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Building the Tamiya "Original Body"

 

It was an example of how to turn a sketch (in the style of many wedge shaped late 1970s/ early 80s sports and super cars - Lamborghini Countach, De Tomaso Pantera, Matra Bagheera, Bertone X-19, Triumph TR7, Lancia Stratos, Ferrari 512 Berlinetta Boxer etc, etc) into a finished RC car body to fit the 1/12 Tamiya RM (Racing Master) mk. v chassis from the 58049 Toyota Tom's 84C.

jr original body 001

In practice, the article (image 01) is heavy on photos & drawings, and very light on actual technique - but a set of detailed, scaled plans are included. I know the date of the Guide Books in question pre-date the internet, but I couldn't find any references to anyone actually making one - time to rectify that I think.

 

Getting Started

The first step for me was to decide what thickness of styrene sheet to use. Although the thickness of some parts is called out in the article (1.2mm for the rear wing, 1mm sheet & 2mm square beams for the engine grille, plus 0.5mm clear for the windows & 1.2mm for the rear lights) there's no mention of what the bulk of the pieces should be. You could guess at either 1mm or 1.2mm and not be too wrong I think, but I had 1mm and 1.5mm - and as the latter has proved to be a bit on the heavy side in my other builds, I went with 1mm.

Note: having now finished the build, I'm still undecided - 1mm sheet has made a shell that is reasonably lightweight shell, but could be a little fragile in use. 1.2mm sheet (if you can get it) would be a better choice. 1.5mm would end up being a lot more portly, but much more robust.

Next up was scanning in the plans, resizing them, juggling them around to fit A4 sized sheets of sticker paper, then juggling those printouts a bit more to fit them on to one and a bit sheets of A3+ styrene (image 02).

jr original body 002

Cutting out with a steel ruler, mat & basic small snap off craft knife dealt with most of the parts, but I did use a pointed scalpel & holder for the curvier bits. I left the sticker paper on so I could identify the parts as I needed them during construction (image 03), but this did mean I couldn't do the final edge finishing/sanding until I needed them.

jr original body 003

 

Fig.1

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This puts the front wings (fenders) and bonnet (hood) (or more accurately, luggage compartment cover, as this is meant to be rear engined) together. That's fine in theory, but I did find a few issues... part 6 is called out in the diagram where it should be part 7, there's nothing to indicate the position and angles of the internal bracing, and nothing to show how the panels fit together. The sides pretty much have to be butt joints, but where these join the top there's a choice of going underneath, or to the side of the large panels - I choose under, but that could have been wrong.
Note: it seemed to work out ok.

And then there's the standard of fit ... I know there are lots of places that errors could slip in so I was careful, but I had to do an awful lot of fettling. The centre rear sections of the wings (part 22) didn't match the flat on the bracing (part 7) and needed an angled slice taking off the bottom. It also didn't match the curve of the upper part (17) (image 05) so I had to Dremel that later.

The larger bonnet panel (part 3) didn't match the angles of the top of the wings & needed a portion (c.5mm) cutting off the bottom; and the lower panel (part 2) was so wrong after that I had to cut an entirely new piece. The underside (1) needed shortening, and the final infill part (21) was several mm short and probably only 1/3rd of the height needed.

I mention this not to complain, just to point out this really isn't a snap together kit. I think that if you have a little more experience under your belt, it'll come out OK in the end (image 06).

jr original body 005 jr original body 006

Reinforcing the joints isn't mentioned until Fig.3, but I knew I wanted to fill & sand before then so needed the extra strength. 5mm square is suggested, but that is impractical on the front end, so I used 80 though (2mm) square and 0.25mm sheet.

 

Fig.2

jr original body 007

This seemed to go more smoothly, or perhaps I was just getting more used to it. Still no mention of how to fit the sides to the top (I chose "under" again), and still a few issues with fit around the air intakes forward of the rear arches - the largest of them (I found out much later) being my misinterpretation of the placement of part of the air intake ducts (image 08). Although I suspected it was wrong & tried to just "tack" them in place so I could make adjustments later, they turned out to be too well bonded by the time I realised my mistake & are now a permanent part of the build.

jr original body 008 jr original body 009 jr original body 010

Internal bracing was again 0.25mm sheet & 2mm square, with 3.2mm square in a few places too (image 09). The structure looks very boxy at this point (image 10), but it turns out ok later.

