Silicon ChipMaking Front Panels For Your Projects - February 1999 SILICON CHIP
  1. Outer Front Cover
  2. Contents
  3. Publisher's Letter: Sending mail by email
  4. Feature: Installing A Computer Network by Bob Dyball & Greg Swain
  5. Feature: Traction Control Systems by Julian Edgar
  6. Project: Low Distortion Audio Signal Generator; Pt.1 by John Clarke
  7. Order Form
  8. Feature: Making Front Panels For Your Projects by Ross Tester
  9. Project: Command Control Decoder For Model Railways by Cam Fletcher
  10. Product Showcase
  11. Serviceman's Log: The set that languished and died by The TV Serviceman
  12. Feature: Radio Control by Bob Young
  13. Book Store
  14. Project: Build A Digital Capacitance Meter by Rick Walters
  15. Project: A Remote Control Tester by Leo Simpson
  16. Back Issues
  17. Feature: Electric Lighting; Pt.11 by Julian Edgar
  18. Project: LEDS Have Fun by Leo Simpson
  19. Vintage Radio: The classic Atwater Kent Model 32 by Rodney Champness
  20. Notes & Errata: Turbo Timer
  21. Market Centre
  22. Advertising Index
  23. Outer Back Cover

This is only a preview of the February 1999 issue of Silicon Chip.

You can view 34 of the 96 pages in the full issue, including the advertisments.

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Items relevant to "Low Distortion Audio Signal Generator; Pt.1":
  • Low Distortion Audio Signal Generator PCB patterns (PDF download) [01402991/2] (Free)
  • Low Distortion Audio Signal Generator panel artwork (PDF download) (Free)
Articles in this series:
  • Low Distortion Audio Signal Generator; Pt.1 (February 1999)
  • Low Distortion Audio Signal Generator; Pt.1 (February 1999)
  • Low Distortion Audio Signal Generator; Pt.2 (March 1999)
  • Low Distortion Audio Signal Generator; Pt.2 (March 1999)
Items relevant to "Command Control Decoder For Model Railways":
  • Model Railway Command Control Decoder PCB patterns (PDF download) [09101991/2] (Free)
Articles in this series:
  • Radio Control (January 1999)
  • Radio Control (January 1999)
  • Radio Control (February 1999)
  • Radio Control (February 1999)
  • Model R/C helicopters; Pt.3 (March 1999)
  • Model R/C helicopters; Pt.3 (March 1999)
Items relevant to "Build A Digital Capacitance Meter":
  • Digital Capacitance Meter PCB patterns (PDF download) [04101991/2] (Free)
  • Digital Capacitance Meter panel artwork (PDF download) (Free)
Articles in this series:
  • Understanding Electric Lighting; Pt.1 (November 1997)
  • Understanding Electric Lighting; Pt.1 (November 1997)
  • Understanding Electric Lighting; Pt.2 (December 1997)
  • Understanding Electric Lighting; Pt.2 (December 1997)
  • Understanding Electric Lighting; Pt.3 (January 1998)
  • Understanding Electric Lighting; Pt.3 (January 1998)
  • Understanding Electric Lighting; Pt.4 (February 1998)
  • Understanding Electric Lighting; Pt.4 (February 1998)
  • Understanding Electric Lighting; Pt.5 (March 1998)
  • Understanding Electric Lighting; Pt.5 (March 1998)
  • Understanding Electric Lighting; Pt.6 (April 1998)
  • Understanding Electric Lighting; Pt.6 (April 1998)
  • Understanding Electric Lighting; Pt.7 (June 1998)
  • Understanding Electric Lighting; Pt.7 (June 1998)
  • Understanding Electric Lighting; Pt.8 (July 1998)
  • Understanding Electric Lighting; Pt.8 (July 1998)
  • Electric Lighting; Pt.9 (November 1998)
  • Electric Lighting; Pt.9 (November 1998)
  • Electric Lighting; Pt.10 (January 1999)
  • Electric Lighting; Pt.10 (January 1999)
  • Electric Lighting; Pt.11 (February 1999)
  • Electric Lighting; Pt.11 (February 1999)
  • Electric Lighting; Pt.12 (March 1999)
  • Electric Lighting; Pt.12 (March 1999)
  • Electric Lighting; Pt.13 (April 1999)
  • Electric Lighting; Pt.13 (April 1999)
  • Electric Lighting, Pt.14 (August 1999)
  • Electric Lighting, Pt.14 (August 1999)
  • Electric Lighting; Pt.15 (November 1999)
  • Electric Lighting; Pt.15 (November 1999)
  • Electric Lighting; Pt.16 (December 1999)
  • Electric Lighting; Pt.16 (December 1999)
Items relevant to "LEDS Have Fun":
  • LEDs Have Fun PCB pattern (PDF download) (Free)
Producing Perfectly Professional Project Panels for Peanuts By ROSS TESTER One of the questions we’re often asked here at SILICON CHIP is “how do you make those great‑looking front panels on your projects?” The answer: We cheat! Every project, whether it's one published in a magazine or one you design and build at home, needs a dress panel. Dymo labels have their place . . . but not on a front panel! However, we’ve seen these – or worse, hand lettered panels – on many projects over the years, including some submitted to us for publication. It might be a brilliant design but it looks cheap and nasty. If only the designer knew how easy it was to make it look professionally built! We make our front panels using basic resources which the vast majority of readers would either have, or have access to. And once you know how simple it is to make a professional looking front panel, you’ll never again have an excuse to leave that project in an “almost finished” state. So how do we do it? And more to the point, how can you do it? Believe it or not, few of the projects you see published in SILICON CHIP now have a metal dress panel (that's the external