Author Topic: The new Stuart model - no7 V twin.  (Read 7314 times)

Offline Gas_mantle

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The new Stuart model - no7 V twin.
« on: May 09, 2018, 02:57:09 PM »
A few days ago some of us were discussing the new addition to the Suart engines range - a No7 V twin.

Their website has now been updated to show this, for the benefit of others who may not be aware here is the new engine :-

http://www.stuartmodels.com/item/2335/stuart-twin-7v

What's your first thoughts of it ?

Offline Jasonb

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Re: The new Stuart model - no7 V twin.
« Reply #1 on: May 09, 2018, 03:29:04 PM »
Well I suppose it is one way to use up all the failed standard castings where the metal only fully flowed down one leg :)

Interesting to know if they made a new standard master pattern from scratch or modified a casting in which case machining allowance may be even less. If it is meant for marine use I would have thought they would offer the option of a disc type flywheel and reversing gear, 3.5" spoked flywheel sounds a bit on the small side. description of contents has now been updated and it looks like it is a cast boxbed.

Looks like the eccentric strap has one cast rod and the second one pivots rather than having two separate straps.

J

PS if you click on the image on stuart's site it comes up this big.


Offline Gas_mantle

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Re: The new Stuart model - no7 V twin.
« Reply #2 on: May 09, 2018, 03:37:44 PM »
Presumably, the trunk guide castings are completely new to accommodate the bracing bar fixing lugs ? I still think it looks a bit flimsy and I'd have thought the inlet manifold could easily get damaged in a working model.

You raise an interesting point about a reversing kit, I wonder that will follow shortly.

Offline bent

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Re: The new Stuart model - no7 V twin.
« Reply #3 on: May 09, 2018, 05:32:41 PM »
I always swallow hard when I see prices for the bigger Stuart model kits.  But someday...

Offline Jo

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Re: The new Stuart model - no7 V twin.
« Reply #4 on: May 09, 2018, 07:16:19 PM »
I won't be buying one  :ShakeHead:

At the price you could almost have a set of Gypsy Major castings :pinkelephant: Or a choice of any of the Alyn Foundry engine casting sets or perhaps two  :naughty:

Jo
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Offline Jasonb

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Re: The new Stuart model - no7 V twin.
« Reply #5 on: May 09, 2018, 07:40:10 PM »
Thought so, it's going to take a while until some rusty half made ones with bits missing find their way onto the market at the price you like to pay  :Jester:

Good point about a set or two from Alyn, though I fear the latest ones may not come with the special coating ;)

Offline Laurentic

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Re: The new Stuart model - no7 V twin.
« Reply #6 on: May 09, 2018, 08:25:54 PM »
Jo - where do you go for a set of Gypsy Major castings?  Nothing seemed to come up when I googled it.

Chris

PS.  Is it just me, or is that blue elephant dying for the loo?   :ROFL:

Offline Jasonb

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Re: The new Stuart model - no7 V twin.
« Reply #7 on: May 09, 2018, 08:38:10 PM »
It's just you. Everyone else sees a pink elephant that wants a P**s

Engineers Emporium do the Gypsy Major castings

Offline bent

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Re: The new Stuart model - no7 V twin.
« Reply #8 on: May 09, 2018, 09:41:54 PM »
Gypsy engine you say?  Sounds interesting.  Any links, as I can't find it on the engineer's emporium web page?

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Re: The new Stuart model - no7 V twin.
« Reply #9 on: May 09, 2018, 10:36:27 PM »
When did it appear? Too late for a April fool?

Offline b.lindsey

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Re: The new Stuart model - no7 V twin.
« Reply #10 on: May 10, 2018, 12:49:15 AM »
Even at a 1"bore, that Stuart twin seems very pricey to me. And to have to add the reversing gear? Nope, don't think so.