 

Fig.3

jr original body 011

(This sees the two ends (image 12) (after a lot of filling & sanding) come together via door panels & lower sills, plus the addition of an engine cover & front wheel arch spats (image 13). That doesn't sound like a whole lot, but there's plenty of guesswork & fettling to do. My assumptions included:

  • bottom edge of the panel forward of the rear arches should be flat on the bench with the tail lifted;
  • rear edge of the front wing (fender) should be vertical - meaning the nose is lifted clear of the bench (this + the above makes bonding the doors & lower sills quite tricky);
  • front wheel arch spats fit under the arch - this will involve a lot of Dremelling back of excess material on the inside, and epoxy putty on there too;

jr original body 012 jr original body 013

Note: and, in hindsight, I'd assumed that because the parts were parallel/square, and mirrored left to right, that they'd go together true. This wasn't the case: somewhere an error crept in & the whole nose section has become subtlety rotated clockwise, meaning the left side of the nose is further forward than the right, and the bottom edge of the windscreen is lower and further left than it should be, and the right side too far left & a bit high. It's not clear which part(s) the issue stems from, all I can suggest is double checking the parts for squareness/mirror images & join the two ends on a board with square lines on it?

As previously mentioned, it became apparent that I'd got the positions of part 27 (angled strip on the fake air intakes forward of the rear arches) wrong (image 14) - it should have gone outboard to double up the thickness there, not where I'd put them doubling up the door thickness at the rear edge. It's quite obvious in hindsight, even looking back at Fig.2. Despite only "tacking" the parts together they were far too well bonded to come apart, so I'll have to live with it.

The engine cover I made with an oversize 1mm thick panel, and from looking at the finished photos, estimated dimensions of 70mm and 46mm for the 2x2mm square strip "louvers" (image 15). I'll glue that panel in after painting, for the moment it'll just be held in with tape.

Note: in hindsight, the base panel needs to be thicker, or at least weighed down until complete curing has taken place - mine warped (image 16) and had to be braced with a layer of 2mm styrene later on.

jr original body 014 jr original body 015 jr original body 016

At this point, according to the text, the body should be test fitted to the chassis, and the body post positions marked and drilled - but without a chassis, I had to skip that.

 

Fig. 4

jr original body 017

The roof pillar/side parts & roof go on, along with the top halves of the door sills. Photos of the roof suggest it should be one full size layer, a much smaller second layer, and a lot of filler, whereas the drawing, plan, and text show/describe it as two layers the same size, with the edges curved by sanding - which is what I did. All those parts fit reasonably well (although without bracing there'd be almost nothing holding them together), but the sill tops were another matter - considerable reshaping was needed (image 18).

There was a bit of a delay at this point for filling - this time with Milliput epoxy putty, which is great for blending/smoothing joints & seams as it can be wetted, then shaped with tools (or fingers), cutting the need for sanding afterwards. The trade off is a long (overnight) curing time.

jr original body 018 jr original body 019

Having completed all the filling and sanding (image 19), the text says that the body should be painted, but I really wanted to make & test fit the windows, rear lights & spoilers first, as shown in Fig. 5 and Fig. 6.

Note: in hindsight there are problems with squareness here too - despite everything looking square/mirrored, the roof has ended up rotated very slightly clockwise & shifted to the right. Again all I can suggest is double checking everything - including not trusting that the plans will give you parallel/truly square parts.

 

Fig. 5

jr original body 020

I scanned in, resized, then printed out the window pieces on light card ... they turned out to be very poorly sized, the front windscreen in particular was too tall and too narrow. Side windows were a little undersized, the rear I couldn't tell you as by that point I'd given up & was making my own templates for guidance.

Note: and it's very obvious to me now - making up for the alignment issues in the front end & the roof has resulted in an asymmetric windscreen where the bottom left corner has to be much further out that it should be - making the angle on the left side really obviously wrong.

 

Fig. 6

jr original body 021

I went my own way with the tail lights, cutting a 11.5mm wide strip of Lexan, shaping & folding the ends to suit the recess, and cutting discrete indicator (turn signal), rear light and centre panels, which I'll paint clear orange, clear red and "smoke" respectively before assembly. All the "glass" panels also need smoking - and require "synthetic rubber adhesive" to fix in place. I'm never quite sure what that means, that never really translates in to English English - do they mean the stuff out of a bicycle repair kit? Copydex? I ordered a fresh tube of Stormsure, that'll hold it.

