Etch design etc for all

[jonhall]

It's also about having the time to devote to it, having the inclination to do so, and (most importantly) being able to break through the psychological/confidence barriers that encircle most peoples' comfort zones.

 

Based on personal experience and that of some of my friends, I am absolutely convinced that achieving success in these 'hi-tech/software-based' areas isn't as easy for some, as it appears to be for others.

 

I think there is a barrier to learning a lot of these sorts of skills - I certainly couldn't use pen and paper to draw artwork for etch, and neither could I have used a CAD program to do so, until I did a single term of AutoCAD at nightschool - the simple commands I learnt in 10 weeks were more than enough to draw etched sheets, and when the tutor discovered I was doing this course out of interest, and that I didn't have a copy of the software to practice with, made arangements to aquire a copy for me

 

I discovered that AutoCAD is rather like drawing graphs, and once I'd realised that - there was no stopping me.

 

My first set of artwork was printed at twice size and sent to Grange & Hodder, who did the phototool for me photographically - so if you do have the skill with a pen, you can still etch, and there is at least one supplier of etched kits who still does things tradtionally - because he was trained as a graphic designer, and has been knocking out etched brass kits for more than 30 years he prefers to stick with what he knows.

 

There does seem to be a number of people who write some techniques off as too difficult, without even trying...

Jon

[Barry O]

I have etches from people who have "hand drawn" them - and, I have to say , that those created using Autocad are a lot better.

 

But in comparison to the first etched Kits I saw/built today's etchings are so much better in comparison the use of computer based drawing aids is a boon for us modellers - just wish it had been available while I did my engineering degree in the late 1970s!!

[45609]

Not so, sorry. This pdf file is essentially about the virtues of changing to P4 which I accept, not about doing, in a practical way, that change. There's a difference.

 

But the Society has also been offering practical workshops for almost a year. See the links below.

 

http://www.scalefour...kbench-2011.pdf

 

http://www.scalefour...workbenches.pdf

 

In addition to this the Area group structure of the Society offers the support network necessary to develop your skills and technique.

 

Once upon a time I couldn't do a number of modelling tasks that I now take for granted but the point is I'm still learning new stuff now.

 

There does seem to be a number of people who write some techniques off as too difficult, without even trying...

 

Absolutely! PMA required when it comes to tackling anything new. You have to want to do it.

 

My first attempts at etch design weren't entirely successful and were done in 2D only. I took a methodical approach to determine what was wrong and applied this to a revised etch with some success. I then realised that approaching the design in 3D could help with some of the assembly issues I had encountered by purely working in 2D. For me this works as it is essentially like doing a virtual build and avoids the cost of repeating etches if something is not right. The added advantage of 3D modelling comes when you need exploded diagrams for the assembly instructions if you are doing things commercially.

 

This is a slightly different ethos to what Jol has said previously but each to his own. Jol, there is no doubting that some of the work you have done for LRM over the years is, and continues to be, first rate.

 

An example of how I do things is shown below.

 

 

 

cheers....Morgan

[t-b-g]

Taking it a stage further there was an article by John McCrea in MRJ No 193. He not only does the artwork (having taught himself quite quickly) he also built himself a DIY etching tank and has produced some very nice etches from it! One of the down sides to getting things etched, particularly for small batches/items is the cost of the initial photo etch tooling. Doing that part yourself really does bring the cost down. Does anybody out there actually do the acid etching part themselves?

[craigwelsh]

Taking it a stage further there was an article by John McCrea in MRJ No 193. He not only does the artwork (having taught himself quite quickly) he also built himself a DIY etching tank and has produced some very nice etches from it! One of the down sides to getting things etched, particularly for small batches/items is the cost of the initial photo etch tooling. Doing that part yourself really does bring the cost down. Does anybody out there actually do the acid etching part themselves?

We have had examples of circuit board etching shown on here before done at home. Personally I wouldn't really want a bath of acid sitting around!

 

A 1 off first go at an A5 sheet of etch will set you back about £28 from experience.

 

 

I haven't tried importing anything from SolidEdge (linked earlier) into AutoCAD yet but its a very nice drawing program and if the dxf is read ok by AutoCAD perfect for people to have a go with.. You'll see I was inspired by page 175...

 

 

edit: AutoCAD import works so etch companies should be fine..

 

I agree with Morgan that 3D is useful for applications - Being able to do a belpaire firebox and cone boiler for example along with the holes in it!

