Stuart Twin Victoria: Advice & General Questions

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Stuart Twin Victoria: Advice & General Questions

This topic has 94 replies, 12 voices, and was last updated 1 November 2020 at 22:24 by Dr_GMJN.

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20 October 2020 at 21:22 #502352
Dr_GMJN
Participant
@dr_gmjn
All,

As discussed elsewhere, my second ME project after building a Stuart 10V will be their Twin Victoria.

Since I've not started it yet – it will probably be early next year funds permitting – I didn't want to start a "work in progress thread", but I will do once I make a start.

I thought I'd start this thread to keep all my questions, and people's advice, in one place. From my "which second model?" thread, I've concluded the following:

* I will buy just the main castings, and brass/gunmetal extrusions etc. from Stuart, the rest I'll source myself, and hopefully save some cash.

* As suggested by Jason, I will fabricate the beds out of aluminium, modified slightly to omit the un-used bearing pads. I've not decided whether to machine casting draw on their sides yet, or whether to add a step around the bases.

* I have sourced all the fasteners, although according to the images on the BA Bolts website, the terms "bolt", "set screw" and "part threaded" aren't clearly defined in terms of which type is available in which size. I know the difference between a "set screw" and a "bolt", but not between "part threaded" and a "bolt". All a bit confusing; the images show a mix of types under "bolts". Of course I may have misunderstood their definitions. Anyway, I've found the threaded rod, and will buy lengths and cut to size. Same with some of the shorter bolts/set screws (or whatever they end up being!).

* I have a local materials supplier, and am awaiting his price for all the stock materials.

* I have already bought the Stuart plans, and have the parts list.

* The model will be mounted on a hardwood base, and possibly only ever be run on air.

* I'll go with Ramon's suggestion of bronze pistons with PTFE impregnated yarn rings.

* I'll try to reduce any drawn Bright Mild Steel in size symmetrically to avoid too much distortion, although I notice that the upper crosshead guide bars are tapered on their upper faces from nominal stock size. Can't be much of an issue presumably. Likewise the connecting rods are turned from square, leaving the angular ends. Presumably turning in this way wouldn't be much of an issue becasue they are symmetrical (bulged in the middle), or would distortion in-process be a potential problem?

So on to some other questions (there will inevitably be more):

1) Is it worth getting the Stuart book on building the Victoria (or are there any other relevant books I could request for Christmas)?

2) I'd like to add a governor, but am aware that they are not easy to get to work effectively at this scale. The Stuart governor kit appears to have linkages that imply it works – is this correct? Even if the governor wouldn't be functional in terms of controlling speed, I'd still like to include one, with operational linkages that perhaps feed into dummy valves. I like the look of the governors on a separate central pedestal – Jason mentioned a "Princess Royal" version, but I can't find a reference – are there plans for this type? I'd also like to use a shaft and bevel gear drive, I think the spring band drive looks a bit Mamod.

3) I'd like to add a few details like railings, which isn't an issue, but are there any other details I could add, such as perhaps a feed pump, or mechanical oilers? If so where can I get kits or plans for them?

4) Bearing in mind it will be run on air, is it possible to add oilers with isolation taps to the valve chests (or somewhere else) to lubricate the valve gear and cylinders?

5) Does anyone have reference images of real-life twin cylinder mill engines as inspiration for perhaps adding a few other details?

Thanks very much all.
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20 October 2020 at 21:22 #27719
Dr_GMJN
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@dr_gmjn
20 October 2020 at 21:49 #502358
John Olsen
Participant
@johnolsen79199
So here are my thoughts:

1 It is usually worth having the book for a project, even if your equipment requires a different approach it is useful to see how someone else did it.

2. A governor would look good, whether it is actually controlling the speed or not.

3. Feed pumps and oilers would certainly be a possibility, although to be in scale they might get to be fairly fiddly. What about something appropriate for it to drive? Maybe a workshop full of 1/12 scale machine tools?

4 Bear in mind that if it is to run on air, the oilers must be mechanical, not displacement. Displacement ones don't work on air, since the air does not condense easily!