panel you see, not to be confused with the inner panel which usually is metal or plastic). Once upon a time, of course, virtually all dress panels were made of metal – usually aluminium. Older readers may remember a product called “Scotchcal”, made by 3M and introduced more than twenty years ago. There were many variations of Scotchcal, the most popular being a photosensitive aluminium sheet with Here's a close-up of the dress panel of our new Audio Signal Generator featured elsewhere in this issue. Bet you didn't realise that panel is made out of paper, did you? 34  Silicon Chip a self‑adhesive backing. A piece of Scotchcal was exposed to UV light through a negative or positive film which contained the image of the panel required. Slosh‑developed using a proprietary developer and cotton balls, a quick, easy and very professional front panel resulted. After drying and coating with a thin spray of clear lacquer, the adhesive backing was removed and the panel was stuck in position on the case, ready to be drilled, cut or shaped as required. Why are we telling you all this? For two reasons – one, it leads on to the way we are making panels today and two, because many readers would be unaware of the detail it took to present good looking projects. Sadly, Scotchcal went off the market. There were a few similar products which appeared and disappeared over the years, a recent one being Dynamark. But even that became difficult to obtain – even for a magazine which was able to buy in reasonable quantity. For the reader, wanting just a small sheet for the very occasional panel, it was nigh impossible. Incidentally, we’ve heard rumours that one reason products such as these went off the market was the suspicion that some of the developers used contained some quite nasty ingredients – you know, the ones that make laboratory rats and mice grow spare heads and that sort of thing. Anyway, back to the story: the difficulty in obtaining these products made us start looking for alternatives. As you might expect, we design our panels on computer “in house” to suit the project under development. We either use a CAD package or more usually, a graphics package. As well as printing, these programs have the option of outputting files in a variety of ways, not the least of which is as a file which another service provider, such as a specialist panel maker, can handle. For example, in a commercial process, the file might be used for making a silk screen, allowing mass production. Not surprisingly, one‑offs using this method are prohibitively expensive. Scratch that idea. There were other options available to us, particularly through the people who put together kits for our projects. But we were looking for a viable method for our readers. If you’re not reproducing a panel from the SILICON CHIP website or photocopying one from the magazine, you’ll need to draw up your own. The easiest way is with one of the commercial graphics packages now available. A tip: if making a “reversed” panel (such as shown here, white type on black background), prepare it first the other way around (black on white) and either reverse everything when it's finished or print it as a negative. For a while we tried photographic images, using the same type of high‑ contrast photographic paper used extensively in the printing and graphic arts industry. While these worked reasonably well, they had a major disadvantage. Even if the paper was properly “fixed”, in time the image started to fade. While good enough for a short term solution, after a time we had to replace the front panel. Scratch that idea as well. In recent years, a couple of other products have come onto the market. They looked promising at first but (at least the ones we tried) proved too fiddly; too difficult to achieve consistently acceptable results. Scratch them, too. The along came the laser printer. The first models didn’t produce a great Here is our paper label, laser-printed directly onto standard 80gsm bond. Compare this to your screen image to make sure nothing has gone awry. February 1999  35 Ready to start with everything we need: we have the label, a roll of clear self-adhesive plastic, a sheet of thick cardboard, a can of spray adhesive, a sticky tape dispenser, a clear plastic rule and a surgeon’s scalpel fitted with a new blade. We also had an old newspaper handy for the overspray from the spray glue. The light box is handy but is certainly not essential. black but in recent years, laser printers have made great progress in this area. In a properly adjusted, modern laser printer, blacks are solid, dense blacks and whites are just that – white. For a while, we played (for want of a better word) with clear film designed for laser printers. Perhaps this could be used? Try as we might, though, we could never get the blacks on the film to match anything like the rock-solid blacks on plain paper. Scratch that idea. But this started us thinking (always a bit of a worry, that . . .). If the blacks on paper were so good, could we simply use a laser print of our front panel artwork? Would it need special paper? Would it be accurate enough? How would we protect the surface? How would we stick the panel on? After some experimentation, we came up with the answers to those questions (which in order are yes, no, yes, read on and read on!) and in the process came up with a dead simple yet highly effective method of making dress panels. Well, it must be highly effective – because it’s managed to fool most Stick the label back down onto the cardboard again and commence cutting out the internal holes with straight edges. Another tip: use a cheap plastic rule because, no matter how careful you are, you’ll take nicks out of it. And most important, be extremely careful when using a scalpel against a rule. The photos do not quite show a superb scar on my finger, still there after twenty years, from doing exactly what we have photographed. I learnt the hard way (the irony is I was cutting out artwork for a safety sticker!). 