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A place to aggregate discussion of drawing etch artwork, designing etches, sending off to etching companies and etching at home  split from the "Any Questions Answered" thread as clearly is not a simple Q/A.

 

Extremely helpful advice already provided by @2mm Andy , @Crosland , @Ian Morgan , @Caley Jim and @richbrummitt :

 

20 hours ago, 2mm Andy said:

 

You'll need to learn CAD or some other drawing package first if you haven't already. You can usually import images into the program and trace over the drawing, but this is usually a very good way of finding the inaccuracies/inconsistencies in the original drawings! Better to work from direct measurements if possible, but that depends if you have the information or if what you want to reproduce still exists in full-size form.

 

Bob Jones (of Fence Houses fame) also ran an etching seminar for 2mm members some years ago, and produced a series of handouts. I'm sure he would be willing to email them to you if you asked nicely.

 

PPD Ltd (who a lot of 2mm modellers use for etching) have some useful guides on drawing for etching on their website, and Grainge and Hodder do a information pack for £3.

 

https://ppdltd.com/

https://www.graingeandhodder.co.uk/photo-etching1.html

 

There also used to be some very useful online guides from an Australian company called Hollywood Foundry, but they closed last year and the website has unfortunately disappeared. I think I've got a paper copy of at least one of their tutorials somewhere - I'll try to find it.

 

Also worth studying etches from various sources to see how people have tackled problems. 2mm modellers are very good at coming up with ways to make assembly easier - Stephen Harris's more recent wagon kits are excellent examples of this, and pretty close to origami in metal at times!

 

Andy

 

19 hours ago, Crosland said:

 

Still available from the wayback machine https://web.archive.org/web/20170424131149/http://www.hollywoodfoundry.com/HowToPapers.shtm

 

There was also an article in the June 2013 2mm Magazine (members only link) http://www.2mm.org.uk/membersonly/backnumbers/2010s/2013/Jun2013.pdf#page=6 which has further links

 

 

15 hours ago, Ian Morgan said:

I have only created one etch. It was a tough learning job, and finding the required software without paying out any cash was another problem. Moreso, now that one of the programs I used is no longer free.

 

I ended up using one program to draw, another to create a good quality render in PDF and another to do intermediate file type conversions.

 

Not sure I remember all the programs I used. DraftSight was the drawing package, and DWGTrueView was used along the way.

 

Fortunately, my first etch worked first time :D

 

 

14 hours ago, Caley Jim said:

I too have a copy of Bob's notes which is what I used as a guide when I started out.  Any basic CAD package should be OK.  You can sometimes get older versions of them free.  This link came from a Google search for 'Free CAD programs'.

 

Jim

 

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Thank you for starting this William.   I think somewhere to place all the useful information and advice about the topic plus our own experiences will be a very good resource.   It's been done for 3D printing and, in other forums (fora?), for CAD/CAM and CNC so why not for etching.   Notwithstanding the march of time and technology, I firmly believe there is still a very solid place for etched metal in our hobby.  For one thing, bearing in mind some of my cackhanded efforts, metal will take a deal more abuse without becoming scrap than will 3D plastic.

Speaking for me, I am reasonably competent in driving a computer and have used several design packages that are a sort of halfway house between something basic like 'Paint' and full CAD suites like Turbocad and Autocad, examples being CorelDraw, Serif DrawPlus and Affinity Designer, so am happy working with Layers and other design tools.   Where I struggle is in mastering 3D work and, although I keep trying, do wonder if this bear of ageing brain will ever master it.   In some ways there is a usefulness factor, do I spend £x on a low end 3D printer or do I spend a similar amount on something like a Proxxon milling machine or a s/hand watchmakers' lathe, both of which may give me more utility.

Hopefully this thread will be a resource we can all benefit from.

