Designing a shadowbox diorama

[Hauk]

This is a fixture I made many years ago to build small wooden spoked wheels. 

Wow! I dont even understand how that impressing looking thing works! What is the function of the holes neatly lined up in curves? Is it for making wheels of different sizes?

[5thwheel]

This is a fixture I made many years ago to build small wooden spoked wheels.

Wow! I dont even understand how that impressing looking thing works! What is the function of the holes neatly lined up in curves? Is it for making wheels of different sizes?

Yes the spiral holes are for locating pins for different diameter of wheels.   For trusses: I clamped two plates together and drilled holes at four corners and installed pins solid in bottom plate. Need to ream out the top plate holes a bit to allow for a slip fit. Then mill the patterns for the truss. At key joints I drilled holes through the plates (again ream out the top plate holes holes.   Put a spacer block between the two plates so that the pins are just flush or a little lower than the joints. Assemble your truss and when glue is dry remove the spacer block and carefully push the top plate down.  The pins push up on the bottom of the joints and help remove the truss in one level.

[Hauk]

Closeups are great for checking the quality of your work. The wood is a bit on the fuzzy side, so a little light sanding might be in order.
Those Grandt Line NBWS look the part as always. Sad to see that Grandt Line closed down recently. O, the things we took for Gran(d)ted. Sic Transit Gloria Mundi. But I was lucky that several hundreds of just this typeof NBWS in my stock. They are spot on for the type used on the prototype.

[Design-HSB]

yes Hauk, even with glasses you can not see what a macro shot shows mercilessly. Your macro shot shows only good.

[Ray Dunakin]

It's funny, the first thing that came to my mind when I saw your jig for the trusses, was, "I wish I had the means to make jigs like that!"   

From a modeling standpoint, a good jig is worth its weight in gold, regardless of what tool you used to make it.

[Hauk]

It's funny, the first thing that came to my mind when I saw your jig for the trusses, was, "I wish I had the means to make jigs like that!"   

From a modeling standpoint, a good jig is worth its weight in gold, regardless of what tool you used to make it.

When you have access to to a CNC-router, you never run out of ideas for what it can be used for. And I can see that I  will make a few more jigs during this project. First up is a jig for the trusses on the fantry crane.

Regarding the fixtures for the roof trusses, I find them more and more useful. Especially the joints involving the curved beams requiers an incredible amount of pressure to make a tight glue joint. Even if I pre-bent the stripwood, it does not hold the curve on it is own.  The double-width channels used with filler blocks works especially well. Wich was a nice surprise, as they were almost included in the design by accident. This concept combined with the precise angels you get on a good disk sander makes for really tight joints:

[Hauk]

Next up, installing the steel rods:

0.6mm nickle silver rod blackened with  Birchwood Casey.

Quite a challenge to line up the holes in the upper and lower beams. It will take some evenings to get all trusses done...

[Lawton Maner]

While artistically the patina on the washers under the bolts on the trusses looks pleasing, the burnishing on them would only come from regular contact with another surface.  Any undisturbed metal develops a uniform coat of oxide (rust) as a reaction to its environment.  Otherwise, the trusses are spectacular.  Once installed don't forget to add soot, dust, and bird droppings along the upper surfaces of them. 

[Hauk]

While artistically the patina on the washers under the bolts on the trusses looks pleasing, the burnishing on them would only come from regular contact with another surface.  Any undisturbed metal develops a uniform coat of oxide (rust) as a reaction to its environment.  Otherwise, the trusses are spectacular.  Once installed don't forget to add soot, dust, and bird droppings along the upper surfaces of them. 

I agree that the shine has to go. The shine on the bolts is purely coincidental, they were painted years ago.  I will add some final weathering when the trusses are completed to blend everything together.  The strengthening rods are also too shiny. They were wiped to get rid of the black crud that  I am never able to avoid completely during the blackening process, and this polishes the nickle silver somewhat. I am also not entirely sure about the brown color of the wood, so some adjusting with sanding and restaining might also be neccesary. It is a bit frustrating that I have no idea how the wood was painted/impregnated. It is just my guess that they were brown.