36  Silicon Chip Fix the label to the cardboard using sticky tape on the edges. Cut a piece of contact slightly larger than your label and remove its backing paper. Commence sticking the contact to the label from one corner, using your flat fingernail as a burnisher. Burnish diagonally back and forth, working to the opposite corner of the label removing any air bubbles as you go. Burnish to a consistent finish. people into believing we have discovered a secret source of Scotchcal or Dyna-mark material! The laser print Obtaining dense blacks and white whites were only part of the equation. We also needed to ensure that (a) the laser print was dimensionally quite stable (ie, it didn’t stretch or shrink markedly in one or both directions) and (b) that the printer didn’t leave any heater or wheel marks or other imperfections on the surface (which can happen on solid sections). When cutting circles, it’s much easier to hold the scalpel in roughly the same spot and rotate the work underneath. You need to be quite accurate when cutting small holes, especially ones not covered by knobs or large nuts. Finally, cut the panel away out of the paper. Again, be careful cutting against the rule! You might prefer to use a metal rule but you can’t see underneath a metal rule and it’s also easier for the blade to run up the metal edge and into your finger. If you have any air bubbles in the plastic film, they can be removed by piercing them with the very tip of the scalpel blade and burnishing out with your fingernail. It is essential that the blade be very sharp with only the faintest nick in the surface. Imperfections can also be hidden with a black felt-tipped pen. It took a little mucking around with the density control on our laser printer but eventually we were able to achieve the results we wanted. And no, we didn’t have to use any special paper – we use the standard 80 gsm five-dollar-a-ream bond paper all of our laser printing is done on. Not only that, we were able to duplicate the results using a photocopier. As long as your copier is capable of dense blacks with no streakiness or marking (either in the blacks or whites) you can use your copier to make panels. That means the front panel artwork Unstick the label from the cardboard, turn it over and stick another sheet of plastic film on the opposite side. Use the same techniques (eg working from one corner, etc) but you don’t have to be quite so careful with the back because it won’t be seen. Any air bubbles, though, should be removed. we almost always publish in SILICON CHIP can be the basis for your panels! Protecting the surface We first tried a number of spray‑on products but, without exception, they weren’t up to the task. They allowed the panel to be marked or scratched too easily. The penny dropped one night when I was putting the cutlery away in the kitchen drawer after washing up. (OK, darling, I lied. When I was watching you put the cutlery away . . .). I looked at the self‑adhesive plastic All cut out – and ready for gluing. Use plenty of newspaper because spray glue does just that – sprays everywhere and glues! There are many types of spray glue available; we used 3M 75 Repositionable Adhesive – it allows you to move the panel after placing in position to get the fit just right. Don't use too much spray glue – a little goes a long way. Most spray glues also require the nozzle to be cleaned after use by spraying the can upside down for a short period. covering on the shelves and noticed how little it was damaged – even with continuous use. Was that plastic covering available in clear (as distinct from the most attractive floral pattern in the cutlery drawer, which might tend to detract from a front panel)? I contacted a couple of suppliers and confirmed that it was indeed available in clear. To be truthful, it’s more translucent than clear but that’s actually an advantage, as we will see shortly. We printed a few front panels from artwork we’d done and proceeded to Speaking of fit, a light box is handy (though not essential –an outside window and daylight also works) to check the line‑up of your panel holes to the underlying holes. If necessary, peel the label off and re‑stick it. If you find that some holes are just slightly out, try placing the knobs etc in position and check the "fit" – perhaps a little bit of error won't matter. February 1999  37 PRODUCING PANELS FOR YOUR OWN PROJECTS This method of producing panels is just as applicable to your own one-off