 

Basic 2D like the above can be useful to stick to brass or plastic anyway and also for doing some basic building design too..

[dajt]

Taking it a stage further there was an article by John McCrea in MRJ No 193. He not only does the artwork (having taught himself quite quickly) he also built himself a DIY etching tank and has produced some very nice etches from it! One of the down sides to getting things etched, particularly for small batches/items is the cost of the initial photo etch tooling. Doing that part yourself really does bring the cost down. Does anybody out there actually do the acid etching part themselves?

 

All the brass underframe parts in the post http://www.rmweb.co.uk/community/index.php?/topic/19460-your-forgotten-projects/page__view__findpost__p__206902 except the W-irons are home etched. The process is pretty easy, but tedious and messy.

 

I drew the parts using a free program called Inkscape. For home etching, any drawing program will do because you're just going to print the parts onto a special plastic sheet.

 

You print the parts onto said special plastic sheet. I think it is called press-n-peel. You need a laser printer for this.

 

Now you clean a sheet of brass that is big enough to hold the parts, and iron the image of the parts onto it, like those old iron-on transfers for t-shirts. This will leave the image of the parts on the brass, and the remaining brass will be etched away.

 

Cover the back of the brass sheet with plastic electrical tape to protect it.

 

Stick the brass in some etching solution. You can purchase the acid from electronics shops.

 

Keep checking it until the brass has etched away and your parts are left stuck to the tape.

 

This only allows for single sided etching. You could do double sided but that would require some skill and care getting both sides to match up.

 

Making the acid warm with a cheap aquarium heater, and sending bubbles though it with a cheap aquarium air pump speed up the process.

 

I was very happy with the result, but I didn't enjoy drawing the parts much. I found it quite tedious. As and CW says you're left with a container of acid sitting around. But then almost everything in a workshop is hot, sharp, poisonous, or will cut you up, so what's one more hazard? Soldering flux isn't any better.

 

Regards,

David.

[Pugsley]

My first attempts at etch design weren't entirely successful and were done in 2D only. I took a methodical approach to determine what was wrong and applied this to a revised etch with some success. I then realised that approaching the design in 3D could help with some of the assembly issues I had encountered by purely working in 2D. For me this works as it is essentially like doing a virtual build and avoids the cost of repeating etches if something is not right. The added advantage of 3D modelling comes when you need exploded diagrams for the assembly instructions if you are doing things commercially.

That pretty much sums up my experiences so far. I've also started designing in 3D, then producing the artwork from the resulting model. I've only just started, so haven't quite worked out how to do it in the package I'm using, but have designed some other parts that will end up being 3D printed, then cast.

 

Craig, that SoildEdge looks quite good, I might have to download that and give it a go.

[Jol Wilkinson]

 

My first attempts at etch design weren't entirely successful and were done in 2D only. I took a methodical approach to determine what was wrong and applied this to a revised etch with some success. I then realised that approaching the design in 3D could help with some of the assembly issues I had encountered by purely working in 2D. For me this works as it is essentially like doing a virtual build and avoids the cost of repeating etches if something is not right. The added advantage of 3D modelling comes when you need exploded diagrams for the assembly instructions if you are doing things commercially.

 

 

 

cheers....Morgan

 

Hi Morgan,

 

You've clearly identified several very good reasons for using a 3D software package.

 

My own views, which I have clearly failed to get across to most readers, are based on my own experience with 3D TurboCad (although quite a few years ago) and 2D CorelDraw. These have been reinforced through contact with several other designers, the etchers (mainly PEC bit also Chempix as well as Grange and Hodder) and through running training workshops on etch design.

 

I believe 2D programs such as CorelDraw and Illustrator are easier to learn than the 3D ones. Most of us are used to looking at 2D drawings and diagrams and the 2D packages simply replicate that format on screen. I think that they are therefore more intuitive. On the training workshops we found that people with no experience of CorelDraw could get the hang of the basics in a couple of hours. They had usually turned up with some free/cheap software with no experience in using it and we found it more productive to load CorelDraw onto their PCs and start again.

 

As you have said, 3D gives major benefits in producing illustrations for instructions, etc. Most designers I know still use 2D, having "grown up" with those particular programs. Several still prefer to draw artwork by hand because they are comfortable with it (and it still has a couple of real advantages). However, a CAD system gives greater accuracy and repeatability. I've just drawn four new carriage kits and was able to easily repeat the ventilator hoods, droplights, etc. to create the number I needed (quite a few!).