5 You might be able to find something on the various museum websites, or from books, maybe from the library. Older issues of ME have been known to have articles on such engines, you might be able to find a club with a full collection.

John
20 October 2020 at 22:22 #502367
Mike Henderson 1
Participant
@mikehenderson1
Reference Jason's mention of a "Princess Royal" variant, this was a construction series by Tubal Cain (Tom Walshaw). It offered enhanced detail to represent a mid 19th century textile mill engine alongside "Goliath", a reversing steel-mill engine from the same base castings.

The series ran in alternate issues of the M.E. from 1984 vol153 issue3736 to 1986 vol156 issue3768.

As with all Tom's build series, it offered sound guidance and would be worth reading, even if there was no intention to dress the engine up with the added detail. Given the era, it was probably based around doing everything in the lathe.

IIRC the mill engine included at least a representation of a governor, while the steel-mill engine included gear reduction to a layshaft
20 October 2020 at 22:42 #502371
Dr_GMJN
Participant
@dr_gmjn
Thanks both.

Don’t get me wrong – I’m not after a true-scale model, just a bit more than the basic workings. Some railings and a shaft-driven governor would be fine without going OTT.

I guess the “Princess Royal” articles weren’t compiled into a book? They sound like what I’m looking for, but obtaining all those magazines would be painful.

Cheers.
20 October 2020 at 22:43 #502372
Paul Lousick
Participant
@paullousick59116
As mentioned, displacement lubricators will only work with steam. When running on air use an airline lubricator available from hardware and compressed air accessory suppliers.

Paul.

Edited By Paul Lousick on 20/10/2020 22:49:59
20 October 2020 at 23:06 #502378
Dr_GMJN
Participant
@dr_gmjn
Thanks all – I realise a displacement lubricator isn’t appropriate for running on air – that’s why I only mentioned a mechanical one, or perhaps a “tap under a cup” oiler (if such a thing exists) to occasionally allow oil into the valve chests.

Cheers.
21 October 2020 at 07:13 #502394
JasonB
Moderator
@jasonb
1. As the book is not too expensive it may be worth getting though I've not read it myself so don't know how much detail is in it and whether it was written with use of a vertical slide or mill in mind.

2. Most governors will have a linkage back to the valve but generally don't work well at slow engine speeds and small scale. The princess Royal articles have these added details and are as good if not better than the book. Leave it with me

3.bear in mind that any pumps, governors etc will all add load and drag to the engine so could affect slow speed running. I would not fit the Stuart feed pump that you see on some engines as it is out of scale

4.An oil cup with lid and cock valve along the lines of a drain cock would be best on the chest as you can fill it with oil while the cock is closed, put on the lid and then open up the cock and it will slowly drain into the chest

This is a nicely done Princess Royal
21 October 2020 at 08:25 #502410
Henry Artist
Participant
@henryartist43508
Since it will be some time before you begin your new project you may find it beneficial to watch Keith Appleton's videos on YouTube.

Keith Appleton's videos
21 October 2020 at 08:27 #502411
Ramon Wilson
Participant
@ramonwilson3
Hi Dr G,

Well it looks like you have set out on another enjoyable and satisfying journey – I wish you well

My thoughts based on my own build.

I made the Stuart governor and yes it did work – after a fashion – on both air and steam. Applying a drag to the flywheel would open the valve. The issue as I see it is not so much getting the 'governor' to work but in the valve it actuates. To get the variation of air/pressure required to be effective requires a small inlet area (not ideal) or a large movement of the governor arm (even less ideal). I like your idea of a gear driven central governor and there are several to choose from but do bear in mind it has to be in keeping with the period of engine design.

