From info to finished model...

Share your build process step by step
Forum rules
Open to ALL SCALES!

1. Pictures of your starting materials. Choice of body, Chassis type and material (brass, plastic etc.)
2. Pictures of the tools you will be using, and any alternative ways to do the same thing. for example, tubing bender versus bent around a screwdriver handle. etc.
3. List where parts come from, or where they can be purchased from, or if they are homemade.
4. As many pictures of the build during the whole process as you can.

From info to finished model...

Postby Guildman » Fri Jan 13, 2017 7:44 am

Some here will already know me as a patternmaker. I now do it for fun and to keep my hand in. If I don't do it for a few days my hands seize up!

Anyway. I can probably best do this by showing more than one model as I always have a few on the go at one time. So I might show information on an Autobianchi A112 rally car, but master making on a Piper GTA and finishing on a TR2. Whatever I show it will show the whole process right through to screwing the chassis in to the body after priming and painting.

I hope it all works out and is informative.

To start with, you need information, references. I start with a google images search to familiarise myself with the real vehicle. Here a first word of warning....you may find that modern restorations, done in the best intentions, are often far from accurate. Little changes to details, even shape, can be a common factor, so try to get period pictures if you can. Not only will they be bang on accurate, but they'll likely be black and white which will always be more contrasty and therefore clearer. You can now view a complete online archive of Motor Sport magazines and there are no greater references than these. If you can find drawings, great, but often either what you can get are obviously wrong or at best a bit doubtful. Check them against published wheelbase, track and overall dimensions. Check those from more than one source if you can. They can be wrongly quoted too.
I find the old source of vintage slot racer-online is good for all the drawings that appeared in the old Model Cars and Model Maker magazines of blessed memory .http://www.vsrnonline.com/VSRN_Main.html
A more modern source is https://www.the-blueprints.com/ which contains thousands of drawings. There are others. You will possibly find some more if you google the car name followed by "drawings" or "dimensions". Such a search will probably send you to the very useful resource of Conceptcarz or http://www.ultimatecarpage.com/ These last two will have lots of lovely colour pictures of largely modern restorations, so enjoy, but be careful.

Next, I'll be going into the process of doing drawings from photos, where no drawings are available.

Cheers,
Martin
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Re: From info to finished model...

Postby BARC 1 » Fri Jan 13, 2017 8:54 am

Can't wait

Dan
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Re: From info to finished model...

Postby Guildman » Fri Jan 13, 2017 11:29 am

I have to do this in grabbed moments, so please allow for that.

Let's consider the achingly beautiful Morgan SLR.
Sprinzel Laurencetune Racing. Chris Laurence was the man who won his class in a basically bog standard Morgan Plus Four at Le Mans in 1962 against all wishes of the French who tried their best to stop him entering saying the car was "too old". Not too old to beat any French competition, eh?

So, here we have another of his attempts at sports car racing. I don't know if anyone knows who penned this gorgeous shape, but the famous Williams and Pritchard in North London made the bodies in ultra thin, lightweight aluminium.

To start with there was a Triumph TR4 based car. But three Morgan based cars were built. All 4 were very similar, but the TR4 chassised car was a few inches shorter and now wears a set of HUGE wire wheels and chubby boots. Yummy!

Now, we know the leading dimensions of the car because it is built on either the TR4 or the Morgan chassis, of either of which we know the wheelbase and track dimensions. Now, here I will risk offence by stating what to me seems to be the bloody obvious, but which I have seen done wrong often.
Wheelbase is the distance between the centre lines of the front and rear axles. Axle, in this instance taken to mean the centre of the wheels. Track, however, is the distance between the centres of the wheels, static, ACROSS the car. Static because the wheels on most cars get closer and further apart under braking, acceleration and cornering. The well tempered Klavier, as Herr Bach would have put it, moves as little as possible across its full range of inputs.