 

John

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I use AutoCAD 2007, which a friend gave me.  I did Engineering drawing to Advanced Higher level at school 55 years ago, so I am familiar with the drawing principles involved.  For etching I now use PPD for a number of reasons.  In N/S they use 300mm wide metal and their minimum length is 150mm, both inclusive of a 10mm margin.  PEC, for example, only do A3 size and it takes a lot of 2mm stuff to fill an A3 sheet! (you pay the same whether the sheet is full or only has one etch on it).  Also PPD can take the files as I send them, whereas PEC seemed to have to split them into many other layers.  They would send me PDF's of the two films they had produced from my file and they were always full of errors which took several emails to sort out.   PPD, on the other hand have picked up errors (such as fills missing or holes being accidentally filled) and asked me to correct them before producing the films.  Their turn around time was also much quicker - used to be 10-14 days, but they quote 6 weeks now, which I think is due to Covid restrictions.  Prices per square cm of etch are similar.

 

The major cost is the production of the films to which you then add a much lower cost per sheet.  the more sheets you get from one set of films, the cheaper per item.  For example getting three sheets from a set of films will almost half the cost per item compared to one sheet.   It is, however, safest to get a trial sheet done first and assembling that, especially for your first few attempts, before committing to multiple sheets or sheets with multiples of the same item.

 

I create a separate drawing for the parts for each etch, then arrange them into a fret (on the same drawing) making the most economical use of space (which I often find is what sometime takes the longest time) and then copy that onto a separate drawing which is the file I send to PPD, again fitting them in as economically as possible.  Having said that for some things where I know I'm only going to be doing 'one-offs, such as my signal box or the footbridges and canopies for Dunallander, I just copy the parts straight onto the sheet.

 

For wagons I have a template drawing which has all the various basic parts I've drawn out for different wagons, W-hangers, underframe ends with coupling mountings, brake levers, etc. on it which I then just copy and paste into place.

 

I would recommend drawing up something small and simple to begin with and then seeing if someone is about to send off some artwork onto which it could be fitted.

 

Much more I could say, but I think that's enough for folk to digest at the moment.  Happy to add more if there are questions.

 

Jim

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I will probably surprise no one (including Jim) that my experiences with PEC and PPD are quite different than his. Like him I use a 'proper' CAD program, in my case TurboCAD, which to me has a user interface more akin to a standard Microsoft windows program than AutoCAD, which was around long before Windows and still shows the evidence of its command line interface origins, having said that they have added a lot of Windows functionality.

 

However, if you fancy turning your amateur efforts into a possible future career in CAD, AutoCAD is the one to go for because it is what the pros use. Which is why it costs an arm and a leg. If you get a free one offered, snap it up.

 

David Eveleigh introduced me to CAD design (he uses AutoCAD), and I still use the system of layers he taught me with a few tweaks of my own. It has served me well. I cannot get on very well with the more graphic design type packages, but it probably is down to your background and how you brain is wired. I break a single drawing e.g. a loco chassis into a lot of components which I can then position and/or repeat.

 

I draw each item in its own file and then collate them onto the production sheets. But I then turn them into front and rear PDFs myself, which I then converted to eps files. I send these to the etcher so they have no interpretation of layers and the like to do. And I can grahically check the sheets before I ever send them, as they are already at the final stage. Nor are there issues with incompatible format of CAD files. Perhaps that is where our experiences differ. PEC have etched over 150 different designs for me over 15+ years, with a total of around 1500 sheets produced (and counting).  There have of course been a few quality issues i that time, but not that many. The few sheets I sent to PPD in the same manner produced complaints that they were poor resolution, and things were drawn way to thin to etch successfully. Sent the same to PEC, they etched it fine. This is probably down to technical differences in the way the two etch (dip versus spraying), but anyway with PEC there is no need to account for any etching undercut ( at least on 10 thou material) which is a great blessing, I just draw the items at the size I want them. The few sheets I did do with PPD were of variable end quality, with a couple coming back with holes in half-etched areas. PEC use sheet material, whereas PPD use rolled, which I understand can cause some issues.

 

The outlay with PEC for a single sheet is significantly higher, they will do artwork for A4 size, however they double it up to produce an A3 sheet. And their artwork costs quite a bit more. Against this each sheet costs about half. The crossover point I think is around 4 sheets, higher than that and PEC works out cheaper. Turnaround is not that quick, varies between 1 and 3 months at the extremes. That probably tells you how popular they are with their clients.

 

I would concur with drawing something simple to start with. But if you plan to get someone else to put it on their sheet, find out how they draw, and do it the same. It is not plug and play to insert your design into someone else's sheet. Even when David E and I were using in essence the same drawing system, it took a bit of tweaking to put one of his designs onto a sheet of mine.