 

Your experience of avoiding design errors with 3D (if I may put it like that) and additional test etches is an interesting one. I don't think it always works - as one designer who has written up his experiences in a 4mm society journal has found.

 

The reason I do not favour the free/cheap software programs against the "commercial" offerings is based on the experience of one designer who uses such a package. In converting his files to a format that the etcher can use, minor errors sometimes creep in. This needs additional work - and hence cost - by the etchers if they spot them, or if un-noticed results on mistakes in the finished item. The fact that such programmes are free or very cheap, and have not established themselves against the major commercially accepted programs, sums it up.

 

Jol

[Horsetan]

.... belpaire firefox......

 

An improved browser for generating more heat?

[Revolution Mike]

The reason I do not favour the free/cheap software programs against the "commercial" offerings is based on the experience of one designer who uses such a package. In converting his files to a format that the etcher can use, minor errors sometimes creep in. This needs additional work - and hence cost - by the etchers if they spot them, or if un-noticed results on mistakes in the finished item. The fact that such programmes are free or very cheap, and have not established themselves against the major commercially accepted programs, sums it up.

 

Sorry Jol, but that is unfair or ignorant of open source software! It may be true for some packages, but it certainly isn't true for all - how many people use Firefox/Chrome/GIMP/Open Office etc in choice over paid for software...

 

A lot of open source software is actually funded by or worked on by large software companies who see a mutual benefit of the work.

 

For 3D work - blender is nice, though as with any CAD package there is a learning curve.

 

Where I agree with you is that for 2D vector drawings there probably isn't so much choice out there in open source s/w - Inkscape springs to mind, but I agree with you that Coreldraw is probably an easier starting point.

 

Cheers, Mike

[Jol Wilkinson]

Back to etching.

 

I wonder if there is a service to convert someones rough sketches to CAD drawings suitable to be sent to the etchers? Just a thought anyway.

 

 

I have been asked on many occasions, when standing behind London Road Model's show stand "why don't you do a kit for a so and so, you'd sell loads".

 

For several years I have replied by pointing out that a great deal of the work in developing a kit is the prototype research and that, unless it's an LNWR prototype, we don't have any information readily available. However, if the enquirer was enthusiastic about the model, had the information and would like to produce a set of rough dimensioned component drawings - as though they were scratchbuilding the model - I could create artwork from that so that they could commission a test etch, etc.

 

Cost wasn't even discussed, although LRM might adopt the kit if it seemed to be commercially viable and thus the enquirer would have no outlay, other than his time in doing the research and producing the rough drawings.

 

So far, no takers!

 

Jol

[Jol Wilkinson]

Sorry Jol, but that is unfair or ignorant of open source software! It may be true for some packages, but it certainly isn't true for all - how many people use Firefox/Chrome/GIMP/Open Office etc in choice over paid for software...

 

A lot of open source software is actually funded by or worked on by large software companies who see a mutual benefit of the work.

 

For 3D work - blender is nice, though as with any CAD package there is a learning curve.

 

Where I agree with you is that for 2D vector drawings there probably isn't so much choice out there in open source s/w - Inkscape springs to mind, but I agree with you that Coreldraw is probably an easier starting point.

 

Cheers, Mike

 

Hi Mike,

 

as I've said, my opinions are based on my experiences. I'm always willing to change my views, but I don't have the time or inclination to put any effort into investigating the various alternatives on the market. I prefer to stick what I know works and think it's correct to recommend those.

 

Jol

[craigwelsh]

Hi Mike,

 

as I've said, my opinions are based on my experiences. I'm always willing to change my views, but I don't have the time or inclination to put any effort into investigating the various alternatives on the market. I prefer to stick what I know works and think it's correct to recommend those.

 

Jol

If it works for you why change it? Makes sense to me. I know Chris Gibbon at High Level uses TurboCAD and his recent instructions have had some nice 3D work too.

 

However for someone starting with nothing and wanting the help of a PC there are benefits to CAD packages if people can master them.

 

 

We could make this thread a bit more practical if someone had something basic they have dimensions for and would like to see how it'd be drawn up for etching..

[Talltim]

Something that seems to have been missed in this thread is that there is a difference between designing a flat etched component and a kit. For example, you want to etch some new grill for a diesel. You don't have to think about how they fit with other etched parts, so a hand drawing or 2d drawing package will do in nicely.its only when you get into etched kit design, where the parts have to fit together that a 3D package comes into its own.

