Etching in 2mm

[Michael Edge]

My artwork has 6 layers - front, back, both, white front , white back and white both but all this is printed out on two films, one for the front one for the back. Where they coincide it's all etched away. The three white layers are used to cancel out something on the others - e.g. tags and corrections. Nobody at PEC or PPD sees these layers though, they are just what I work with. Colours are just what I work with on the coomputer screen, fill outlines are not required and may well confuse the process.

I usually work to a minimum of .33mm in our usual .015" sheet, I wouldn't expect .25mm to disappear in .010" sheet which we use for our 2mm etches - these are simply reduced from the 4mm etches and some very thin parts occasionally disappear - but PEC do these for us, not PPD.

[Collett]

2 hours ago, Lacathedrale said:

Is there a meaningful difference between using something like QCAD vs Inkscape for etch design? I've used the former to trace out some GA drawings for scratchbuilding but not used it in anger with fills so either one will effectively be starting from scratch.

 

Many thanks for the pointer to QCAD, I haven't come across the name before and having read through the spec sheet it appears to be more Engineering Drawing based than Inkscape which may be better suited to the drawings necessary for model making.

I consider that Inkscape is primarily a Graphic Artist's tool, but has much better control over Vector Node positions and features such as guide lines than the drawing software that comes with the Silhouette cutter.  Inkscape can get you started using vector drafting software but it has its drawbacks, as with any other tool, and the Online User Manual is pretty useless.  One thing in its favour is a large number of online tutorials and it isn't a mountainous learning curve like I found Fusion 360 to be.

The other software I am starting to learn at the moment is FreeCAD, which seems to be structured much like Fusion 360 for 3D design, my interest is mainly due to the recent changes announced for the Fusion 360 'hobby' license users.

I'm going to download QCAD and see how well I can get on with it.

This is my fret design for the windows and door of the GWR weighbridge office at Winchcombe produced using Inkscape, also the 'blueprint' for the building, Inkscape again.  The main front window was a Yorkshire Sash arrangement, the side windows sliding behind the centre window allowing the Weighbridge Operator to serve the carriers through the window. 

[Chris Higgs]

OK, these are the layers I use, inspired by David.

 

These three are used to draw the outline(edges) of the parts, they are never directly used on the etching artwork:

 

Outline_Both

Outline_Front

Outline_Rear

 

From these the filled parts are produced:

 

Surface_Front 

Surface_Rear

 

I draw the tabs, the framing and the text separately:

 

Tabs

Framing

etch from front (the text)

 

In addition, there is a layer where you can just doodle, draw things like distances, wheel sizes, motor positions etc: to check clearances.

 

Construction

 

and another for descriptions for instructions:

 

Description

 

Why so complicated? well it gives me flexibility. It really is easier for me to see the parts initially as outlines, rather than fills. And then to distinguish what is really parts of the model, rather than the surrounds.

 

And I can use the same artwork to produce diagrams for instructions, for example here:

 

http://2mm.org.uk/products/instruction_sheets/pdf4-742_drwg.pdf

 

This is just produced with  Surface_Front , Surface_Rear  and Construction switched off (and the layers recoloured).

 

Here is an example of why it's good to draw your stuff with separate components -  you can lay them out to see whether they all fit (and explain the parts of valve gear)

 

 

(that's layers outline_both, outline_front and description - I forgot to turn tabs off)

 

Chris

Edited October 4, 2020 by Chris Higgs

[Caley Jim]

I prefer to work with a white background, I suppose it's because of my being taught with pencil and paper.   The layers I use are construction (Magenta), front etch (red), rear etch (blue) unetched (black) front etched tags (orange) and lettering, the latter's colour depending on what side it is to be on.  All outlines go on construction, the 'etch' layers only have the fills on them and anything else goes on layer 0.  The only reason I put the tags on a separate layer is so that I can show them in a separate colour on my instructions.  That layer gets changed to red on the file for the etchers.  Construction, and layer 0 are turned off on that file when I send it.

 

Like Chris, I draw parts out separately and then bring them together on the fret.  I've found that where you have parts to be folded over on one another (e.g. solebar layers) it helps to have the 'hinges' with a 'fishtail' on them Making them narrower in the middle so that they tend to fold there and so mate up more readily.  I also only make the two parts 1mm apart, if possible, to keep the hinges as short as possible.

