holders to support the drive system for the governor. You will note that because there was no brass 'V' pulley in the curved cast mounting, a filler was employed.

[simplyloco]

I've been doing some online research on governors, and just about all the u tube  demos I've watched -running at a slow speed -  had the governor running far too slowly to be even remotely effective. Sluggish is the correct word I think! Are you gearing yours up or are you 'governed' by the available bits??
Regards
John

[J.L.]

Hello John,
You ask a very good question. You are right. The RPM of a beam is so slow that the appearance of a governor seems simply cosmetic.

I can have the governor run at any speed I wish by increasing the diameter of the drive pulley that will be mounted on the crankshaft. Right now, the ratio will be 2:1.
I'm sure I will be making another couple of drive wheels until the governor runs nicely.

John, as you know, beam engines pumping water move the ram up and down very slowly - at about 12 revolutions per minute! You will get that feeling by having a look at the link I've provided.

This begs the question whether small scale model beam engines can run smoothly without hesiation at such slow RPM's. If that is the cae with compressed air as well, I hava a plan in mind to run my engine very slowly. 

Thanks for asking.

<a href="https://www.youtube.com/watch?v=dBdJQYbGZJM" target="_blank">http://www.youtube.com/watch?v=dBdJQYbGZJM</a>

[AOG]

My understanding is that the flyball governors we see on beam engines  weren't intended to regulate the normal operating speed. They they are intended to prevent overspeeding in the event of a failure. From that perspective a scale governer will work just fine.

Tony 

[b.lindsey]

I love all the old beam engine videos and how slow they run. I can't help but imagine how back then they managed those huge beams and flywheels when erecting the engines , or machined them to start with to such levels of precision.

Bill

[Jasonb]

Looking through a couple of my books the rpm given for the smaller beam engines of which the Stuart is based is more than the big pumping engines at 40-60rpm compared with 10-15rpm. So the actual engines would have run faster in real life and as they could have been used with things like line shafting the loads would not have been constant so some means to maintain a constant speed was needed so the governor would have been used for this. a large engine always lifting the same volume of water per stroke would see a constant load so less likely to need governing. I think you will have a job to get the model to run at much below 40rpm and probably a bit more to look smooth.

as for the Stuart governor on the beam the supplied spring drive belts do tend to slip a bit which reduces the speed and makes for irattic rotation.

I must make a new video of mine as I only have a poor quality clip taken quite  awhile ago and it is hard to count the revs due to the jerky images.

[J.L.]

Thank you for your informative reply Jason. I also think it will be a challenge to get the beam running smoothly with steady ease at slow revolutions per minute.

I have seen first hand the jerky and hesitatnt motion that can occur from using spring belts. They are easy to install, but not steady or historically accurate. On Victoria, I made my own leather belt and stitched it together with no overlap.

On this engine, I plan to follow your lead with flanged pulleys and flat belts. Your picture inspires here again:

 

[J.L.]

Something is needed to support one end of the helial gear shaft on the bed of the engine. Then I thought of a word I learned as a child in the early 50's while playing with my Meccano set - a trunnion!

Part 126 in the kits.

So here I am 50 years later thinking of and making a trunnion.

[J.L.]

...actually, two trunnions.

I think a 'U' shaped bracket made to look like a casting should fill the bill to hold the governor and allow its helial gear to mesh with what you see here.

A work in progress...

[Chipswitheverything]

Hi John, as with so many of us that are that little bit older, my glorious Meccano set was a wonderful early introduction to the world of mechanical principles and terminology:   contrates, pinions, flanges, sprockets, racks...  I'm sure that it was a big factor in heading me towards model engineering as I entered my teens.  I wonder how many eight or nine year olds of the present day would know what a trunnion was..?     Dave

[Ian S C]

Started my mechanical construction using a Meccano Set handed down from my father, who in turn had it handed down from his brother who was fortunate enough to be born before WW1, and grew up before the depression of the 30's.  I'm not over keen on the modern system that Meccano has of having a set to make one model, where as with the old sets you got the bits and it was up to you to design what ever you fancied at the time.  My favourite cranes.
Ian S C

[J.L.]

Hi Dave,
My two boys played with 'Dad's' Meccano set pieces for awhile, but LEGO soon took over.  You ae right about questioning what skills and knowledge about mechanics are being passed along with toys today.

Hello Ian,

Bring back memories...?

Your right about the versitility of the original sets. Once you built a model, the first thing you did was take it apart and start another one.

[Jasonb]

Go On, you know you want to

[steam guy willy]

Because i was poor i only had a TRIX set and when mother did the Hoovering and there was a clattering sound going up the tube i got a clout round the ear as that was one less nut or bolt gone. How i envied the posh kids !!! Also no bright colours and dad on the box had a cigaret not a pipe, but you did get extra holes!!!