[Pugsley]

However for someone starting with nothing and wanting the help of a PC there are benefits to CAD packages if people can master them.

I completely agree. I've moved from CorelDraw to CAD for 2D work, mostly because of the ability to use blocks (effectively master templates) so if I need to revise anything, I just have to change one item and not all the instances. I'm sure that someone will pipe up now and tell me that I can do the same thing in Corel

 

I would recommend that anyone starting out goes straight for a CAD program, but that's just my opinion.

 

We could make this thread a bit more practical if someone had something basic they have dimensions for and would like to see how it'd be drawn up for etching..

That's a great idea. I'm willing to participate in that as well, using the 2D from 3D method.

[Jol Wilkinson]

I completely agree. I've moved from CorelDraw to CAD for 2D work, mostly because of the ability to use blocks (effectively master templates) so if I need to revise anything, I just have to change one item and not all the instances. I'm sure that someone will pipe up now and tell me that I can do the same thing in Corel

 

 

Martin,

 

too good an opportunity to miss

 

I quote;

 

"The CorelDRAW application has three types of styles you can create and apply in drawings: graphic, text, and color. After you create a style, you can edit it and apply it to any number of graphic and text objects. When you edit a style, all the unlocked objects using that style are automatically updated, letting you make design changes to many objects in one step."

 

There is also Corel Script, which are short programs that automate drawing tasks. I've never used them, but will have a go on the next loco design project.

 

I think that most CAD or Desktop Puublishing programmes will have similar features, my (old) Adobe PageMaker includes "Styles", where you can set up particular parameters for text, etc. If you then edit that "Style" all the text produced in that category will also change automatically.

 

Jol

[45609]

My own views, which I have clearly failed to get across to most readers, are based on my own experience with 3D TurboCad (although quite a few years ago) and 2D CorelDraw.

Jol, I have the utmost respect for your views. Pragmatism is a virtue in my book and why change a process or procedure that is proven.

 

I believe 2D programs such as CorelDraw and Illustrator are easier to learn than the 3D ones. Most of us are used to looking at 2D drawings and diagrams and the 2D packages simply replicate that format on screen. I think that they are therefore more intuitive. On the training workshops we found that people with no experience of CorelDraw could get the hang of the basics in a couple of hours. They had usually turned up with some free/cheap software with no experience in using it and we found it more productive to load CorelDraw onto their PCs and start again.

I guess I'd challenge that a little. If you think of the basics of 3D modelling as an extrusion or revolution of a 2D cross section which are then combined into a more complex solid shape then I think the basics of 3D modelling can be mastered in a similar time frame. In my experience of, admittedly high end 3D packages like NX, Solidworks and CATIA, the biggest hurdle to learning the software is familiarity with the menu structure. The basic premise for 3D modelling is the same for all these systems and more than likely the packages aimed at the home user market.

 

Your experience of avoiding design errors with 3D (if I may put it like that) and additional test etches is an interesting one. I don't think it always works - as one designer who has written up his experiences in a 4mm society journal has found.

I may have been a bit glib with that statement because I come from a professional engineering background and I also have enough experience from building good and bad etched kits to know instinctively what is likely to work. I do still resort to freehand sketches to visualise different ways of design/assembling some components. To expand on what I see as the benefit is that all the components can be assembled in the virtual environment. You can visualise potential clashes of parts or assembly issues and you can use the overlap of components that fit together to generate ("associate" in 3D terminology) the slots and tabs. The life saver is that if, for instance, a change is necessary to the tab length of one component then the slot on the adjacent part will change in line with this.

 

However for someone starting with nothing and wanting the help of a PC there are benefits to CAD packages if people can master them.

Advice that I'd support. As explained above the time spent in mastering 3D modelling reaps it's own rewards. The danger as I see it is that the virtual modelling environment can soemtimes lead you down a path of making something over complicated or too fiddly to build despite the fact that it might all fit together perfectly.

 

We could make this thread a bit more practical if someone had something basic they have dimensions for and would like to see how it'd be drawn up for etching..

Dimensions not always required. I have recently been modelling something up from a fellow RMWebber by scaling and importing a scanned general arrangement drawing into the CAD environment. I'd like to post details of it but I'll seek agreement from the third party before posting.

 

Something that seems to have been missed in this thread is that there is a difference between designing a flat etched component and a kit. For example, you want to etch some new grill for a diesel. You don't have to think about how they fit with other etched parts, so a hand drawing or 2d drawing package will do in nicely.its only when you get into etched kit design, where the parts have to fit together that a 3D package comes into its own.