 

Jim

[justin1985]

I've never actually taken an etch design through to production (have started a few and abandoned), but it seems like the main difference from designing for laser cutting or Silhouette cutters is the need to worry about fills/hatches, rather than lines. 

 

13 hours ago, Chris Higgs said:

OK, these are the layers I use, inspired by David.

 

These three are used to draw the outline(edges) of the parts, they are never directly used on the etching artwork:

 

Outline_Both

Outline_Front

Outline_Rear

 

From these the filled parts are produced:

 

Surface_Front 

Surface_Rear

 

 

Chris, just to make sure I'm following properly, you're saying you complete the design entirely using the outline layers, then activate the "surface" layer to create the fills, so they are derivative of the shapes you click into from the outline layers? 

 

If I've got that right, it is quite a distinct CAD workflow, which is very clever - the outline and the fill remain separate, but linked (in Fusion360 this kind of workflow is called "Projection"). I don't think that wouldn't really be possible in a vector graphics app like Illustrator / Inkscape / Affinity: I'm not aware of being able to link together shapes between layers in those kinds of programs. 

 

14 hours ago, Collett said:

 

Many thanks for the pointer to QCAD, I haven't come across the name before and having read through the spec sheet it appears to be more Engineering Drawing based than Inkscape which may be better suited to the drawings necessary for model making.

I consider that Inkscape is primarily a Graphic Artist's tool, but has much better control over Vector Node positions and features such as guide lines than the drawing software that comes with the Silhouette cutter.  Inkscape can get you started using vector drafting software but it has its drawbacks, as with any other tool, and the Online User Manual is pretty useless.  One thing in its favour is a large number of online tutorials and it isn't a mountainous learning curve like I found Fusion 360 to be.

 

 

For laser / Silhouette designs I always use AutoCAD (2019 for Mac) because I find the snapping, mirroring, arraying etc options, and the ability to work directly with dimensions and angles MUCH more intuitive than in vector graphics software like Inkscape and Affinity. Also, one I learned Blocks, that was a game changer - being able to store a reference design (e.g. a window, W iron, coupler pocket) and replicate it across a design, but then change the original and have all the instances of it also change, is amazing, and so much better than just copy/pasting (this is a very basic CAD feature since the dawn of time, but I only recently got to grips with it). I'm lucky to have free access to Autodesk products through their education license scheme (all university staff and students can register for free access), although of course this is strictly non-commercial. To be honest though, I hardly scratch the surface of the functionality, and the free version of QCAD probably does everything I need. 

 

Some people have said the AutoCAD interface is not intuitive compared to other CAD tools - yes it does have a command line at the bottom (I think virtually ALL CAD applications do, at least as an option?) - this is super useful for working with precise coordinates, lengths, angles etc. However at least the most recent Mac version feels like a perfectly normal (albeit technical) application, with perfectly normal menus and tool panes.

 

You can definitely create the right kind of designs and do the kind of precise work on shapes and sizes etc in Inkscape etc., but it seems much harder work to me. You also have to worry about the difference between dimensions including or excluding line widths etc in a graphics program, and which things snap to, etc. I've always struggled with Inkscape, but I do sometimes use Affinity Designer (successor to the old Serif DrawPlus which was a staple on PC magazine CD-ROMs in the 1990s, and is a bargain at about £50 one off payment, not subscription, from the Mac or Windows app stores) and I find that to have much more intuitive snapping and guidelines than Inkscape.

 

It really is horses or courses though - I think people will EITHER take to CAD and its precision, OR to vector graphics and its more organic approach, but most people would struggle to get to grips with the other when used to one.

 

J

[Michael Edge]

17 hours ago, Michael Edge said:

My artwork has 6 layers - front, back, both, white front , white back and white both but all this is printed out on two films, one for the front one for the back. Where they coincide it's all etched away. The three white layers are used to cancel out something on the others - e.g. tags and corrections. Nobody at PEC or PPD sees these layers though, they are just what I work with. Colours are just what I work with on the coomputer screen, fill outlines are not required and may well confuse the process.

I usually work to a minimum of .33mm in our usual .015" sheet, I wouldn't expect .25mm to disappear in .010" sheet which we use for our 2mm etches - these are simply reduced from the 4mm etches and some very thin parts occasionally disappear - but PEC do these for us, not PPD.

 I should have made it clear that the three "white" layers are only turned to white at the last stage - while I'm working on the drawing they are shown in three shades of yellow, otherwise i wouldn't be able to see them on the white screen.

