Using Inkscape to produce cutting files, a worked example

[BG John]

I can't help with tiles, but have just measured some Welsh roofing slates, and they range from around 5-9mm thick. I reckon the average in my small sample is about 6mm. In 4mm scale that's about 0.08mm, and 0.04mm in 2mm. A sheet of printer paper is about 0.10mm. Tiles are presumably thicker, maybe by quite a lot, but 10thou/.025mm plasticard scales up to 36mm/1.4" in 2mm scale, which is pretty thick.

[MikeTrice]

Made a minor change to my assembly technique which will be familiar to many but had not dawned on me until several strips on.

 

With lighting far from optimal and eyesight not proving 100% accurate a simpler approach is to place the point of a scalpel blade in one of the engraved grooves and slide the ruler up to it. Check both ends of the ruler and place weight on top. Much better.

[BG John]

Made a minor change to my assembly technique which will be familiar to many but had not dawned on me until several strips on.

 

With lighting far from optimal and eyesight not proving 100% accurate a simpler approach is to place the point of a scalpel blade in one of the engraved grooves and slide the ruler up to it. Check both ends of the ruler and place weight on top. Much better.

I usually mark with a knife rather than a pencil when I'm cutting by hand, and find it's worth rechecking the first end, as sometimes the ruler moves a bit when I line up with the second end.

[MikeTrice]

Well I have used up my first batch of roof tile strips and need to cut some more, however I don't fancy listening to the Silhouette chattering away for the next few hours. Instead I thought I would return to the initial drawing of Erstfeld. These notes are being typed up some days after the actual work and screen captures were taken so I hope I can remember the points I wanted to make.

 

When last looking at Erstfeld I had got to the point where the reference drawings and photos had been positioned and sized. With that in mind I can start drawing one of the window bays.

 

Various horizontal lines were added and the top and bottom lines aligned to the edges of the windows and the vertical lines also drawn in:

 

All horizontal lines were selected and then evenly spaced using the Align and Distribution dialogue:

 

Next the vertical lines were selected and also equally spaced:

 

Line lengths were then tidied up:

 

The window recess has a tapered edge to it so this was added:

 

The first window was duplicated just to check they would look ok when in groups of 3. I should add at this point that I am ignoring the doors at the moment:

 

There is a surround around the window that I intend to engrave so it is also drawn in:

 

Bottom edges were drawn in:

 

And a quick comparison against the guidelines added earlier. Some additional adjustments will be needed later:

[MikeTrice]

As with previous models I felt I needed to establish the various layer thicknesses and check that they stack up against my expected tapered widow surround.

 

With a new layer added a horizontal line was drawn right across the window:

 

I then roughed out an approximate profile using the known verticals:

 

The determine the rue wall thickness I drew a rectangle using the end elevation:

 

This was rotated, the colour changed and moved to where I was doing the wall section:

 

The thickness can now be adjusted to suit:

 

I used a similar technique to trace one of the buttresses from the end elevation:

 

The original profile could now be modified to suit and the temporary buttress deleted:

 

Now I knew my desired profile I could start working out how many layers of 10 thou would be needed and how they would have to overlap in places to allow filing back:

 

Happy that everything was working out ok I could hide the thickness layers and finish adding the bottom window details:

[MikeTrice]

While I am on a roll I will press on.

 

A rectangle was added with centre line based on the 630cm dimension of each bay:

 

The rectangle and previous windows were grouped, duplicated and abutted to the first:

 

The right window and left buttress were selected:

 

And duplicated to form the third bay:

 

And repeated to form the fourth and fifth bays:

 

One of the buttresses is duplicated and moved to the left:

 

With the spacings removed/hidden the final window positions can be seen:

[Julia]

Any chance this topic could be pinned? Really useful topic.

 

J

[MikeTrice]

Hopefully I will be able to do some more later, however in hindsight I need to explain some aspects of the photos I am using. Erstfeld depot is aligned NNW to SSE with the main frontage being NNW. For simplicity I will assume it is aligned North and South. The area I am intending to use for my diorama is the West side of the main shed. Unfortunately I do not have, nor have I found, a good image of the West wall to use as a basis for tracing, only fragments. Fortunately the main shed is predominently symmetrical so I am currently using an image of the East wall (the one visible from the platforms). Like the East wall there are doors either end in the West wall but for some reason the one at the North end of the wall has been modified over the years and now differs from those shown. I will be tackling these aspects soon.