See the comments to Jol above. I don't see the need to run a 2D and 3D package in parallel. 3D software will always have the ability to do 2D stuff but obviously it doesn't work the other way round.

 

Cheers....Morgan

[Mike G]

 

Dimensions not always required. I have recently been modelling something up from a fellow RMWebber by scaling and importing a scanned general arrangement drawing into the CAD environment. I'd like to post details of it but I'll seek agreement from the third party before posting.

 

Cheers....Morgan

 

Morgan

If you're referring to my little project crack on, no objections to sharing. I'm just downloading 'solid edge' - see if that runs on Vista, as AutoCAD 2005 will not. Save me having to use my old laptop to draw on, which is so S...l...o...w. I'll send the dimension we talked about over later. Haven't had a chance to look at the file you sent.

 

From a newbie point of view - as I've only been doing this on and off for 6 mths - it's a steep learning curve and as CK says you really only need to master the basics to get a result. And I'm honest enough to say that's all I've done. I'll let Morgan put a bit more flesh on this skeleton....when he gets round to it.

 

regards

 

Mike

[Pugsley]

Martin,

 

too good an opportunity to miss

See, I knew that would happen!

 

I'll have a look at that feature then. Although I'm firmly committed to using CAD for artwork now, I still use CorelDraw for graphics work, so it'll come in handy for that.

[hollywoodfoundry]

I have used Autocad, Turbocad and Coreldraw to produce artwork for etching. I would rate Coreldraw as the easiest to learn, then Autocad and finally Turbocad, in that order. Oddly, Autocad, probably the oldest CAD program, is actually very easy to use once you become familiar with the command line interface. I was forced to learn it for my job many years ago and now find I can work much faster with it than any other program. Most modern packages rely on a mouse-based interface, whereas the ancient command line interface is much faster to use in conjunction with the mouse.

 

I do not advocate the idea of creating hand-drawn artwork, much less scanning it, reducing it or any of those tricks, particularly if you are going to produce any items of critical dimensions, such as connecting rods that have to match locomotive frames. There is so much potential for errors, distortions and problems when you use progressive processes like that. Photographing drawn artwork is not a precise process either, as distortions in the lens at various distances from the art, or even which direction the artwork is oriented, will introduce minor dimensional errors. Far more precise results are produced by laser photoplotters, and they produce repeatable results as well, and these machines are used by the better etching companies to produce negatives from computer files. Etching companies hate physical artwork, as they have to photograph it to produce the required negatives for etching, and many companies just won't do it anymore, or farm it out to external companies. Companies like Chempix do not even produce negatives any more, but effectively 'print' the design onto the photo-sensitive surface of the metal.

 

If you wish to modify hand-drawn artwork, even just slightly, then you have to retrieve your original artwork, probably from the etching company, make the changes, send it back to the etchers, have it re-photographed, etc etc. There is a lot of potential for errors in that process, whereas you make a simple change to a CAD file, email it to the etchers. Job done. And you have a record of both the original and the modified drawing.

 

I have also taught etch drawing preparation to self-confessed computer Luddites, one of whom went on to become an 'etching fool' (his words), who now turns out etches faster than the local baker makes bread. It is really worthwhile making the effort to learn a computer-based drawing program for a whole lot of reasons, and once you do, there is almost no limit to what you can create with etches.

 

Most etching companies will accept files from Coreldraw or a .DWG file from Autocad or Turbocad, as these are the most common file types they encounter. And if you ask them, they will provide you with a list of their requirements, preferences and rules for computer files.

 

For what it is worth, I have a number of papers on my web site explaining etch file preparation: http://www.hollywoodfoundry.com/HowToPapers.shtm

[John M]

I had a go at producing my own artwork using DesignCAD a cheap combined 2D draughting 3D modelling software from the same family of Software as TurboCAD. Over the past year I have gradually progressed from producing detail overlays for a diesel shunter to my first complete coach kit.

 

I initially produced some fairly basic artwork of an open wagon body to tests folds and progressed to more complicated items.

 

While there is a cost associated with learning to understand the oddities of a particular software and the limitations of the etching process, the number of errors and element of re-work decreases with experience. In the case of the coach I printed out artwork and assembled a paper model to check the principal fits before comissioning the test etch.