 

Chris

 

 

 

 

 

 

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8 hours ago, Doncaster Green said:

Thank you for starting this William.   I think somewhere to place all the useful information and advice about the topic plus our own experiences will be a very good resource.   It's been done for 3D printing and, in other forums (fora?), for CAD/CAM and CNC so why not for etching.   Notwithstanding the march of time and technology, I firmly believe there is still a very solid place for etched metal in our hobby.  For one thing, bearing in mind some of my cackhanded efforts, metal will take a deal more abuse without becoming scrap than will 3D plastic.

Speaking for me, I am reasonably competent in driving a computer and have used several design packages that are a sort of halfway house between something basic like 'Paint' and full CAD suites like Turbocad and Autocad, examples being CorelDraw, Serif DrawPlus and Affinity Designer, so am happy working with Layers and other design tools.   Where I struggle is in mastering 3D work and, although I keep trying, do wonder if this bear of ageing brain will ever master it.   In some ways there is a usefulness factor, do I spend £x on a low end 3D printer or do I spend a similar amount on something like a Proxxon milling machine or a s/hand watchmakers' lathe, both of which may give me more utility.

Hopefully this thread will be a resource we can all benefit from.

 

John

 

3D is a different matter, and probably should not be conflated with etching. I have not found the 3D functionality of classic CAD programs like AutoCAD and TurboCAD to be all that hot, and would definitely think about using programs that specialise in 3D, like Blender or Rhino (or others).

 

As to the 3D printer/Proxxon mill/Watchmaker's lathe debate, I went for all three, albeit several years apart! None get anywhere near as much use as my 'full-sized' pillar drill and Chinese lathe though, as they are all way too small and puny to fix stuff around the house.

 

Chris

 

 

 

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We (Judith Edge kits) use both PhotoEtch and PPD, quality and reliability much the same from both but PPD still usually a bit quicker. Almost all of our production work is with PEC and has been since we started. I draw everything in Turbocad but the etch tools are printed from .eps files. Working with PPD I send the eps version of my .tcw file directly to them but for PEC I get the films done myself, check them visually and post them on. The film work is done by Phillips Digital Printers in Letchworth, they send the films back the day after I email the files to them - I wish all our suppliers were as quick and reliable as they are! The cost is roughly the same either way, PPD a bit quicker but with the films here I get a second chance to check for errors, usually missing tags.

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As someone who used to play around at this for living way back in analogue days as an industrial photographer do I take it that the reference to ‘films‘ infers the photo etch ‘tools’ are still lithographic film sheet? I have often wondered since digital arrived whether the tools were now digital printed instead and no darkroom work was involved any longer although I have still read of ‘photo resist’ etching.
 

I must say I have often wished I could pop back in time and knock something out to make in the present when I’ve got stuck...!! But I’ve never got around to learning any CAD for present day work. Photoshop has been my limit...
 

Izzy

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8 hours ago, Chris Higgs said:

 

3D is a different matter, and probably should not be conflated with etching. I have not found the 3D functionality of classic CAD programs like AutoCAD and TurboCAD to be all that hot, and would definitely think about using programs that specialise in 3D, like Blender or Rhino (or others).

 

 

One fairly large player in 3D is Fusion360 from Autodesk.    There is a free version for hobby use, and varying types of paid license for commercial use, and a massive amount of online tutorials on how to use it.   There is an application on your computer, but its heavily cloud dependent, so does need reasonably regular access to broadband to update things related to the drawing in progress. 

Autodesk have just changed the features available on the free version, whether you adopt the Autodesk view ("we're stopping a few things to make it less sensible for commercial users to abuse the hobby free license, but it still does all a hobby user needs")  or the raging forum views ("Autodesk are evil, like a drug dealer giving you free shots then upping the price") is debatable.   I'm towards the former view.   I use Fusion360 for the 2mm loco wheel manufacture, with a lot of parameter driven stuff (so don't need to redraw wheels from basics to change diameter, spoke count, etc..).  

