7mm Geordie bruiser (NER A7)

[mickoo]

Having a bit of spare time last week I decided it was time to make good a promise to a colleague and do something with all the drawings he'd sent some time ago.

Naively I figured it'd just be a simple tweak here and there from the last NER tank, err no! It ended up being almost all needing changing. Being lazy and quite honestly useless at cutting parts out I've added lots of the simple shapes, I'd rather pay the bit extra and take the cusp off than try to cut straight and to size and then get cross

So a few days in CAD and it spat out the etches which were duly sent off for processing.

This week the labels were added so once back, work can begin on the test build with no further ado.





The only parts missing are the boiler sheet and formers, I've little issue cutting those and the above represents a late BR engine with small boiler and smoke box (but extended). The other options, and there are a few of them, will be better served with small supplementary sheets later.

The only problem now is it'll take a week or more to return and I've got itchy CAD fingers already

 

[Rob Pulham]

You wicked man Mick,

I haven't built the last one yet.....

 

[mickoo]

You wicked man Mick,

I haven't built the last one yet.....

Chop chop lol.

Due to work commitments I can't get to NRM in the next few weeks, if I could then I'd be on the A8 drawings like a rash as that's the one 'I' really want as well as a couple of other engines in the pipeline.

 

[7mmMick]

I love the thread title Mick, you've hit the nail on the head there. I'm very looking forward to this as you know, at one point most of the class were in Hull but maybe the whole class in model form will be a stretch in one life time

Mick

 

[Eastsidepilot]

Geordi Bruiser ? .....sure that 'aint a pseudonym for Cheryl Ann Tweedy ( ex Cole)

 

[mickoo]

Ok idle fingers and all that, back to Autocad and some 3D work, nearly got the chimney and dome base radius process sorted but not quite just so as yet.

I've also been learning rendering so the images are a lot better and easier on the eye to look at

Smoke box door, some engines were fitted with a Doncaster / Thompson front door, very close if not identical to the B1 and later Peppercorn K1 classes, fortunately I had one kicking around so it was a case of taking off the number plate and just copying it over to the new project.

There are....so far as I can tell to date....three types of smoke box door. I'll do them all eventually but I need this one first for my build.



Then the LNER style chimney, slightly taller than the NER one due to the slightly smaller diameter smokebox used on the small boilered versions.



The overly thick base is there for two reasons, it makes sure the thin edge at the bottom can be rendered in 3D and meet the minimum size threshold, though that depends on the material selected. Although the base looks huge it is in fact only 1.2 mm thick.




The idea being to sand it down to the required thickness myself before fitting to the model.

Finally the overall view of bits so far.



That in light grey being for the later small boilered version, that in orange for the large boiler version, there are two types of dome, each slightly different is height and shape and two types of sand box, there is a third used in later years when the balancing pipes were removed.

The sand box fillers and lids I'll turn up in brass, easier that way in the long run.

You'll have to excuse some of the artefacts and slight rendering niggles as these are quick and dirty renders and not full blown desk top artwork ones, I don't have the time to run those, nor are they required to visualise the shape.

MD

 

[mickoo]

Busy day with other stuff so only a couple of castings processed. The cylinder front cover needs cross checking and maybe a bit more detail, but the bulk is there so only a few moments to redress once I have the info. I need to check the rib thickness and get as close as I can to the printers tolerances by reducing the thickness until it squeals.



The other two items are the steam brake cylinders, one flipped so y'all can see each end; the end with the large flange is the working end where the piston rod comes out of.

There's a flat plate that goes on top which bolts to the stay but that's easier as an etch soldered to the stay and then the cylinder fitted on top.

Next up will be the backhead and then I need to look into some thistle lubricators which might work out easier to turn than cast.

Excuse the gritty shadows, it's the coffee break render mode

 

[mickoo]

Just a couple more bits this evening.

Backhead


Despite having virtually the correct profile the firebox door ring doesn't seem to render very well or look right so I'll try some different settings later.

Cylinder covers.


These are the covers at the front ends, most engines had smooth covers over them but later in life these were left off to reveal the front plate underneath. Much happier with the shape and webs and have managed to decipher the correct profile inside. To the right is an outside one, the rest are inside and are in fact four parts with spigots on the rear.

There are normal cover plates so one can mix and match to suit their whim like so.

Cylinder cover plates present, valve cover missing.


The centre cylinder cover has a drain tap port at its front base and centre hole for the thistle lubricator; the valve covers have dimples for the oil line entry above the cover for the tail rods.

