Thompson Class B1 Springbok

[springbok]

Thanks Reg
Sound advice BSMEE at Thornbury last week had a chassey running on air but always with a member present and a large screen. "little fingers"!! I worked the Workshop area with a mini warco donated for the occasion I will not say what I thought of it. I used alley to get kids to help make spinning tops but would not like to try BMS or a casting on it.
I will post a picture of my heath robinson attachment.
The club has a rolling road which I hope to borrow to run in once I have got everything going

Bob

[springbok]

Hi Jones1972

Have looked at the slide bar drawings, drawing 4 I have made my slide bars as per the drawing on sheet 4 which is 5.3/8" also checked article 12th May 1960 page 582 and it is identical. I do note from your photo's that you have not put in the dirt catcher slots at either end, I am not sure how important this is but it would appear in the full size to aleviate any blockages at eiter end with grit.

I was very interested in looking at the lovely castings in I presume gunmetal where did you get them my ones were from Reeves in cast iron. Also interested in what I can only call a hood on the valve spindle guide.

Thank you for the fantastic pic's

Bob

[jones1972]

Hello,
valve spindle guides were machined from brass bar with with phos bronze guides bolted separately to them as per full size . i admit the slotted holes in the guides have been admitted but i think the effect is pleasing much better than the horrid bits of plate with a slot in them that the drawings shoe nothing like full size. Yes quite right i have not put end slots in guide bars better do that!! the 5" design has been built in great numbers and go well but i do think it could be improved upon ie,driving wheels too small and should have spoke in line with crank pin ,tender and engine way over width and many more.If i was building this engine for myself i would have a go at changing the design just to bring it in more to like big sister or brother! thank you for kind words on pictures.

[springbok]

How hard is it to get a boilermaker to even talk to you. !!! I have contacted a number now but no feed back is business so good. There was one at a show recently who promised to get back to me "next day" but even after leaving messages no reply. So the big question is what doese one do to get them to talk to you. With the current reg's on our beloved EEC we need the stamps.

Help Please

[springbok]

Hi Jones 1972
Found this pic and it shows your design is spot on wish I had not followed ME so slavishly. What drawings are you useing.

Bob

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[jones1972]

Hello springbok,
The drawings i am following is a set of Martin Evans plans but as i have said this engine is being built for a friend and not for me.If i was to build the engine i think i would still use the said plans but alter the point already mentioned and i expect others will come to light to bring a more realistic look to the engine.I must say however all the B1's i have driven or seen running do put up a good performance and in no way am i condemning the design . I have made changes on this engine i am building for said friend but only ones i can change easily changing the drivers would entail new pattern etc.Do not despair i am sure your loco will look and go superb and any way when you are driving any engine looks or super details do go out the window for a while because you are only looking at the top of the engine and listening at the chimney!!
I repeat the comments on the design are my view and nothing else.
thanks for kind words.
Regards
jones 1972

[jones1972]

Springbok i forgot to add that i did cheat with return cranks in that they are counter-bored to .005" less the width and a square filed in the end i think this idea came from a bloke called Clarke in Australia and was described in ME in @ 1967. here is a picture of the illusion!![/img]
Regards
Jones 1972

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[springbok]

Yes I was concerned about slippage on the return cranks and drilled and reamed for taperpins
but yours look a lovely tidy sollution must try and find out how the full size one was.
I think there is a lesson here (for me) to check on the full size before relying on ME's drawings
the reverser is a classic if you look at Chris Vines Bongo and photo's ME has has made it up for simplicity. Would love to find a source for that casting or maybe Chris fabricated it, but it would certainly make the cab more authentic looking and would allow space to put in seats ect;

Please keep me posted on other changes.

Bob

[kenn]

Hi All Name's Ken I am busy getting ready to build the LNER B1 Loco, but I am also redrawing the drawings in 3D and I am looking for good quality photos to help me. I am busy with the underframe and at present drawing the connecting rods

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[Smifffy]

Welcome to the forum Ken.

Nice drawing, you'll notice we like pictures and progress reports here, so please do keep us up to date.

Smifffy

[kenn]

Hi I am busy drawing the LNER B1 in Cad 3D and looking for input of any problems found with the ME drawings and improvements which could be made

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[abby]

I recently made these castings in gun-metal for 71/4" gauge "Roedeer"!

The pattern was rapid prototyped from a 3D cad drawing which can be scaled to any gauge required.
Dan

[springbok]

Hi Dan
Well beyond my capabilities, congratulations, could you post pic's of finished item
will look forward to it. Just a question what part is this for on a B1

Bob

[donashton]

I noticed the very neat 'cheat' to depict the square on the driving crankpin, but why cheat at all? The position of the return crank appears precisely on the full size drawings and there is no excuse for a designer not to do this on a model. Alas, it is inexplicably left adjustable so that with a spot of extraordinary luck we might hit the right angular setting!

Don

[donashton]

Come to think about it, any photos of B1s in side elevation will clearly show that the expansion link 'backset' is zero, whilst its cousin the K1 featured all of 1/4". Has anyone noticed this?

Don

[abby]

Bob they are the valve spindle guides that you asked about in an earlier reply , I have also cast the cross-heads in steel and the motion plates , no photo , in gun-metal.
Currently making 5" gauge A1 tender spring hanger brackets.
Dan

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[springbok]

Hi Dan
fantasic work but I would not advertise to much or you will have the world and its wife knocking at your door for castings.. I was really asking about the pic you posted about the castings for roedeer what they for.
I think SWMBOBEYED would try and kill me if I tried to attempt to make castings.

Kindest regards and keep everyone posted about your fantastic casting skills
It would be great to see a thread on how you do it.

Bob

[Shawki Shlemon]

Very nice and interesting , looking forward to see more . Thanks.

[abby]

Bob the Roedeer castings are two pairs of valve spindle guides , made for a group who are building a number of 7 1/4" gauge B1's.
Here is a picture of one.
If the world and his wife beat a path to my door then whoopee ! I make castings for a "living" as well as my own use.
If you want to see how they are made just visit my website/forum.
www.unionsteammodels.co.uk/

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[springbok]

Abby
Wow seriously impressed will retract my statement and hope they do come banging at your door. Is the dog your MD as my 2 think they are mine. I do get asked about castings so have put into my favourites. and can pass on.
Good luck and a prosperious new year

Bob