 

Another is SketchUp from Trimble (was originally a Google development).   I don't think the free one (almost totally cloud based) quite cuts the job for model making purposes, though could be used.   Its quick to learn, so might be useful as a beginner tool before moving to something else (the design course I teach at the OU uses it to introduce students to 3D design tools).   The commercial paid version would be usable.  

 

 

- Nigel

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50 minutes ago, Nigelcliffe said:

 

One fairly large player in 3D is Fusion360 from Autodesk.    There is a free version for hobby use, and varying types of paid license for commercial use, and a massive amount of online tutorials on how to use it.   There is an application on your computer, but its heavily cloud dependent, so does need reasonably regular access to broadband to update things related to the drawing in progress. 

Autodesk have just changed the features available on the free version, whether you adopt the Autodesk view ("we're stopping a few things to make it less sensible for commercial users to abuse the hobby free license, but it still does all a hobby user needs")  or the raging forum views ("Autodesk are evil, like a drug dealer giving you free shots then upping the price") is debatable.   I'm towards the former view.   I use Fusion360 for the 2mm loco wheel manufacture, with a lot of parameter driven stuff (so don't need to redraw wheels from basics to change diameter, spoke count, etc..).  

 

 

 

 

- Nigel

 

I tend to fear the latter view, having had similar experiences in another field with open-source software that stopped being so in a small way, but breaking a whole business model. We ended up implementing the whole feature ourselves. It only takes removal of one key feature from a free version to render it unusable for a certain set of customers. And given the paid price of Fusion360 is far from peanuts, that is a big issue.

 

I use OpenSCAD for 3D work, which is another approach altogether, basicially a style of programming langauge. and as you can download all the C++ code that comprises the program, I am able to even add a features to it if I want!

 

Chris

 

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1 hour ago, Chris Higgs said:

 

I tend to fear the latter view, having had similar experiences in another field with open-source software that stopped being so in a small way, but breaking a whole business model. We ended up implementing the whole feature ourselves. It only takes removal of one key feature from a free version to render it unusable for a certain set of customers. And given the paid price of Fusion360 is far from peanuts, that is a big issue.

 

I use OpenSCAD for 3D work, which is another approach altogether, basicially a style of programming langauge. and as you can download all the C++ code that comprises the program, I am able to even add a features to it if I want!

 

Chris

 

I am with Chris here. I have tried OpenSCAD, Sketchup, Designspark Mechanical, Fusion360 and Blender. Admittedly I am still learning that last 2, but OpenSCAD is most definitely my favourite. I find it less likely to produce  leaky meshes.

Reteurning to etching, I have no experience whatsoever, but the 2D CAD package I use is DoubleCAD  -a freebie from the TurboCAD stable. It appears to be positioned as a rival to AutoCAD LT.

 

Bill

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2 hours ago, Izzy said:

As someone who used to play around at this for living way back in analogue days as an industrial photographer do I take it that the reference to ‘films‘ infers the photo etch ‘tools’ are still lithographic film sheet? I have often wondered since digital arrived whether the tools were now digital printed instead and no darkroom work was involved any longer although I have still read of ‘photo resist’ etching.
 

I must say I have often wished I could pop back in time and knock something out to make in the present when I’ve got stuck...!! But I’ve never got around to learning any CAD for present day work. Photoshop has been my limit...
 

Izzy

Tools are still on film for what we do, I think there was a different process for two stage etching but we have never tried that. The few examples of two stage etching I've had to build have been fairly unsatisfactory.

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Just a quick note to say that it's not absolutely necessary to use CAD software for your etch artwork.

 

Coming from an illustrative/graphic design background, I find CAD software has a very steep learning curve and is not as simple to use (for me) as 2d drawing software. On the occasions that I have had etches made by PPD I have used Adobe Illustrator to good effect. Files need to have clearly labeled layers and can be sent as native Illustrator documents. Of course, Illustrator is expensive and now has the disadvantage of being subscription based. As an alternative I would use Affinity Designer, which is also professional software (and a bargain at £55), and export as an .eps or .pdf.

 

Whatever software you use, it pays to take your time and to check, double check and check again that your drawings are correct before sending them. That'll save you money and disappointment.

