Whilst we are known for mainly OO scale kits, we do have the ability to resize kits to different scales - either up to O and beyond, or down to TT:120 and N.
But how do we do it?
Material choice
The first step is to consider what material we need to use for the new scale. Obviously, going down to TT:120 or N, we can reduce the thickness of the walls from the usual 4mm MDF to 3mm MDF or even 2mm MDF.
Going up to O or larger, we will still use 4mm MDF, but then consider additional bracing floors or internal walls to maintain the rigidity of the structure.
Using a 1mm grid
All of the designs for the kit we make are created in a standard drawing application.
Whichever scale we are working in, we generally draw kit parts to a grid of 1mm. This allows us to accurately match tabs and slots across joints.
Simple OO, two piece kit, using 4mm MDF
Resize the drawings
To rescale the drawings, we apply a percentage to create the new scale size. However, an accurate rescale rarely produces pieces which align with the grid.
Rescaled to N Gauge, to use 2mm MDF
So now comes the skilled part of tweaking the tabs and slots for each of the joints.
The blue piece has been re-aligned with the grid
Tags
The tags are the little pieces of fret that hold the parts in place. We try to add just enough tags to hold the pieces securely, without having too many that you spend ages cleaning the parts afterwards. If the tags are too short the pieces are liable to drop out; too long and they become more difficult to cut through. We’ve found that a tag of 0.4mm is just about perfect.
A OO scale piece, with 6 0.4mm tags
Of course when the kit is resized, everything is resized.
So any resized kit needs to have all of these little tags redone. And sometimes, there are hundreds to do, as every piece will have at least two.
If a kit is resized larger, then for any given piece the number of tags will probably need increasing. Conversely, a smaller resize will possibly need tags removing. All of this is down to the designer, and their best judgement for the individual piece and the new material.
Rescaled to N, the tags are now too small
The upper row of tags have been resized and the centre one removed
Even when pieces are repeated, such as window, every instance needs to be updated, either by hand, or cut / copy / replace from one updated piece.
Changing details
When a kit is scaled smaller, not everything will be viable. Sometimes, the detail needed on a 4mm scale kit becomes either invisible, or just impossible to cut on the laser.
In this example, the OO scale piece on the left has been resized to N Gauge. However, the centre design will be lost when etched, so has been simplified.
Conversely, what may be acceptable as an impression of detail in OO, needs to be fully defined in O or larger.
For example OO gravestones are not written with any definite text, but in O gauge, they have to be readable, and need to be all different.
Extra detail
Moving to a large scale often allows for extra detailing to be added. The UW2008-N Low Relief Hayle Church has a pair of simple steps in front of the main door. For the OO version, we enlarged the steps and added railings, details which would have been too delicate to do in 1:148 scale.
Extra strength
When a building is upsized to O, or larger, the material used for the kit parts will still be a maximum of 4mm MDF.
However, whilst this is perfectly adequate for most OO-sized buildings, for a larger building we need to maintain the rigidity that the 4mm version has. This is usually achieved by adding internal bracing walls or floors,
Introducing an extra strengthening piece involves a slight re-design of the kit walls. It will almost always affect the main structure’s build order.
Wraps
The various wraps for each building also have to be re-sized. As we’ve seen, the building pieces are tweaked to match the 1mm grid - this of course means that the wraps also have to be tweaked after the resize.
But again, it’s not just a case of shrinking or stretching each section to match the wall. Bricks need to be correctly sized, so there might need to be more rows or columns added, or removed, to fit around the window and door apertures.
If a kit has been enlarged, we might need to add internal wraps where the inside of the rooms can be viewed through the much larger windows and doors.
Window and door openings
Each window and door is sized appropriately for the building’s design.
However, to allow for the thickness of the wrap, each opening is made slightly larger so the paper can be folded around the edge of the wall material and into the reveal. When the drawing is rescaled, this small difference has to be reapplied to each and every window and door opening.
Roofs and Slates
In the same way that all the walls and wraps need to be resized and tweaked, this is also true of any roof covering in the kit. For wrapped roof panels, such as in the KX054-OO Tony's Cart Shed, this would mean a redraw of the wrap piece in the same way as for the walls.
For kits such as the KX057-OO Barn, we needed to resize the rows of slates, and then adjust the tags.
Does it fit on a raw MDF sheet?
Each kit is made from several thicknesses of MDF or laserboard sheet. All the parts that need the same material are drawn together on a cutting plan, or fret. Depending on the parts needed, to be efficient and minimise wastage we try to keep the size of each fret to be a regular size, that can be easily multiplied on the raw sheet.
Resizing a kit means we have to ensure that the number of kit frets per sheet is still making best use of the available material.
Test build
As we’ve now essentially got a new kit, we need to do a test build. This is vital to ensure all the joints have been changed correctly, all the tags are 0.4mm long, and any design adaptations from the OO version have been done as planned.
To do a test build, we need to send the new files to the laser cutter, for each of the various material thicknesses. Once we have the frets back, we can check the tags are all correct (as none of the pieces fall out, or are difficult to cut out).
The kit is built, adapting the order of parts/wraps, as required. Any mistakes found will need that piece, or pieces, to be corrected on the drawing, then resent for cutting or printing.
Instructions
Each OO kit obviously has its own set of instructions. But, when we resize a kit, we always have to rewrite the instructions too.
We need to take a whole new set of photographs, and then amend the text to suit. It might be we resize the instructions themselves, from a folded A5 to full A4.
Can you do it in ‘N’ ?
As you’ve seen, resizing a kit isn’t a simple, or quick, process.
To rescale the drawings, even for a modest kit, can take 2-3 hours, for a more complex kit possibly 7 or 8 hours, especially if adding or changing some of the detail.
To re-scale and adjust the wraps also takes a minimum of 3-4 hours.
Then there is a test build, a 2nd build for the instructions photos, re-writing the instructions, a 3rd cut for the Sample pack for the production team to follow.
Then we need to add the new kit to the website, the other sales channels, and find a space in the warehouse to store the new kits.
And then hope someone (lots of someones) buys the resized kit.