Rebuilt Bulleid West Country 3D CAD designed & mft in 3.5 in

[masahiraoka]

Brian 
the CAD designed boiler, the existing physical 1/16 scale boiler and the original full size boiler drawing are shown in my posts of 5th May 2020 and 18th May 2020 

my posts of 13th March 2021 and 9th April 2020 show the fairly conventional steam oil lubricator set up in the 3D CAD drawing of the front end of the chassis

my post of 13th April 2021 shows the injector set up in the 3D CAD drawing of the rear end of the chassis.
this drawing of the same from a slightly different angle shows one of the two conventional mechanical water pumps located in front of the rear coupled wheel axle driven from the crank axle in a conventional manner



and finally my post of 14th September 2022 shows the double acting handpump located inthe tender

hope these help
ciao MArtyn

[masahiraoka]

Brian
Phil has pointed out that in fact there is only one mechanical pump as we’d run out of axial space on the crank axle to locate another eccentric to drive a second pump.
Always pays to check with the chief engineer!
ciao martyn 

[runner42]

Hi Martyn,

thanks for the references to the 3D CAD drawings. However, these are not dimensioned drawings from which to build the parts, no doubt these are in train. I was of the opinion that your project objectives are to provide the necessary data for others to build such a detailed locomotive? 

Brian

[44767]

Nov 26, 2022 4:57:12 GMT runner42 said:

Hi Martyn,

thanks for the references to the 3D CAD drawings. However, these are not dimensioned drawings from which to build the parts, no doubt these are in train. I was of the opinion that your project objectives are to provide the necessary data for others to build such a detailed locomotive? 

Brian

This is only the prototype model so that the best way of making the components for the model may be established. Methods to build this first model are not necessarily those that will be employed for the model's final design; proper use of rapid protoyping.  Detail drawings of the final design's parts will follow, I'm sure.

Mike

[Doug]

Nov 26, 2022 10:05:08 GMT 44767 said:

Nov 26, 2022 4:57:12 GMT runner42 said:

Hi Martyn,

thanks for the references to the 3D CAD drawings. However, these are not dimensioned drawings from which to build the parts, no doubt these are in train. I was of the opinion that your project objectives are to provide the necessary data for others to build such a detailed locomotive? 

Brian

This is only the prototype model so that the best way of making the components for the model may be established. Methods to build this first model are not necessarily those that will be employed for the model's final design; proper use of rapid protoyping.  Detail drawings of the final design's parts will follow, I'm sure.

Mike

Thing is many may not want to build it with 3d printed parts etc. are you holding off publishing the drawings till you have made a complete model or as it’s now finished in cad are you considering a BETA release? That would be very good if you did as you could get feedback on the design.

[masahiraoka]

Thanks Brian and Mike for the question re detailed drawings.



Mike is right that we’re still exploring the optimal way to produce parts for the loco. In many cases they will be either 3D printed directly in metal or cast from 3D printed patterns (either in PLA or wax). For these parts we will provide drawings to model engineers with enough detail necessary to transform the printed or cast part into the machined finished part ready for assembly.



Given the investment I’ve made in the 3D CAD design, we won’t be providing fully detailed 2D drawings which would enable a model engineer to eventually reproduce the printed or cast parts from scratch, but instead the model engineer would save the design and fabrication/pattern-making tedium by purchasing the non-machined parts from us. This commercial approach replicates that that has been used for decades for castings for other locos from other suppliers.

Rest assured I will be pricing the parts marginally above the third party cost to produce them ie not build in a cost to recover the cost of design which has been substantial.



The end game is to provide lots of super detailed parts that enable a model engineer to quickly (relatively!) build a high quality loco. The upfront cost of lots of parts might seem high at first but the saving in time and improvement in quality should more than compensate.


ciao Martyn

[masahiraoka]

thanks Doug

It's worth adding that our design has been deliberately slanted towards the 3D printing of parts / casting and therefore would not be all that useful for someone wanting to build a loco from scratch using more traditional techniques.

This means that our design includes far more detail than many would want to include for a scratch build and to do so would mean that the design / build time would be much too long.


hope this and my earlier comments explains our design / commercial approach

ciao Martyn

[runner42]

Your approach is the optimum one given such factors as economy of scale, producing detailed drawings for a limited market will provide small returns. Also the target audience will not be beginners and therefore anyone attempting the build should be able to utilise the 3D CAD data together with the 3D printed parts. To only issue is the boiler, in Australia detailed drawings are required to show construction and compliance to the code.

Brian

[masahiraoka]

thanks Brian
good point regarding the boiler. it is our intention to provide an AMBSC and European approved design for the boiler but we won't be in the business of providing completed boilers with the model engineer either building it themselves or commissioning one from one of the exsiting suppliers.