 

David

Edited by Kylestrome
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I am not sure what two stage etching means. For plate making for printing then etching is just of course one-sided, with separate plates for all the primary colours CYMK and achieved using colour separation. For the kind of etching concerned here then two tools are needed for etching through from both sides, so accurate registration is key as with 4-colour printing. This is also where the ‘cusp’ arises if the material isn’t given enough ‘cooking’ time. Of course the issue here is it might over-etch in places so is a question of balance, what is deemed more important. A bit like dodging and burning with negative and print production to get the right result over the entire image. Important here is also getting the litho film tool to the correct density. It is often described as being as ‘hard as nails’ and orange safelights are all that is needed, but can still be over-cooked quite easily. Often hand processing rather than automatic can be beneficial in experienced hands but it’s based on what is on the sheet. This and many other factors explains why one processor might be better than another for what is needed. 
 

Izzy

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58 minutes ago, Kylestrome said:

As an alternative I would use Affinity Designer, which is also professional software (and a bargain at £55), and export as an Illustrator document. There may well be other suitable drawing packages that are capable of exporting in Illustrator format:

 

David

Is that the .EPS export option.   I have Designer for both Windows and Mac and am beginning to get to grips with it and finding it a very useful and well featured package considering its price

 

John

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1 hour ago, bill-lobb said:

I am with Chris here. I have tried OpenSCAD, Sketchup, Designspark Mechanical, Fusion360 and Blender. Admittedly I am still learning that last 2, but OpenSCAD is most definitely my favourite. I find it less likely to produce  leaky meshes.

Reteurning to etching, I have no experience whatsoever, but the 2D CAD package I use is DoubleCAD  -a freebie from the TurboCAD stable. It appears to be positioned as a rival to AutoCAD LT.

 

Bill

 

You can use OpenSCAD for 2D etching stuff too, I don't but I think Alan Cox has.

 

Chris

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As chemical etching of brass is a 2D process then, to begin with, a vector image software such as Inkscape (open source - free to download and use) should be perfectly adequate.  Inkscape permits files to be saved in a number of commercially recognised formats if a professional printed mask is required for transfer to photo-resist film.

 

My initial attempts at home DIY brass etching have involved using a Silhouette cutter to produce a stencil mask on a 5 thou brass sheet that is then suspended, face down, in a Ferric Chloride/Citric Acid solution (see Edinburgh Etch).  For a first attempt this has produced reasonably satisfactory results, although the Silhouette cutter has a definite limitation concerning the minimum width of features such as glazing bars, and the adhesive stencil/mask approach will also have a limit of circa 0.4mm, below which the mask could have limited adhesion to the brass and allow mordant to seep under the stencil.  With fine features there's also the issue of the metal thickness to consider and the effect of cusping once the mordant has gone past the etch resist mask.

 

Presently I am having some frustration concerning the transfer of artwork to the brass, either directly via toner transfer or as a negative mask to a photo-etch resist film.  More experimentation required, but it appears that modern 'cheap' laser printers do not deposit as much toner on the paper as their predecessors, making the production of a UV opaque mask that much harder.  I think I may need to enlist the services of professional printers as noted by Michael Edge (above) to overcome this particular hurdle and successfully transfer designs to a photo-etch resist film by exposure to UV light.

 

20200927_203957.jpg.2f61656944d96d59e913649f50dab68b.jpg.6ee040dfceecb4a24bd05e3330bc2f1c.jpg  

 

An etch resistant mask is cut into stencil material pre-applied to the brass sheet (5thou) and weeded out prior to etching in an Ediburgh Etch - Ferric Chloride/Citric Acid mordant.  The stencil has already been 'weeded' to remove the mask from areas to be etched.

 

20200928_193355.jpg.e0d5845879f5d920b4a9dbe05ddbb11b.jpg.b6147db5f2fc53fb05151543af441ae1.jpg

 

Freshly washed from the etching tank (a repurposed plastic take-away food container) - TIP:  This is a single sided etch so a piece of transparent vinyl covers the back of the brass sheet to prevent etching on the reverse side.  The sheet is suspended face down in the mordant, which better allows oxidation to clear from the etched areas.  Using transparent vinyl/parcel tape allows you to see when the etch has broken through the sheet and avoid over etching.  It also removes the need for tags to hold parts onto the fret - the backing vinyl holds the parts in the fret until released by soaking the fret in Acetone.