projects as it is to published magazine projects. Design your panel to suit your project, PC board layout and so on, drawing a rough version on paper. Draw any knobs, switches, meters or other components approximately right size so you get a feel for their positioning (and also to make sure nothing is over the top of anything else!) Some designers like to cut out little circles and shapes representing the front panel components so they can move them around to get the most pleasing “look”. It’s up to you. You don’t have to be a Michaelangelo – the panel simply needs to look good but also be functional. Sometimes you will design a dress panel to fit an existing case or panel layout. That’s another option. When you are satisfied that everything is where you want it on your rough, carefully measue and mark your drawing with the sizes of component holes (yes, the holes, not the size of its knob or nut, etc), then also dimension it so that everything is fixed in position. Now’s the time to start work on your computer. As mentioned before, we generally use a graphics program such as Corel Draw to prepare our panels. There are lots of similar programs to choose from – just as long as it allows you to accurately place components to a measure. If you don't have such software, there are loads of shareware graphics programs available on the web. Alternatively we've seen superseded versions of big $$$ commercial software selling very cheaply in all sorts of places – eg, genuine new Corel Draw 5 for $19.95 at Woolies supermarkets just after Christmas (current version 8 sells for $1200+). Regardless of whether you want your final panel positive (black type on white background) or negative (white type on black background) you will find it much easier to design your panel as a positive image, then reverse it later. We generally draw the outside of the panel to size, then pull down guide rules (vertical and horizontal) to the positions of our front panel controls. It is usual (for best appearance) that as many controls as possible are located on the same vertical and horizontal lines, so guides make it easy to place components in a line. Place circles, rectangles, etc, the same size as holes in the underlying metal or plastic panel or case (not the same size as the knob or switch nut!). At the centre of the hole we usually place a cross‑hair target to make final location and gluing easy. A tip about type: one easy way to ruin a good looking panel is to use too many type fonts. Have a look at commercial panels and those published in the magazine. With rare exceptions, you’ll find a bare minimum of fonts used – often just one, with perhaps a second (more decorative?) font for the name. If a logo is used, it’s important to choose a font that neither clashes nor competes with it. Also, for normal panel labelling it’s better to stick to the basic fonts. Normally, serif fonts (which have little tails on the tops and bottom of the letters like this) are best left to “body copy” or printed matter like this magazine. On a panel, it’s much more pleasing to the eye to use one of the “garden variety” sans‑serif fonts (which look like this – notice, no tails?). Fonts such as Helvetica, Arial, Dutch, Futura or similar are fine. What if you want a negative image (ie, white type on a black background)? If you are drawing up your own panel, it would be rare these days to find any drawing or imaging software which would not allow you to print a negative image. If downloading from the website, Acrobat Reader can also print negative (File- Print- Setup - Properties- Graphics- Print as negative image). 38  Silicon Chip cover them with the self‑adhesive film. It took a couple of attempts to get the technique right, particularly when it came to cutting out the holes for controls, switches, etc. Again, more of that in the step‑by‑step pictures. The advantage of a translucent film instead of a fully transparent film is that it looks much more natural. Indeed, our film‑covered front panels have the appearance of the matte aluminium panels of old, with a lacquer coating. Clear film looks, well, shiny and fake. The brand of the material we used is Raeco “Magic Cover” but there are many others available. It’s actually sold as clear book covering and is available at most department stores, stationers and even supermarkets. Woollies have 1.5m rolls for less than a dollar (they even have it in translucent colours. Now there's a thought!). The method of applying the film and the equipment to do it also took some experimentation. After trying a variety of burnishing tools (to evenly apply the film), in the end we came up with a “digital” instrument which is free of charge. It won’t take long to find – just look down your arm at those long pointy things. Notice the hard bits on the tips? Yes, your flat fingernails make ideal burnishing tools! (Of course, if you bite your nails you’re gonna get scratches). Cut it out! Cutting the panel out (actually cutting the various holes) is perhaps the most difficult part of the whole operation. Remember, you need to cut through two layers of plastic and one of paper. The most difficult things to cut out are small circles for mini panel switches and the like. They have small nuts so any slip