[Chris Higgs]

32 minutes ago, justin1985 said:

Chris, just to make sure I'm following properly, you're saying you complete the design entirely using the outline layers, then activate the "surface" layer to create the fills, so they are derivative of the shapes you click into from the outline layers? 

 

If I've got that right, it is quite a distinct CAD workflow, which is very clever - the outline and the fill remain separate, but linked (in Fusion360 this kind of workflow is called "Projection"). I don't think that wouldn't really be possible in a vector graphics app like Illustrator / Inkscape / Affinity: I'm not aware of being able to link together shapes between layers in those kinds of programs. 

 

 

J

 

Yes, that's pretty much it. Or at least, let's say I complete the various component designs that way, then fill them in, typically in a 'filling-in' session. Laying them out onto e.g. a complete wagon chassis and adding the tabs and surround gets done next. And then finally laying out a set of designs onto a sheet to be etched. As Jim observed, that can be an awful lot of them in 2mm.

 

Of course, that's the theory. It becomes iterative once you notice some mistake you made, or are struck by a better idea.

 

Chris

[Chris Higgs]

42 minutes ago, justin1985 said:

Some people have said the AutoCAD interface is not intuitive compared to other CAD tools - yes it does have a command line at the bottom (I think virtually ALL CAD applications do, at least as an option?) - this is super useful for working with precise coordinates, lengths, angles etc. However at least the most recent Mac version feels like a perfectly normal (albeit technical) application, with perfectly normal menus and tool panes.

 

 

 

TurboCAD doesn't. Instead if you click on an item you can edit its properties precisely in a set of edit boxes in an action bar.

 

My day job for the last three years has been to design touch-screen UI software for machine tools, mills and lathes (large ones that typically fill a whole room). We have the same approach there. Action bars or indeed whole tabs with the parameters laid out. We even have a CAD module that is entirely touch operated, no keyboard or mouse.

 

Chris

Edited October 5, 2020 by Chris Higgs

[MinerChris]

2 hours ago, justin1985 said:

Chris, just to make sure I'm following properly, you're saying you complete the design entirely using the outline layers, then activate the "surface" layer to create the fills, so they are derivative of the shapes you click into from the outline layers? 

 

If I've got that right, it is quite a distinct CAD workflow, which is very clever - the outline and the fill remain separate,

 

Just to prove that it's all horses for courses, my personal preference is to draw the parts in an older autocad style program, using closed plines. 

 

 

Then import the dxf into inkscape, scaled 1:1, set the line width to 0, and fill the shapes with front etch, back etch, and no etch colour's. Tabbing between parts is normally done in inkscape using rec shapes, again with 0 line width.

 

 

Front and back images are then created by using the 'Same Fill select' tool to fill in the half etch colour's, black or white. The back image is then mirrored vertically before saving as PDF and sending to PPD. (After bringing both images into another screen to check everything is as expected.)

 

I'd imagine that people are going to say that this is quite a backward way of doing things, but I for one like the simpler user command line interface of the older CAD programs. It's just unfortunate that the CAD program I have access to doesn't have fill functions. As you might see, this process isn't without risk of introducing additional errors - this signal post was missing a couple of alignment holes in a couple of the layer's. Another gotcha I've found previously is that LibreCAD couldn't really handle islands in fill, which tends to be quite important for our stuff (I can explain more if required.) 

 

One other thing that I've observed in consuming and designing etches is that some design parts to fill an etched space, whereas others design space to mark out an part. Contrast my signal post above which is the former with one of D869's wagon chassis designed on the latter principle, (helping me to fill up some space on a etch.) My gut feeling is that the latter is better, as there is less metal to be eaten away by etching, but this leads to more design work when you inevitably have to revisit a part of the design.

 

 

I hope these ramblings make at least a little sense.

 

Best Regards,

 

Chris.

 

Edited October 5, 2020 by MinerChris
Extra image removed

[Michael Edge]

I always draw all parts with their own outline and tags, rather than the multiply connected style you are using. It makes it much easier to re-arrange the etch, to copy parts to  another job and to correct errors.

[Penrhos1920]

When drawing a 2mm planked wagon how wide do you draw the grove between planks?  PPD guidance gives the minimum as 0.18mm which works out as just over 1” !!

