Another new loco, Sir Keith Park in 2.5" gauge

[Dougs]

Well as if i didnt have enough to do i have gone and taken on another project.
why? well i have as you know been given a loco (Butch) that got me started then after fixing that and getting it working i took on a half bult loco (Speedy) however i have always fancied building one (from scratch) and didnt know where to start now i have fixed one and i am finishing one, i know whats involved and fancy a bigger challenge of designing one too (not from scratch but building a copy of one), i love the big locos as they are the sports cars of the loco world but normally these are too big to build unless you have some BIG machines so if i go down to a size i can build with my machines then,,,,,,
I am going to build a model loco in 2.5" guage thats half the size of my speedy, but not in actual size as a Rebuilt Merchant NavyBattle of Britain Class Bulleid light Pacific is as PW can confirm is MASSIVE!!!!!! as ther are no plans for a train in this size i have got to draw and design it myself, i have been very lucky indeed in that someone else had the same idea and got about halfway throug the process of making a set of plans, so i have a head start.
the loco itself is 24" long without the tender so its going to be pretty big over 3 feet long in total. I decided it was going to be a copy of Sir Keith Park as it combines my fave, things flying and steam engineering.
sorry i dont have any photos of anything yet just a 3D model that they guy had produced,

its going to take a year or so to do all the drawings and double check everything before i can start building it so its not going to be a five min job but i have my other loco to finish first and this should drop in nicely behind that, however if i do make any parts/ porgress i will keep you up to date.

[Sooty655]

You're a braver man than me !!

I'd be inclined to get a set of plans in 5 inch gauge, and convert by simple division by 2.

How about something like this?

[Dougs]

You're a braver man than me !!

I'd be inclined to get a set of plans in 5 inch gauge, and convert by simple division by 2.

How about something like this?

funny you should mention that, its what the author of the drawings said i should use So I am using 5" plans to get a ref. however because of the reduced guage the scale will not allow all the dims to be used the same way, i have started drawing the frames for instance and they look like they will need at least 3 sheets of drawings to get all the detail in so i will have to adjust the design to suit and simplify if possible.
mmm King class now thats a monster, 4 cylinders and a whole load of trouble.
3 cylinders is enough for me i think. already getting a bit of a sweat on with the RMN there is so much detail in the loco's is a real problem deciding what to keep and what to alter. i need space for a pump for example to get water into the boiler and i only have 1.75" between the frames and thats full of crank and cylinder so its very snug.
it will keep me off the streets

[34053]

I am, obviously, absolutely delighted at this news from Dougs and am looking forward to seeing the progress on this Locomotive. You could say that I am well and truly 'chuffed'.

PW

[Dougs]

just a quick teaser my first draft of the frames drawing;

i suspect it will have to be altered by the time i release them for building but it does give a good idea of the size
just over 23" long this is going to be BIG!

[Vulcan Bomber]

It must be said, 2.5 inch doesnt appeal to me at all, to small!!! 5 inch or 7 1/4 for me.... for now.

[Dougs]

It must be said, 2.5 inch doesnt appeal to me at all, to small!!! 5 inch or 7 1/4 for me.... for now.

If you have the machines I am 100% with you as the larger the scale the better the working detail, however I am tied by the equipment I have and I can do a 2.5" loco with ease on my machines, I am going for very high detail as well considering the scale so it should be quite unique.
Plus I also have two 5" loco's already

[Dougs]

Well all new loco's start with a bit of cut metal and this is going to be no different i have found a supplier of laser cut parts he is very reasonably priced £19 for the frames as drawn above, i have done some modifications to them to bring them in line with BoB class loco's not merchant navy class so they are 2" shorter and some details are added. I would not normally get them this early as i havent done much of the drawings but i want to try out this supplier and its the only steel i need cutting at the moment so why not! I will post some pics when i get them delivered.

[Shepard]

That's like one of the coolest things I have read about in my life! Doug - you're awesome man! I can't wait to see the progress and I am more than sure that you are going to rock. Fantastic! Incredible! Kudos and oh fingers crossed so tight!

...

...

I sound like a fanboy

[Dougs]

Been busy drawing, I love CAD it's such a good idea I am drawing it up in 2D them building a 3D model from the drawings then going back and making alterations where needed its fantastic in that I can do the prototyping in the computer so when I build it it will be right first time, I have already found a half dozen faults that I have corrected on the drawings


It does not seem like a lot of progress so far but it's perfected about ten components in half a day by the time I have finished I should have done at least 6-8 months work on this.

[Dougs]

a loco is born! i have my new frames this is the first loco i have not had bits for so its really my very first train build.

thats it now i have to build it i have got no choice

[34053]

Congratulations on the 'Birth' of your first Bulleid 'Pacific', Dougs. I am really looking forward to following this Build.

PW

[34053]

Any further developments on this project Dougs?

PW

[Dougs]

Ok it's been quite a while since I have updated on progress to be totally honest there has not been much going on, work has had me tied up with very little spare time so my hobby time has taken a beating. But research has continued and I am learning quite a bit about how it's built. The really good news is I have some new parts on order, the front bogie frames and the tender frames. My model is SKP in 2014 so it will have a 5000gl tender I will be making it as close as I possibly can. I will be making slow progress when I can but getting parts/materials together should help alot when it comes to the build stage. I will post a photo when my frames arrive.