Oilers – a mechanical oiler could be fitted and driven of the crosshead but getting it in scale will be difficult. Small oilers around the model can be made of varying types. I have successfully used the glass clear tubing that protects artists paint brushes. After running my engine for several years on steam at a local event the gas was forgotten at one time. Coupling up to the air system gave an instant freedom to wander at will with the engine running – something not possible on steam. To 'oil' the internals I injected a godd slug of steam oil into the air inlet before connecting the airline. This has proved totally sufficient to coat the inside surfaces for three or four hopurs running on all engines built since. Not realistic perhaps but certainlt effective. I would agree with Jasons suggestion that the feed pump is out of scale but it does work. Given you are likely to run only on air a more scale like version could be fabricated – doesn't neccsarilly have to work but that's your choice

Fastenings – at the moment I am fitting what seems like a never ending amount of studs and screws to my current build. Most source their fastenings from EKP though there are other sources. Bolts (or part threaded) are not so easy to find these days especially with the smaller head size. Having just fitted 32 8BA studs to two steam chests only to find despite careful manufacture the protruding parts are of differing heights I removed them all (two, BTW being extremely difficult to remove) I made new 'studs' by loctiting nuts on surplus screws at the right height then turned the top to length holding them in a small fixture – all identical as they would have been full size – studs were always fitted to each hole and the height of projection equal within limits. Maybe not for the perfectionist but theres no difference to using hex headed screws which aren't correct to proto type.

There's quite a lot of engine reference on the net these days to help with realism. There are also books by George Watkins worth looking for but most of these cover engines much larger than the Twin Vic. They do have pages and pages of inspiration though! The Twin Victoria was a conjecture – the original 'Victoria' was based on quite a small engine found in a small workshop. Most engine manufacturers offered twin layout versions of their engines so this design was based on that approach I believe and not on any true prototype.

Hope some of that is of use to you

Regards – Ramon

Edited By Ramon Wilson on 21/10/2020 08:27:53

Edited By Ramon Wilson on 21/10/2020 08:29:45
21 October 2020 at 08:58 #502414
Ramon Wilson
Participant
@ramonwilson3
Dr G –

Heres a pic of my version which may be of interest. I have uploaded other images to an album though I don't know how to provide a link to it.

Ramon

PS I would, if possible, mill the draft angles on – surprised how much difference that makes when trying to replicate a casting.
21 October 2020 at 09:13 #502417
Dr_GMJN
Participant
@dr_gmjn
Posted by JasonB on 21/10/2020 07:13:04:

1. As the book is not too expensive it may be worth getting though I've not read it myself so don't know how much detail is in it and whether it was written with use of a vertical slide or mill in mind.

2. Most governors will have a linkage back to the valve but generally don't work well at slow engine speeds and small scale. The princess Royal articles have these added details and are as good if not better than the book. Leave it with me

3.bear in mind that any pumps, governors etc will all add load and drag to the engine so could affect slow speed running. I would not fit the Stuart feed pump that you see on some engines as it is out of scale

4.An oil cup with lid and cock valve along the lines of a drain cock would be best on the chest as you can fill it with oil while the cock is closed, put on the lid and then open up the cock and it will slowly drain into the chest

This is a nicely done Princess Royal

Thanks very much Jason – the Princess Royal looks pretty much exactly what I had in mind.
21 October 2020 at 09:15 #502419
Dr_GMJN
Participant
@dr_gmjn
Posted by Henry Artist on 21/10/2020 08:25:58:

Since it will be some time before you begin your new project you may find it beneficial to watch Keith Appleton's videos on YouTube.

Keith Appleton's videos

Thanks Henry – I watched a lot of his videos on YouTube before and during building the 10V. I found it useful to see the features of a "good" engine, and, probably more interestingly, the faults and errors (all in his opinion obvously).
21 October 2020 at 09:28 #502420
Dr_GMJN
Participant
@dr_gmjn
Posted by Ramon Wilson on 21/10/2020 08:58:32:

Dr G –

Heres a pic of my version which may be of interest. I have uploaded other images to an album though I don't know how to provide a link to it.

Ramon

PS I would, if possible, mill the draft angles on – surprised how much difference that makes when trying to replicate a casting.

Thanks Ramon (and for your previous post). That looks brilliant. I can immediately see refinements such as a round eccentric rod rather than the flat one as per the plans – looks so much nicer.

