What About The Bee
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Posts posted by What About The Bee
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Touch the cradle....
Touch the locomotive...
Contaminant transfer complete.
Yes, I worry too much.
Bee
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The eBay post did state that the directions were the photos in the image. Looked straightforward in any event.
The advert was specific that you only get one size jaw or the other, but not both. That's fairly nice of the seller to give you both.
If it were me, I'd give those parts a good clean before they come close to my locos. No telling if there is something from process that could transfer, smudging paintwork. Probably not necessary....
Bee
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Hi ThreeLink
Taking a break from the gear train, I thought to review the period images of Planet and the planet-class locomotives I know of.
The first appears in Walker An Accurate Description of the Liverpool and Manchester Railway... 1831. This is drawn by Issac Shaw, a known good first hand observer. He shows us 5 links and a hook on center. It is unclear if this is Planet or merely a planet-class.
The only other image that shows the front chain is Armengaud. This is definitively a 3 link chain. The locomotive illustrated is La Jackson, a planet-class locomotive.
So there we have it. One type each. A 3 link and 5 link. No other image, that I know of, bothers to include the chain.
Austen would have us believe there wasn't even a buffer beam, let alone a front chain!
Bee
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Hi Al
I had a look at the assembly.
One thought I had was to set the articulated cradle to hold your nominal foam cradle. Full support at the length of the foam, the locomotive presented at the angle of articulation.
I look forward to your review
Bee
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I should hasten to add:
Pressure angle. The pressure angle if the teeth must also match.
There would be little reason to change the pressure angle from the nominal 20°, so I am working under the assumption that both gears are at 20°. It is quite possible that one company or the other may have used a different angle. Common cutters for involute teeth include 14½° pressure angle.
I do apologize for not including this earlier, yet it is a refinement to the basic module size.
Bee
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Hello John
Both gears appear to have involute teeth. The issue then, is one of the mesh.
Ignoring the old money terminology of 'diametrical pitch', we have something called 'module'. A module of 1 is one tooth plus one space, along arc at the radius of contact, equal to 3.141593mm. That is pi to 6 places. A module of 1 is equal to pi.
Now small gears will have a corresponding small module. Common sizes are 0.3, 0.4, 0.5 etc. Technically, you can have any module you like, but then you need the cutter, either hob or single tooth type. So given that Hornby isn't investing in custom tooling to protect a spares market they do not maintain, we can assume a common size.
Herein lies the rub. Suppose Hornby have specified module 0.3. That's one tooth plus one space, along the contact line, equal to 0.942478 mm. Now suppose Ultrascale have specified module 0.4 or 1.256673mm. Thats a delta of 0.314159 mm. In old money, that 0.012". Pretty hard to see that in a photograph, given that one is at an oblique angle.
Module 0.4 gear teeth WILL NOT mesh with module 0.3 gear teeth. That is a simple fact of life.
There is a relationship between module and gear diameter (radius) but I do not see this specification of either gear. I do suppose you could measure your damaged gear's overall diameter, but be very aware that this is not the diameter at contact. We can infer the gear module from your measurement. Likewise, you can request the diameter from Ultrascale, again, being very careful to ask for "overall diameter". You could ask Ultrascale for the module directly.
Unless someone has directly tried precisely what you suggest, there can be no answer without further information. If you find some more information, I will be very happy to help you. Alas, I cannot, given the information.
Bee
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Hi XYZ
Well said.
Polite and respectful. Full stop.
I've listened to Hornby, themselves, as they explained the problem vis Android versus IOS. IOS is a much tinier environment, Android is complicated by the many flavors. Harder, therefore, to have an app functional across Android than IOS.
Whilst I commiserate with some early adopters who found their devices incompatible, this is the issue with early adoption. Surprises. As some youTube reviewers have pointed out, there are some apparent size / fitment issues, as well.
In my view, perhaps it is better to wait and see before jumping in. I would like to use the system. Before I spend the cash, however, I want to be sure it is not wasted. My locomotives are all tiny, will the decoders fit? Can I use my devices, which are all Android? Right now, that doesn't appear to be possible. I can wait whilst the bugs are worked out.
Bee
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That satin finish truly complements the green. It virtually glows as it goes around the layout.
It will be quite the puller too, with all that weight. You should see how many carriages you can pull.
I enjoyed the review. Your enthusiasm can be heard in your comments, smiling from ear to ear.
Beautiful loco JJ!
Bee
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Did they state a reason why they would rather it not be discussed here?
Hi DRC 👋
I will go way out on a limb at this time.
Hornby would prefer to quietly handle these start up glitches without great fanfare and public notice. Can't say as I blame them.
Social media, these pages excepted, has been unfairly unkind to Hornby. Hornby does not need bad publicity regarding their new rewards program.
