How Good Are Drawings ?

[Guest Lyonesse]

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Theoretically true but numerically ill-conditioned, i.e. not very accurate for a shallow roof.  Far better to use the formula d^2 = (2R-t)t, i.e. R = (d^2/t +t)/2, where t is the rise of the roof, R is the radius, and d is half the width, i.e. the distance AB is 2d.

 

Doesn't  work for an elliptical roof, of course.

[Guy Rixon]

Surely relaxing hobby knows that radius already? He drew out the templates; does the graphic tool not tell the radius?

[Compound2632]

As a check on any of these methods, it's highly likely that the radius is a whole number of feet.

[JohnGi]

At the larger wagon works there must have been mass-production methods - probably including the use of templates and jigs - rather than individual marking-out of components. 

 

.....

 

No two items were precisely identical but very large numbers of items were identical within acceptable tolerances. That wasn't luck but judgement.

 

 

Hi,

 

If I may belatedly add to the above comment, people may be interested in this memoir by Albert Wright entitled "Wagon building in the 1930s" http://www.wrightsaerials.tv/annexe/wagon-shops.shtml.

 

 

Albert Wright was born in December 1918. From 1934 to the outbreak of the Second World War he worked at S.E.Stevens Wagon Works building and repairing railway wagons. The works was on Stevens Road, Balby, Doncaster. In 2003, aged 84, Albert wrote an account of those days.

 

 

People may also be interested in the account of rebuilding a wooden wagon on the Settle station water tower blog https://settlestationwatertower.blogspot.com/2013/06/ 

 

I found the best way to read this account was to scroll down to the post dated 13th June 2013 and start reading from there.

Edited July 30, 2018 by JohnGi

[relaxinghobby]

 

 

Two photos showing an addition to the D-tank, thats D for the cross section. The top of the tank looked a bit plane, not enough texture as the artists say so I've made a wrapper to represent a riveted on layer.

This is were a drawing program on the computer is very useful, I modified my original drawing to give a rectangle 23 mm wide and used the dashed line drawing capability of Inkscape to make the lines into dots and dashes, picking one of the options where the dots look like they are nicely spaced to represent 4mm scale rivets.

 

For some reason Inkscape calls these dots and dashes “ strokes”.

 

Printed on about 110gm cartridge paper seems to give a nice thickness. Pricking out the dots with a needle once turned over this gives a neat representation of rivets, work the white PVA glue into the dimples so they are held solid when it's stuck on. I'm building up a man hole on the top by gluing ring binder punchings from the same paper. The green wrapper was an earlier experiment to gauge what width to make the wrapper.

 

A piece of balsa wood is super-glued to the metal chassis for somewhere for the tank fixing screws to go. Fisrt stick cellotape across the top of the frame, glue side down towards the wheels, this will stop the super glue running away and gluing the wrong stuff.

[relaxinghobby]

More work on the D-tank

 

Finally found the original drawings, they have showed up at last, they had disappeared without trace so I drew up my parts and cutting plan in Inkscape keen to get going using an on line diagram which was not sop accurate. So now comparing it with the original drawing it is 2mm to long and too tall. But it was so far advanced I've carried on. I wanted to get stuck in with the model rather than wait for the plans to show up.

 

You can see the couplings being prepared and the tips of the self tapping screws coming up through the balsa wood in-fills in across the chassis centre. The two tiny discs to the left show how much weaker cardboard is than plasticard. They were part of the man hole tower on top of the tank, when I went to drill a hole into it to fit the lid the card layers it was built up from tore apart from the action of the drill. So I've dived into my parts box to find some thing else to use and found a metal stud and domed plastic something or other from some old kit. Never throw every thing away.

Edited August 30, 2018 by relaxinghobby

[relaxinghobby]

P1010167a.JPG

 

Details beginning to stuck on gunpowder van, mostly strips and rectangles of postcard.

 

 

A little side project making a wagon boiler load out of a tube, a smoke box from a Hornby 14XX loco and plasticard.

 

 

 

The under carriage is each sole bar glued to cross pieces, the sole bars extend down to form W irons all cut from one layer of card.

Brass bearing are inserted into holes, the whole thing works but is a bit flimsey, I hope glueing white metal combined spring and axle box moulding will strengthen them enough. The undercarriage is a seperate thing, once glued together and running with all wheels parrallel and true it is screwed to the van body with small wood screws.

[Martin S-C]

What was the source of the little yellow milk van? I need a couple of these 1880s GW O1s for my layout and am contemplating sawing bigger siphons up.

[relaxinghobby]

It's a cut down K's low Siphon, the plastic one, they occasionally turn up at exhibition rummage stalls.

[relaxinghobby]

 

Should this be in the modified section as I'm modifying one of my own kits, kind of ?

When drawing up the shapes to make the sides of my cattle wagon there was lots of empty space on the A4 printout so I filled it with spares, cutting and pasting until the sheet was full.

 

So there where enough spare sides and ends to almost make a second one.

Pleased at how strong the sides where when all sides where glued together even before the roof went on I thought it may be a good basis for a really old fashioned open topped cattle truck.

So I've modified and bashed my own kit, namely changing the ends to loose the curved tops where they would meet the underside of the roof and give an more open look.

 

 

First cattle wagon during construction.

Edited October 17, 2018 by relaxinghobby

[Siberian Snooper]

Just come across this thread, so there are a few likes on earlier posts. Some good ideas and food for thought. Thanks for some inspiration.

[relaxinghobby]

 

The 4 sides stuck  together, the new lower ends are keyed into the sides with tags each unique at the corners so I labelled the corners A to A, B to B etc. See the pencil marks.

 

Cardboard floor and cross pieces will need to be replaced with plastic detailed parts showing planking as this will be an open top truck and all can be seen. I'll have to find some chassis parts from the spares box. End stanchions and structure needs to be finagled into place.

[relaxinghobby]

 

The unpainted body from above in post #85 is completed and nearly painted just needs transfers and varnish.

One of the W-iron-axle-box castings needs gluing back on, but nearly ready to go on the layout.

Edited October 21, 2018 by relaxinghobby