Now there is a thing of which I know only a little, called parallax. 'Tis summat to do with distortion caused by lenses of cameras. What happens is that the closer you get to an object the worse the parallax. It can actually "bend" the ends away from you and do all sorts of 'orrible things to the poor wee motor car. SO...the further away it is in the picture, the less distorted it is. Find such a picture at all costs. Do unmentionable things to get one and then use that as your reference point. Your main picture. Don't bother photo-copying it to "size" because it won't be. Just use it for the shapes as I shall explain.
Here is what you are after:-
Image
Oh be still my beating heart.
First on a clean piece of paper draw an horizontal line which will represent your ground, smoother and more straight than Lord March's best bit of tarmac. A few inches in, draw a vertical faintly from this line. Then at a scale distance away to the right, mark the wheelbase dimension and draw another vertical from that. There, now get yer chisels out....Oh! no, some more lines needed dammit.
OK, here's where a certain licence is required and it ain't one you can get from the Town Hall. You need to draw on those verticals a scale tyre on each. We can find out easily enough that the wheels will be 15"s. We must guestimate the tyre's
width as about 6". On old 100% ratio tyres, that means that the tyre will also be 6" from Freddy's tarmac to the outside of the tyre. That's 12 " PLUS the diameter of the wheel. Here we have again a bit of myth busting. Wheels that are said to be 15" AIN'T! They are something in the order of 16 1/2 " diameter on the extreme visible rim. The diameter is, for some reason as clear as mud, measured in the well of the wheel. And even in metric countries where Napolean's daft measurements system is preferred, it is still traditional to quote wheel and steering wheel diameters in inches, or Zoll in Germany, where, instead of saying that the steering column splines are Ein Zoll, they show them as 25.4mm!
So...we have 16 1/2" plus 12", gives us 26 1/2". That, in 1/32nd scale (I'm assuming most are using this scale) is 0.828125". Yeah we all have that on our pocket rules don't we? And so this is where the Napoleonics come into usefulness. 21 of Boney's best millimeters will be near as dammit. Much easier to use mm. where small sizes are concerned. Now draw two circles around a point 10.5 mm above the ground line on the wheelbase verticals. From here, it's all easy.

It's now my tea time and I'm not letting my wife's nice curry get cold for anyone!

Cheers,
Martin
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Re: From info to finished model...

Postby btaylor » Fri Jan 13, 2017 11:52 am

This is great. on the edge of my seat.
Good stuff Martin!

Bob
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Re: From info to finished model...

Postby Guildman » Fri Jan 13, 2017 12:29 pm

Thanks, Bob. My main problem will be taking good enough pictures as my camera only likes good sunlight. And I don't possess a Klevaphone with a camera in it. So pics of the process will be a bit difficult to get. For today, I may get something on paper to take some pics of. Or, having had a busy day I might just doze contentedly in the cumfy chair.

But I also have a V-12 250F master to put all the vents and holes in!

Cheers,
Martin
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Re: From info to finished model...

Postby Guildman » Tue Jan 17, 2017 11:41 am

Ok, Austin 7 Ulster master finished, so a quick few words on the drawing.
If you have a nice distant side view, like the one above, by all means go round it on screen with a pencil and a bit of tracing paper. In fact, if this looks possible (and I should have said), use tracing paper from the outset. Cooking greaseproof paper is fine.

I used tracing paper here.
Image

The wheel/tyre diameter is the same as a set of Mitoos p/e wires and their tyres, so that seems to me to be about right. 'Tis all yer got, folks, so go with it. The side shape is taken from the distant view and tidied up a bit. The plan view is an interpoation from the side view, but the width is front and rear track plus an allowance for tire width. BUT...I think it looks way too narrow, so I am sitting here checking Morgan Plus 4 dimensions, trying to work out why it looks so narrow. It will not stay like that because I am a firm believer in "if it looks right, it is right".

More of this anon.

