Major Beam Drawings - Errors - Omissions - Modifications

[GWRdriver]

I've started this thread separately to avoid cluttering up SimplyLoco's thread but I hope there is some cross-talking.

I'm about to begin making chips on Yet Another Major Beam from approximately 1987 vintage castings and have discovered I don't have the drawings I expected to find (large format, paper) in my drawing file.  What I have are reduced size scans of the H.A.Taylor drawings dated 1979.

My question is, are these the current latest and greatest or are there later drawings in print?

After this question is aired out I hope this thread is used to post E & O's and Mods to the drawings.

[Chipswitheverything]

  Hello GWR Driver, you may have seen the posts on this forum about my Major Beam engine that was substantially completed some years ago, ( but which, for various reasons, still awaits the painting and re-assembly being finished ).
 My castings also dated back to the mid 80's and the drawings were the 1979 ones that you would appear to have.  My posts do identify a number of issues that I encountered with the drawings, and a few points to bear in mind with the build as a whole.  This link is for the posts :                                                            https://www.modelenginemaker.com/index.php/topic,5941.0.html

Yours, Dave

[GWRdriver]

Many thanks Dave.
Yes I remember your build thread and because time and chores didn't then allow, I plan to read through both yours and John's thread as time permits.  Mine will be a slow build, spasms of progress interrupted by thought, error correction, other projects, and Sloth. 
The first job to be tackled will be the flywheel, primarily because I have momentary access to a 16" lathe and I'd best make use of it while it's available.

Harry

[snip] the drawings were the 1979 ones that you would appear to have.  My posts do identify a number of issues that I encountered with the drawings, and a few points to bear in mind with the build as a whole.  This link is for the posts :  https://www.modelenginemaker.com/index.php/topic,5941.0.html
Yours, Dave

[Chipswitheverything]

Hello Harry, thanks for that, your projected "progress" sounds just about spot-on for how my highly protracted build proceeded...

I was able to do most of the machining of the flywheel on a big Cochester lathe at work, long ago, but I daftly gave myself a problem by leaving the flywheel rim a bit meaty : the casting had plenty of depth, and I thought I'd take advantage of giving the rim a bit more heft, but when, much later on, I saw the flywheel on the engine, I didn't like it, it looked out of period, and needed reducing.  The use of the big lathe was no longer possible, I ended up with a bit of a nightmare session on my milling machine, using a small rotary table  ( I've got a big rotary T. now..!)  and an arrangement to support the rim right by the cutter. I took 1/8" cut or so off.
 The only incidental benefit of this session was that I was able to clean up the inner rim between the spokes effectively at the same time, and get that running truely.   The dia. now is just a trace under the 13 7/8" that Stuart give on the drawings... and the rim width just under 7/8" .   I think it looks OK.  Dave

[GWRdriver]

Dave,
I agree about the period appearance and reducing.  I've dust-binned one thought however, attempting to make it appear segmented, as there's not much can be done with this wheel, at least convincingly.  I'm now sketching other options to wind the clock back as well as the possible addition of barring pockets.  Sketches when I've arrived at something.

Harry

[snip] but when, much later on, I saw the flywheel on the engine, I didn't like it, it looked out of period, and needed reducing.

[ettingtonliam]

The full size engine which this model represents wouldn't have been very big really, so probably wouldn't have had barring pockets, they'd just rely on grabbing a spoke and heaving on it.

[Chipswitheverything]

Yes, I would agree entirely with the comment about it being not a large prototype, more the sort of thing that would have powered a workshop or perhaps a pump at a brewery or large country house?  Possibly no more than about eight feet high, and every bit accessible with a pair of steps.
From looking at what information I could find about actual engines of this size and period, it seemed to me that the details given in the H A Taylor drawings are just about correct for a prototypical model, without looking for embellishments that would really only be appropriate for a really big sort of beam engine like the magnificent Brighton and Hove pumping engines.  About the only thing that I did, a minor point and partly for appearance, was to make the nuts ( I made all the studs, bolts and nuts )  a bit deeper than modern practice, that did seem to have some validity.
 What I felt was worth taking the extra trouble over, was machining the various oval ended rods properly,all in one piece with spherically turned ends, and the little bit of elongation of the ovality specified in the Stuart drawings. It does help give the elegance that machinists of that period loved to create, and does reinforce the period feel..  Dave

[GWRdriver]

I have wondered from time to time what size the original inspiration for the model would have been, which would indeed dictate various aspects of construction.  If one assumes a scale of 1.5"/ft that would give us a wheel of around 9ft diameter.
Thanks for your insight.