[Pixie]

I can’t really add much to the debate aside from being an advocate of Autocad, the Hollywood Foundry guides and PPD - no relationship with the latter aside from being satisfied customer. They did seem to to go through a period of occasionally supply a slightly ‘fluffy’ etch but everything I’ve had recently has been razor sharp. The below is 4thou stainless steel with each vent on the grille being 0.1mm wide.

 

I still find unwrapping an etch for the first time one of the the most satisfying elements of our hobby, akin to a metallic Christmas morning. 

 

 

Cheers,

Steve

[Caley Jim]

1 hour ago, Penrhos1920 said:

When drawing a 2mm planked wagon how wide do you draw the grove between planks?  PPD guidance gives the minimum as 0.18mm which works out as just over 1” !!

I  make mine 0.125.

 

 

Once painted, they don't look too prominent.

 

 

Jim

[Sithlord75]

I think I shall have to read though a lot of this again - being an Antipodean Bear of very little brain I seem to have gotten lost somewhere with the layers.

 

I've Autodesk Inventor and Adobe Illustrator thanks to work - from what I gather, it may be "better" (for a given value of better) to use Illustrator for etches (having used Inventor very successfully for 3D prints) as I can understand the layer function there.

 

Just to clarify - it would appear that you end up with one colour for no etch (when doing fills), another colour (red it would appear) for etching from the back, and another (blue seems popular) for etching from the front.  So if an area on layer one is white it would be masked and if red it would be etched from the back, and on layer two, white would be masked and blue would be etched from the front.  If red and blue are in the same place, you get a hole.   If white is in the same place you get no etching at all and if red on layer 1 is matched with white on layer 2 you get it half etched from behind (and conversely if blue on layer 2 is matched with white on layer 1, it is half etched from the front).

 

I prefer looking at pictures to learn things like this.  If someone would be so kind as to post the full set of layers that would be tremendous.  The next step in the Australian evolutionary process (at least as far as the SEQAG is concerned) is to work out etching as we have some ideas....

[Lacathedrale]

@Pixie I saw you did stainless etching for the grills on your diesel detailing - but it seems you are in the minority for this material - can you give any thoughts behind its use?

[Nig H]

On 04/10/2020 at 18:12, Nig H said:

 PEC told me to use four layers - the outline shape, white hatch for no etch, red hatch for etch from above and blue hatch for etch from underneath. This all seems very simple to me so that's how I draw my artwork. I use Autocad LT, arrange it all in a final sheet, send it off and get the sheets back from PEC some weeks later. I've used PPD too but found on one occasion the quality of the final product was poor, so I tend to stick with PEC.

 

Nig H

Here is a pic of the layers I use as described above.

 

Top left is a drawing of a frame spacer for a Fowler tank. To the right is the 'construction' layer with the basic outline of the part. Middle left is the layer with white hatch for no etch. To the right is the red layer with etch from the top only, and the last layer is for blue hatch with etch from underneath only. So the part has outer fold lines on the underside, and inner half etched fold lines on the top only. The part number '5' is on the top only. The small red rectangles are the fills for the attachment tabs.

 

Hope this helps.

 

Nigel Hunt

 

 

 

 

 

[Pixie]

2 hours ago, Lacathedrale said:

@Pixie I saw you did stainless etching for the grills on your diesel detailing - but it seems you are in the minority for this material - can you give any thoughts behind its use?

 

Hi William, 

 

For most of my 'construction' etches (things like wagon chassis, bogie inners, etc) I use 10 thou/0.25mm nickel silver which seems to pretty common in the 2mm world; I am a fan of how it builds up and take solder. The use of 0.1mm stainless steel is only for items that I need the finesse and strength, whilst also being thin. PPD do not offer 0.1mm nickel silver, but if they did I'd be very worried that the roof grilles would just tear. Likewise, the coach sides shown above are in 0.1mm stainless steel - if they were nickel silver I would be worried about deforming the window bars and kinking the sides when rolling. I've never tried soldering stainless steel but I believe it's more challenging that nickel silver. It's more about choosing the right metal for the situation rather than personal preference. 

 

Cheers,

Steve

[Chris Higgs]

3 hours ago, Pixie said:

 

Hi William, 

 

For most of my 'construction' etches (things like wagon chassis, bogie inners, etc) I use 10 thou/0.25mm nickel silver which seems to pretty common in the 2mm world; I am a fan of how it builds up and take solder. The use of 0.1mm stainless steel is only for items that I need the finesse and strength, whilst also being thin. PPD do not offer 0.1mm nickel silver, but if they did I'd be very worried that the roof grilles would just tear. Likewise, the coach sides shown above are in 0.1mm stainless steel - if they were nickel silver I would be worried about deforming the window bars and kinking the sides when rolling. I've never tried soldering stainless steel but I believe it's more challenging that nickel silver. It's more about choosing the right metal for the situation rather than personal preference. 