 

The observant amoungst you might also have noticed that I am probably inconsistant regarding ground level currently using the buttresses as my basis. With the window bays being recessed back they are slightly smaller due to parallax however I will continue to trace from them as they are then adjust them later to compensate.

 

The West wall of Erstfeld has changed somewhat over the years, mainly that Northernmost door. It started like its Eastern counterpart with the door in the centre of the three windows but was later modified to be in the right hand of the three with the centre being blocked in. The door itself has been solid panelled and at other times has glazed top panels. The left two lower windows were taken out and had louvres fitted which have subsequently been taken out and glazing reinstated.

 

All this amounts to the high likelihood that I will use some combination of configuration that is inconsistent in time.

 

Hope that all makes sense?

[MikeTrice]

To save my own sanity and make it easier to follow I have decided to make some changes to the imported images to more accurately reflect the West wall of the shed.

 

I added a new layer above my Images layer then selected the East wall image, duplicated it then moved it to my new layer:

 

The duplicated image was now mirrored using the icon on the toolbar:

 

And now moved horizontally until the rightmost bay windows lined up with my drawing:

 

I had managed to find a reasonable image of the leftmost door on the internet so cropped the image and squared up the door then imported it into my new layer:

 

The new image was sized to match as best I could the drawn windows:

 

Now I have a much clearer set of images to work from that are close to what I need for the West wall:

[MikeTrice]

What about those pesky tiles I hear you ask!

 

Quite late in the process I realised that things could be sped up and made more accurate by adding a left guide out of 10 thou styrene:

 

The finished sheet sprayed in grey primer:

 

And in detail:

 

My only concern is how strong the bond of the adhesive labels is to the underlying styrene.

[MikeTrice]

Zooming in on the right hand window a start turning it into a door. After ungrouping the lower edge is deleted:

 

Then the two little diagonal fillets:

 

The lower edge marked and door styles extended down:

 

Inner edge also extended:

 

Spare glazing bar removed from centre of door:

 

You might be wondering why I am doing everything with lines rather than rectangles? I am hoping it will make adjustments easier and I can always convert the lines to paths later.

 

Here is an example showing my reasons, albeit exaggerated. On the left are two shapes the top contructed with rectangles, the lower a rectangle and central dividing line. If both shapes are duplicated and stretched, providing none of the buttons illustrated are selected, when using the line it retains its thickness whereas with the two rectangle the gap between them increases requring further adjustment to correct:

[Stanley Melrose]

Here I am again . . .

 

I was looking forward to making my first cuts today - besides the breakdown train stores van, I've drawn up some replacement sides for the 1927 LMS EMUs and thought I'd run them through Mike's process to ensure that I had usable Studio cutting files.  There are handles a-plenty on non-corridor coaches so I had included 0.5mm x 0.5mm circles to be cut out so I could accurately locate the parts in the assembled coaches.  When I opened the .dxf files in Silhouette, all the straight lines were there but my little circles have all vanished.  They were initially "filled" with no stroke so I tried "filled" with a "stroke" (of 0.1mm) but still they didn't appear.  I tried "no fill" but "stroke" (of 0.1mm) with no result.

 

Is it a question of the size of hole I am using or is there something else eluding my addled brain?

 

Again any light shone on this will be gratefully received.

 

Stan

Thanks, yet again, Mike, that worked just fine so I can contemplate some cutting plastic at last!

 

Cheers,

 

Stan

[MikeTrice]

Before saving the file as a dxf select all objects and make sure they are ungrouped. Now with them all selected click on "Path->Object to Path". Now see if it works.

Edited October 25, 2016 by MikeTrice

[Stanley Melrose]

Before saving the file as a dxf select all objects and make sure they are ungrouped. Now with them all selected click on "Path->Object to Path". Now see if it works.

Bingo!!

 

Many thanks yet again.