I like the program. Sure, there are some glitches. Perhaps some questions how it works. But overall, I think it a winner.
Bee
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Hi ThreeLink
Not drawn is the, ahem, three link chain and hook on the front buffer. I want that to be a real chain, therefore no need for 3D printing or presence in the model.
This has been an amazing journey so far. The chance to stand on Robert Stephenson's shoulders, to see the man at work, has been a major treat. The discovery of his thought processes is beyond exciting. Details of the LMR that would otherwise remain out of sight, hidden in plain view.
On the shoulders of giants.
I will soldier on. Thank you for the encouragement!
Bee
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Hello Rana
FreeCAD is very powerful. A real engineering tool, which is what attracted me to it.
At first, I duplicated some starter tutorials. I fiddled around with them for a bit but then, I decided to try a (very) simple project on my own. It was the front buffer adaptor for Tiger, to try the banking test. Of course, I complicated that by drawing in all the threads on the rods and nuts, but I do like an intellectual challenge. The buffer adaptor worked a treat and I felt confident moving on.
I now keep two active projects going. One is Planet, the real object of my efforts. The other is Sandbox, wherein I try out new tools and methods in safety.
When I need some new technique, I play in safety in Sandbox, until I am confident in attempting it in the design of Planet.
I continue to just scratch the surface of the power. Next for me is the OO mechanism to drive Planet. Imagine my astonishment in finding that not only will FreeCAD structure involute gear trains properly, there is the capability to animate those gears! Wow!!
Bee
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Tic in the box
With the exception of sprinkled rivet heads, this full scale chassis drawing is complete.
Onwards to phase 2
Bee
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+1 on the blue/black tack JJ.
If you ever want to change them, you will regret using super glue.
On the other had, if you are certain the boards you select are the ones to use, then superglue will certainly work.
Bee
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it's given me years of fun
That is exactly the right answer ThreeLink. If we wanted an investment vehicle, perhaps a wiser choice would be bonds, annuities or precious metals.
There was a fellow I formerly subscribed to on YouTube, who had loads of beautiful locomotives. They nestled in their coffins, er boxes, eternally. Never played with, never enjoyed. The man simply purchased them to rest on a shelf. His heirs will simply dump them.
Bee
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Under the assumption you want to keep them
You could get the pipes off a similar model. Flying Scotsman has been in production for quite some time. Get a damaged FS and move the pipework over.
You could make some. Our hobby is more than just purchasing a locomotive and turning it on. Get busy modeling! The satisfaction of making your own will be very rewarding, I promise you. Copper wire is the way to go.
Accept that your FS will never have pipework. The lads at the engineworks had a bad day and forgot to install them. Drunken lot that they are 😉
Tell Hornby that you expect some material compensation for their errant practices.
Under the assumption that you find this unacceptable
Simply return them. Hornby have admitted fault. You will not have the FS you wanted. Maybe another day or another model.
Bee
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Hello Gary
I am a very long term eBay participant. I've both bought and sold some very high value items, since before the turn of the millennia.
I've also experienced some of the not so pleasnt surprises.
Here is what you do.
(1) Put the seller on notice.
write to the seller. Be polite. Use the words "material mistepresentation" "hidden damage". Explain that you know your rights under the ebay system. Tell the seller there is a time limit under that system.
(2) you do have 30 days [last I looked it up] to dispute an item
(3) you may avail yourself of the 'Disputes' service. When in this situation, I tell the vendor I will open a dispute on the 27th day. eBay typically sides with the buyer. Vendors know this and this threat is usually enough to get them to settle.
(4) whilst it may not provide much satisfaction, leaving a negative feedback will cost a vendor money in the long term, as higher fees are charged to those with less than stellar feedback.
(5) follow up persistently and always remain polite. Use the eBay contact system, as this becomes a record that eBay will use to evaluate the situation.
I typically just settle for a partial refund. Most vendors prefer this as well, since their reputation is maintained and will not be receiving back an item that, for want of better words, 'got damaged in the post'.
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Your pictures did not come through, so I cannot see the damage. Perhaps try again?
Bee
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Having absolutely no idea on how much it costs to produce items in no way impacts on your ability to decide how much it should be sold for as its your right to have what you want.
And if Hornby will not sell you the models you want, at the price you can afford, that is somehow Hornby's fault.
Example: I've always had a fascination with the South Pole and Shackleton. I want to go to the South Pole. When I looked into it, the flight was $30,000. They fly you there, you get to walk around for 4 to 6 hours and they fly you back. No overnight stays, period. But I could not afford that and now, decades on, the flight is likely much more expensive. Is that somehow the flight operator's failure? Should they not give me that adventure for $2500? That's all I am willing to pay. Not a penny more! Don't they know I deserve this? At my price? Costs be disregarded, it is my right!!