 

20200929_002750.jpg.93423a294055ae48b9baad5fb00f93ad.jpg.6f1178c86c1b60842fc5f35cfe8e9096.jpg

 

Fairly satisfactory for a first attempt.  The stencil seems to have slightly variable width of the glazing bars, I haven't measured them with a Vernier as I fear the jaws might just snip through - it is only 5 thou brass after all, but they are certainly <0.5mm.

 

 

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3 hours ago, Michael Edge said:

Tools are still on film for what we do, I think there was a different process for two stage etching but we have never tried that. The few examples of two stage etching I've had to build have been fairly unsatisfactory.

 

I agree that photo resist UV sensitive film remains the principal method of getting the fret design on to the brass sheet.  However, things are moving in new directions and the pre-film techniques are still available but with the advantages of CNC tools with which to utilise them. 

 

Our cousins in the electronics hobby have been working on DIY printed Circuit Board production for years and can certainly show us much regarding etching techniques.  The latest transfer method I have seen concerns use of UV sensitive liquid resin used in 3D printing - a thin layer of resin is applied to the sheet and exposed to UV using the LCD/UV screen from a 3D printer.  After exposure the surplus (unexposed resin) is washed off leaving an etch resistant mask on the surface of the metal.  As these LCD screens are limited as to size then the size of brass sheet would be restricted.

Further - while still using UV sensitive film, a low power 405nm laser attached to a CNC frame, such as a desktop 3D printer, can be used to draw the design directly onto the photo-etch resist film giving a level of granular detail that is quite mind-blowing. 

An  engraving laser (stronger than the 405nm laser) can be used to remove paint (or other etch resist) from a brass sheet, similarly a normal metal engraving tool can be used to scratch away the resist, suitable detail and accuracy can now be achieved with a low cost Chinese 3018 CNC machine or a 40W Chinese CO2 laser.

StazOn spirit ink and Sharpie/Permanent Marker inks provide an etch resist on the metal surface - the fret image can be drawn directly onto the brass sheet (StazOn ink can be used in a lining pen) and the sheet etched once the ink has dried.

   

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3 hours ago, Izzy said:

I am not sure what two stage etching means. For plate making for printing then etching is just of course one-sided, with separate plates for all the primary colours CYMK and achieved using colour separation. For the kind of etching concerned here then two tools are needed for etching through from both sides, so accurate registration is key as with 4-colour printing. This is also where the ‘cusp’ arises if the material isn’t given enough ‘cooking’ time. Of course the issue here is it might over-etch in places so is a question of balance, what is deemed more important. A bit like dodging and burning with negative and print production to get the right result over the entire image. Important here is also getting the litho film tool to the correct density. It is often described as being as ‘hard as nails’ and orange safelights are all that is needed, but can still be over-cooked quite easily. Often hand processing rather than automatic can be beneficial in experienced hands but it’s based on what is on the sheet. This and many other factors explains why one processor might be better than another for what is needed. 
 

Izzy

I don't really know anything about it, just what I was told by PEC years ago. Normal process is a front and back film, where the two coincide all the material is etched away.

The time in the etch is obviously variable and presumably done by time/eye/guesswork - our production etches do vary quite a bit but I am very often pushing things to the limit. PPD usually tell me I'm over (under?) the limit but they generally work out OK and we mostly use them for test etches anyway.

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2 hours ago, Collett said:

As chemical etching of brass is a 2D process then, to begin with, a vector image software such as Inkscape (open source - free to download and use) should be perfectly adequate.  Inkscape permits files to be saved in a number of commercially recognised formats if a professional printed mask is required for transfer to photo-resist film.

 

My initial attempts at home DIY brass etching have involved using a Silhouette cutter to produce a stencil mask on a 5 thou brass sheet that is then suspended, face down, in a Ferric Chloride/Citric Acid solution (see Edinburgh Etch).  For a first attempt this has produced reasonably satisfactory results, although the Silhouette cutter has a definite limitation concerning the minimum width of features such as glazing bars, and the adhesive stencil/mask approach will also have a limit of circa 0.4mm, below which the mask could have limited adhesion to the brass and allow mordant to seep under the stencil.  With fine features there's also the issue of the metal thickness to consider and the effect of cusping once the mordant has gone past the etch resist mask.

