Using Inkscape to produce cutting files, a worked example

[MikeTrice]

I am two minds as to whether to continue this thread. So far I have covered the production of artwork for carriages and wagons in 4mm and a carriage in 7mm. Along the way and on other Silhouette related threads I have mentioned an earlier attempt to produce a small diorama featuring Erstfeld Depot in Switzerland in N Gauge. The more I look at it the more I think I could now do better. A lot of shortcuts were originally taken and I now find some aspects of it unsatisfactory so I have taken the decision to start again making full use of Inkscape and my trusty Silhouette Portrait cutter.

 

The question is whether to bore everyone and include it as a final topic in this tread, or to give everyone a break and stop at this point?

[BG John]

If you can keep it up I think it would be very useful. I haven't been actively following for a while, just quickly reading new posts, but am finding it very useful. I almost got to the cutting stage with the Metropolitan coach, but had a few bits to sort out. I realised it was best to leave it for now, and try something simpler, which is why I started on a wagon. But I have a use for the coach body, so intend to finish it.

[Siberian Snooper]

Hi Mike

 

I find that your threads are very informative and useful, for us lesser mortals, that sometimes struggle with the software.

 

I think it would be better to keep going with this thread, as it will keep it all together, but put an edit in the first post so that newcomers to the thread that a new and improved method is further on.

[mvrattler]

Hi Mike,

Please continue on. I find the threads extremely useful in the Inscape learning curve. I have downloaded the LNER coach file and hope to cut it out sometime next week. Many thanks for sharing your time and information.

 

Kerry

[MikeTrice]

Erstfeld in the Canton of Uri is a Swiss depot on the Gotthard line. It also has the distinction of being one of the homes for the SBB Historic organisation housing a number of preserved locomotives and carriages.

 

I have had the pleasure of visiting on two occassions and been fortunate to have been taken behind the scenes to see the collection, but for some reason I have virtually no photographs of the depot itself. I guess at the time of my visits I had no idea I would want to model it. My own photos are limited to these two:

 

 

Some time ago I started a small diorama featuring the depot in N Gauge. I had no drawings available so ended up trying to estimate dimensions from Google Earth images and by posing various model locomotives:

 

 

The diorama was limited to an A4 footprint so it would fit in a Really Useful 9ltr storage box:

 

I never finished the model as there where a number of issues with it. The windows were not right and the sides not thick enough. I also subsequently learnt that I had not included a door that should have been present. All in all I was unhappy with it and decided to start again.

 

With so few images of my own I kept searching for suitable images and possible plans to build a better model.

 

A couple of days ago I made a couple of interesting discoveries. I found a PDF showing the latest rebuilding of Erstfeld (they have added a long building to the side) which appeared to be an architect's drawing. Now modern architect's drawings such as this are usually very accurate and even better can be scaled without losing quality. Another web site covering an N Gauge model of the depot featured some low resolution images of their model shown against some original drawings: http://www.gotthardmodell.ch/anlagen/neue-anlage/gebaeude-infrastruktur/depot-erstfeld/lokremise/. Although they were low resolution images a few key dimensions could be read.

 

So with this improved starting point Inkscape was fired up and the pdf image imported and scaled to provide a 500cm spacing between centrelines of the tracks (based on Continental N Gauge being 1/160):

 

Once the drawing had been scale I could select the various track and change their line widths to 9mm:

 

Various photos and drawings were identified, straightened up in a graphics program, imported into Inkscape and sized based on the identified track spacing. Another key dimension was 630cm for the window spacings in the main hall:

 

Once the images were scaled correctly their orientation was changed to something a little easier to follow:

 

Not shown in the images I also deleted quite a lot of entries from the imported plan that was outside my areas of interest. At this point my Inkscape document has been set as A2 size.

Situation_Erstfeld.pdf

Edited October 17, 2016 by MikeTrice

[MikeTrice]

Having scaled the various building elevations I felt it sensible to attempt a mock-up in order to validate the scaled dimensions. The elevations were printed off and glued to foam board. The plan was printed off as a PDF then tiled to produce a scale track plan:

 

 

I had some concerns regarding the height of the doors for the side shed (more later) and tried to see where the catenary wire would result if the pantographs were compressed:

 

 

The mock-up can be seen here in all its glory:

 

 

Surprisingly the mock-up matched the printed plan very well. On trying my original attempt against the drawings I had built it about 10% too large.

Edited October 17, 2016 by MikeTrice

[BG John]

I said it would be worth continuing!

