What About The Bee
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Posts posted by What About The Bee
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Hi Three Link
Thank you for the compliment. I'm working very hard to keep the CAD in line with the Armengaud drawings. Details make a model pop, and since the lad doing the labor works for free, I shall have all the details.
Wood has a low modulus of elasticity. Further, the material isn't homogeneous. It is certainly NOT an ideal material from an engineering standpoint. I'm not positive why Stephenson used sandwich frames, but they indubitably would bend and wear poorly.
The side wooden frames have outside metal plates, creating the sandwich of the sandwich frames. The stiffness of a beam goes by the cube of the height and linearly by the width of a beam. The plates opposing the load rods are ~180mm high, only ~10mm thick. So yes, the sandwich frames clearly prevent the load rods from straightening out by that bowstring girder effect.
The rod itself is ~1 inch diameter. That was my first real clue that something special was going on. A 1" rod, even in wrought iron, is very strong indeed.
Perhaps Robert Stephenson wanted to reduce the cost of the frame by reducing material costs (solid wrought iron v sandwich frames). It is far easier to machine wood than wrought iron, perhaps it was a labor savings. Perhaps it was a weight savings, as George Stephenson established an upper limit on weight. Solid wrought iron would absolutely be far heavier than wood.
I just never could understand why those rods were there, before I started this CAD model. Now, it is fairly clear. The load is transferred by them. Not exclusively, of course, the sandwich frames do contribute.
Bee
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Hi DRC
I knew this would catch your eye, just as it caught mine. I saw that observation coach and was immediately captivated.
The photograph was taken in late November, so we are 4 months on from the image.
One of the fundamental lessons I am learning is that making an accurate model takes an eternity! I work on Planet nearly every day, for hours at a time. The progress seems glacially slow. Its all in the details, that is what makes the model pop. Details take time.
I will never complain about how long Hornby takes, ever again! They are still orders of magnitude more swift than I.
Bee
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I encountered this image of the Coronation Coaches while on another search. I remembered this thread and thought to update for those who are interested.
The coaches were in the Hornby booth at Warley, said the person who posted the image.
They appear to be an engineering prototype of some sort. There is plenty of detail, just zoom in!
Bee
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Translating Armengaud's fabulous period drawings into CAD continues. A massive task, to be completed one tiny step at a time.
I left off here last time with the boxed frame and the axle plates. Illustrated was the concept of the draw pin retainer, wrapped around the WOOD rear frame.
How odd, I thought. Planet's tractive effort is applied through a wooden beam.
But what is the tractive effort effort of a Planet class locomotive? The value reported ranges from as little as 1400 pounds up to 2000 pounds. Not a tremendous amount. ~30HP, far less than your automobile. The frictional load of carriage and wagons is known far more precisely and due to exhaustive empirical experiment by the LMR. 1/248 is almost entirely due to the primitive bearings and friction. One part in 248, for flat, straight track.
In 1833, Penny wise magazine
https://books.google.com/books?id=cqDfAAAAMAAJ&pg=PA167
documents Planet drawing 80 tons at 12 to 14 mph [top right column]. This required a tractive effort of 695 pounds. The tractive effort calculation does not account for curves or inclines, both of which are on the LMR. 695 pounds, or even 2000, will not rupture wood, but there will be some bending!
I decided to move on, and add the tie rods between the wheel plates and the frame. Here, I encountered yet one more oddity. The rear most bolt was huge!
Why would they need that? Just above the bolt was the forward most pillar of the railing. Certainly, a bolt of the dimension shown (1" diameter) isn't required for a lightweight railing.
The last bit of strange design was that the draw pin drops down through the footplate. Not only a tripping hazard, but also a nasty pinch point, as the load is taken up by Planet. Golly, none of this made any sense.
And then the penny dropped.
The draw pin goes thru the ¾" thick footplate. This transfers the load from the draw bar to the footplate. The foot plate is connected to the rear diagonal strut, green, via that enormous bolt (actually 2, one on either side), transferring the load to that rear diagonal strut.
Transfer the load through the rear axle box link to the middle strut
Transfer the load through the front axle box link to the front diagonal strut.
And then on to the front beams via another massive bolt.
As the Planet class wheels turn, they apply a forward vector of thrust through the side sandwich frames and thence to the front beams. This thrust is transferred, via that massive bolt, to the front diagonal strut. Where the load is also applied!