Bill

Offline Jo

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Re: The new Stuart model - no7 V twin.
« Reply #11 on: May 10, 2018, 06:28:44 AM »
I hear that this "new" Stuart engine is at Doncaster today on their display stand.

Jo

P.S. The Gypsy Major casting sets should be there as well  :mischief:
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Offline Gas_mantle

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Re: The new Stuart model - no7 V twin.
« Reply #12 on: May 10, 2018, 06:58:20 AM »
I hear that this "new" Stuart engine is at Doncaster today on their display stand.

I'll take a few photos just in case you want to assess its fondling potential  ;)

Offline Laurentic

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Re: The new Stuart model - no7 V twin.
« Reply #13 on: May 10, 2018, 10:58:14 AM »
It may be pink to everybody else Jason, but I'm colour blind so it's a blue elephant to me as I see it, though now you mention it, perhaps there are some pink overtones in it.

Thanks for the Gypsy link,

Chris

Offline Jasonb

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Re: The new Stuart model - no7 V twin.
« Reply #14 on: May 10, 2018, 11:35:21 AM »
  Any links, as I can't find it on the engineer's emporium web page?

There website has not been updated for ages, shows about 10% of what they actually do. Think they would do better having less full page adverts in the mags and use the money to update the site.

I believe it is the Reinhold Krieger  design, bit more detail on Model Engine NEws

http://modelenginenews.org/gallery/p6.html
« Last Edit: May 10, 2018, 11:40:03 AM by Jasonb »

Offline Jo

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Re: The new Stuart model - no7 V twin.
« Reply #15 on: May 10, 2018, 12:25:48 PM »
Yes it is Reinhold's design but some of the patterns have been slightly modified by Adrian G and he was going to do steel pressings for the heat shields rather than the original plastic ones.

I don't know how far Adrian has got with his translation of the drawing from German into English....ours is done and put on to individual A4 sheets  ::)

Jo
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Offline bent

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Re: The new Stuart model - no7 V twin.
« Reply #16 on: May 10, 2018, 04:56:08 PM »
Deutsch drawings don't bug me too much, they are usually straightforward to translate with aid of Google etc.

Don't get me started on Italian drawings though.

$800 Euros for the casting set...gulp.  Maybe someday.  Be a reason to buy a full size mill and lathe, too.

Offline Jo

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Re: The new Stuart model - no7 V twin.
« Reply #17 on: May 10, 2018, 05:00:39 PM »
They are around £650 from EE  ::)

Jo
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Offline Vixen

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Re: The new Stuart model - no7 V twin.
« Reply #18 on: May 10, 2018, 05:06:05 PM »
At the current exchange rate £650 converts to about EU740.

So grab a bargain from EE before common sense says no to yet another big engine.

The Gipsy will look much nicer than that Stuart no7 V twin

Mike
« Last Edit: May 10, 2018, 05:10:24 PM by Vixen »
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Offline AOG

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Re: The new Stuart model - no7 V twin.
« Reply #19 on: May 10, 2018, 06:24:07 PM »
I kind of like the looks of the number 7. I think I might end up ordering one.

Tony

Offline wirralcnc

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Re: The new Stuart model - no7 V twin.
« Reply #20 on: May 10, 2018, 09:01:27 PM »
I would have to go with jo and vixen. I would be buying the gypsy castings over the no7 v. The 7v doesn't look like a classic stuart engine.

Offline Florian Eberhard

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Re: The new Stuart model - no7 V twin.
« Reply #21 on: May 10, 2018, 11:35:23 PM »
What's your first thoughts of it ?

Well my first thought was "that was not an engineer who designed it".

No one would ever have designed the trunk guide like this in big size.
The mounting surface to the base is way to small for being mounted only on one side of the guide.
That will of course work in the model but in big scale it would have been pretty unstable and I guess not up to the forces which are being produces by the steam cylinder.
I also doubt that in big size they would have chosen to keep the trunk guide mounting surfaces at a right angle to the cylinder, I would have rather expected them to be parallel to the ground (in order to have the two mounting surfaces in one plane on the base.

