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Allan Wakefield
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Discussion Starter · #1 ·
Discuss it properly.

Mecoprop began this in another thread so I moved it here to start this off..

QUOTE The single thing that would take any manufacture to the next and perhaps final level of body craftsmanship, would be provision of the finest of black lines between adjoining body panels. Those lines that are so difficult to produce accurately and finely enough that they don't simply look crude and crass, as so many do. I don't know if it's feasible as a factory option, but the first to do it RIGHT would set the standard forevermore.

The bonus of this difficult achievement is 'detail' that isn't subject to loss or damage in robust racing conditions, as are mirrors and other small parts.
 

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Allan Wakefield
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The question of body lines or 'shut lines' has risen before and I think that the main technical problem is of colour or shade.

Pure black will always be too much on a model of this size and be overstated regardless of thickness. What is needed is a darker shade of the body colour and seeing as how this would change between liveries and also between colours on some liveries, I can't see it being feasible.

A few people know how or have stumbled on a good finish with shut lines in the past and I also had a lucky paint job where the yellow I used was too translucent to cover the grey primer and so the lines looked fair. However this WAS pure luck even though it sahows how a tone of the body colour is what's required..



The first I tried was this - WAY too thick and it shows how badly black works for this purpose, it is just too much contrast.. This is my 'Tron' Porsche




I have also tried using a brown shade Indian Ink (0.2mm is the thinnest I could find) for the red on this 959 but I just can't get the thickness and depth (inside the joins) right so they simply end up looking like bad lexan jobs too..



Talking of lexan, Russell? whose was that Great 962 lexan body over on SCI a long while back? That surely showed how great shut lines CAN be.
 

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the yellow car does look good, but if the manufacturers were going to do something amazing it would be better to make the moulding gaps thinner and deeper, or actually use seperate panels (as in the join of the front and back section of scaly gt40, or the under-door panel of the fly gt40, which look great)
 

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Astro is right about the separated panels doing the job perfectly and there are examples on the Scalextric Mitsubish rally car that look great too. The downside here could be whether those separate parts will stay on the car - they do on the Mitsu and maybe this could be expanded upon in future models.

Also right about the desirability of making the shut lines narrower and sharper in the original moulding, but I have some doubts whether this is feasible for the manufacturers. I have a feeling that if it were, they would have already done it, but maybe they are still working at this technique . . .

Black or dark gray as the color for lining, is imho, perfectly correct, IF it can be made fine enough. When I look at a real car, the final color fade in the lines looks near enough black to me as all reflected light is eventually eliminated. The problem seems to be with that great big IF! Fineness is the problem. The trick seems to be in scoring the existing line slightly deeper with a knife and wiping the ink or paint off again while still wet, yet retaining the tiniest line at the very bottom of the groove. It's a technique in which I have never managed any success, unfortunately, but I have seen successful examples by other people.
Jealous I am!
 

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Allan Wakefield
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Discussion Starter · #5 ·
Lets have some pictoral examples and seeif we can come up with a solution, if only for us to add at our leisure


I would not want all my cars done like this but some would definately be improved, unlike my sad Lucchini Porsche

Luckily it is a hit with the kids or it might have gone onto the shelf for a relivery otherwise.
 

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Mindful of the request to treat this one properly, I've never seen a truely successful execution of this. One that didn't make me think,

"Oh look, they've drawn the shutlines in."

Please God, the manufacturers never go down this route.

[Spock]
It's an opinion, Jim. But not as we know it.
 

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QUOTE Please God, the manufacturers never go down this route.
Done badly, I would agree, but done WELL, I would be 100% for it.
I think we need to clearly differentiate between those extremes.
Just because one may not have seen it done well doesn't mean it can't be done!
 

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Al Schwartz
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Just walked out to the garage and looked at the cars - one black, one silver - two observations: the largest gap that I saw was a bit over 1/8" or, in 1/32 scale, 0.004" or 0.1 mm - pretty small but, perhaps even more confounding is the observation that there is not one line (dark) but at least two and in some cases, three. One sees a highlight at the edge, a shadow in the recess (which may be abrupt or may shade from the highlight) and, depending on angle of light and view, sometimes another highlight on the other edge. Of course, on the black car, the panels are defined only by the highlights and, at best, a "lack of reflection" in the shadow areas. Furthermore, in my small sample, the highlight "lines" were much narrower than the shadow area whose width is already a struggle in scale.