Re. fasteners – I suppose set screws or bolts aren't too relevant at this scale, and if anything specifically needs a shank, I can make my own fasteners. Re. stud protrusion – I made a very simple adjustable tool for the 10V where I screwed the stud up to a stop, added retainer, then screwed it into it's hole (with or without a washer as required). Once the retainer had set, I unscrewed the tool and did the next one. It guaranteed every stud protruded by exactly the same amount.

In general, what type of inlet valve is used on a governor? Is it a balanced type like a butterfly, or perhaps a barrel similar to on an rc aircraft engine? Presumably a needle type (like the Wilesco valves) have far too much friction? I was wondering if, for running on air, a valve body could be machined from Teflon, the spindle bearing being long enough and a good enough fit to not require further seal (like an SU carburettor butterfly spindle).

Yes, to Jason's point, I can see avoiding rotational impulses at low RPM would be a challenge.

Cheers.
21 October 2020 at 10:07 #502428
Ramon Wilson
Participant
@ramonwilson3
This engine is certainly one you can put lots of personal refinements into.

Apart from a twin oscillator this was my first attempt at a steam engine. The images were taken just before I sold it which was some years ago now.

When I look at it now I can see all sorts of things that would/could be improved upon. As mentioned some time back I definitely would not groove the flywheel as drawn – far too over scale and would not put the barring holes in the centre either. An extra groove per wheel plus another instead of the barring rack would be about right I would say – the rack could be milled pockets on one outer (or inner) edge

The big end could be improved along with many other parts – just down to a bit of research and personal desire. Making the con rod from round bar milled square would eliminate most of the stress problem – my latest is a composite – big end and rod all one piece, little end milled and turned separately set into the rod with loctite and pinned.

I have made three engines with governors so far – all have had a throttle barrel similar, as you say to an R/C carb, set in each manifold block. All have worked to a small degree – none have worked what you could call effectively. If that characteristic is something important to you then it's worth persuing if only for self satisfaction but personally I'm quite happy if the engine runs well and the governor is to a degree 'in sympathy'. Not sure about a Teflon body – very 'greasy' stuff to machine. I would favour a minimal fitting o ring but keep any radial drag to an absolute minimum – it's worked for me so far.

Your method of fitting studs is certainly a viable method – I had relied on the stud seating at the end of the thread. The two that were difficult to remove had, I'm sure, bottomed out in the hole. I first saw the method I turned to on Graham Bantocks scratch built Andrew Mount models at our local Forncett show. As said, an effective if not true to prototype way to achieve realism.

Some what topically I have several more 8BA 'pseudo studs' to do this morning (54 to be precise!) so that's where I'm now off to

Regards – Ramon

Edited By Ramon Wilson on 21/10/2020 10:09:52
21 October 2020 at 10:51 #502435
Ramon Wilson
Participant
@ramonwilson3
Posted by Ramon Wilson on 21/10/2020 10:07:45:

I first saw the method I turned to on Graham ~~Bantocks~~ scratch built Andrew Mount models at our local Forncett show.

Apologies to Graham Brundall – senior moment I'm afraid Graham. Bill Starlng send his regards.
21 October 2020 at 11:44 #502452
Dominic Bramley
Participant
@dominicbramley60728
Hi,

I haven't read the full series on Princess Royal and Goliath so can't comment on whether it is worth tracking them all down, but based on some advice on this forum I did obtain Magazine Vol. 153 Number 3742. This issue details how to join the 2 flywheels together which is the job I'm most unsure about looking at the plans – and something that is unique to the twin so not detailed in the book.

Regards

Dom
21 October 2020 at 12:32 #502465
JasonB
Moderator
@jasonb
The 1" x 2" Stuarts tend to use a butterfly valve in an elongated piece of their oval pipe gland material, I have used butterfly style on other engines as well as the barrel type and balanced bobbin type on the 2" traction engine.

I'm not dead keen on the doubled up flywheels, Think I would source a wider one or get some thick wall tube and fit that around the spokes of a standard 7" stuart one.