I wonder if anyone thought the same things about this design?
Cheers Florian

Offline Tennessee Whiskey

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Re: The new Stuart model - no7 V twin.
« Reply #22 on: May 11, 2018, 12:09:31 AM »
Now just because ol Cletus is a Harley head; I’d be tempted to buy it. I think perhaps with this one, Stuarts may be trying to stir interests with a different sort of buyers, rather than us old farts :shrug:. Structural misgivings aside; I find it quite eye appealing: but hey, I like “V style” engines.

Cletus

Offline Jasonb

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Re: The new Stuart model - no7 V twin.
« Reply #23 on: May 11, 2018, 07:12:22 AM »
There are several two and three cylinder Vee form full size launch engines about so it is not just a flight of fancy, the use of existing standards has obviously had a big influence on the design.

http://prestonservices.co.uk/item/3-cylinder-marine-engine/

https://prestonservices.co.uk/item/v-twin-steam-car-engine/

https://www.stationroadsteam.com/v-twin-launch-engine-stock-code-7910/

Closest is probably a Sturgiss and Tolston, have  alook at page 17 http://www.museumofthebroads.org.uk/uploads/1/2/7/2/12726474/36reedlighter_spring_2013.pdf very similar single sides trunk guide standards with not a lot between them. Model of this engine on youtube.

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

Peter, this is a decent size boiler and mobile too ;) complete with 3 cyl engine





Now had  Stuarts spent a bit more time and effort on a whole new pattern something like this sexy little v twin then even I might have been tempted to splash the cash, guess I will just have to fabricate my own. ;)

https://collection.maas.museum/object/215204
« Last Edit: May 11, 2018, 08:04:35 AM by Jasonb »

Offline Gas_mantle

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Re: The new Stuart model - no7 V twin.
« Reply #24 on: May 11, 2018, 12:52:21 PM »
I think if we keep talking about it long enough Jo's casting fetish will get the better of her and she will build one in the forum.  :stir:

Offline Chipswitheverything

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Re: The new Stuart model - no7 V twin.
« Reply #25 on: May 11, 2018, 01:01:41 PM »
Most of the Stuart range of engines are quite attractive, and some of the older Stuart Turner era classics - the No 1, the No. 9 horizontal and others, are especially pleasing and look like proper specimens of engineering. But I must say, the appearance of this new Vee format engine, I do not find at all pleasing, nor well designed, with the rather desperate contrivance of chopping away a leg of the trunk column casting and perching the thing in the air.
   The price is ridiculous, and yet the engine suggests an attempt to use the parts bin to concoct something with the least extra expense on patterns or design.   Sorry if this sounds a bit off....!!    Dave

Offline Gas_mantle

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Re: The new Stuart model - no7 V twin.
« Reply #26 on: May 11, 2018, 01:07:44 PM »
Jason, I'd love a go at making something like that steam car/buggy thingy  :)

I don't really have the room for a 4 wheeler but I have given thought to some sort of steam bike as a bit of fun. I can't see it being too difficult if I was to make a decent sized engine and weld to an old bicycle. I'd have thought with the right gearing something the size of a Stuart no1 would power a bike at modest speeds over short distances.

If I could lay my hands on a ropey old boiler at a bargain price I could make a suitable engine relatively easily, it doesn't need to be anything attractive, just something fairly sturdy with a bit of oomph  :)

This looks fairly easy to build and a lot of fun ;-

<a href="https://www.youtube.com/watch?v=7OirlNA49iI" target="_blank">http://www.youtube.com/watch?v=7OirlNA49iI</a>
« Last Edit: May 11, 2018, 01:15:23 PM by Gas_mantle »

Offline Jasonb

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Re: The new Stuart model - no7 V twin.
« Reply #27 on: May 11, 2018, 01:19:20 PM »
Peter, this shows you all you need to know to make a steam bike.

http://flashbackfab.com/other-vintage-antique-projects/1896-roper-steam-engine-2/

Offline Gas_mantle

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Re: The new Stuart model - no7 V twin.
« Reply #28 on: May 11, 2018, 01:29:18 PM »
Cheers Jason, that looks to be a well made and attractive design. I think I'd be more inclined to start of with something fairly crude but a lot of fun.