A suggestion ( I have never tried this on car models but I did use it to simulate copper plating on ship model hulls) - try to create a discontinuity of reflection rather than an area of different color which will almost certainly be too wide - by scribing the panel lines with a fine pointed scriber or a heavy knife blade ground to broad but sharp "V" - the objective being to create a very narrow furrow with a slightly turned edge which will create a sharp shadow in the joint. The proof, as we would say in my teaching days, is "left as an exercise for the students" ( for the same reason that I no longer assemble parts with blind threaded 00-90 nuts and bolts!)

EM

(How long can age and guile hold out vs youth and enthusiasm?)
 

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Yes, on checking my 4-year old Vectra, the lines are averaging around 1/8" width.
I measured in mm at around 3.5mm, with some variations. Interesting to check assembly accuracy, with my boot (trunk) lid showing 2mm at one side and 7mm at the other - Belgian rather than British or German workmanship in this case, I think!

Anyway, agreed that this scales out near enough to 0.1mm and that's half the thickness of the finest marker Swiss has found to date.

I think some of the finest static modellers actually cut out some of the panels and then glue them back in, to create authentic gaps. The workmanship must be incredibly fine and also weakens the body, unless an additional fillet is then glued across the back of the gap. I wouldn't DREAM of attempting this cutting myself!

Regarding inked markings: on looking at some of the incredibly fine tampoed text and logos, this might actually be be a practical proposition for a high quality manufacturer. Equally, I'm not sure of the practicality of producing moulds with 0.1 mm lines that translate to truly vertical grooves in the body, which in turn create the shadows we want, rather than the usual V sections with too broad a radius that don't. The sharpness of these moulded lines does seem to vary quite a bit from maker to maker and Swiss's yellow Ferrari appears to have sharper definition than most, though it's hard to be sure from photos.

For a mass producer, other than the previously mentioned inked markings and finer etched moulds, I see two possibilities, one of which is feasible and the other is perhaps not. But let's throw the ideas on the table and kick them around.

Bodies could be designed with a flat inset for every opening or detachable panel. The panels - doors, flaps etc would be then glued solidly and strongly in place on those 'flats' afterwards, leaving authentic, sharply defined gaps. This would undoubtedly add to the manufacturing complexity and cost but COULD be done to good effect. Cost of extra body parts would probably outweigh the improved appearance though!

The other approach would be to produce MUCH simplified one piece bodies with NO panel line moulded in at all - bound to be cheaper to make. All panel lines would then be ground in by computer controlled routers with 0.1mm (or less) bits! I don't know if this miniature technology yet exists or what the cost would be. But possibly a better, more practical alternative could be precision laser etching.

You see, I suspect it may be easier to produce an accurate groove (negative 'pit') in the final body than it is to produce a corresponding line (positive 'land') in the mould that produces the body. But I could be talking nonsense, of course! Conversely, the beauty of an 'all in one' mould solution is that, although initially very expensive, it only needs making once, rather than extra, repeated procedures on every single body after basic moulding has been completed.

Does anyone have any direct access to any injection master mould makers? It would be FASCINATING to chat with one of these guys. How I would love to spend a day or two in the company of one! What a coup if we could persuade one to write us an article from his first hand experience!

OK, now pull my suggestions to pieces - that's what they are here for!
 

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QUOTE (Tropi @ 3 Dec 2003, 01:57 PM)Anyway, agreed that this scales out near enough to 0.1mm and that's half the thickness of the finest marker Swiss has found to date.
Have you tried a Rotring radiograph pen? - they go down to a 0.13mm nib. They're a technical drawing pen filled from a fountain-pen like cartridge so you could fill the pen with a different coloured ink. Bit pricey though, I paid about £16 for mine from Staples

Coop
 

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If it works on plastic, that's just the ticket.

£16 though . . .
If it works well enough, it's even worth the money - wonder if I can get one on sale or return!
 

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QUOTE (Tropi @ 3 Dec 2003, 02:35 PM)If it works on plastic, that's just the ticket.

I've been using for them on model paint for years - on little wargames figures to line edges of armour, do little slogans on shields that sort of thing. As for unpainted plastic - that might be a suck it and see sort of thing. They don't work on lexan, I've tried that to no avail.