Spot on AndyMac
Bee
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In translating Armengaud's fabulous 2 dimensional drawings into a 3 dimensional CAD model, I firmly decided on two changes.
The first is that the Armengaud drawings are of a Planet-class locomotive, intended for France. Not Planet, a Planet-class locomotive. It is a Left Hand Drive locomotive. That is, the engine men drive it from the left hand side of the plate, as they faced forward. This, I cannot abide. Planet, LMR#9, was a Right Hand Drive. It is relatively straight forward to flip the Armengaud image over, making it a mirror image. The back head and controls will be a mirror image of Armengaud.
The second major deviation is that Armengaud shows the forward suspension (spring assembly) under the frame. Yet Robert Stephenson and Co show the front suspension over the frame [red arrow].
The existing Planet reproduction also has the front suspension over the frame. So over the frame it shall be, in contravention to Armengaud. I did follow Armengaud, simply leaving off the bits that supported the spring under the frame.
All was wonderful until I placed the forward spring assembly into position. The blue riding rod, under the spring, goes through the wooden sandwich frame via a hole in the wood. Here is the general arrangement.
I was immediately struck by the futility of what I had drawn. That seemingly meaningless segment across the gap has a purpose! [Red arrows] As drawn, the blue rod can take an agle from the vertical. The bottom of the riding rod would then move dramatically over to the side. Causing major force to be applied to the horn guides from the axle box being forced to the side. Premature wear and probable suspension failure would result from that sideways force. Oh no!!
That meaningless segment across the gap is support for a block, with another through hole.
This keeps the linear travel of the end of the rod limited and restricts any sideways force to a minimum. It is present on the reproduction Planet, but is incredibly hard to see, being a black object, inside another black object, without perfect illumination. We can, however, see the bolts that hold the block in place!
The Road Map Ahead
With the front spring assembly finished, I just have some minor cleanup and the chassis is complete. The first major component will have that nice check mark next to it.
Next up is the OO drive assembly. The motor and gears, with the intended oscillating handles. Drawn in OO as OO, to speed match the tender. This should prove quite interesting (well, to me anyway!). The second major assembly.
Then, the drive assembly and the scaled chassis will be married, the third major step. The Armengaud Chassis and the OO drive will be made into one.
The last major step will be the shell to fit over the lot. With this, the design shall be complete!! Hooray!
Of course, then the real fun begins, when Shapeways tells me that none of it can be built and nothing fits as intended!
Bee
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In a way, I've already been through this, albeit for a different hobby. I had grown bored with the hobby, yet I had several thousands invested in the bits and bobs. It sat, idle for many years.
I finally just placed all the bits on eBay, individually. It was a monumental effort, as each item needed a description. Each item would need be sent to the correct winning bidder.
I did all the work beforehand and then, listed all in sequence, with the ending to happen in sequence, just minutes apart. I set my starting no reserve price at one dollar. Let it go!!
Now bidders after they examine one of your listings, check the others. This is why it all had to go at once. To create the frenzy! They see one, and want more!
I did well. Got most of my cash back for investment in other hobbies.
If the items are to go, Son Of Triangman, then let them go.
Bee
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Hello RT
FreeCAD documentation says that an STL file can be imported and subsequently converted to a 3D body. From a 3D body, a scale can be done, zero issues.
I did not attempt to convert the STL file you wanted, as the site demands you "sign up" before downloading. No, thank you, I will not sign up!
If we want models that are not produced RTR, then 3D printing is the best option. As any engineer will tell you, it is the control of the model which is important, maybe more so than the means to produce it. FreeCAD offers you absolute control over the software, it resides on your computer. The models also reside on your computer. Nothing can ever be placed beyond a paywall. The other packages can easily hold all your intellectual property ransom. No thank you!
Whilst FreeCAD is quite powerful, it also has a few drawbacks. Firstly, its a bit clunky. The interface isn't obvious. Example: Scaling. In order to scale an object to OO, you need to divide by 76.2, yet FreeCAD won't let you do that until you set a preference in the Draft toolbox. Why? Because. I finally had to Google it and experiment. I will happily walk you through this non obvious step. FreeCAD has a steep learning curve. Its only now, a few months in, that I am starting to understand.
Is it worth it? Absolutely. The next major step in OO Planet is the chassis and drive train, to include those oscillating handles. Those will be drawn 1:1 at OO. Now, I have no idea if it will actually work, but I will make a valiant attempt!
Cheers
Bee
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Hello RT
Here is a straightforward scaling example.
Planet's footplate, full size and scaled. All in one image!