 

I've started building full size mock-ups of layouts I'm planning. As they're not models of a prototype, I design them in SCARM, adding buildings as fairly plain boxes with a roof, and basic landscape. I can view them in 3D from any angle. For what I've done so far, I don't think your technique would help, but for things I've got in mind for the future, importing the SCARM plan into Inkscape and designing the buildings to fit could be a big help. I'm working towards an idea for Cyril Freezer's Minories combined with buildings based on Plymouth Millbay, that I think will be pretty complex. Keep going, this is useful .

[MikeTrice]

This is how things were left:

 

Measurements on the mock-up caused some cause for concern. Using the end drawing a door was blocked in. The inner red block represents the height of the catenary from the rail top (570cm):

 

Copying this to the side shed things did not line up:

 

The blue line along the top of the door opening lines up correctly with the side windows and is noticably lower than the original end doors.

 

At this point it dawned that the most logical reason for the discrepency is that the side track must be on a slight slope. With this in mind the height of the side shed was adjusted:

 

 

As another method of validating what I had discovered I traced the profile of the end:

 

The same was done for the side shed:

 

The profile was then duplicated and mirrored then moved into position:

 

Cloning the end profile and moving it across I was able to compare it with photos to see if it overlapped correctly:

 

The workings can now be hidden or deleted:

[MikeTrice]

A digression.

 

When I built my first version of Erstfeld I used Noch N Gauge 3D Red Tiles. Sadly these seem to have been discontinued so another solution is needed, so why not try producing them with the Silhouette?

 

Here is a photo of what the tiles generally look like. They seem to be referred to as Bullnose or Beavertail style:

 

I managed to find an image of the Noch tiles and imposted it into Inkscape. Three circles were added 1.5mm diameter and the image scaled to suit:

 

Two of the three circles were deleted as they were only for use in rescaling. A rectangle 1.5mm wide was added overlapping the circle:

 

"Path->Union" combined the two shapes into one:

 

The combined shape was moved to the top left of the page and the tile image hidden:

 

Now for a new command. Having selected the new tile shape click on "Edit->Clone->Created Tiled Clones...":

 

In the parametrs in the dialogue box set the entries to clone 130 columns and 1 row then click "Create":

 

Any changes made to the original will now be reflected in the cloned items. To break this link select them all and then click "Edit->Clone->Unlink Clone":

 

We now have 130 individual tiles. I want to space them out slightly so I selected the rightmost and moved it to the right, then selected them all, and using the Align and Distribute dialogue selected the button to equispace them.

 

Zooming in on them afterwards and I now have the following:

 

A quick sanity check against by original image:

 

I now added a rectangle to represent the remainder of the tile:

 

The rectangle was stretched to match the rightmost tile then them all selected and "Path->Union":

 

The initial tile strip is duplicated and overlapped with a view to determining the amount of overlap needed:

 

A line is added and its width adjusted to match the overlap:

 

With the overlap line move out of the way the duplicate tile strip is deleted and the remaining tile strip given no fill and a black style:

 

"Edit->Clone->Create Tiled Clones..." was again used but this time the rows were set to 40 and columns to 1 then "Create" clicked:

 

Again the resulting clones were unlinked from the original, the lowest moved down and the spacing for all equalised:

 

The spacing line was stretched to match the length of the tiles then cloned to give me 120 clones. They are unlinked but not respaced.

 

All the lines are selected and their style width reset to 0.05mm:

 

The Inkscape file was saved and copied so I could try things out but with fewer items:

 

Under normal use I would expect to create a sheet of just the overlap guidelines and a second sheet of just the tile strips. For the test I arranged them on a single sheet.

 

[MikeTrice]

Time to fire up the Silhouette.

 

First off the pen holder is used in conjunction with a Mitsubishi UniPin Fine Line 0.05mm pen. The pen sits too deep in the holder so the holder is not seated fully down in the machine. Enough clearance has to be left to allow the pen to rise above the surface of the workpiece:

 

The guidelines were drawn onto a piece of 0.25mm styrene using a speed of 1 and thickness of 1:

 

Next the pen was replaced with the Premium Blade and the tiles cut. At the slowest speed and sending the cut to the cutter twice (in both cases with doublecut set) cutting 15 tile strips took a massive 3.5hrs to complete:

 

Closeup of one of the cut strips:

 

The strips were fixed to the piece of styrene with the guidelines. I used a big piece of Aluminium plate and aligned it against the next guideline:

 

The next strip can be butted up against it, the stagger adjusted, and when happy solvent applied:

 

Working along the strip and fixing it I finally laid a steel rule against the plates front face to give some downward pressure to the top of the tile strip:

 

On completion the process is repeated for the next strip. You will note that the dran lines are not permanent but will rub off so care is needed with handling:

 