Coop
 

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I think the problem is that the shut lines on our slot cars are too shallow and consequently too wide which is accentuated when you try to highlight them with ink or run a wash in them (eg, Swiss's red Porsche).
I'm sure most of you already know that model kit manufacturers such as Tamiya pay an amazing amount of attention to detail right down to individual rivets. The panel lines on a 1/43rd scale aircraft are very thin and actually quite deep. Running a scribe down them makes them deeper still and applying a wash to the lines (or inking them in, whichever you prefer) really does a fantastic job of highlighting the individual panels without ruining the appearance or scale of the aircraft. I can take some pics of what I mean if you like but someone will need to host them for me.

I havent seen any of the more expensive resin kits but I assume them to be more akin to kit manufacturers such as Tamiya.

So, to my point about slot car moulds....deeper/thinner panel lines can be done by the manufacturer quite easily but he will need to invest in costlier precision tooling.
My suggestion for the moment is to run a very thin scribe down the existing panel lines to try and get some depth into them. The resultant line should appear much thinner.

Try it out on a Scalleti Arrows first though, ok ?
 

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Al Schwartz
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I have had some experience with injection molding and can assure you that you can incorporate essentially arbitrarily fine detail, panel lines etc. into a mold HOWEVER, this carries a cost in mold material and machining, mold life and molding cycle times and resin. Referring to a comment I made above, some very high quality lenses and camera bodies are made by well known manufacturers such as Canon using injection molding.

Consider the problem of creating a 0.1mm wide by0.5mm deep panel line. Not only will the mold need to have a "fin" of something less than these dimensions (to allow for shrink) but the radius of the corners will be extremely small. This will not be a robust feature.

EM
 

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Unfortunately Tropi, my digital camera has no Macro facility so I can't offer any photos up - which would make a 'how to' feature rather weak...

I just tried it with a ProSlot 911 I was race-prepping this afternoon, using black ink with a .25 nib. It's a fairly subtle effect, probably because the car is the brown Prestat Truffles one so the black isn't that noticeable. THe ProSlot has fairly wide panel lines so the lines themselves have come out a bit wider than I would have liked. It took a few goes to complete each line, the plastic used is very greasy and flexible so the ink is probably only going to stay in place because it is sat at the bottom of a recess and tucked away from prying fingers.

It definately works well on painted cars, the paint surface gives the ink something to 'bite' at and it dries quickly.

Coop
 

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Russell Sheldon
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In the 60's we used to merely run black Indian ink into the door lines and wipe off the excess with a cloth before the ink dried. In most cases they did however look too thick.

On Lexan (polycarbonate) clear bodies, I use Rotring Isograph 'P' pens and Rotring 'P' ink, usually doing the detailing on both the inside and the outside of the body. The ink is indelible and etches into the polycarbonate.

The pens are expensive at around £ 20.00 each, but nibs are available separately at around £ 10.00 a piece. If looked after properly, they seem to last forever. Nibs are available in 0.10mm, 0.13mm, 0.18mm, 0.20mm, 0.25mm, 0.30mm, 0.35mm, 0.50mm and 0.70mm.

Here are some pictures of vac bodies done using a Rotring pen:







The Lister was painted by Piet Beukes.

Kind regards,

Russell
 

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if your planning on using drafting pens..such as rotring or faber castell try to get some nib cleaning solution to let the pen nib soak once your done... 0.13 draws the finest architectural lines on tracing paper..and if my memory serves well you can also get 0.1...HOWEVER..these things clog up very easily and the only way to keep them working is to let them soak in the pen nib cleaning solution overnight..which either rotring or faber castell sell...often a replacement nib =2/3 rds of the cost of the pen itself...
also...tie a piece of string around the pen and thie the other end to your wrist..it sounds extreme but when these things fall onto whatever surface..the pen tip is effectively useless...its handy to keep a piece of tracing paper handy to draw some random lines to get the ink lowing before going over to the panel lines on a model...safest ink to use is probabaly drawing ink....
from experience i find faber castell gives a better ink flow compared to rotring and are also cheaper..the pen "top"also has an inbuilt humidity sponge which you just add a drop of water to to keep the nib from drying out once the pen is sealed...rotring pens tend to develop a permanent "blob" at the tip once in use which can make the start of any line look like a drop of ink as opposed to a straight line...
i used to drop a nib on a drawing board at least once per weekfor three years in a row
...very expensive habit on a student budget..
hope it works
 

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Don't rattle my cage Tropi!

I'm mindful of the way this thread started and Swissracer's request to discuss it properly.

That said...

The R8 looks okay. Well the paint job, anyhow. Too much fiddly detail to really tell if the shell is blobby though.

The Lister? The Lister is interesting.

Ouch! Just drew blood biting my lip.

 
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