Another Stuart Major Beam Engine ( some comments and photos)

[Chipswitheverything]

Have been passing a wet and cold day here rummaging around in my photo files for what I may have as a record of the building of my Major beam engine.
The castings were bought back in 1989, and are from the original Stuart Turner foundry as far as I know.  The quality of them was not as good as the castings that I had had in 1979 for making the No 1 engine.
  As with my vertical engine featured here, a lot of the machining has been done before the digital age, and set ups have gone unrecorded. The photos that I do have of the later stages and components have only been taken as record shots with no thought of making them public, so please bear with some rather poor photography done with an ancient digital camera!
  I have enjoyed a good look at the build log that Andy ( Chipmaster) has been writing up, and his good work on the castings covers most of what I might have attempted to illustrate on that anyway.  Alan ( Steamhead) has indicated a lot of the drawing errors that Stuart has strewn in the path of builders.  I've got a couple more...

  As Alan himself has said, when the rather long job of building this beam engine is already mostly done, where do you begin in trying to do a write up?

Well, what might be as good as anything may be to bung in a few photos to get things under way, and add more pictures and remarks over a period of time.
 If there are aspects of the build or individual components that members are interested in particularly, do bring them up and I'll see if I have photos concerning those items.  Otherwise, I'll just chunter on......!
 
 Presently the whole engine is dismantled and the castings have been masked off and mostly sprayed with filler primer, - so they are not really accessible for extra photography.
 Before the model came to bits before Christmas, I grabbed a few shots of the unpainted engine assembled  - more or less - on it's simple plywood box that made a base to build the thing up on. These are the first couple of photos.

I'd made the parallel motion links way back when I first got the castings:   though I was doing other model engineering projects I just couldn't wait to see how they'd look!  For ages, that was the only bits of this engine that I had done, kept them propped up on a shelf to remind me to make the rest of it!

The governor has been made fairly recently, got some pics of that.  An interesting sub- assembly as one might say ( through gritted teeth...)  I haven't modified the height overall, as although it might thereby miss the flywheel, it seemed to me that it was still going to clobber the forked end of the con-rod with little extra travel gained.  To be honest, I'm not entirely convinced that it will effectively govern the speed anyway, but others may be able to answer that one...

The stop valve and lubricator...   quite fun to make!

More later on, cheers, Dave

[Chipswitheverything]

Whoops, didn't put the stop valve picture up.....    sorry!

[zeeprogrammer]

Nice stuff!

I don't even know where to begin...the governor, that handwheel, and a bunch of stuff I don't know the names of.

 

[jeff l]

great job

[10KPete]

Beautiful engine, Dave! Great detail and attention to fit and finish. I could stare at that for hours just soaking up the little
'engineering' things like the way the bearings adjust on the two short drop arms; a strap with the wedge at one end. Cool!

Pete

[fumopuc]

Hi Dave, this engine looks very well done. Nice details are shown.

[Chipmaster]

Hello Dave, another Stuart Major, this is like buses - you wait ages then along come a stream of them together!
It is both reassuring and an inspiration to see your excellent model. I am sure craftsmanship like that pictured on the MEM website has a benchmarking effect. You bought the castings in 1989 and I bought mine in 2013 it seems Stuart Major builders don't rush things. May I ask what machine tools you have?
Andy

[Chipswitheverything]

Many thanks for your interest and generous comments guys.
  Andy, I'll put up some workshop photos in the Workshop thread, that might be the best way to feature the machines.  Any members who are already familiar with the Yahoo forum for Tom Senior mills can skip looking at the pictures, they will already be bored with having seen them before!  For any member with a Tom Senior mill who hasn't found that particular forum, it's a very handy resource, a lot of helpful people and info...

Cheers, Dave

[Don1966]

Nicely done engine Dave and great attention to details. Lovely work...........

Don

[Dave Otto]

Beautiful engine Dave!

The governor is spectacular and your attention to detail on all the parts really shows.
It is going to be a stunning model when finished.

Dve

[scc]

It's already all been said,   an outstanding engine and an inspiration to a  lot of us.   Very well done.          Terry

[cwelkie]

Simply gorgeous!  I'm glad we got to see it before (and hopefully) after paint.

[Chipswitheverything]

Hi Guys, I've taken a few more photos of dismantled bits of the beam engine.   Here are a few shots of the steamchest which will illustrate a snag that I met up with.
  Made the valve rod with its cap like end to the drawing, rod seems to be the right length, but Houdini wouldn't get it in to the steamchest without bending it with pliers!  ( I'm using 1980's drawings, by the way, just a chance that later issues have dealt with some of my points...? )
 So, I drilled and threaded a fine pitch screwed hole in the bottom of the casting, 3/8" dia. I think, and have made a bronze plug that will go in when the engine is finally assembled.  Won't really be visible when all is done.