 

Stan

[MikeTrice]

After a bit of research it appears all the side doors of Erstfeld are six panelled steel. With that in mind I roughed out one of the doors using blue lines of various thicknesses and adjusted them till they looked "about right":

 

Zooming in the top rail was adjusted to fit the gap and the length noted:

 

The bottom rail could now be set to the same length:

 

I next selected the top, bottom and left hand side and aligned then to the left using one of the horizontal rails as a reference, then repeated the process to align the right hand style, selected a rail to centre the middle style then the four rails and equispaced them:

 

All door elements selected and "Path->Stroke to Path" clicked:

 

And now the magic happens by clicking "Path->Union" to create the door panels:

 

With the fill turned off and the stroke set to a more realistic thickness I ended up with this:

[MikeTrice]

Door duplicated and moved to the left hand end. Unwanted previous lines deleted and sides extended down:

 

Large rails increased in width. Earlier I stated that at some time the windows had been replaced with louvres. It seems that these are slatted blinds that can be slid up into these containers:

 

Lower rails selected and equispaced:

 

Right hand rails over door adjusted to match photos:

 

Some of the red lines were a bit on the thick side (unintentionally) so one of the culprits was selected then "Edit->Select Same->Stroke Style" and their style width changed to 0.05mm:

[MikeTrice]

Next task is to tackle the end doors that admit the locomotives. The end view I have currently does not really provide a good basis for tracing as the locomotives are in the way:

 

Another image found on the internet had a clearer unobstructed view of one of the doors so I cropped it, corrected and distortions then imported it into Inkscape in its own layer. By setting its opacity to less than 100% it is a relatively easy task to scale it to match the original image. Another trick is to keep toggling the visibility setting for the layer to see if the top image appears to move in relation to the lower image:

 

All is fine so the new image's opacity is turned up to 100%:

 

As before I start to rough out the door with lines of various thicknesses:

 

Then adding the verticals:

 

The various lines were then adjusted to match each other, centred where necessary, converted from strokes to paths and unioned together:

 

The panel lines on the door panel were roughed in. Care is taken to allign the left one (which is temporary) and the right hand one:

 

The panel lines are then equidistanced:

 

And the temporary one deleted. The panel lines were then duplicated and moved to represent the upper panels, twice:

 

The door surround has had its fill turned off and the style width set:

 

While I was at it I also added a representation of the hinges and central door clip:

 

The whole thing is now grouped, duplicated, mirrored and moved to the left:

 

Finally lines representing the door frame added:

[MikeTrice]

For the window to the left of the door I had no usable image to trace as the window is partially obscured by the buttresses. I did find an angled view albeit slightly out of focus so printed off a copy for reference.

 

As before a style is roughed out:

 

And duplicated for the second style. A centre line was added and centred on the two styles:

 

The right hand frame added and its thickness adjusted:

 

The right hand frame is selected along with the centre line:

 

They are then duplicated, mirrored and moved left until the two centre lines line up. Remember to delete one of the centre lines as there is now a duplicate:

 

The horizontal frames added then the whole lot selected, converted from path to object then unioned together:

 

Right hand side of alcove sketched in:

 

Selected along with centre line, duplicated and mirrored, moved and duplicate centre line removed:

 

Top recess outline added with best guess for its left extreme:

 

Added outline of what might be an access panel:

[MikeTrice]

For the circular window I started by drawing two centre lines, then aligning them centred on each other:

 

Various circles were added at various thicknesses and centred on each other and the centre lines:

 

One of the horizontal glazing bars is added:

 

This was then duplicated and moved to the left hand position:

 

The two bars were selected, duplicated then rotated 90 degrees using the icon on the toolbar:

 

Now all 4 bars are selected, duplicated and "Object->Transform..." clicked. Now click on "Rotate" enter a value of 45 degrees and click "Apply":

 

The thick ring was converted from a Stroke to a Path, the fill turned off and the stroke set to 0.05mm in red:

 

OK not exactly the effect I was after as the "spokes" overlap the outer ring. Rather than try and fix them it was easier to delete the spokes and redo them:

[MikeTrice]

One of my original spacing guidelines was duplicated and rotated to abut the end profile. The left hand door was then duplicated to provide the centre and right hand door:

 

One half of the end profile was drawn:

 

Then duplicated and mirrored then moved to the left:

 

Likewise for the main shed the spacing guidelines were positioned against the drawing then one of the doors duplicated and moved into position:

 

The door was then duplicated 5 times and positioned against the other door positions. At this point I added a centre line.