 

Cheers,

Steve

 

I agree, stainless is for special circumstances where nickel silver is too soft - thin material or thin detail items.  4 thou stainless is more robust than 10 thou nickel-silver is.

 

I'd tend to glue rather than solder it.

 

Chris

 

[Chris Higgs]

18 hours ago, Caley Jim said:

I  make mine 0.125.

 

 

Once painted, they don't look too prominent.

 

 

Jim

 

I use 0.12mm as well. Smaller than that ad they tend not to come out reliably. Never tried to measure one, but I suspect they actually are not that thick when etched.

 

Rivets is another area where you go as small as you dare. But if you want really thin plank gaps or rivets, then 3D-print them.

 

Chris

[Chris Higgs]

On 07/10/2020 at 16:30, Chris Higgs said:

 

I use 0.12mm as well. Smaller than that ad they tend not to come out reliably. Never tried to measure one, but I suspect they actually are not that thick when etched.

 

Rivets is another area where you go as small as you dare. But if you want really thin plank gaps or rivets, then 3D-print them.

 

Chris

 

Perhaps another thing to mention is that the thinner the material you use, the finer the half-etch detail you can produce as it will be eaten away less by undercut. 

 

Chris

[Michael Edge]

On 07/10/2020 at 12:12, Pixie said:

 

Hi William, 

 

For most of my 'construction' etches (things like wagon chassis, bogie inners, etc) I use 10 thou/0.25mm nickel silver which seems to pretty common in the 2mm world; I am a fan of how it builds up and take solder. The use of 0.1mm stainless steel is only for items that I need the finesse and strength, whilst also being thin. PPD do not offer 0.1mm nickel silver, but if they did I'd be very worried that the roof grilles would just tear. Likewise, the coach sides shown above are in 0.1mm stainless steel - if they were nickel silver I would be worried about deforming the window bars and kinking the sides when rolling. I've never tried soldering stainless steel but I believe it's more challenging that nickel silver. It's more about choosing the right metal for the situation rather than personal preference. 

 

Cheers,

Steve

Stainless steel should solder OK with phosphoric acid as flux.

[queensquare]

I'd like to teach myself basic CAD (no laughing at the back please), initially just 2D for basic etching and laser cutting but potentially 3D in the future. I have been recommended Onshape as a free package, any thoughts from those who know more than me about these things (thats pretty much everybody!)

 

Jerry

[richbrummitt]

47 minutes ago, queensquare said:

I'd like to teach myself basic CAD (no laughing at the back please), initially just 2D for basic etching and laser cutting but potentially 3D in the future. I have been recommended Onshape as a free package, any thoughts from those who know more than me about these things (thats pretty much everybody!)

 

Jerry

Onshape is a 3D package. It’s very good at what it does but I cannot  recommend it to a casual user who wishes to do some etch artwork. 
 

Until recently I would have said DraftSight but they changed the business model on that and it got expensive. I would look at something like LibreCAD (free) or NanoCAD (Free and paid options). A lot of pro users are making satisfied noises about nanoCAD. I’ve not tried nanoCAD yet so we could learn together if you like? It would be a fun and useful thing to do a thread on, I think. 
 

 

[Caley Jim]

Would like to help, Jerry, but as an AutoCAD user (which is probably overkill) I've no experience of any of the free packages.  I'll send you an email with Bob Jones' notes on the basics of etching art work generally if that would help.

 

Jim

[03060]

I'm in a similar position to Jerry; being an allegedly mainly 3mm modeller I would like to be able to produce some items in the future for myself that would maybe be of interest to others. 3D is not for me at the moment. I do know several people (including Mike Edge) in the LMRS who produce their own artwork for etches, I'll pose the question to them on our What's Ap group and see what comes back.

 

Please give a 'nod, nudge and a wink' on here if you start a new thread as I don't seem to receive notifications for new threads in certain topics any more since the last 'upgrade' ....I've tried adjusting my settings.

 

Regards,

Ian.

Edited October 20, 2020 by 03060
Correction.