 I didn't have the almost illegible "errata" sheet that has been mentioned, but luckily I twigged that something was wrong with the length of the long fish-bellied eccentric rod that runs most of the length along the engine to meet up with the hand-lever.
 Like Alan did when he met up with the problem, I did a lash-up to get a measurement from the engine itself.  Made up a couple of wooden laths that fitted the eccentric strap and the pin on the lever, and mucked about with the bits of wood clamped with a couple of little toolmakers clamps until I was happy that the lever swung equally about the vertical position, and the links also moved on equal arcs about the horizontal and didn't clobber anything.  Just measured off from the wooden bits then, of course.  That long fish-bellied rod isn't an easy component, you'd really have something to moan about if you made it the wrong length thanks to the dwgs!

The valve links were drilled off and pinned with the taper pins after their positions along the rod that sits in the little bronze bearings was taken from the engine itself, with the rest of the valve gear rigged up.  Working from the hole positions given by Stuart could result in binding - they are not necessarily wrong, but you do need to see how the assembly sets up on your own engine.   I used my Finger Plate to the George Thomas / Hemingway design to do a holding set up to drill for the taper pins, as shown.

I think that the Stuart drawings are in error when it comes to the pinned longitudinal position of the hand lever at the end of this valve link shaft.  Having cut the small keyway, I did drill and pin the lever where they had indicated, and later found that the pin on the lever was well out of line with my eccentric rod, - had to move the lever inboard and re-drill.  So leave that job until you have the rod and lifting "gab"  ( and the eccentric on the crankshaft! ) to do the alignment with.

Need for coffee calls, I think!,  laters....

[smfr]

Very interesting, I haven't seen that kind of valve rod/valve setup before. The plug seems like a fine solution to the problem!

I wish we had one place where we could keep track of errors in plans. I keep having vague memories of reading about errors in Stuart plans, but can never find them again. Perhaps we could have a curated section here on MEM?

Simon

[Chipswitheverything]

Here is another view of the drilling on the Finger Plate, which might make it clearer.   Dave

[Don1966]

Dave thanks for showing a well demonstrated use of the finger plate. Don't you just love how well it works? I keep mine on the Pillar drill.DON

[Chipswitheverything]

Hi Don, every model engineer should treat themselves to a finger plate, even if they only fancy an intriguing paperweight!   I only made this a few years ago, but I was thoroughly pleased with it, it is certainly very useful and has got a chunky sort of appeal.  This one is a bit bigger than the size given by Geo. H Thomas. ( Sorry, this should really be in the tool section....)
  For many years I was fortunate and privileged to often visit George Thomas in his fine workshop here in the south of England.  On his surface table were always the finger plate, the miniature scribing block and the rule holder to his own design. I've made up the latter two items as well...  Dave

[10KPete]

Gentlemen:

How big is that plate? I know how big I would make one but I'm curious how big that one is. 

Pete

[Chipswitheverything]

Hi Pete, just nipped out to the workshop to measure the thing!, it's 3 1/2" square by 5/8" thick...    I think the original design was for 3" by 1/2" thick.  Just depends what stock you have and the sort of components you work on.  I'd say the bigger size is a good one.   Dave

[10KPete]

Thanks Dave!  I was thinking 3 1/2 to 4 but that was before I started giving serious thought to these small engine models. Said models seem to be the way I'm going as I get older. Used to be that I wanted to build a H&M about 2 1/2" bore but the one on
the drawing board is 1 1/4" bore. And even that is looking large now! 

Pete

[Don1966]

Pete the original design from Hemingway is 2.5" by .75" thick. Love the photos Dave. This is the one I built quiet a few years ago.



Don

[10KPete]

Thanks for the pics, Don. What is the big screw knob on the back side used for? Do you attach the plate to the pillar tool sometimes?

Pete

[Don1966]

Yes I do Pete with the big screw knob you see. That's where it stays....

Don

[10KPete]

Thanks Don.

Pete

[Chipswitheverything]

Been a bit too busy being distracted by getting the bits of my Stuart Steam Hammer almost done! ( and the usual "life gets in the way" stuff...)    But here are a few, not too great, pictures of the beam engine parallel motion.
 
  The second photo of the assembly gives an idea of the close clearance that exists between the headed pins that support the radius rods and the extreme width of the moving links themselves - the clearance is about that shown in the upper gap, ie. not a lot!

