More on the GT

Well i've been offline for around three weeks due to a malware attack on my PC. Twice in seven days! I managed to sort it the first time around but the second attack pretty much wiped out everything. Photographs, artwork for the photo etched parts, documents, the lot. So I had no alternative than to let a specialist have the machine and sort it all out. Luckily he managed to retrieve everything I thought i'd lost which is a huge relief.

The GT is now more or less as I want it although the PC problem has causes a little setback. One more cast part to make then everything can go off to be produced. The bumpers have been re-profiled as the constant polishing had thinned out the lobes at each end. The glazing formers are all done and each window fits very snugly apart from the rear screen. This for some strange reason is coming out with too much of a curve which at the moment i'm struggling to understand why. The dreaded headlamp covers turned out to be fairly easy to make this time round and fitted at the first attempt.

Decals for this one are also proving to be a problem as the guy who's been making them for me up till now has decided he does'nt want to carry on and he's not even answering emails. Oh well

The plan is to produce the kit in two versions. The 1959 Le Mans car which had scoops around the brake cooling ducts and an air inlet on the front offside wing just forward of the door. The other veriosn will be a road/race car with decals for the two Essex Racing Stable cars, 17 and 18 TVX. The colours for all of them of course are a source of mystery as ever, but they will all be varying shades of green. What esle did you expect?

Graham.

Ackermann Steering

The Ackermann steering principal was invented by the German ( no surprise there!) Carriage Company Lankensperger in 1817 and then patented by their agent Rudolph Ackermann in England. Why this system was worked out and applied to a horse and cart, I really have no idea. But the basic principal is that when steering wheels turn, the inner wheel should scribe an arc of a smaller radius than the outer. To achieve this, the steering arms are angled inwards and by projecting a line backwards from both arms, the point where they meet should be dead centre of the rear axle. This creates a differential and causes the inner wheel to turn slightly more than the wheel on the outside. I have endeavoured to produce a unit to fit a slot car chassis. In particular the PCS 32 chassis although I guess it will fit a Slot Classic unit in just the same way. The unit is produced using the trusty photo etching method and is made from .55mm brass. It comprises four parts as shown. The main cross piece which is folded in two planes to form a channel section and carries the four "wishbones". Two uprights are fitted into .55mm holes in the ends of the wishbones, with the whole piece being held together by the tie bar. A tab at each end of the tie bar is bent over to keep everything as one.

The uprights need to have the axle "bearings" soldered in and these will be made up from two 3mm lenghths of 3mm o/d brass tube. The stub axles are being made up from steel.

The complete unit moves very freely. An important point in any trail steer unit, but there is no slack, with the whole piece being quite a precision item.

How it performs, I have yet to find out, but if it works half as good as it looks, i'll be very pleased.

Graham.

Small parts.

The GT is now starting to appear as I want it to. The art that was put into the original car is not easy to replicate. All the major styling points can be included, but without that arty ingredient the model will look almost but not quite there. I've been messing around with this one for getting on for five years now, so I guess it's about time it was finished. As it's my personal favourite of all the DB Astons, there'll be an extra bit of finnessing. The photo above shows the patterns for the rear lamp lenses. I was introduced to pearwood some months ago, but never really did anything with it. But the delights of pearwood are now obvious. It carves easily and has a close and very consistent grain giving a finish way above anything else i've used. The lenses themselves are approximately 7.5 mm high by a shade over 2 mm wide. There is a horizontal cut around halfway up that hopefully will take photo etched trim piece. The particular small part may be pushing things a bit far. We'll see how it turns out.

The glazing formers shown above were made from pearwood too. These have had only handwork with 320 grade wet and dry apart from the single cutline at the B post point. The part on the extreme left is the second of the two tail lamp lenses. The final shaping and detailing takes place before the piece is cut off and trimmed. My next step is to experiment with clear casting resins adding a touch of red pigment. This particular process is very wasteful of materials as the smallest amount of resin I can mix accurately is 25ml. Of this i'll probably use 0.001% and throw the rest away.