The 2D drawings will be provided free of charge as i've already done so for several of them through this blog. This is the list of current drawings

Drawing No. & Name

SHT-A Inside Cylinder Assembly & Details

SHT-B Inside Cylinder Details

SHT-C Outside Cylinder Assembly & Details

SHT-D Outside Cylinder Details

SHT-E Locomotive Arrangement

SHT-F Tools & Jigs

SHT-G Coupled Wheel & Axle Assembly

SHT-H Driving Wheel & Axle Assembly

SHT-I (not used)

SHT-J Mainframes Assembly

SHT-K Stretchers & Buffer Beams

SHT-L Slidebar & Motion Bracket Assembly

SHT-M Engine Bogie

SHT-N Trailing Truck

SHT-O (not used)

SHT-P Inside Rods & Motion

SHT-Q Outside Rods & Motion

SHT-R Reversing Gear

SHT-S Mainframe Details

SHT-T Engine Brake Assembly & Details

SHT-U Engine Brake Details

SHT-V Grate & Ashpan

SHT-W Smokebox Assembly

SHT-X Smokebox Frame & Saddle

SHT-Y Smokebox Top, Door & Chimney

[Cro]

As much as I love the idea and concept I do fear, from my own experience, that where people have an option for less expensive castings with less detail/quality vs higher cost but far superior casting they pick the low cost option.

We have the BR Pony Truck wheels at I think £30 each which are injection die wax made and investment cast with only 1mm to remove from the thread/ rear face and bore essentially. Where as you can buy the sand cast option for approx £20 a wheel or less and people pick the latter option as in the years we have had them available we have sold 2 pairs(?).

When it comes to loco castings I’m not sure many people see the economy of the better quality parts over the less expensive and it’s a tough market to break. It’s very limited and you then have to find someone who wants to build a bulleid loco.

I do look forward to seeing it being built.

[44767]

I think the main selling point will be that it will be 100% error free on the drawings. That doesn't happen often in model engineering so anyone looking for an unusual model, in a scale which is becoming popular again and which should be an easily machined set of parts, this would be hard to ignore.

Mike

[masahiraoka]

Hi Adam
you may be right but i'm willing to give the whole project a go, particularly that the 3D and 2D CAD design is essentially complete.
our next step is the completion construction of two prototypes to confirm the design and make any necessary adjustments.

once this is done we'll continually explore options to reduce the cost of parts and hopefully produce a package that some model engineers are willing to pay for.


ciao martyn  

[44767]

Nov 29, 2022 6:29:50 GMT Cro said:

As much as I love the idea and concept I do fear, from my own experience, that where people have an option for less expensive castings with less detail/quality vs higher cost but far superior casting they pick the low cost option.

We have the BR Pony Truck wheels at I think £30 each which are injection die wax made and investment cast with only 1mm to remove from the thread/ rear face and bore essentially. Where as you can buy the sand cast option for approx £20 a wheel or less and people pick the latter option as in the years we have had them available we have sold 2 pairs(?).

When it comes to loco castings I’m not sure many people see the economy of the better quality parts over the less expensive and it’s a tough market to break. It’s very limited and you then have to find someone who wants to build a bulleid loco.

I do look forward to seeing it being built.

I think what is happening here is the builder is staying loyal to the castings supplied by the designer, in the first instance. Unless he's aware of an alternative, this is the way he'll go. The high quality lost wax castings would be more attractive to a builder short on time or working on commission as they will save many hours of fettling or fabrication.

As far as this model is concerned, the castings offered will suit the design and require minimal machining to make the build quicker and as close to scale as possible. There won't be alternative, cheaper sand casting options, I suspect.

[44767]

Nov 29, 2022 2:42:18 GMT runner42 said:

Your approach is the optimum one given such factors as economy of scale, producing detailed drawings for a limited market will provide small returns. Also the target audience will not be beginners and therefore anyone attempting the build should be able to utilise the 3D CAD data together with the 3D printed parts. To only issue is the boiler, in Australia detailed drawings are required to show construction and compliance to the code.

Brian

I'm not sure I follow your logic, Brian. Why can't a beginner cut his teeth on a model like this? All of the hard work to establish how to make a part is already done; castings and kits of laser cut parts etc. are supplied and are fit for purpose. He'll spend time on each part learning how to set up and machine and fit knowing that if he follows the drawing, the part will fit, unlike many who get disheartened having made a part only to find that the design is incorrect and it will not fit.

Why should anyone have access to the CAD model? There's thousands of hours of work to create a new design like this and all that is necessary to build the model is the set of detail drawings showing dimensions and assemblies. There's no need to give away the IP with it. There is a way of saving the CAD model so it can be viewed as a 3D model, with the ability to measure, cross-section, hide, hide others, etc. without providing the file types to manufacture the parts. Is this what you mean?