Orange arrow points to draw pin hole.
Much like the collar on a horse pulling a horse drawn carriage, Planet pulls its load from the front beam. The pull is transferred, via those diagonal struts, to the foot plate. Similarly, the load is applied to the footplate. A horse drawn carriage would have been much better understood in the 1830s. Now, not so much.
A great sigh of relief, as I understand Planet's design. It finally makes sense. Those diagonal struts transfer the load.
Who knew the footplate was such an integral component of a Planet's class design and not just a place to stand? A ¾" thick plate to stand on. Ha!
Bee
PS. I will no longer whinge about how long Hornby takes to produce a design. Surely their Mechanical Engineers are much, much faster than I. Yet the amount of detail to wade through is stupendous. It takes a very long time to properly construct a model!
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On another project, I required casien glue. This isn't sold commercially anymore, but the Forest Products Laboratory (US Govt Agency) did preserve the recipe
Off I went, and purchased the requisite chemicals. As this was a marine application, a small dose of copper chromate was required. This is to be added last.
Imagine my surprise, upon adding the copper chromate to the pale grey glue, the entire mass turned bright purple!! Copper chromate is greenish. After drying, the glue eventually turned brown.
There is little doubt in my mind, ThreeLink, that your green ballast is the result of a chemical reaction betwixt your glue and stone.
Bee
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Hello All
I thought to give an update on this project, so as to keep motivation high.
As I plod thru the Armengaud drawings, I am struck by the dimensional accuracy. I have found each pixel is 1.3 mm, this on an overall length of 5.056 meters. That is an astonishing 1 part in 3800+.
Presented here is my CAD model. It is drawn 1:1, not 1:76.2, as the model will come after the full scale representation of Planet
The sandwich frames are shown with the metal in purple, the wood in gray. The metal wraps around the corners and on the outside, is let into the front wood member.
The front corner brackets tie the frames together. There should be rear corner brackets, but as these will be buried under the footplate, I saw no need to model them. Similarly, no effort will be made on internal boiler tubes, even though Armengaud shows those as well.
The rear draw pin bracket is two parts, the outer member wraps around the rear frame, and is let into the wood on top.
The front and rear plates are different in more than just height, to my great surprise! Modern standards would require commonality of design and therefore commonality of parts. Stephenson did not feel so constrained. In any event, all 8 plates are present and accurate to Armengaud.
A dilemma presents itself. It occurs because the Planet Class was quite large and widespread over many railways. Armengaud shows the front springs BELOW the frame
Yet the Stephenson drawing, used in the animations, shows the front springs ABOVE the frame.
Finally, the replica shows the front springs ABOVE the frame.
Above the frame they shall be. This is relatively easy to do and will be consistent with Stephenson.
Bee
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Hello Peter
Your post motivated me to look at my points. I ordered Tiger within 15 minutes of Range Launch and have received it about the third week in February. My points were accurately credited and are available to "spend".
It is extremely likely that Hornby run an update utility on the database, as I cannot believe it is done manually. It runs at an unknown update frequency. A periodic reconciliation. Like DRC says, it appears a bit random, so we can see that it is not every day. Give this a few days and check back.
If not mistaken, you are the fellow who was also waiting on his membership kit. I do hope that you were able to confirm your membership as suggested. Fingers crossed that has been resolved.
If I may, here is a bit of completely unsolicited old man advice, and who doesn't just adore that!!! This hobby runs a bit slowly, and Hornby epitomizes that statement. Their heart is in the right place, undoubtedly so. Your situation(s) will be sorted. Patience!! End of unsolicited advice. Please disregard at your whim!! Thanks!
Bee
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Hi DRC
I seem to recall CAD images from Hornby on that 'drawbar'.
If not mistaken, the drawbar contains all the electrical signals and power, eliminating those cable loops hanging down.
Just the interconnecting loco and tender blocks.
Is that the one?
Bee
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Hi ThreeLink 👋
With regards to the packing gland, or 'stuffing box', Armengaud is silent.
In the image of Planet's cylinder, two packing gland cavities are shown. Both are at working boiler pressure.
