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

[masahiraoka]

Looking through the list of West Country and Battle of Britain loco names I see that several of the important RAF airfields of WWII were used but not Duxford. 

I like the idea of Duxford as it is still an operating airfield owned by the Imperial War Museum and the base for a branch of their museum. It’s also the base of The Old Flying Machine Company which was founded by a Ray Hanna, who was a close friend of mine in New Zealand, see www.old-flying-machine-company.co.uk/ray-and-mark-hanna/.

Also during the war its importance as an airbase was strengthened because it was shared between the RAF and the USAAF. It was also the base for the first squadron to be equipped with Spitfires.

finally Duxford sounds like it could be a name of a West Country town although of course it’s not.

I’ll cogitate on the name for a while but Duxford seems a strong contender.
ciao martyn 

[kipford]

Martyn
Slightly off topic, I saw Ray fly many times over the years and was so sad when Mark was killed in the accident in Spain. I did not realise he was a Kiwi. The following photo I think sums up Ray Hanna. It was taken on the either the Thursday or Friday morning of the 1998 Goodwood Revival meeting. The CAA were not impressed and he got a talking to! A friend of mine who ran a corporate hospitality firm there witnessed it and in an understated way said it was a bit impressive. 
Dave

Ray Hanna by Dave Smith, on Flickr

[andyhigham]

This was linked on another forum (Brit bike) this week as BSA also made a Spitfire
youtu.be/4iOoiEbtf2w

[masahiraoka]

There is no doubt Ray was one of the very best pilots of the second half of the 20th century.
we saw him fly many time at War Birds over Wanaka in NZ.
i don’t think they make pilots or aircraft like that any more.

[masahiraoka]

Hi all

It's been a long time since our last posting but work continues - Phil has worked on lots of smaller details as you can see in the screen shots below and is just about ready to start work on the tender.
Andrew has just about finished the streamlined Duchess so should be able to start work again on the chassis.





here is the loco with the "cheekless" cab which as mentioned before I prefer - to be named  No. 34111 Duxford



Bristol SMEE member Rob Speare had previously organised an excellent exhibition of Bulleid Locos at the 2017 Bristol exhibition and had hoped that they could repeat the exhibit at this year's exhibition which I now see from their website has been postponed for obvious reasons till May 2022, hopefully Aussies will be able to travel to the UK and Europe by then when i plan to bring the chassis for display on the Bulleid stand should it go ahead.

till next time

Martyn

[masahiraoka]

Phil's been working on firther details

these show the lubricators located in the usual position between the frames at the front of the engine

[masahiraoka]

and the firehole door

[masahiraoka]

hi everyone,
like others i'm having some trouble with images showing on the thread from my Dropbox folder.
strangely it seems that the images are displaying correctly on my computer and mobile phone but not my ipad.
is anyone else having trouble seeing the images i've posted?
ciao MArtyn

[barlowworks]

Yes, I just get a square box in the text but no image on my iPad.

Mike

[masahiraoka]

Mike
could I ask you to try accessing the thread through your computer.
If you can access it through your computer that would narrow the focus to Apple products
thanks martyn 

[uuu]

My Windows PC shows the pictures perfectly - as does my Android phone.

Wilf

[masahiraoka]

Thank Wilf
Likewise my PC and android phone are fine, so it’s something with Apple - again!
ive asked Dropbox about the problem but who knows if or when they'll respond
ciao Martyn 

[masahiraoka]

iPad display of images seems to be fixed.
the joys of working with modern technology!
thank goodness they don’t build aero planes.
whoops Boeing recently tried to fix a fundamental design problem with a software solution with tragic consequences.
im now battling the joys of a new car with an “all glass cockpit” with far far too many options and features available through the almost unusable software user interface. I wish industry would stop calling writers of software, engineers when I’m guessing most in fact are not engineers, call them what they are ie software programmers who often have very little understand of the fundamental principles of engineering.
glad to see the UK is finally getting on top of the virus.
ciao Martyn 

[terrier060]

Mar 13, 2021 5:46:27 GMT masahiraoka said:

Phil's been working on firther details

these show the lubricators located in the usual position between the frames at the front of the engine




Hi Martyn
I assume the lubricators take their power from the crosshead?  If it comes off the valve rod you may have the same problem I had with my Hunslet, in that the stroke varies with cut-off and I was getting no oil to the cylinders when notched right back.

[masahiraoka]

The lubricators take their drive motion from a bar clamped directly to the Inside cylinder Piston Rod just in front of the Crosshead.
So the full movement of each of the piston strokes (1-1/2”) is taken to the reducing lever arm where it is leveraged down to a more manageable ‘swing’, giving a normally intended two ‘clicks’ of the ratchet.

Screenshots attached (lots of hardware to dodge, avoiding collisions!) These are shown with the Inside Cylinder piston/rod at virtually extreme Front-Dead-Centre, which still leaves clearance between the clamp and the rear cover.

the first shows the clamp from the top side of the cylinder




the second shows the same from the underside

[masahiraoka]

Phil continues his design this time working a commercial 12 ounce injector by Les Sheppard into the chassis.
With so much now included in the design it's getting tight fitting new components into the chassis.

That said Phil has done a great job making the pipe runs look like the full size.

[masahiraoka]

Phil has 3D printed the fire hole door components in plastic and put together the working subassembly

the first photo shows the fire door assembly in both 7 1/4 and 3 1/2 inch gauge



these next two are of the 7 1/4 inch assembly





the heat baffles on the inside of the doors "work" ie there is an air gap between the baffle and the door itself and secondary air for the fire can pass in a zig zag route through the deliberately misaligned holes in both.

the gears built into the doors mesh correctly and when the long operating handle is pulled both open simultaneously in a clam shell fashion.

the only modification for the scale design as compared to full size was that the casting at the base of the actuating handle had to be made to fully encircle the door operating pin as you can see in the 7 1/4 inch example wherease in full size the handle casting only pushes against the door operating pin as per the 3 1/2 inch example and in the 3D CAD screen shot shown on 13th March

[masahiraoka]

we've had some great progress this past week.
Phil has recieved from the foundry sufficent large and small wheel castings for two protoype loco builds.

these wheels are cast in steel from 3D CAD printed patterns and include on the main wheels the undercut pockets which is such a feature of the Boxpok design.
these should machine up nicely!

[masahiraoka]

Hi all
Phil has rightly pointed out that the original full size design of wheels were strictly speaking not Boxpok rather BFB or Bulleid-Firth-Brown ie a collaboration between Bulleid and the foundry.
ciao Martyn 

[masahiraoka]

It's been too long since we posted but progress continues.
Phil's son Nigel, a very experienced model engineer and CAD draughtsman has joined the team to produce, from Phil's 3D CAD model, the 2D drawings that will ultimately be made avaiable to model engineers everywhere.
here are two examples of early issues of the Inside and Outside Cylinder assembly drawings