Some engines seem to have a an oval packing gland on the outside cylinder covers in the centre, not sure why as nothing comes through here or is bolted onto there, I need a better detail shot but that'll be a sub part that can added by simply drilling a small hole in the middle of the current outside casting.

I think I need to go back and give the render engine a right good slapping, it's faceted some of the items in the middle image when it shouldn't of, probably trying to conserve CPU or GPU grunt even though it's been told not to.

 

[Overseer]

Mickoo

Shouldn't the bolt heads on the cylinder ends be nuts on studs? If so the stud should protrude through the nut slightly. It is not a big difference but does look quite different as there are more bits to catch the light.

 

[mickoo]

They're easy enough to add



They are studs on the engines but the studs are near flush with the nut so that from even a few feet away they look like bolt heads, I've some detailed scrap yard shots and i'll scan the best one in tomorrow, it's a Q6 but the construction and design is very close to the A7 and A8.

 

[oldravendale]

Hi Mick. I know that you have loads of photos but this one, a very small section from a large format neg of Q6 63435 shows the cylinder front rather well, I thought.

B

 

[mickoo]

It does and shows clearly the studs, some proud of the nut, some recessed and some near flush. I think I'll make a random selection and see how it looks. The minimum 3D print level for detail is 0.1mm so I'll try a difference of 0.3 or so to see how it looks. Sadly the minimum print level for a Web is 0.7mm which thicker than the real thing so a compromise there unless I can try and get some PE webs down inside.

I'm not going to model that bent casing though

 

[SimonT]

Or the bulging footplate?

 

[mickoo]

Or the bulging footplate?

certainly not.

 

[Big Train James]

Can you offer printing details? From whom, material, that type of thing.

With Shapeways, you can often tell them to print things anyway even if they don't cleanly pass all the tests. A lot of the limits imposed have more to do with surviving the process of cleaning support and packaging/shipping then with actual limitations of the printer or material. You can get away with forcing prints for yourself. I don't think they are keen on offering for sale to others as they don't want to continually be on the hook for failed prints.

If you are going local, finding somebody that can print or machine waxes would be ideal. Often that would be a custom jeweler. I know that the Modelu and downspout prints shown on WT have looked quite good, so a consult might be in order with whomever produced those parts.

Shapeways FUD and FXD are decently capable media, but there are better printers and better materials out there. It's a matter of finding them of course. But in my experience, people are often willing to help with prints, if not outright curious, as every print job puts the printer to use and amortizes the capital investment to some degree.

 

[mickoo]

James, the observations above are based on shapeways FUD and FXD though they do have a new material called Acrylate but it prints at 50um not 25 or 16 of the others.

However it seems to have a better surface but details and minimum thresholds are understandably slightly higher by the odd 0.1 or 9.2mm. I'll try it with a couple of parts and see how it goes.

Overall I was not impressed with the finish on the GEVO truck frames in FXD from shapeways, I think the (relative) large flat sides show up the layering really badly so might try Acrylate or another printer service.

 

[oldravendale]

Here's another of those cylinder fronts. It's from another Q6, 63391. I failed to mention that this and the previous one are by permission of my good friend Tim Mills from whom I have an amazing selection of images, all large format slides. Regrettably Tim has failed to record date or location details on any of his slides so far - and in some cases loco details too!

I challenge all our "re-creators of the original" to do this one. Maybe Yorkshire Dave?



Apropos not this thread - and with apologies where appropriate - the GCR at Loughborough are holding a "Last Day of Steam on the Southern" gala this weekend. Only two Bulleid Light Pacifics, but the newly released to traffic Standard 5 4-6-0 as well. Added to which you can have the joy of seeing a selection of Tim's and my photos of the last days in two separate displays. We'll try to reproduce this in real life:



34013 and 73043 at Basingstoke Shed. 6th July 1967.

Actually we can get pretty close to it.

Brian

 

[Tim Humphreys ex Mudhen]

Brian, have got a clearer shot of the lubricator like fitting on the footplate above the cylinder. I'm trying to get some details of this for Q6 I'm starting.
thanks very much
Tim

 

[Yorkshire Dave]

I challenge all our "re-creators of the original" to do this one. Maybe Yorkshire Dave?

Only if a rogue set of cylinders ends up in this direction ........

 

[Big Train James]

I haven't tried the acrylate firsthand, but I haven't been impressed with what I've seen and read.

I'm going to get some parts printed soon in the FXD, with the intention initially being just to test fit and function. After that, I will make a decision on printing for use, or as masters, or the alternative of getting waxes machined or printed. There's going to be some experimentation before I figure out exactly what I want.

Did you set the orientation of the parts when you printed the sideframes? it can make a big difference in the finish of some of the faces of an object?