Completed test piece shown against a ruler for size comparison:

 

After spraying with grey primer the finished item looks like this:

 

Not everything went to plan. Alignment of some of the strips ran off. I think this was due to the aluminium block not laying perfectly flat on the workpiece:

 

Two of the strips were bent on removing them from the cutting mat. Unfortunately this has cause a couple of bumps in the surface:

 

So doable however care is needed to get a good even finish. The finished tiles are a little on the big size. It would seem that the prototypes are approximately 6" across so I will need to scale down the artwork a bit before doing it for real. I also think it would be better to use 0.5mm styrene for the main surface before applying the tile strips. I think I will also need to increae the cutter speed from 1 to something like 3 and hope it does not spoil the clean cut acheived so far. Strictly speaking the shape of the tiles is not quite right however in "N" this is not apparent. I will also try using a pencil to mark the guidelines instead of the pen.

[JCL]

Looks good Mike, and for people asking if the software will support the scribing of bricks, I think here's you're answer. You just have to be prepared for a long wait.

[Stanley Melrose]

Hi,

 

I've got this far with my Inkscape "creations" but when I open the .dxf file in Silhouette, the dimensions have been messed about - the imports have larger dimensions than the carefully scaled .svg files.  I have re-scaled the images in Silhouette so the pieces to be cut should be OK but I wonder why this happens and whether there is something I am missing.

 

Any thoughts on how to avoid this would be much appreciated as I would like to start cutting but do not want to waste too much plastic sheet.

 

TIA

 

Stan

 

So we have our basic artwork and want to cut it out. There was a time I could send it to the cutter direct from Inkscape, however since upgrading I have lost this capability and have not resolved it yet. Instead I have to export the drawing as a dxf file and open it in Silhouette Studio. So let's give it a go and see what happens.

 

The 10thou layers from the previous posts:

screen 1.jpg

 

"File->Save As.." and change the file type to dxf then save:

screen 2.jpg

 

When the dialogue box appears I leave it as default and just click OK:

screen 3.jpg

 

Now open the dxf in Silhouette Studio. OK not what I expected:

screen 4.jpg

 

It is clear that Inkscape is saving ALL layers to the dxf file, not just the visible ones. So back to Inkscape and delete all non visible layers:

screen 5.jpg

 

Save as dxf and open in Silhouette Studio. Looking much better:

screen 6.jpg

 

However zooming in it appears that some of the shapes have spurious cut lines which were not present in the original Inkscape drawing:

screen 7.jpg

 

Back in Inkscape select all objects. Note that the status bar at the bottom states there are a mixture of groups, rectangles and paths:

screen 8.jpg

 

Keep selecting "Object->Ungroup" until no more groups are reported, then "Path->Object to Path:

screen 9.jpg

 

Now change into node edit mode and click on the node break apart icon on the toolbar:

screen 10.jpg

 

Finally back in selection mode select all objects and select "Path->Break Apart". We now have lots of small path segments in the drawing:

screen 11.jpg

 

Save as dxf and open in Silhouette Studio:

screen 12.jpg

 

That will do nicely.

[MikeTrice]

If anyone is wondering where I have been during my absence I have been trying various options to produce the roof tiling. Every attempt so far has not been neat enough to satisfy me.

 

Stan will reply to your issue when Silhouette Studio has finished its cut.

[MikeTrice]

Stan, you are not alone in this as other threads will confirm.

 

In your Inkscape drawing click "File->Document Properties...". Make sure the "default units" are set to "mm". I always set both units in the dialogue to "mm" whenever I start a new drawing. Resave.

 

In Studio click on "Edit->Preferences" then "Import options". Make sure all entries are set to "As is".

 

Try reloading the drawing in Studio.

[Stanley Melrose]

Hi Mike,

 

I have followed your tutorial doggedly so the document properties have been meticulously set to "mm" in both parts of the dialogue ab initio.  When I went to the Studio preferences they were already "as is" in both entries.  I made a few mods to the Inkscape files, went through the break up process, re-saved them and re-opened the saved-as .dxf files to Studio.  No change!  I used "Object -> Scale" to bring the opened files back to the overall dimensions of the Inkscape files so all should now be OK, even if the import process still doesn't do what I hoped it would do.  Can you give me a pointer to the other threads to see if there is any info that might shed light on what I may be doing wrong?

 

Cheers,

 

Stan

 

Stan, you are not alone in this as other threads will confirm.

 

In your Inkscape drawing click "File->Document Properties...". Make sure the "default units" are set to "mm". I always set both units in the dialogue to "mm" whenever I start a new drawing. Resave.

 

In Studio click on "Edit->Preferences" then "Import options". Make sure all entries are set to "As is".