Bee
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Hi RT
FreeCAD does direct scaling of parts. You could likely import the file directly and scale it to OO.
My Planet project is drawn full scale. I've already tried to scale for OO, it works spectacularly. BTW, FreeCAD is free!
Hello 81F
That model does look good. I suspect the hopper will tip?
Bee
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Hopefully, JJ will be along with the lights he used.
JJ used multicolored lights to generate quite realistic "time of day" videos. You may see it here
Bee
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This is a two part post about Planet. First, the current state of the CAD model, which shows those parts which I intend to be on my OO Planet. Second, I investigate the rear axle, which was notoriously prone to breaking.
Current State of CAD
The primary focus since the last update has been the rear axle and how it is connected to the frame.
The wheels and nominal axles were sketched. As commercially available components will be used for these, no details are needed. Every effort was made to capture detail for the the rear axle spring assemblies and axle boxes. These are highly visible components.
The axle boxes are captured in all four corners by the wheel frames (yellow). The travel of the axle box is thereby constrained to be vertical, while all four ends of the wheel plates are rigidly tied together by the load transfer link (green) at the bottom.
At the top of the axle box is the oil well, for the total loss lubrication system. There are two tiny holes leading from the well to the bearing, but this will be lost when I go to OO, so it is not represented. The well should be visible, and therefore is represented.
The spring assembly (blue) and riding rod go thru the wood part of the sandwich frame. The spring assembly was a ridiculously difficult part to create in CAD. Each leaf at a different radius and progressive arc length, with an elliptical shaped end, at the angle of the terminus of the leaf. I think the effort worth it. It is a highly visible component and will absolutely draw the eye in.
Next up will be the front axle spring assembly, as we can see in this image of the reproduction Planet. Note that the builders of the reproduction likely used genuine spring steel for the leaf springs, not wrought iron, and thus required far less material than Stephenson.
Stephenson's Fragile Axle
When Stephenson went from outside pistons to inside pistons (Rocket-Class to Planet-Class) the plain driving axle was changed to a crank axle. Given the state of metallurgy and machining in the 1830s, it is no wonder that these axles were prone to fracturing. There were also other reasons for breakage, as you will see. Stephenson, in response to this problem, added several other axle supports, such that when the axle fractured, the locomotive would still be supported.
There are SIX, count them, SIX support bearings on the rear axle. The two outer bearings, green arrows, are shown in my CAD model. The yellow arrows point to a pair of bearings around the left crank, the red arrows point to the bearings around the right crank. These comprise part of an internal frame, running between the piston assembly and the firebox. Not only do these members support the rear axles via bearings, but also each crosshead.
From this, we can infer that the breakage generally occurred at the cranks, leaving the wheels supported by the outside green/yellow and red/green bearing pairs.
Stephenson's solution comes with knock on problems. All six bearing centerlines must be co-linear. Any imprecision in co-linearity will create an eccentric of that bearing. This will result in lots of friction as it wears in, just before the bearing wears out. All six bearings are free to move only in the vertical dimension, any other direction results in wear and stress.
Further, the axis of rotation for the crank bearings must be parallel to the axle axis of rotation, otherwise stress will be placed on the crank as the driving rods twist left and right to account for a non-parallel seat.
The rear axle is a large piece of metal. It is well over the track guage long, as the axles extend beyond the frames. To machine this object in a lathe, without causing axial deflection due to tool pressure, will be difficult, particularly near the center of the axle . Then, to turn each of the crank bearings, the part must be shifted in the lathe, once for each crank. Maintaining parallelism during these shifts will also be difficult.
Overall, this is a very significant machining problem on a very large piece of stock. Even today, this represents a very large lathe.
And now the cherry.
Look at the axle boxes depicted in the CAD and in the Armengaud axle drawing. Axle motion, from side to side, is constrained by the rounded ends of the bearing seat. The axle, as shown by Armengaud, has rounded surfaces to match. By this, we can see that the axle cannot slide to the left or to the right. Each end of the axle is trapped. Each end of the axle has an independent spring. Therefore, each end of the axle can move vertically and do so independently. With one side up, and the other down, a triangle is formed. This, in effect, tries to lengthen the axle!!! Yikes! All the components along the axle are stressed. The weakest part of the axle are the cranks. As the axle is stretched, the stress will be concentrated right at the bend for the crank. Right where I think it breaks. Right where Stephenson tried to protect the system.
For the Stephenson system to work, the entirety of the axle must move only vertically, whilst maintaining parallelism to the frame. Any angular deviation from parallel results in stress. Stress leads to breakage.
Having inside pistons had benefits. A cranked axle is not one of them. Just my opinion of course, your mileage may differ.
Bee
My GWR broad gauge locos
in General Discussion
Posted
Very nice indeed!
Bee