 

The learning process was quite extended I bought the original version of the software about 10 years ago and only got to grips with its capabilities within the last 12 months. Personally I prefer to work from the command line menu in combination with the < >keys and mouse, than using shortcuts or the mouse based command interface used with more contemporary software.

 

I have found the 3D modelling capabilities useful for designing and interfacing detail parts with the artwork, I have experimented in producing detail parts for 3d printing unfortunately the results in producing printable parts have been somewhat unreliable and difficult to predict.

 

John

 

 

[Pyewipe Jct]

I had a go at producing my own artwork using DesignCAD a cheap combined 2D draughting 3D modelling software from the same family of Software as TurboCAD. Over the past year I have gradually progressed from producing detail overlays for a diesel shunter to my first complete coach kit.

 

John

 

Hello John, you've pricked my interest with your mention of DesignCAD, as I've used that on & off in the course of my work for the past 10-15 years or so (& to be honest, you're the only person I've come across 'in the real world' that's actually heard of it... ).

 

Could I ask what format you output your files in? From experience, the native .dc or .dcd files aren't compatible with any other software & I've not had wholly satisfactory results converting to .dxf with it, either...

 

 

Cheers,

 

Kevin

[John M]

Hello John, you've pricked my interest with your mention of DesignCAD, as I've used that on & off in the course of my work for the past 10-15 years or so (& to be honest, you're the only person I've come across 'in the real world' that's actually heard of it... ).

 

Could I ask what format you output your files in? From experience, the native .dc or .dcd files aren't compatible with any other software & I've not had wholly satisfactory results converting to .dxf with it, either...

 

 

Cheers,

 

Kevin

 

Hi Kevin

 

I upgraded to the current version of the software last year and convert files to dxf.for etching and have had few issues with convetred files. Previously I had issues with reliably converting hatched areas vital for photo etching with the LT2000 version of the software.

 

 

I usually export in dxf. as the first part of the conversion process in preparing a file for 3D modelling, however the results to date using the same techniques and following the same processes are best described as unpredictible, with seemingly random outcomes in producing manifold or non-manifold models.

 

 

John

[45609]

If you're referring to my little project crack on.....

 

OK so here are a few pictures exported from NX this evening. The aim is to come up with an etched pony truck design to replace the cast parts in a DJH Britannia. The plan is to use Comet axle box castings on the side frames so there is no need to replicate the cosmetic outer frame work, rivetting and leaf spring detail. I still need to have a discussion with Mike about the model springing arrangements and how to accommodate so the purpose of this posting is to show how some basic data can be utilised in 3-D to lay out the design. The drawing provided was a PDF general arrangement drawing as below....

 

 

There were no readable dimensions on the drawing sent to me but Mike provided a linear dimension scaled from his master copy. This was the horizontal distance from the centre pivot to the vertical axle centre line. The dimension given for 4mm scale was 27.3 mm. I was then able to scale the picture within an image manipulation program (I'm using GIMP) and generate a side, top and end view that could be imported into the CAD modelling software. The CAD software I use (NX 7.5) will only accept a TIF image format. Each image was placed on the global XY, XZ, YZ plane and datum planes projected from these reference images to give a three dimensional grid onto which profile sketches could be laid out. The next 2 images show the 3-D model of assembly of the pony truck. This is not necessarily the definitive design but just a possible way that I thought it could be made from flat etched metal. So far there are four components shown. The main frame (in gold) is the largest and most complex piece having four folds. The two grey and one orange piece at the rear are stretchers that are tabbed into place and soldered to stiffen the whole structure. The image also shows the imported images and hopefully give an idea of how the 3-D model has been developed from them.

 

 

 

As the design develops, in parallel, I generate a projection of the folded assembly into a flat component that will eventually be used to create the etch artwork. The CAD software "unwrap" function comes into it's own as it is possible to project the edge curves of the solid onto a single plane and from that produce (extrude) a solid of the flat component. This includes all the fold lines and importantly takes across the length of the folds to automatically give the necessary bend allowance. The picture below shows the pony truck main frames in the folded and unfolded state. As both folded and flat models are linked or "associated" any changes made on the folded model are automatically made on the flat model.

 

 

The final picture shows the flat etch of the main frames on it's own which in time will be imported into another assembly of all the components. Each component can be moved around to get an optimum etch layout (i.e. using the minimum amount of metal) before the artwork is fixed and sent to the etcher.

 

[Horsetan]

Amazing.

 

Ask Mike to let you have drawings for the rest of the engine, and let's see etch design taken to its logical conclusion B)