you make is likely to be visible. The most essential ingredient is a v‑e‑r‑y sharp knife. A typical hobby knife is not really adequate for the task. We use a surgeon’s scalpel with a new blade. Just be careful – you know why surgeons use them! Where a straight cut is involved, don’t use scissors. Always use a knife and a guide to make sure you get the cut straight. No matter how good you think you are with a pair of scissors, straight cuts aren’t! Another tip: when choosing front panel components for your projects (eg, panel meters), if possible go for the And here is the finished panel, ready for final assembly. When you are assembling the project, take extra care when placing the panel into a slotted case or when tightening nuts on pots and switches. one with an escutcheon or surround to hide edges. Stick it, by gum! Our first attempts at gluing the panel to the case where slightly less than successful because of the type of glue we were using. Again, we experimented to find the right one. What we required was a glue which will stick to anything – metal, plastic, paper, you name it – and one which wouldn’t shrink as it dried. And there weren’t all that many glues which will do that without causing damage to the panel. I then cast my mind back a year or twenty to a glue commonly used in the graphic arts industry (before computers were invented) – spray adhesive. It’s not cheap but what the hell, we bought a can of it and tried it on a paper panel . . . with instant failure. Our good‑looking panels suddenly looked awful! The problem was that the glue “bled” right through the paper label, turning it into, well, it’s hard to explain. But it wasn’t the effect I was looking for. How could I stop the glue bleeding into the paper? The answer turned out to be right under my nose: the self‑adhesive plastic sheet. By placing a piece on the back of the label as well as the front, a plastic/paper/plastic sandwich if you like, I solved the problem completely. Result: no more bleed‑through – and a more durable panel into the bargain! You don’t need much spray glue – just a couple of seconds is more than adequate. Don’t overspray or you will get runs of glue which might harden to become visible ridges. Speaking of pots and switches, their knobs and nuts can hide a multitude of sins. As you can see, the hole cutouts are no work of art but are hidden when the knobs and nuts are fitted. If you find a blemish which did not become hidden, a black Pentel pen can often fix it for you! Incidentally, there are several types of spray glue available. We use a “repositionable” glue which means you don’t have to be spot on when you first place the label on the case. If you have to move it slightly, you can. (Come to think of it, that was always a major hassle with Scotchcal and Dynamark – you couldn’t!). Softly, softly When assembling the project, great care must be taken to prevent damage to the panel. Needless to say, even a plastic/paper/plastic sandwich panel is not as tough as a metal one. The biggest problem is when doing up pot nuts, switch nuts, etc. If you’re not careful the nut or washer can “grab” the plastic and twist it, pulling it off the paper. This creates an obvious flaw. Fortunately, pot nuts usually have a knob over them to hide any minor imperfections; with small USING OUR WEBSITE PANELS As you probably know, front panels recently published in SILICON CHIP are now also published on our website: www.siliconchip.com.au These are normally in Adobe Acrobat format, ready for printing (if you don’t have a copy of Adobe Acrobat Reader, you can download a copy of it free of charge via our website). All you need do is print the panel out on a laser printer (or even a quality inkjet printer) for use as described in this article. switch nuts you have to be very careful indeed. Using tools such as spanners or pliers to do up nuts etc also requires care. Ensure the tool does not come into contact with the panel itself. Finally, be careful if your panel has to fit into slots, as in some of the two‑piece plastic cases commonly in use. You need to take your time, making sure that the edges of the panel go all the way down into the slot without creasing or folding. But still, even if you do botch it, a brand new panel is only a few minutes away, isn’t it? Having said all that, when completed, these panels with their plastic coating are surprisingly robust. The plastic can take quite a deal of punishment and has the advantage of being easily cleaned – a wipe over with a damp sponge and it’s as good as new. Just remember, though, that the edges of your panel are not sealed so if any water gets in you might find yourself making a new panel! (Naturally, the same comments apply around any holes cut in the panel). Another option? Since preparing this article a few other thoughts have occured to us. Notwithstanding the comments we made earlier about clear film looking a little fake, if you have access to a laminator it might be worth a try. Laminating would, of course, be even tougher than our self-adhesive plastic covering so would be even more durable. And while we haven't tried it, we cannot see any reason why the spray glue wouldn’t be just as effective on SC a laminated plastic. February 1999  39