[34053]

Thank you Dougs. Good to know that you are still 'on the case'

PW

[Dougs]

I am having a bit of a beavering session with the drawings for SKP as I am getting some frames for the bogie truck I thought I should make the drawings to produce it

This is what I am trying to replicate

I think it should be very close indeed when complete on and on a very positive note I have found a loco that is very local its a rebuild West Country class called Boscastle only a few miles away so I will be making a visit soon to get some photos

[34053]

Thanks Dougs.
I am really impressed with your drawings! Reminds me of the time I spent in the Drawing Office at the start of my 5 Year Engineering Apprenticeship, back in the 60's. It was 'T' Squares, Set Squares, 'chisel pointed pencils', 'ruling pens' and 'Graphos' nibs then (not forgetting the, wonderfully named, set of 'French Curves'). How so much simpler and easier it is now, with CAD. (Although a drawing has, of course, lost its 'personal' touch, not having the unique 'printing style' of the Draughtsman who produced the drawing).

PW

[Dougs]

Hi PW
That's how I started on a drawing board, was prob. The last of the bunch to be taught that way. The CAD came later to be honest there are still styles and personality in the drawings but the Art has defianately gone, I guss like all jobs it's only easy once you know how. The rules of convention still apply though.

Progress, the frames have arrived I am very happy with them, the bogey frames need a little work but are essentially ok. I just wish I had more spare time to get on with the build got some great ideas on how to go about machining it all up.

[Dougs]

A little more progress on SKP I am still doing a lot of the design work which means lots and lots of drawings and 3d modelling it's very slow progress but I am getting there. Anyway the tender has started to get some bits together, I have got some steel for the wheels (these are going to be CNC milled) and I have got some spring and horn block castings for the chassis.

Theses are very close but not quite right as the spring hangers are slightly wrong so I am going to cut off the little hangers shown below in the photo they should then look about right .

I am still going to be collecting as many parts and materials as possible while I am doing the design work so when I get to building it I can just get to it without too many hold ups looking for bits.

[34053]

Thank you for your latest Update, Dougs. Just as a matter of interest, how will you be making the (unique) 'Bulleid' Wheels on the Tender (and Locomotive)?

PW

[Dougs]

Hi PW
I have some steel bar which I will cut into sections, I will then use 3D milling to firstly rough out the pockets then a small ball nose cutter to finish off the pockets. The tender, bogey and trailing truck wheels are relatively easy to machine the main driving and coupled wheels will be a bit more of a challenge.
I could get some castings but they are quite expensive and I fancy the challenge of making them myself, I may use cast iron bar for the main wheels and fit steel tyres, I will see how hard they are to machine first before I make that decision.

[Dougs]

Ok some small progress on the 3D model of SKP, this is so time consuming as I need to cross reference all my sizes and parts with the real thing and while I am trying to get it as close to the full size as possible obviously because of the scale and other practical issues I have to accept that it can't be an exact copy.
First off the bogey frames and stretcher

Then the axe boxes although these may change a bit as I want to put roller bearings in them nut I have a solution for the springs which will be coil springs under the horn stretchers covered by a faux leaf Spring


And finally the full assembly so far

The great thing about drawing it in 3D CAD is that I can produce drawings of individual parts as I need them and I know that as long as I make it to drawing it will work and I won't have any bits that don't fit. Which seems to be very common with traditional model locomotives as I am having to make it up as I go along with my "Speedy" build
I can also design improvements and alterations and test them before I actually build the real thing.
I also have a boiler design that I can use from a friend who is building an un rebuilt west country class so that's a large part that I won't need to worry about too much.
A couple more years and I can start building it for real. In the mean time I am still collecting materials.

[34053]

Many thanks for the Update, Dougs. I find all this 3D stuff both fascinating and really quite amazing. (When I started work, it was in the Drawing Office on the Drawing Board, with scale rules, 'chisel pointed' pencils, ruling pens, 'Graphos' pens, 'T' squares and Set Squares!! How things have moved on).

PW

[Dougs]

Many thanks for the Update, Dougs. I find all this 3D stuff both fascinating and really quite amazing. (When I started work, it was in the Drawing Office on the Drawing Board, with scale rules, 'chisel pointed' pencils, ruling pens, 'Graphos' pens, 'T' squares and Set Squares!! How things have moved on).

PW

TBH thats how i started too i hit the first few bits of CAD before it truely became mainstream in the late 90's I now confess to be a full convert as i use CAD CAM and CNC. its truely amazing how far its come in the last few years you can now do full stress analisys form your drawings and also pressure and force calculations oh and also calculate the weight and stock material needed. How much diferent would a steam loco look if designed now using modern methods and materials i would bet it would be a truly ugly beast but very efficent.
i have a lot of detail to add to the CAD model including adding bolts etc. these as i have found can be very important as they often give you issues with clearances etc.

[Dougs]

Had a fantastic day today and got to see the real thing
I took hundreds of photos

Lots and lots of detail shots basically things that are not on any drawings so I can get the details correct like the lack of steps on the tender buffers and he buffer heads that are riveted on


And even got a selfy with the old girl

One of the shots inside the cab

And a nice vid of it leaving the station