Harry

The full size engine which this model represents wouldn't have been very big really, so probably wouldn't have had barring pockets, they'd just rely on grabbing a spoke and heaving on it.

[GWRdriver]

Dave,
I'm tempted, but perhaps this isn't the time to ask whether the jamb nuts are on the top, or on the bottom. 

Harry

About the only thing that I did, a minor point and partly for appearance, was to make the nuts (I made all the studs, bolts and nuts )  a bit deeper than modern practice, that did seem to have some validity.  Dave

[Chipswitheverything]

That's easy to reply to in my case  - all of the nuts and fastenings are just loose in a tin, while the whole thing is dismantled! 
But in fact, apart from the gland studs and nuts, the deeper nuts will just have to be done up tightly and take their chances. ( Though I've just found a few photos of older engines , like the fine Boulton and Watt engine at Crofton in Berkshire, where the glands are not lock-nutted...!)   Arguably the bearing caps should be lock nutted.
 While you are wondering about mods that might be made,  it might interest you to see a picture of a very beautiful, medal winning Major Beam that was at a show in UK in 2014, ( can't remember the builder..) I thought that the way in which the flywheel was partly sunk into the base, and needed a less deep plinth, was attractive.  I might try and take a cue from this base and plinth when I eventually make a proper base for my engine.  I think that the builder did a "cut and shut" on the flywheel bearing support casting.   Dave

[Jasonb]

I have always felt that the bearing support on this engine along with the smaller ones for the beam and Victoria look rather spindly. In full size the end of the crankshaft bearing may well have been built into a wall of the flywheel pit been a lot deeper with the bearing sitting on a similar height masonary plinth or down at ground level.

On both my Victoria and my beam I went for a deep pit with a 1" high support for the bearing which matches the height of the Victoria bed plate and cut down the tall beam bed plate to 1" tall.

If I were building the major then I would do similar

[Chipmaster]

Hello Harry & Dave et al,

Pictures of the medal winning Major Beam were at a UK show in 2014, they are featured on the Model Engineering Website, here's a link, the article states it was built by Theo Clift

https://modelengineeringwebsite.com/Stuart_beam_engine.html

Harry, I sent you a personal message yesterday about the Major drawings which might be helpful.

Andy
   

[GWRdriver]

Andy,
Thanks for the information.  That will indeed be helpful.

Harry

[GWRdriver]

Hello All,

Since my last I've been working on a scheme to restore the geared cross-shaft and outboard belt wheel of the original George Gentry design (and the ME Beam Engine) to the Stuart engine.  That detail was left off the Harry Taylor re-design of 1968, as apparently Taylor didn't care for the cross-shaft arrangement, instead locating the single belt wheel on the crankshaft next to the flywheel.  This made no sense to me, locating a primary belt wheel in such an inaccessible location, and it removed mechanical interest from the model as well.

I began with two objectives, first to replicate the gearing proportions of the ME Beam Engine which was, after all, re-scaled from the Gentry design, and secondly to avoid making an orphan of the Stuart belt wheel casting although it was apparent from the outset that the Stuart casting would make a proportionately larger wheel than on the ME Beam.  If closely adhering to the proportions of the ME Beam, the re-scaled gear wheel would need to be about 4.25" (±108mm) OD, however the casting won't allow that and is best suited for a gear of around 5.50" (±140mm) OD.

After much experimentation with Diametral Pitch and number of teeth I found that an 86 tooth x 16dp gear produced the most appealing tooth size and gave a well-proportioned look to the wheel rim - not too much metal left on, not to much metal taken away.  The pinion will be 24t x 16dp and the photo represents this arrangement.

At a demonstration speed of say 15rpm I'll end up with somewhere around 50rpm at the belt wheel, and I'll look to pick up a nicely proportioned flywheel casting somewhere for the belt wheel.  Gear wheel spokes tended to be meaty, but belt wheel spokes tend to be more delicate so a traction engine flywheel might fit the bill.

I've not laid this out on the base to see what will be required for the cross shaft bearings but I suspect little more, if any, that what one sees on the ME Beam.