Of course you now realise that the more of this stuff we get down, the nearer to physical hard graft we come. Saws, chisels, files and yes, even a bit of sandpaper if you really must! Of course we must, there's no other way to make a smooth curve. Even my cabinet maker Granddad had to use that in some small part and he was the one who told me, "Cut the wood, boy, don't scratch it, make it bleed to see the colour".

More when the width conundrum is sorted out. Ain't it good that after over 600 masters for model kits in my working life I can still be thrown a googly like this?

Cheers,
Martin
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Re: From info to finished model...

Postby Guildman » Tue Jan 17, 2017 5:00 pm

Aha, I now realise I gave that drawing initially the width of a Plus 4. I should have used the width of the Plus 4 Plus. That gives me a much more likely looking width, which I've drawn outside the earlier one.

Cheers,
Martin
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Re: From info to finished model...

Postby Guildman » Tue Feb 06, 2018 7:41 am

I really must apologise for suddenly disappearing like that, but non-hobby stuff got in the way and I lost my sign-in details and just sort of gave up trying. If the same people are still keen I can pick it up again from the point of having done a drawing. It may not be the Morgan SLR as I couldn't get anyone interested in producing it, or the Piper, but I still have them here if anyone changes their mind. However, there is usually a car being modelled or modded from another on the bench and I can go that route if preferred.

Cheers,
Martin
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Re: From info to finished model...

Postby waaytoomuchintothis » Tue Feb 06, 2018 11:10 am

Finegan beginagain! Just repost the photos and go full speed ahead!
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Re: From info to finished model...

Postby Guildman » Tue Feb 06, 2018 1:07 pm

I can show typical models in various stages. At present I don't have a full master on the go, just modifications of other stuff as favour jobs. But I can explain the principles.

I tend to use Ureol these days. In America it's known as Renshape. It's a variable density self skinning foam. Some is epoxy, some polyurethane. In it's truly rapid prototyping form it's like the popular sweat bar, Crunchy and in it's densest form it's like a hard milk chocolate colour, intended for 5 axis CNC machining, but very useful to us as it takes a good edge and can be worked with metalworking tools.

I usually make a solid master and that gets "slush" moulded, where a silicon rubber mould is made from the master and then polyurethane resin is poured into the open mould and slushed around, so that the resin makes a skin in the mould of, one hopes, an even thickness. Later, the windows will be removed with a dental burr in the mini-drill and finished with files and of course chassis mounting pillars must be decided upon. Many current shells are still done with this system as making inner mould halves for the extreme tuck under of say a 1 1/2 Litre F1car would be impracticable. A 2 part mould pattern is a lot more work to make as the master pattern has to be made to a regular thickness which takes a LOT longer to do, so I'll be speaking in terms of a slush moulding here.
That's it for now as I have to find some suitable pictures.

Cheers,
Martin
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Re: From info to finished model...

Postby Guildman » Tue Feb 06, 2018 1:10 pm

Just testing for uploading photos.
Ah, we're stumped then as I have no other hosting site but Photobucket and we know how that's turned out. Any suggestions? I thought the forum might have changed as so many have to enable photos to be drawn from one's own computer.

Martin
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Re: From info to finished model...

Postby Guildman » Tue Feb 06, 2018 1:12 pm

Hang on, maybe we're OK.....
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Re: From info to finished model...

Postby Guildman » Tue Feb 06, 2018 1:20 pm

Yes, good, I'd just missed how to do it. Well there is an example of a Capri. I did this for Mel Ault's TinTops range and I believe it is now in production. Here the photo-copy of the drawing is glued to the block of Ureol and it has been cut loosely around the outside on the bandsaw. For this particular car this is effectively it for the "Big cuts" as the car is essentially parallel and requires chisels and files.
If you have a car which needs to be cut in plan view, do that first as even with a shapely car there'll be less to cut than the side view so less problem sticking the side view to a cut surface than if you tried sticking a plan view to a cut side view.

OK, break to take that lot in. Now I know I can do photos, I'm happier.

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