The shot above shows just how the GT is now looking. Sometimes when I look at it and see something that just isn't right, I can't quite work out why or where. With everything in place around the front and looking very balanced, from one or two angles it still didn't do it for me. I found it eventually and added 1 mm to the top of the screen extending the headrail forward. The difference is quite amazing.

Graham.

DB4 GT

Being the shortest of all the road cars, with five inches missing from the mid section of the chassis and body, the GT isn't the easiest of shapes to capture.

The standard DB4 in it's early form was probably the most balanced and elegant of all the Touring bodied cars.

The GT by comparison is a little stunted and doesn't quite have the flow of the longer bodies. But it's still a stunning shape.

Rear three quarter views are very pleasing but the frontal treatment is giving me a hard time.
The original shape has something of a sweptback look, no doubt to exagerate it's performance.

I think that look is now starting to appear, but it needs patience and constant minor changes to extract it.

Other little changes required include the lobes on the ends of each bumper. A little too bulbous in length, but due to continual polishing they've lost a bit in depth. I'll re-profile these with the addition of a little milliput and a jewellers file before they go for re-casting.

It's close! Graham.

Hurg first cast.

The first cast of the HRG came out a few days ago and it needs more work. The side louvres have moved at some point. Probably the fact that I didn't cement them in place prior to filling with modelling paste and constant handling caused the lower louvre on each side to be pushed in a few thou. Not a lot but enough to spoil the thing some what. No doubt this has caused a few bubbles on the upper edges of the louvres. The only way to rectify this is to cut them out and refit them. The tile spacers that make up the louvres are made of a hardish plastic and seem a little tricky to shape. I'll be taking a mould of some of these spacers with a view to re-producing them in resin which will be much easier to shape and trim.

Overal the shape of the car is very pleasing. Panel lines have turned out nice and sharp and most of the detail is good. The spats also need a little work allowing them to fit with a much closer gap.

Graham.

Gathering of the Clans

I was running this build in the Slot forum, but putting pictures up there is a pain and all the backslapping can get a bit tiresome, so I thought I'd join in with the other proper scratchbuilders on here.The roof had been glued on last time on SF and since then I have filled the windscreen and side window apertures with Milliput and shaped the glass areas up. Unless I do this I can't be sure the final aperture shape will be right when I come to make the vac-form patterns for the glass areas.

I also couldn't resist cutting out those weird dips where the Clan's headlights go.

I still need to shorten the roof slightly which will also enable the b-pillars to be fined down a bit.

The value of pear wood is shown here by the very sharp edges that can be held and the fact that the panel lines have been cut in exactly the same way I would engrave CIBATool/Renshape carving block, which I will use next time to show it's use. Pity CIBATool is a bit pricey, though.

Only once the main body is finally shaped and its typical GRP edges radii put on can I put on a pre-made back window area because it is equally recessed all the way round and it would be very difficult to carve in a recess, when it could just be prefabricated, set in and just cleaned up.

More on the Aero

Well a slight delay in taking the mould of the Hurg has resulted in a little bit of history popping up from no less than the HRG Society. Don Courtney, the editor of the HRG Gazette, contacted me requesting a little feature on the model for their magazine, which i'm more than happy to do. There's no better people to talk to than those who have an intimate knowledge of any subject, and in the case of the Aero, Don and a gentleman by the name of Ian Dussek have been very helpful. A request for any information regarding colours, details and any available competition history has been met with quite a lot of enthusiasm and the recent email recieved from Ian threw up a lot of interesting points. The fact that the competition cars were all painted a shade of British Racing Green comes as no real surprise but some of the details i'd added to the model proved to be incorrect. Seperate side lights for example just never happened and the boot lid handle was never on the car either. The boot release mechanism was an internal afair. So some very slight mods to make before I take a mould, but nothing major. The photographs show the model painted up in what I thought it might be. More of a Moss green than BRG, but it shows the shape well. The aluminium strip has been added to the hood to give the impression of the stitching and once a rough coat of paint has been applied, hopefully it should have the fabric look and I can take a mould of that too.

In the next day or so, i'm hoping that the quarter bumpers have been cast and that I can make some headway with production.

Graham.