 

Try reloading the drawing in Studio.

[JCL]

Hi Stan, is the DXF file something you'd be willing to add as an attachment to a post so it can be looked at? Then we could check to see if it's the export from Inskscape or the import to Studio that's the problem.

[MikeTrice]

Interestingly I have just had the same problem. This was not previously a problem but I recently re-installed an earlier version of Studio. Will need to investigate.

[Stanley Melrose]

No problem . . .

 

What I'm working on is the production of the ex-MR 54ft coach that was modified to serve as a tool-van in a breakdown train.  What I've attached is my .dxf file of the inner sides of the van, a picture of which is also attached so you can see what I'm trying to reproduce.

 

Cheers,

 

StanInner sides 10 thou.dxf

[MikeTrice]

Ok managed to fix it but not 100% certain how.

 

The dxf file exported from Inkscape was produced using mm units and correctly results in the correct dimensions. The problem was in the importing into Studio.

 

As stated earlier I needed to select "Edit->Preferences..". Under "General" I selected "Millimeters" as the Unit of Length. Now what I had not appreciated was the need to click on "Apply" to save the changes so I did it now. Now under "Import Options" for dxf I selected "Centred" (selecting "As Is" resulted in some odd positions being used). Again click "Apply".

 

Now opening the dxf resulted in the correct size being adopted.

 

Hope it works for you.

[MikeTrice]

No problem . . .

 

What I'm working on is the production of the ex-MR 54ft coach that was modified to serve as a tool-van in a breakdown train.  What I've attached is my .dxf file of the inner sides of the van, a picture of which is also attached so you can see what I'm trying to reproduce.

 

Cheers,

 

StanInner sides 10 thou.dxfBHS112.jpg

What size do you expect this to be?

[Stanley Melrose]

215.637mm x 149.134mm according to Ctrl a in Inkscape having lassoed the drawn objects.

 

Thanks for the help so far - I've been busy outdoors most of the day so I'm probably too tired to concentrate on your suggestion from earlier.  I'll give it a go tomorrow but my wife has a large voucher for the garden centre that must be spent this weekend so it may well be later in the day . . .

 

Stan

 

What size do you expect this to be?

[MikeTrice]

The dxf you provided is definately too large which suggests the problem is when saving the dxf file from Inkscape. I note that when saving a svg file as a dxf there is an option for "Base unit" which for me is set to "mm".

Inner sides 10 thou resized.dxf

Edited October 22, 2016 by MikeTrice

[MickRalph]

I had the problem of sides being undersized when opened in Silhouette Designer Edition and I found that to get them the right size I had to set the "Custm Size" units to px while leaving the "default units" as mm in "File -> Document Properties -> Page".  As I have Designer Edition, I save in Inkscape SVG format (I haven't had to save in plain svg format), so I don't have to worry about dxf conversions - problems with sizings was the reason I went for DE.  I changed the Inkscape default document to these units so that I don't have to remember to change them when starting a new drawing.  I covered the px v mm issue in this post in the main Silhouette Cutter thread

[Stanley Melrose]

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

 

Cheers,

 

Stan

 

The dxf you provided is definately too large which suggests the problem is when saving the dxf file from Inkscape. I note that when saving a svg file as a dxf there is an option for "Base unit" which for me is set to "mm".

[MikeTrice]

Continuing with my tiling issue I have changed tactics.

 

Instead of trying to draw the guidelines with a pen I ended up scribing them and swapped over to 20 thou:

 

Cutting the tiles out of 10 thou styrene resulted in them being too thick in N. Using solvent was also a bit hit and miss, once stuck, that was it.

 

I found a reference to York Modelmaker's doing tiles in 2mm using self adhesive paper so decided to try some A4 sized labels I have. Needing a single cut at a blade depth of 1 and speed of 10 they took a fraction of the time that styrene took:

 

Application is by lining up a steel rule with the engraved lines and weighting it down. Adjust under magnification if necessary until happy:

 

One of the cut tile strips was lifted from the sheet with a dental probe:

 

Placed against the ruler and aligned with the previous strip the probe was worked along pushing the tiles into place:

 

The ruler was then removed and the strip smoothed down with a finger:

 

Progress can be seen by this image. Note that in spite of everything one of the strips is still not quite lined up properly:

 

Believe it or not the errant strips were lifted in a corner and peeled back then repositioned and smoothed down again.

 

Overall I am very happy with the way these are going (I will probably jinx things stating this). The self adhesive label is more foregiving and can be readjusted if an error is made. Without having to wait for solvent to go off it is also a lot quicker. To the naked eye I am more than satisfied.