Construction notes for the rear wing/spoiler suggest two layers of 1.2mm styrene, scored and folded at the ends, and mounted on 8mm clear tube with 4mm countersunk screws ... well, I got close to that. I had to use 1.5mm sheet, which required multiple, deep scores on each end to bend in a satisfactory radius. The two layers were taped & clamped up overnight (image 22), then the excess Dremelled off - along with some basic shaping, followed up with successively finer grades of wet & dry paper. For the supports I used styrene tube, cut at a slight angle - and lighter M3 fasteners as I'm sure they'll be more than adequate.

jr original body 022 jr original body 023

I also added 4 pieces of small bore pipe to reproduce the fake exhaust pipes shown in one of the Tamiya photos (image 23).

 

Painting (and Lining)

The main body, spoiler and engine cover all got a rub down with 1200 grit paper + wiping down & drying time before 2 coats of grey plastic primer.

After curing, they all got a very light rub down with 2000 grit paper, before two coats of generic metallic silver colour (Hycote 400ml "Aluminium Coat"). I did think about using a bright white, a la James Bond's Lotus Esprit (there's another "wedge" to add to the list), but thought I really ought to go strictly "by the book" in this case.

After curing baking time, I applied Kyosho "Micron" 0.7mm line tape to act as panel lines as per the photographs, and added the outline of pop up headlamps (image 24). Body, spoiler & engine cover were all clear coated following that.

The engine cover was given light coats of satin black, then the tops of the louvers lightly sanded back to reveal the silver colour underneath (image 25). Lights & "glass" pieces were painted as described above, with black outlines on the "lights".

jr original body 024 jr original body 025

Note: I'll buy an aerosol of TS "smoke" paint next time, rather than try to airbrush it - I just couldn't get a dense enough shade & had to resort to brush painting.

Short lengths (c.100mm) of 2mm square styrene I painted in Rubber Black ready for bracing the windscreen later.

 

Extras

Not mentioned in the text of the Guide Book, but clearly visible in the photos are "HYPER CAM ENGINEERING" decals on the sides of the body, "TAMIYA" on the left side of the tail, and further text on the right side of the tail which is unreadable, but almost certainly repeats the "Hyper Cam" legend.

These I replicated on transparent inkjet waterslide transfer paper, cleared over to make them waterproof - although I did change the right rear text to "Original Body" in a suitable font. I also added the two star Tamiya logo in black as a bonnet emblem.

The only other additions I made were fine mesh on the nose and side pods, plus Lexan front indicators and repeaters.

 

Final Assembly

There's really not much to say here: waterslide transfers and the spoiler are obvious enough; the lights I glued on with Canopy Glue; mesh parts with double sided tape, and the windows with the aforementioned Stormsure.

First the front windscreen had a thin bead added to the top & bottom outside edges & was held in with tape & small clamps (image 26), and the rear window fitted & the rubber glue added to the top & bottom edges on the inside.

Five or six hours later when that had set, the side windows & internal A pillars were added (image 27)... and this is where it started going horribly wrong - and not (just) because of the alignment errors previously mentioned - it's the wrong method to hold windows together/in. It becomes a nasty, sticky, smeary mess of a juggling exercise to hold everything in place - I ended up using a combination of tapes, blue tac, weights, and even a small drill bit in an Archimedes drill (image 28).

jr original body 026 jr original body 027 jr original body 028

Note: most of the smears on the windows and paintwork (left after the struggle to get it together & keep my hands clean) polished out ok.

 

Conclusion

I'm really struggling to know how to sum this up ... there are flaws in the design and method - and how I put it together, though I'm sure I could do a much better job now I know where the problems are. The result is a decent enough looking shell ((images 29 to 34), as long as you don't look too long or too closely (image 35).

jr original body 029 jr original body 030
jr original body 031 jr original body 032
jr original body 033 jr original body 034
jr original body 035

 

Update April 2016:

It's taken a while, but the "Original Body" is now sitting on a Tamiya RM chassis (a mk.VII from a 58052 Newman Porsche - which differs only in the body post materials as far as I can see) and fitted with the outer bumper from a 58059 Porsche 959.

 

jr original 012 001 jr original 012 002
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jr original 012 007 jr original 012 008

 

* Footnotes

Thanks to Lars for looking through all the RC Guidebooks to find which editions the "Original Body" appeared in.

There are also pages in the 1982 and '86 Japanese editions of the RC Guide Book relating to building a much more complicated body: the 1979 Brabham BT48, to suit the vintage F1 chassis (see image 36). It appears Tamiya even made some decals for it (see http://www.victor101car.com/tamiya-vintage-f1-decal-sheet-tyrrell-009-brabham-bt48.html).

 

________________________
Written by TB member Jonny Retro

Comments  
#1 yogi-bear 2015-08-08 08:04
that is awesome! Thanks for taking the time to build one. I wonder if anyone ever made the BT48?