Mike

[runner42]

Dec 7, 2022 19:26:17 GMT 44767 said:

Nov 29, 2022 2:42:18 GMT runner42 said:

Your approach is the optimum one given such factors as economy of scale, producing detailed drawings for a limited market will provide small returns. Also the target audience will not be beginners and therefore anyone attempting the build should be able to utilise the 3D CAD data together with the 3D printed parts. To only issue is the boiler, in Australia detailed drawings are required to show construction and compliance to the code.

Brian

I'm not sure I follow your logic, Brian. Why can't a beginner cut his teeth on a model like this? All of the hard work to establish how to make a part is already done; castings and kits of laser cut parts etc. are supplied and are fit for purpose. He'll spend time on each part learning how to set up and machine and fit knowing that if he follows the drawing, the part will fit, unlike many who get disheartened having made a part only to find that the design is incorrect and it will not fit.

Why should anyone have access to the CAD model? There's thousands of hours of work to create a new design like this and all that is necessary to build the model is the set of detail drawings showing dimensions and assemblies. There's no need to give away the IP with it. There is a way of saving the CAD model so it can be viewed as a 3D model, with the ability to measure, cross-section, hide, hide others, etc. without providing the file types to manufacture the parts. Is this what you mean?

Mike

Mike we are both speculating on the business model, because we are not members of the project team we don't know the finer details. It is best left to Martyn and others to make comment on whether or not the 3D CAD details will be available if needed, or that all that's required to complete the locomotive build is rudimentaty tools that a beginner would have. Of course there are beginners that have a great experience as a machinist that are entering the ME field, able to read drawings and interpret them in setups able to machine cylinder castings etc.

Brian 

[masahiraoka]

hi Brian
our commercialisation model is similar to Mike's ie the 2D drawings will be issued with more than sufficient detail to machine and assemble the castings/ 3d printed / laser cut parts but not so much detail that an expert model engineer could reverse engineer the 3D CAD design from scratch.
it's worth nothing that something like five man years of work has gone into the design and that last thing i want is for my IP to be lost somehow to some asian manufacturer who goes on to produce poor quality parts - such an event would negate the whole benefit of the details 3D design.
As i've said before i intend to only charge the third party cost of manufacture of the various parts plus a very small margin. my aim is for model engineers to leverage the benefit of the work done to date.
ciao Martyn

[masahiraoka]

Brian
i should have added that i'll explore Mike's suggestion that we might be able provide a simplified 3D model for model engineers to use to visualise the assembly
ciao Martyn

[92220]

I fully agree with Martyn's protocol. Actually, why would the 3D model be so important to a model engineer anyway, if he/she has the 2D drawings? I don't get it. A 3D drawing is great to show what it is like when built, and for the draughtsman, a check on component fitting. I certainly get Martyn's reluctance to provide a fully detailed 3D drawing, because any CAD draughtsman, with the right draughting software, can pull of perfect 2D working drawings. Having taken 5 years to produce a finished design, it would be disastrous if someone pirated the design and started marketing parts cheaply.

Bob.

[Doug]

I personally think the point is being missed, I am building a 2.5” model of sir Keith park, 2d drawings alone just give me the building blocks to build a 3d model from which I CNC all my own parts, this is how I have built speedy and how I do model engineering. I expect new engineers to the hobby would be interested in a similar approach. Using a kit of 3d printed parts for me is not engineering it’s building expensive mechano fine for people without or little engineering skills yet not very interesting for me. Making for me is more fun than using. I don’t see the IP issue being relived by giving away the 2d design and holding on to a cad model. Anyone with drawing skills can replicate the 3d design from 2d drawings. All seems a bit odd and lost on me. Lovely work though.

[92220]

I'm not quite sure what the problem with 2D drawings is. Until CNC came along, 3D engineering drawing was almost unheard of, except to illustrate an object; never to machine it. I was an engineering design draughtsman for many years, and worked in 2D and 3D. CNC was in it's infancy so everything we manufactured, was machined to 2D drawings, but 3D drawings were used to show assemblies.

Everything in the engineering world, was manufactured from 2D drawings, before CNC. 3D drawings give you a picture of what something will look like when finished, or assembled, but for actual manufacturing (machining) 2D drawings are the most important. If you think about the machining of an item, you can look at a solid item, which IS 3D in life, but what you are seeing is actually a 2D face, and dimensions are all against 2D faces.

Martyn is quite right to not publish full 3D drawings. Anyone with access to any CAD software that can read his drawings, can generate full working, fully dimensioned, working drawings. Definitely NOT a good idea to publish fully detailed 3D drawings. If Martyn's drawings have been proved by him manufacturing a couple of models to the drawings, the only need, technically, for 3D drawings is to give an idea of the final shape of things, and to check the dimensioning has no clashes.

Bob.