  I've seen a few engines, and certainly others in photos , that have run into alignment problems here, and the builder has had to thin down the heads of the pins or adopt some subterfuge.  Stuart Turner did not give a GA of the plan view of the motion work, or even a scrap view, but a good drawing ( though the side view GA is no more than a guide to where to put the bits! ) would be a helpful alert to the builder.  I suppose that someone a bit more switched on than me might have made their own, or added up all the dimensions...!  But you do tend to assume that there will be a bit of room...

 Nevertheless, because the componentry that mounts from the spring beam - the motion work, and the tapered strut that links spring beam and cylinder boss - are separated by some considerable distances from the base mounted components ( both in vertical distance and along the length of the engine ), there is a good deal of error that can creep in by extrapolation of quite small discrepancies.  I had the same sort of trouble as Andy (Chipmaster) experienced when trying the correspondence of the end strut hole on the spring beam, with the hole in the lug on the top of the cylinder. ( I'll say a bit more about this later on, I think that both of us met the same  difficulty with the slightly "off" cylinder casting ).

 As for the motion links, I did use a bit of a naughty technique to get the cotter slots looking crisp.  I didn't much fancy my chances with drilling and needle filing. The slots were put in with a slitting saw, while the links were still largely solid blanks. Then loose gap pieces were pushed in, width of cotter and gib, which spaced off the material for the end closure of the links.  The links were drilled through, about 7/64" if I remember from over 25 years ago!, and the pins riveted and flushed. They can't be seen, and for an engine that will only ever do some gentle demo running, there's plenty of strength there.
 As I wondered if the bearing centres would be quite consistent between all four links, with the component stack, I drilled slightly undersize and opened out to finished dia. with the links assembled  ( think that I jigged them up on the mill table and used my little Geo. H. Thomas design boring head...)

Cheers, Dave

[zeeprogrammer]

Nice to see an update.
Those pictures are intriguing. Need more. 

[10KPete]

Nice work. I've always liked the way those original designs took care of adjustments.

Pete

[Chipswitheverything]

Hi guys, thanks for the comments.
 The components that make up the big and little ends of the con rod are quite similar to the elements of the parallel motion links, and were done using the same kind of sawing and pinning technique.  In the cast iron rod casting itself, I put three small pins in the big end, and two in each side of the small end.  I've made the straps the same width as the rod ends. But what I thought was a mistake on the Stuart drawings, with the strap width narrower than the cast rod ends, does actually seem to be intended, (I've seen a superb example of the Major beam done that way ). I don't think that it matters which route is followed as long as the dimensions are checked out for either scheme.
 Gauge plate form tools were made up to do the decorative rings while the rod was between ctrs. in the lathe.  The taper in the centre area was worked in by small adjustments of the top-slide to create a shallow curve.   ( Sorry no photos, it was all a long time ago! ).    Yours, Dave

[Chipswitheverything]

One photo didn't load for some reason....

[Jo]

Nice Dave 

  Now I'm getting the desire for a set of Stuart Major Beam Castings. Not that I would have anywhere to put the finished model  .

Jo

[Mcgyver]

I've always thought that Stuart M.B.E. was a particularly great looking model...and you've done a first class job on the build. 

I was looking the other day at the 1959 ME build, or rather it's a revisit of George Gentry's design published in the early twentieth century.  I believe that is loosely what the Stuart design follows?  Looking a bit further, I found compete 3d cad models for it on grabcad.  Amazing, people who's hobby it is to do 3d cad models have chosen some of these great old engines.   Project number 648 in the queue is to take some hunks of cast iron, a 3d model, a cnc machine and see if I can wittle one of these without castings

[Chipswitheverything]

Jo, having got some idea of your casting stock whilst looking back through ( some of !) your very many, and very interesting posts, I have no doubt at all that a set of these beam engine castings will be joining them....

  Mr Mcgyver, the Stuart Major does take some of its parentage from the old Geo. Gentry design, but by way of the Championship cup winning model that Mr H A Taylor made and exhibited at the Model Engineer exhibition circa 1967.
  H A Taylor did a useful illustrated write up of aspects of his engine build in two issues of Model Engineer magazine during 1968. ( Late June/ early July issues ). His beautiful award winning engine followed the Gentry design in many respects, but where some patterns had been lost, Mr Taylor redesigned the components to his own specification.
 Such patterns as survived had belonged to the SMEE, and they were sent to Stuart turner to be cast.   Some of the other components were made by constructing them from the solid, and a lot of free machining stainless steel was used.  So when Stuart decided to market the Major, they must have had to make up various patterns to supplement whatever was there from the original set.  H A Taylor made his connecting rod from an 18" length of stainless steel bar!, forging the "U" end, so Stuart has at least saved lesser mortals from that operation by producing a nice casting.