It can't be too difficult to make one once a decent sized boiler is found :-)

Not sure what this engine is but it looks very much like a Stuart no5 replica, it seems to power a 3 wheeler adequately.

<a href="https://www.youtube.com/watch?v=8o4lVL7sXR4" target="_blank">http://www.youtube.com/watch?v=8o4lVL7sXR4</a>

Online crueby

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Re: The new Stuart model - no7 V twin.
« Reply #29 on: May 11, 2018, 01:59:42 PM »
Peter, this shows you all you need to know to make a steam bike.

http://flashbackfab.com/other-vintage-antique-projects/1896-roper-steam-engine-2/
Very cool. A trike version would be a great model!

Offline Jo

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Re: The new Stuart model - no7 V twin.
« Reply #30 on: May 11, 2018, 02:03:34 PM »
I think if we keep talking about it long enough Jo's casting fetish will get the better of her and she will build one in the forum.  :stir:

 :ShakeHead:
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Re: The new Stuart model - no7 V twin.
« Reply #31 on: May 11, 2018, 11:39:58 PM »

Well my first thought was "that was not an engineer who designed it".

No one would ever have designed the trunk guide like this in big size.
Well my first thought was "that was not an engineer who designed it".

No one would ever have designed the trunk guide like this in big size. The mounting surface to the base is way to small for being mounted only on one side of the guide.
 
That will of course work in the model but in big scale it would have been pretty unstable and I guess not up to the forces which are being produces by the steam cylinder.
I also doubt that in big size they would have chosen to keep the trunk guide mounting surfaces at a right angle to the cylinder, I would have rather expected them to be parallel to the ground (in order to have the two mounting surfaces in one plane on the base.

I wonder if anyone thought the same things about this design?
Cheers Florian

My thoughts exactly.  Because it offends against sound engineering it looks just wrong. Anyone unclear about the stability should try imagining just one half of the thing.

Offline Jasonb

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Re: The new Stuart model - no7 V twin.
« Reply #32 on: May 12, 2018, 07:11:34 AM »
It is strange that you say its all wrong when that link to the Sturgess and Tolston I posted earlier is an almost identical full size design eg a trunk guide with one sided cast standard and a flimsy looking brace to the other cylinder.

If we imagine this as one half then we basically have a stuart No1 or the old No7 which is a single legged standard and a brace, just a different method of guiding the crosshead. many "open frame" engines like this exist in full size. You even find them without the brace like this Tangye https://collection.maas.museum/object/208092#&gid=1&pid=2

Having said that I still don't like the Stuart offering.

Offline Jo

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Re: The new Stuart model - no7 V twin.
« Reply #33 on: May 12, 2018, 02:50:11 PM »
Quick Jason: Stuarts are looking for someone to make one of these  :-X engines and it will be free if the build is written up  ;)

Jo
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Offline Jasonb

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Re: The new Stuart model - no7 V twin.
« Reply #34 on: May 12, 2018, 03:04:39 PM »
Well give them my name :)

Offline Jo

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Re: The new Stuart model - no7 V twin.
« Reply #35 on: May 12, 2018, 04:42:04 PM »
You will have to find someone going to the Doncaster show then... rumour (from a reliable source   ::) ) is that whoever says yes will be given a casting set to take home with them  ;)

Jo
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Offline Jasonb

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Re: The new Stuart model - no7 V twin.
« Reply #36 on: May 12, 2018, 05:01:27 PM »
Think my friend Neil is going tomorrow, do you think he would put in a good word for me?