 

Before continuing I need to do a little research. The end drawing is the main hall as-built. In reality the roof burnt down twice, once in March 1987 and again in Februry 1990 and it looks as if the new roof line is slightly different to the drawing.

Edited October 28, 2016 by MikeTrice

[MikeTrice]

If in doubt, find another photo and montage it into Inkscape:

 

This drawing confirmed that when the roof was replaced the eaves were extended further out from the walls.

 

Another thing the new image provided was some evidence to support my belief that the two sets of tracks are on different levels:

 

First attempt at tracing the outline of the building using the photo:

 

Hiding the imported image shows a close correlation with the drawing:

 

Assuming the drawing is correct I fixed my outline to match it:

 

To determine the profile of the main roof I duplicated the profile (and changed the colour in an attempt to make it easier to follow), then selected one of the nodes that I thought would not be needed:

 

The node is deleted and the remaining segment straightened:

 

I can now select the two nodes making up the top segment and drag them down until they approximate photographic evidence:

 

Restoring visibility on my image I then drew an outline for the porch over the doors. Trying to adjust for parallax I used the rear join on the right:

[MikeTrice]

A lot to cover in the next two posts so this might be it for a while, so I can get my breath back and work out how to proceed.

 

The various layers required for the window surrounds are difficult to make out accurately on the embedded image so I have printed out a clearer one to refer to as I work.

 

As has been mentioned previously Inkscape is not good at offsetting lines. To get around this I use a technique based on different line widths. So get your brains in gear and hopefully you will be able to follow what and why I am doing things.

 

First off a line is drawn comprising a number of segmens to reflect the middle of the topmost layer:

 

The left three node were selected and smoothed using the icon on the toolbar:

 

And the line thickness changed to fill the layer:

 

In spite of every thing I was still unhappy with the curve so I duplicated it, mirrored it and joined it onto the first curve and smoothed the centre node. Much better:

 

The first line was duplicated, moved to the back of the objects, its colour changed and its width changed:

 

The above was repeated to produce the other lines:

 

More of the same. Done:

 

The same line thicknesses were used to do the side window. Vertical piller added:

 

In hindsight I thought it prudent to remove the left hand portion of the shape. This was doen by selecting them, changing to node edit mode, selecting all of the centre nodes and clicking on the node separate icon. Then with all lines selected click "Path->Break Apart". Phew, now the left hand halves can be selected and deleted:

 

Here all the lines have been selected and "Path->Stroke to Path" selected. The fills have been turned off and the line thickness set to 0.05mm. Hopefully now the method in my madness can be seen:

[MikeTrice]

With all the paths select and on entering Node Edit mode the end nodes were selected and broken apart then "Path->Break Apart" selected:

 

Now the various lines are separate items the unwanted ones can be selected and deleted:

 

 

Vertical columns duplicated and moved into position:

 

I could not think of an easy way to do the upper window curve other than to redraw it between the existing guidelines:

 

The rest of the window is drawn in and joined to the curved portion:

 

Verticals added along with two sacrificial ones to either side. All the verticals were then selected and equispaced:

 

The process is repeated for the horizontals:

 

The side window is done the same way:

 

Finally the unwanted red lines can be deleted:

[Siberian Snooper]

Mike

 

Thanks for another useful and informative insight into the uses of Inkscape, once you can get your head around it's short comings and come up with a usable work around.

 

I look forward too seeing the finished article.

 

You and Ron Heggs are fast becoming total masters of the silhouette and platicard engineering. A great inspiration to us mere mortal modellers.

 

Thanks

 

SS

[MikeTrice]

Thanks SS

 

A quick update.

 

First the horizontal frame for the right hand windows was reduced to halfway:

 

The ends adjusted to try and reflect what I think is happening:

 

Now duplicated and mirrored. Window frame converted from stroke to path, fill and stroke changed and tidied up:

 

Central window tidied up as well:

 

The adjusted horizontal overhang was duplicated and the stroke colour changed then overlaid over the centre windows overhand:

 

And sent to the bottom. Now I can see what adjustments I have to make to the central overhand:

 

Adjustments made:

 

I can now select all the window elements and frames, duplicate and mirror:

 

I think that is the bulk of the work done for the main drawing. Once again I should have picked an easier prototype, but where is the fun in that? Phew, just adjustments left to do.