How much soot and bird droppings to add might be open to debate. I dont know if the single steam switcher Thamsahavnbanen operated ever were allowed into the machine shop under steam. But writing this it strikes me that there is no overhead wire in the shop, so they must have used some kind of switcher to move the electric engines in and out. Regarding droppings, I can see no sign of them in the pictures, so maybe they were able to keep the birdies out.

[Peter_T1958]

Hi Hauk

Very impressiv, clean work! In general, the whole construction looks very attractive. Could it be that this is the only forum, where we can discuss bird droppings and shiny bolts? That's why I love this forum so!
By the way, concerning my own project, I have never ever played with the idea, that there could have been some traces of bird droppings on the upper surfaces. I have to check this soon!

The shine on the bolts struck me immediately too. But I am not sure if I would have mentioned that as I am struggeling in that subject too...   And they also look very nice that way!

[Hauk]

Hi Hauk

Very impressiv, clean work! In general, the whole construction looks very attractive. Could it be that this is the only forum, where we can discuss bird droppings and shiny bolts? That's why I love this forum so!
By the way, concerning my own project, I have never ever played with the idea, that there could have been some traces of bird droppings on the upper surfaces. I have to check this soon!

The shine on the bolts struck me immediately too. But I am not sure if I would have mentioned that as I am struggeling in that subject too...   And they also look very nice that way!

Thanks for the thumbs up!
I agree that this is one of the very few forums were you can get constructive comments from some of the most talented modellers around.

I am not sure that I would have thought about the shine on the bolts myself, and keep such criticism coming!

By the way, I really did not think that a couple of roof trusses could take so much time. Marking out the exact location for the holes for the nickle silver rods is a pain in the A, and I have not found a good method for boring the holes at the precise angles.

The rods are all at slightly different angles, and small differences between the different trusses makes it hard to design a useful jig.

It does not help that my large pillar drill is an rather crude contraption. Maybe I will have to take the work to the local MR club where we have a very precise pillar drill.

Well, enough trivial stories from the workshop for this time.

[Design-HSB]

Hauk, your carpentry construction looks very interesting. I admit the drilling of the holes is not so without and will surely only succeed with a good column drill after precise alignment. Only how will it have happened in reality the carpenter probably simply took a hand drill and drilled the holes in a sense of proportion. This will of course have the consequence that the binders have small differences. The binder construction is built on a stencil like this on the timber place. But I also find it absolutely OK to discuss trifles and that is not enough for us.

[Lawton Maner]

First, for aligning the holes for the truss rods make a spade drill out of the proper size piano wire.  Then you can lay the trusses on a paper template and use lines on it to guide the bit.  Small pieces of plastic could be used as guides to make sure the boring runs true.

As for the color of the trusses, the wood would have oxidized over the years from exposure to air.  Find an old attic truss and see how the wood has aged.  Pine starts out as a pale yellow/orange and darkens to a more reddish/brown tint.  White oak will blacken over time most markedly in a barn where there are ammonia fumes from the animal waste.  Knowing what the chemical environment of the surroundings can help with predicting how wood will react. There would always be some dirt on them from the airborn material from the work in the shop.   

[finescalerr]

That is outstanding information. -- Russ

[Hauk]

As for the color of the trusses, the wood would have oxidized over the years from exposure to air.  Find an old attic truss and see how the wood has aged.  Pine starts out as a pale yellow/orange and darkens to a more reddish/brown tint.  White oak will blacken over time most markedly in a barn where there are ammonia fumes from the animal waste.  Knowing what the chemical environment of the surroundings can help with predicting how wood will react. There would always be some dirt on them from the airborn material from the work in the shop.   

Interesting information!
But it is very likely that the wood was treated with some kind of paint or impregnation when the workshop was built. Take a look at these two picture taken right after the building was finished (in the early years about half of the space was used for an electrical substation):




In the second one, you can clearly see that something har runned down on the walls.
But I can only guess at what it is. I hope it is something brownish...