 

Presently I am having some frustration concerning the transfer of artwork to the brass, either directly via toner transfer or as a negative mask to a photo-etch resist film.  More experimentation required, but it appears that modern 'cheap' laser printers do not deposit as much toner on the paper as their predecessors, making the production of a UV opaque mask that much harder.  I think I may need to enlist the services of professional printers as noted by Michael Edge (above) to overcome this particular hurdle and successfully transfer designs to a photo-etch resist film by exposure to UV light.

 

20200927_203957.jpg.2f61656944d96d59e913649f50dab68b.jpg.6ee040dfceecb4a24bd05e3330bc2f1c.jpg  

 

An etch resistant mask is cut into stencil material pre-applied to the brass sheet (5thou) and weeded out prior to etching in an Ediburgh Etch - Ferric Chloride/Citric Acid mordant.  The stencil has already been 'weeded' to remove the mask from areas to be etched.

 

20200928_193355.jpg.e0d5845879f5d920b4a9dbe05ddbb11b.jpg.b6147db5f2fc53fb05151543af441ae1.jpg

 

Freshly washed from the etching tank (a repurposed plastic take-away food container) - TIP:  This is a single sided etch so a piece of transparent vinyl covers the back of the brass sheet to prevent etching on the reverse side.  The sheet is suspended face down in the mordant, which better allows oxidation to clear from the etched areas.  Using transparent vinyl/parcel tape allows you to see when the etch has broken through the sheet and avoid over etching.  It also removes the need for tags to hold parts onto the fret - the backing vinyl holds the parts in the fret until released by soaking the fret in Acetone.

 

20200929_002750.jpg.93423a294055ae48b9baad5fb00f93ad.jpg.6f1178c86c1b60842fc5f35cfe8e9096.jpg

 

Fairly satisfactory for a first attempt.  The stencil seems to have slightly variable width of the glazing bars, I haven't measured them with a Vernier as I fear the jaws might just snip through - it is only 5 thou brass after all, but they are certainly <0.5mm.

 

 

 

That is a nice idea with the printer, but somehow I cannot imagine getting an A3 metal sheet in a printer and getting both sides printed in exact registration for the kind of etching that will produce anyway complicated. So I suspect the industry will be sticking with films for the forseeable future.

 

Chris

 

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3 hours ago, Doncaster Green said:

Is that the .EPS export option.   I have Designer for both Windows and Mac and am beginning to get to grips with it and finding it a very useful and well featured package considering its price

 

Yes. I've just checked, and an eps from Designer opens perfectly in Illustrator (I wrongly assumed that Designer could save an Illustrator document). A pdf works as well.

 

David

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All I can say in defence of my original remarks is that I seem to have developed a method and found an etching company that works for me.  It produces etches that satisfy my requirements and also seem to satisfy those who have been kind enough to buy my kits (at least no-one has asked for their money back - yet!).   I have found that some fine detail (in my case signal ladder rungs) which etched OK with PEC, disappeared with PPD, but I find that anything down as far as 0.25mm (on 10thou n/s) works OK.  I just have to acknowledge to them that it is below their preferred tolerance.  As far as the cusp is concerned it is negligible on this thickness and Bob Jones in his notes says that it can be ignored.

 

I have seen one of David's files, but could not understand why there was a need for so many different layers, but perhaps that's down to me being a naïve bear of little brain in that respect.

 

Up until recently I was sending PPD front and rear files (with registration marks) but they've now said they would prefer that I just send the original file and let them sort it out.  They've never mentioned .eps files and I had never heard of them until this discussion.

 

All this goes to prove, I think, that it's another case of horses for courses and finding what works for you.  Whatever 'tool' you use to produce the artwork, the general principals are the same.

 

Jim

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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.

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1 hour ago, Caley Jim said:

 

 

I have seen one of David's files, but could not understand why there was a need for so many different layers, but perhaps that's down to me being a naïve bear of little brain in that respect.

 

 

 

Jim

Me too, I couldn't understand why David used so many layers. As he's a lot cleverer than me I just assumed he knew more about it all than I do.  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

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