I added the colors for clarity. The red packing gland seals the piston rod. The green packing gland seals the rod which drives the slide valve. In neither case does Armengaud have letter references or other demarcation to indicate relevant associated text. You would think this of some interest, as the initial packing glands, developed by James Watt, himself, were in the 1760s, a mere 70 years before Planet. Yet Armengaud is silent on the gland itself
Note the piston N. There appear to be two piston rings, I think we can see the split in the ring on the right. Piston rings are still used today in internal combustion engines. So this seal was understood
I'm not sure where we can go further with the Planet's packing glands. If Stephenson could seal the piston rods and slide valve rods against working pressure, he would have little issue sealing the water interconnection between the tender and locomotive at atmospheric pressure.
I poked around at historical packing glands, which brings us to James Watt, who used tallow and oil. I did see one reference to leather piston rings, lending absolute credence to rhino hide seals. Strings impregnated with tallow. All sorts of materials. But in the end, what Planet used on the LMR is currently out of my reach.
I hope that helps!
Bee
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Hello Peter
They take about 2 weeks to reply to emails, given the current volume.
I know this is frustrating, but a bit of patience is required.
The important bit is the member discount on purchases. In my view, that is the primary reason to join the membership. If that is valid, and I firmly expect that it will be, your membership is too!
Check that by making a straw purchase. Confirm that the member discount was applied in 'my orders' under your account. Peace of mind obtained, cancel the straw purchase. Serenity is achieved.
Bee
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Hello Peter
Please do contact Customer Service to address your specific concern.
I know it seems silly, but Hornby does not monitor, nor respond to, posts on the HORNBY forum.
Bee
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Hi Topcat 👋
Please do inspect the drawing with the words "Linear Extension" prominently displayed.
The pipe betwixt the two ball and sockets is actually two pipes, one inside the other. So the inside and outside pipes slide longitudinally with respect to each other. The gland packing is to the right, just before the right ball.
As to canvas hoses, certainly that is possible. The vertical distance from the water level in the tender, down to the interconnection is a few feet. That would have linearly increased pressure with depth. If a canvas hose was used, it would likely leak like a sieve, draining the tender. Armengaud did not invent his connection from whole cloth. He drew something that did exist, albeit maybe not to exclusion of all other solutions.
@ThreeLink
After closer examination, I do think packing could be placed at the join line of the two piece socket. This would effectively seal the ball. Nothing definitive, just a thought.
Bee
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Hi ThreeLink 👋
I must admit that I do not speak or read French. In order to get the relevant text description, I use the plate number, figure and letter references to find likely candidates within the text of the book. I then use a photo translation tool which only permits a sentence or three at a time. It provides, at times, hilarious results.
You raise the point of a hose. To our eyes, this is so obvious! A flexible conduit for water. Why not?
For 1830s England, that would be a complete anachronism. That is, a water tight conduit, that was flexible, simply did not exist. Hancock and Macintosh, along with Goodyear, were in the process of developing the India Rubber patents. Gutta Percha was off in the future.
Do not miss the 1887 advertisement:
https://thegardenstrust.blog/2019/07/13/the-history-of-hosepipe/
So instead of an over engineered solution, the water interconnection appears to be a reasonable approach. The other thing which occurs to me is that Armengaud is simply showing off, ineffective hoses were used, but this seems quite unlikely to me.
The linear extension has the standard packing gland, right hand side between the ball and socket joints. This would be the same type of packing gland used at the steam chest and piston rods, so it would be reasonably effective vis un-pressurized water.
The socket, of the ball and socket, can be tightened down with the threaded rod and nuts present. I do not see any other means of making it water tight. No problem getting the parts to rotate relative to each other, Planet on one side, a full tender on the other. That will provide a large torque moment.
As to the theorized return: we are in full agreement! It, again, is so obvious. Yet try as I might, I could not find one. I thought I had found it with the "squirt", but that connected to nothing AND the translation, whilst hilarious, eventually became clear. Not the return.
I am left with either the pumps constantly pumping OR shutting the flow off with concomitant pump issues.
In the first analysis, the boiler will get water beyond safety pressurization. The full power of Planet from the cross head forcing water into the boiler is an issue. Consider the extrema: it will drive the pressure in that vessel very high indeed. To the extent that it may stop the crosshead, damage the mechanism, damage the pump or destroy the boiler vessel. Perhaps this is why the primary shut off valves are on the tender. The fireman could maintain the correct water level via observation of the glass and adjustment of the valves.