I've read that the 1959 write up and drawings for the 1" scale engine is full of dimensional mistakes, whether these were ever corrected in the marketed drawings, perhaps another member with experience of this 1" engine can tell us.

Yours, Dave

[JR72]

Hi David
What else would I expect? Great pictures model engineering at it`s very best, and to see it on your bench as I have done well it`s just awesome.
John

[derekwarner]

Dave....these tapers as shown, do they act in the same manner as a Morse taper ie., self locking with minimal engagement force and a similar light force for disengagement?...[7 - degrees comes to mind?]

From memory, in older  lathes, the Morse taper in the tailstock did actually deform after thousands of engagement impacts from the hardened sleeves and sometimes required a piece of cigarette paper to take up the  slack.....

So I would assume the same would not apply here as the tapers locking these engine components would not be an often disengaged part

Is the straightness, flatness & surface finish of the tapers still a required or attained constant in model engineering......are they blued & scraped as in full size similar applications in industry?

Derek

[Chipswitheverything]

"Is the straightness, flatness & surface finish of the tapers still a required or attained constant in model engineering......are they blued & scraped as in full size similar applications in industry?"

Hi Derek, I made the tapered cotters and gib pieces to the Stuart drawings and they lock very well on assembly. A tap with a little brass block will free them easily enough.
 These components are pretty small, only about an inch long for the cotter.  I doubt that I did more than draw file the edges by running them along a fine Swiss pillar file. On the real engines I can imagine that the fitting of a foot long by inch thick cotter and gib did involve blue and a careful process.
 The main difficulty with these parallel motion links over the (too ) many years of the Major build has been ensuring that all the separate bits are kept with the applicable link, and all taken apart and reassembled - on such occasions as have been needed - in the right orientation. The pieces are a bit too small to be able to mark effectively. As far as I can, I don't dismantle them at all!
 
John, thanks for your kind comment.    Cheers, Dave

[Mcgyver]

I've read that the 1959 write up and drawings for the 1" scale engine is full of dimensional mistakes, whether these were ever corrected in the marketed drawings, perhaps another member with experience of this 1" engine can tell us.

Hi Dave,

Thanks for the information.  On drawing errors, the 3D modelling should catch errors before the turn into parts.  As I mentioned there are a couple of models of the '59 engine on grabcad, free for the taking.  These let one inspect part by part how it comes together and spot inadvertent interferences.  It would be interested to connect with the cad modeller and hear his take on drawing errors -  at least one of them modeled from the '59 drawings. 

[Chipswitheverything]

Hi Guys,
While I should have been busy with the filling, priming and painting of some more beam engine bits, for some reason I have been mucking about with the Stuart steam hammer bits and pieces that I've mentioned before. I've only had them since 1979, so you can imagine the sense of urgency...

 Yesterday I did a "fer instance" bunging together of the bits of the thing, so that I could make a list of jobs still to attend to on the hammer. The list took up most of an A4 sheet, so there is a little way to go.  But though the hammer is just crudely chucked together with missing bolts, gaskets, and various bits skew-whiff, it was quite exciting to me to get a glimpse of its what may be its potential once it's all eventually sorted out.   ( Not to say, painted...!)  Treat these photos very much in the spirit of a work in progress.

Got the base casting set up on the mill again, for trimming the column plinth with a radiusing cutter, so better go and do that!

Cheers, Dave

[Chipswitheverything]

Just reviving if only slightly, this antiquated post of mine about the Stuart Major beam engine.  The dismantled engine is still in the filled and primed state. Ridiculous, but in the mean time some years have been mostly taken up with totally unrelated things necessary to deal with, and the Stuart steam hammer and the Quorn tool grinder have been much worked upon and now finished.
 I was lucky to see the very fine example of a Major Beam which won a Gold Medal at Sandown Exh. some years ago, and I was taken with the way the builder had designed the plinth , which let about a quarter of the flywheel down into a well, and made the main rather massive plinth for the bedplate lower.  Thought the proportions and general appearance were improved by the change.
 
The casting as supplied to support the outer crankshaft bearing is about 6" high, and it needed a cut and shut modification to about half height to appear like the one on the Sandown engine. There is not a lot of spare iron in the legs of the casting, so I did the drilling for 4BA capscrews and some 3/32" dowel pins in the mill to be sure of the positioning.
 The match of the cast struts with big sections cut out, and the faces milled off, was pretty good;  a spot of filing and rubbing down with primer will fair the bits in and hopefully not show at all .
 Not the most exciting update!, but I'm scheming out some ideas of how to make the base and looking for materials, the project might lurch back into life...  Dave