Offline Jo

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Re: The new Stuart model - no7 V twin.
« Reply #37 on: May 12, 2018, 05:47:51 PM »
Think my friend Neil is going tomorrow, do you think he would put in a good word for me?

If Neil is who I think he is I've seen his excellent editorial ability so I couldn't guarantee he would remember to put a good word in for you  :lolb:

The sales pitch should be that you might be able to do something with their initial concept for a Vee engine to make it more marketable ::)

Jo
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Offline Jasonb

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Re: The new Stuart model - no7 V twin.
« Reply #38 on: May 12, 2018, 06:16:31 PM »
Now that's a thought that would let me earn from a few more pages "pimp my 7V" I had already thought of that as most of the mechanicals could be stripped off the basic engine and put into a fabricated frame like that Steeper Vee one I posted the other day plus a nice bit of wood cylinder cleading etc. Only problem is they might want me to paint it dark green and you know I like my colours ;)

Offline Florian Eberhard

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Re: The new Stuart model - no7 V twin.
« Reply #39 on: May 12, 2018, 06:37:53 PM »
It is strange that you say its all wrong when that link to the Sturgess and Tolston I posted earlier is an almost identical full size design eg a trunk guide with one sided cast standard and a flimsy looking brace to the other cylinder.


Hey Jason

Its not about the pricipal design of a one-side supported trunk guide but about the relations of the mounting surfaces. That real size engine is far more rigid where the trunk guide and the base connect and therefore a "good design". By the way, that flimsy brace is probably not to increase stability but for something like controlling drain cocks or so.
he stuart instead has a very small surface between trunk guide and base. That would have worked if the two trunk were connected through a massive beam but not with that small bar.

I have added a modified picture of the No. 7 to show make it clear what I am talking about.
The green beam would be one solution, the purple "modification" to the trunk guide the other one.
The red line shows the "problem" which is the very short side of the mounting surface.

Cheers Florian

Offline Admiral_dk

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Re: The new Stuart model - no7 V twin.
« Reply #40 on: May 12, 2018, 08:35:01 PM »
I will have to agree with Florian as the Sturgess and Tolston is very substantial where it meets the bottom "triangle" engine mount and the Stuart is flimsy ....  ::)

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Re: The new Stuart model - no7 V twin.
« Reply #41 on: May 12, 2018, 09:20:21 PM »
If we imagine this as one half then we basically have a stuart No1 or the old No7 which is a single legged standard and a brace
Its not that simple. In the No1 the brace is attached to something rigid, the bed, and it is subject to loading along its axis. In the case of the 7-V the point is that attaching one unsteady half to another equally unsteady half achieves little when the means of attachment relies on friction at the single bolted joint to provide any additional stiffness. Florian's annotations illustrate the point admirably.
Trying to make the best of the 'design' as presented, I note that the bolts at the feet of the standards are towards the outside. Ensuring that the tie-bar is a few thou short to ensure it is always in a little tension would help to keep the feet as firmly in contact with the bed as can be expected - but it is still 'orrible.   

Offline Gas_mantle

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Re: The new Stuart model - no7 V twin.
« Reply #42 on: May 12, 2018, 09:34:47 PM »
I took a couple of photos today at the Doncaster show - they aren't great but they may be of interest so I may as well show them.

I thought it was a bit of a let down  :( It's a lot smaller than you expect. I would say it is about as tall as a 10v




Offline steam guy willy

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Re: The new Stuart model - no7 V twin.
« Reply #43 on: May 12, 2018, 11:58:30 PM »
So ,Looking at the eccentric rods  (Noun/Verb) because the right hand one is mounted on the left hand one with a bearing in the slot does this mean that there is less /more valve travel and is this accommodated in the port faces ?  the geometry may need looking at ?? Discuss...

willy...........