In the second analysis, once the water in the pump chamber is slightly reduced, it will not develop sufficient pressure to overcome the upper ball seat. That is, the water sloshes around but goes no where. The pump doesn't run dry, but is ineffective at driving water into the boiler.
I would like to emphasize that this is just my understanding at this time. Further discovery and analysis awaits. The entirety of the Planet class locomotive drawn by Armengaud is very rich with detail. I'm just scratching the surface. I did think it interesting to bring forth, in light of the recent discussion of your model of the Penydarren locomotive. Your solution is correct!
Bee
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As I plod through reproducing Planet in CAD, for my intended model, I study the Armengaud images to see how the parts interrelate. Along the way, I have noticed how water is introduced into Planet's boiler, even though Planet's boiler is under pressure. While this detail is extremely unlikely to migrate into my model, I think it interesting.
We begin at Park Side. Park Side was the approximate halfway point between Liverpool and Manchester. The locomotives took on fuel and water here. The LMR detail appears in Colyer, and shows the water crane in situ, along with a Planet Class locomotive.
This does not offer us many details, but thankfully, Armengaud shows us the complete workings.
The main valve is located below grade, likely to keep it from freezing. When open, water flows up the empty column and into the boom which can rotate. At the top is a pull chain valve, weighted such that it is normally closed. When the chain is pulled, the valve is opened and water can flow in the boom to the tender.
On the top of the tender, we can observe two rotary handles. These handles are on Hornby's Lion and Tiger tenders . I've also seen the video of the replicas, wherein the enginemen turn those handles. I did not understand, at the time, what they did. I do now. These are connected to two valves, located in the base of the tender
When the valves are open, water can flow from the tender.
The interconnection between the tender and locomotive is quite interesting. Here is the view of the device in situ, hanging from a chain off of the footplate.
And here is the cut away.
The middle region, at B', is a linear extension, that is, one tube slides inside of another. To compensate for angular deflection, there are two ball and socket connections at either end of the linear extension. This allows Planet to move relative to the tender, without hoses! Note that there are two of these, one on either side of the footplate
Fantastic, the water is now onboard Planet, still at atmospheric pressure. The water is directed to cross head pumps. There are two, one on each crosshead
Armengaud provides us with a cut away detail of the internal workings of the pump.
When the pump piston retracts, negative pressure is created in chamber, lifting the lower ball from it's seat, drawing water up. The ball, contained in its cage, re-seats due to gravity. The pump drives forward, creating pressure in the chamber. When the pressure in the chamber is greater than the pressure in the boiler, the upper ball lifts from its seat, and water flows into the boiler.
Viola! Water is injected into the boiler.
A couple of details.
1) The tiny upright pipe at the end of the pump is noted to be for the enginemen to check that the pump is pumping! When the valve there is opened, water will come out of the small pipe like a squirt gun, completely visible to the enginemen. Proof the pump is working.
2) Why all the duplication? When water is not present at the top of the firebox, the boiler can fail. Insuring the water remains at that level means a functional pump. Without it, loco go boom. Recall that the enginemen have a way to insure a pump is actually pumping. So two pumps implies that the designers were very concerned about pump failure.
3) What if the boiler is full? How to stop the pumps? The pump is hard connected to the crosshead. It is in motion when Planet is in motion. It cannot be stopped. What can be stopped is the flow of water. The valves in the tender tanks can be closed individually.
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Hi TVR 👋
I just went through that trying to compare the LMR to modern image. There does not appear to be one value.
The numbers are all over the map. The minimum appears to be 3.5 meters, centered on the centerline of the track (1.75 meters from centerline).
But higher speeds demand higher numbers. I have seen numbers as high as 5 meters.
Bee
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Some of the track has distorted over the years which I have straightened the best I can and tried to get the track spacing right.
Hello Simon 👋
Welcome
The track gauge is a fairly critical item. Too wide, and the wheels fall in, leading to derailment. Too narrow, and the wheels ride up, leading to derailment.
This Hornby Railway Collectors Association website claims that the gauge varied a bit, but was 32 mm.
https://www.hrca.net/2-uncategorised/10-o-gauge-fact-sheet
You would be well advised to create a tool to measure the inside distance, from rail to rail, that is 32 mm long. Go completely around your track and insure that the track gauge is correct.