I posted this link on MEM the other day to a PDF of an old book that has lots of interesting engine details that could be included in your own version.

Ramon, I would think a small feed pump like Chris has on his Hemmingway engines would be more in keeping and the recirculation water he has when displaying them adds some interest.

All this talk of fabricating a twin Victoria has got me wanting to draw up my own "Vicky" with 24bore x 48stroke, all metric and maybe she could have a twin sister or if that sister was fat then a compound would be a possibility
21 October 2020 at 14:07 #502486
Ramon Wilson
Participant
@ramonwilson3
I had considered a scaled up version quite some time back Jason so as to incorporate all the thoughts I had after doing the original.

As the engine is based on quite a small prototype however I came to the conclusion that to scale it up to represent a much larger full size engine it would be too light in structure – certainly in the bed plate area so it went the way of many ideas I'm afraid. It would make a very nice model scaled slightly as is though.

Chris makes all his pumps to his own ideas as far as I'm aware. Easy enough to do – there are drawings of many types out there – the 'outside' can be 'however you want' of course.

It's a long time ago Dom, but I believe I recessed one flywheel slightly to take a register on the other. I certainly did that on the Throp flywheel. It was then held together by screws deeply counterbored the holes for which were plugged with cast iron and the faces turned to leave no witness. I would certainly agree with Jason that this would look far better with one set of spokes and a wider rim fitted if possible.

As said before this design lends itself to all sorts of personalisation – sky's your limit Doc

Ramon
21 October 2020 at 15:03 #502501
JasonB
Moderator
@jasonb
As you say Ramon it is based on a small workshop engine said to have had a 5ft flywheel so any handrail posts would need to be about 4" tall unless other things are altered to give the impression of a larger engine.

I've managed to find most issues wit Princess Royal in them but if anyone can scan parts 5 & 6 in issues 3746 and 3748 please PM me.
21 October 2020 at 15:31 #502504
JasonB
Moderator
@jasonb
This horizontal from Gil's collection has some nice features that could be included, I've had some images of it saved in my Future projects" file for a while.
21 October 2020 at 16:07 #502508
Dr_GMJN
Participant
@dr_gmjn
Some inspiration there, thanks all.

With the Princess Royal, how are the cylinder mounts integrated into the casting – I like those. Are they different castings?

I also agree with Jason about the double flywheel – I'd prefer a single row of thicker spokes. Are there any alternatives from the Stuart range, or elsewhere? If it was a bit thinner it might also be easier to fit a governor drive bevel gear next to it.

How could the governor be damped to smooth out speed impulses at low speeds? I like watching the 10V at really low speeds but it is a bit lumpy, same with the Twin Victoria I suppose. I was thinking of something like extending the governor axle down into the baseboard, and mounting a hidden, horizontal flywheel under there. It would probably have to be mounted on a sprag clutch so that only the peaks in speed are used to drive it, otherwise you'd be trying to back-drive the mass of the main flywheel in the low speed bits of the cycle.

Maybe I'm over-thinking this…I really need to read up on governors.
21 October 2020 at 16:26 #502512
JasonB
Moderator
@jasonb
Posted by Dr_GMJN on 21/10/2020 16:07:50:

With the Princess Royal, how are the cylinder mounts integrated into the casting – I like those. Are they different castings?

Should all become clear when you check your e-mail. These days I would go with JBWeld rather than the Araldite if nothing else to boost Ramon;s shares

The geared drive and having two cylinder will make for smoother running anyway so you may not need any damping. My Benson one is gear driven and the smoothest of the governor equiped engines I have made
21 October 2020 at 16:43 #502514
roy entwistle
Participant
@royentwistle24699
Mill engines usually had the flywheel boarded in as did colliery winding engines, so if you did this the spokes, and the fact that you are using two wheels wouldn't show.
21 October 2020 at 16:47 #502515
JasonB
Moderator
@jasonb
Or save a few quid and cut the flywheel from a billet of CI, just machine a recess each side and stick the boarding to that.
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