Offline Craig DeShong

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Re: The new Stuart model - no7 V twin.
« Reply #44 on: May 13, 2018, 02:41:44 AM »
Not meaning to hijack this thread but.... I have fallen in love  :Love: :Love: with the de Havilland Gipsy Major Mk I.  But at nearly $1000 US and metric to boot, I'm gonna pass. :'(
Craig
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Offline Jo

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Re: The new Stuart model - no7 V twin.
« Reply #45 on: May 13, 2018, 06:43:15 AM »
I thought it was a bit of a let down  :( It's a lot smaller than you expect. I would say it is about as tall as a 10v

I hear the comments being made at the show went along the lines of "You want £400  :o for that"

You could have a casting set for any of these: http://www.pollymodelengineering.co.uk/sections/stationary-engines/anthony-mount-models/index.asp at that price  :mischief:

Jo
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Offline Jasonb

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Re: The new Stuart model - no7 V twin.
« Reply #46 on: May 13, 2018, 07:43:53 AM »
Yes it is making the most of available castings so there will be compromises, but lets face it 99% of those made will just sit on a table ticking over on air. Florian's points about a more substantial attachment between the two standards and having a flat base for easier machining are two features of the one I linked to and said would have been a far better design, and a bit more fun to machine. I also think the bed casting should slope the other way if it is intended for marine use as that will get the crankshaft lower for a straighter prop shaft run.



Peter with a 1" x 1" bore and stroke it was never going to be big, that's the same sort of size as your Muncaster.

Willy, the master and slave eccentric strap is quite common on Vee format steam engines, take a look at some double diagonals and you will see it used there, if the way Ramon's one runs is anything to go by there are no issues with valve timing.

Offline Jo

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Re: The new Stuart model - no7 V twin.
« Reply #47 on: May 13, 2018, 11:13:54 AM »
How's your German?  Vee twin steam engine from  :facepalm: Barstock http://www.plans-for-everything.com/downloads/steam_engines/SE%20VGerman.pdf

Jo
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Offline Florian Eberhard

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Re: The new Stuart model - no7 V twin.
« Reply #48 on: May 13, 2018, 11:44:18 AM »
Hey Jo - compared to that plan, the stuart proportions almost look reasoable  :-X

Offline Jo

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Re: The new Stuart model - no7 V twin.
« Reply #49 on: May 13, 2018, 12:10:01 PM »
You can always scale it up to make it easier  ;)

Jo
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Offline Jasonb

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Re: The new Stuart model - no7 V twin.
« Reply #50 on: May 13, 2018, 01:32:04 PM »
You know I don't like barstock engines that look like they have been made from Barstock whatever size they are so not worth learning German for, though metric is metric in any language :)

I've been doing a long boring job this morning and have the frame designed in my head for a nice Vee twin steamer or maybe even a compound, less that £5 material in that part.

ChuckKey

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Re: The new Stuart model - no7 V twin.
« Reply #51 on: May 13, 2018, 04:55:10 PM »
So ,Looking at the eccentric rods  (Noun/Verb) because the right hand one is mounted on the left hand one with a bearing in the slot does this mean that there is less /more valve travel and is this accommodated in the port faces ?  the geometry may need looking at ?? Discuss...
Ok. The right hand valve motion will be very slightly compromlicated (half way through changing my mind about the right word, but I like that, I am going to leave it).
Doing that part of the geometry in my head, I am pretty sure the miniscule 'second order' effects at each end of the r/h valve stroke in fact almost completely cancel out and any difference in the valve stroke would be 'third order' and infinitesimal.   

Offline Florian Eberhard

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Re: The new Stuart model - no7 V twin.
« Reply #52 on: May 13, 2018, 07:58:44 PM »
You can always scale it up to make it easier  ;)

Jo

Well - you can do this of course - but what I actually meant is the connection between trunc guide and base which is even less suitable for a big size engine (which of course also here does not mean it doesn't work for a model engine)

Florian

Offline Jasonb

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Re: The new Stuart model - no7 V twin.
« Reply #53 on: May 13, 2018, 08:32:22 PM »
Got the idea for a vee out of my head and onto the computer, still needs some tweaking but I like it so far, what do you think?