Antique track is also widely available and you may wish to simply replace the wonky track pieces with better.
Bee
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I am a big fan of competitive spirit.
Firstly, the prototypes are there. These prototypes are available to all and sundry. No company has the exclusive rights to a 9F or a Deltic. Yes, certain locomotives are covered under copyright, like Thomas, but those are exceptions, not the rule.
Competition benefits the Enthusiast, as every company will try to out do the others. Be it price, accuracy, detail or what have you, competition is good for us.
If a company wants to compete for business, they would do well to understand the competitions offerings. In detail. Specifically what is good about them and how to do better.
So if Accurascale "muscles in" on Hornby, or Hornby "muscles in" on Rapido, I say....
LET THE GAMES BEGIN!
Bee
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Hi RallyMatt 👋
A big part of the hobby for me is research. I want to run models, yet I want to run them correctly!
For me, this is a gem of detail. The period drawings show a double track mainline, and now I know the proper spacing.
I do agree, the models coming out are wonderful. I'd still be researching, due to my great curiosity about the LMR, but running no models without Hornby and Accurascale.
Bee
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Whilst researching Planet, I encountered a set of mechanical drawings, drawn by authors who also wrote a book, among other tomes, on mechanical drawings! From this, I can infer drawing accuracy in the plates you are about to see.
The Planet class drawings are simply fabulous. More details than I can shake a stick at. Apparently, they were used to construct the Planet replica that steams today. More on those drawings at another time.
Armengaud et Armengaud, L'Industrie des Chemins de Fer, 1839. Yes, in French.
Plates 22 and 23 are very interesting on the topic of curtains.
Exterior and Undercarriage
Exterior end views and cut away interior
These drawings show an "Ordinary Wagon for Travelers". We can be quite sure that this is an early carriage, as there is nothing other than dumb buffers in the undercarriage. The text associated with this carriage indicates it was used on the railway between St. Germain and Versailles.
Note the steps. They are the exact steps that appear on Hornby LMR stock. The text does state that the roof has a metal sheath over wood.
The upper sides of the carriage are composed of "curtains" and "hangings". Those were the exact words used, albeit in French. The text does not specify what they are made of.
Now I can not state what the curtains are made of, but the bottom hem and the drape of those curtains is very suggestive.
Click on the image and select "view image". Then zoom in for a very close inspection.
What do you think these curtains are made of?
Bee
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Here is generation 2 of my buffer adapter.
The middle member has the wood grain running side to side, with the front plates and back plate grain running vertically. The metal threaded rod is installed and bolted. A bit of 242 Locktite to keep it secure. This is far and away more robust than generation 1.
I did have a problem with the #61 drill bits for the thru hole. My drill press could not grip the tiny diameter, so I was forced to use a hand drill. That's never as precise as a drill press, so the nuts aren't in a line, they are a bit wonky. Not noticeable at 3 feet.
The nuts, being a real three dimensional part, really pop on the buffer adapter. The rosewood grain really shows. I may add a touch of varnish to bring out the color
Bee
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Hi 96RAF
Thank you kindly for the suggestion.
I chose FreeCAD for lots of reasons, including the ones you mention. Lots of online tutorials. Rich community. It also has a vast array of real CAD tools and it it is parameter driven.
An example of this is the counter bore radius. I looked in my shop, and could only find a 0.104" flat bottom drill, nothing smaller. Instead of buying another flat bottom drill at the radius I designed, I dialed in the radius of the new drill. This was a problem, as the counterbores now intersected, a no no. So I changed the 2 parameters that represented the axes of the 4 holes....and all the parts, threaded rods, nuts, etc, all adjusted. I did not change the dimension on every part individually, I changed the parameter those dimensions were linked to. Viola!
I do suppose this is like Scarm v AnyRail, or any other track planning tool. Its a choice.
Bee
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Hi ThreeLink 👋
Truth be told, I find making kit is far and away more impressive than purchasing it.
Respect!
Bee
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In consideration that both the utility wagons and flat bed wagons were general purpose, it is entirely possible that broken down wagons were hauled away in this fashion.
Maybe not 3 high!
Bee
Happy Easter from Bubble Car Doncaster North
in General Discussion
Posted
Is that your dog Alberto?
Happy Easter!
Bee