Offline Admiral_dk

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Re: The new Stuart model - no7 V twin.
« Reply #54 on: May 13, 2018, 08:53:32 PM »
That actually looks like it could have been a full size engine and one that is a compromise between perfect balance (90 degress) and compactness + I like the looks better than the previous pictures you have shown  :praise2:

Offline Gas_mantle

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Re: The new Stuart model - no7 V twin.
« Reply #55 on: May 14, 2018, 12:03:14 PM »
Jason,

I've been having another look at your prototype, in general I do quite like the strong workmanlike look about it.

I do think though that the outside edge webs could do with either a bit of a radius cut in to match the top or perhaps a slight taper to mirror the lie of the 'V'. At the moment I think viewed face on it may look too much like a square box. Can you show a face on view in it's present form ?




Offline Chipswitheverything

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Re: The new Stuart model - no7 V twin.
« Reply #56 on: May 14, 2018, 12:41:07 PM »
Jason, your own  Vee concept has a very much nicer look of a well designed piece of engineering.  Would you think of making a separate casting of the lower element, so that the bearing seatings can be milled conveniently, and the holes for the caps drilled and threaded?    Dave

Offline Jasonb

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Re: The new Stuart model - no7 V twin.
« Reply #57 on: May 14, 2018, 01:30:14 PM »
Thanks for the feedback.

Peter. after I posted that Image I realized I had made the distance from crankshaft ctr to cylinder flange too long so went through the drawing again bringing everything else down in size to suit which was actually quite easy with CAD. I also put a bit of a flair onto the side webs and increased the radius where they meet the mounting lugs, did not want to scallop them out as it would make the web narrow right where the stiffness is needed on the inner bend.

Dave, if it is to be a fabrication then some work can be done before finally soldering it all together so the rectangular cutouts and threads could be done first and the bearings bored in situe which would counter any slight movement during soldering. Even if cast the tops can be accessed for drilling & tapping be it with an extended drill and if you did not want to use a shaper or plane it out with the mill quill a rounded bottom could be milled with the casting on it's side.

This is one of the good things about designing your own as you can think about how you will make it as you go along and don't need to add features you can't manage unless you want to try something new. I have actually sized this at the moment to suit the cylinder from my recently completed 24mm bore vertical as a lo of parts from that can be assembled in CAD to give a complete engine, it would be a simple click of the button to make it the size of a Stuart No7 cylinder.

Latest front view and 3D pdf, think the S needs to be a bit smaller and some fillets where the central web meets the cylinder flanges.


Offline Gas_mantle

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Re: The new Stuart model - no7 V twin.
« Reply #58 on: May 14, 2018, 02:31:58 PM »
I think the slight taper to the sides is a significant improvement and gives it more of a casting appearance the square sided original.

I'd be inclined to lose the 'S' altogether or at least replace it with my own initial. I've never quite liked the Stuart 'S' and intend to mill them out of the 10v and no4 castings I have

Offline Jasonb

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Re: The new Stuart model - no7 V twin.
« Reply #59 on: May 14, 2018, 03:16:40 PM »
Yes I agree, if I get round to making my own I think it will just have a rounded off triangular hole that follows the slope of the trunk guides and top curve.

ChuckKey

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Re: The new Stuart model - no7 V twin.
« Reply #60 on: May 14, 2018, 11:17:33 PM »
Well, I think the sides of the 'arch' could do with tapering in. ATM it looks a bit bow-legged to me. That and a gentler radius at the apex of the arch.
« Last Edit: May 14, 2018, 11:21:04 PM by ChuckKey »

 

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