Okrasa Special

[Pandora]

Yes, this is correct Barry. Once we have a good shape we have the slightly daunting task of taking a panel saw saw to it at any chosen point and cutting a thin slot along our chosen line. We can then slip in a sheet of card and draw the adjacent profile onto the card which allows us (using our grid to locate the slot) to transfer it onto a forming buck in heavier MDF / ply.

In terms of checking duplication of panels and gaps undeneath, there is a handy trick where you have, lets say, a slam panel under a bonnet and you want to check clearance between mouldings, and that is to make wee thin cones of plasticene. You position these on the slam panel and gently bring the upper panel down into position. When you reopen the panel, the new height of the cones is your clearance gap. Or at least, that's the theory. I've never really thought if you could use such a tecnique to measure consistency between 2 panels? maybe for flatish ones?

As to how I generated the sections? that is the tricky bit - imagining how a series of 2D shapes will work together in 3D, or indeed, how to break down the 3D shape you imagine into 2D sections. I'm afraid that just comes with practice, and a bit of guess work - when in-filling of the gaps with the foam I tend to over fill the shape and then as you trim down, if you get to a nice shape before you come to the 'intended' profile, you can always stop and fill in the 'slot' left above the former between the foam on either side.

As this isn't my commercial job any more I'm more than happy to share any such techniques etc with any who are interested , perhaps in the hope of insopiring folks to have a go (maybe my attitude would be different if I was hunting for clients ) - but what's the worst that can happen? you waste some wood, foam and filler, and a bit of time, but it is a rewardign process when it works well.

The only thing I can't really explain is how to know when a line will 'work' or not. I think it must be what people describe as 'having an eye for it'. Again, with practice, you learn whan a line flows well, and when it doesn't - sometimes it looks flat and lifeless, others just have 'something'. It all gets a bit 'arty farty' describing it, and I don't considermyself particularly artistic (in the drawing a picture sense) - more sculptor than illustrator, I suppose!

I know I've posted this link before, but it's the best way I can describe the process in terms of step-by-step guide. Of course I was recreating rather than designing from scratch, though in many ways that is harder! (and the rear end of the tail section tape line in the photo on the link was horrid - it would have been changed if I'd got that far!)

http://myweb.tiscali.co.uk/racecar/pandora/body.htm

911hillclimber, if you need any advice or assistance on your project, fell free to ask, if you think I might be able to help / advise.

Al

[Pandora]

Just came across this photo on my phone from when I met up with Steve and Ian at Goodwood.

Whilst I think it shows pretty much what Steve is after in many ways, and is indeed a very nice rear end treatment, I photogaphed it as it clearly shows what I'm keen to avoid - if you look at the exact point of transition between the rear flank / wing and the kick up of the Kamm tail, the transition is awkward - the 2 surfaces jarr, rather than flow together - it might if you were to put a slick of filler across this transition it might be just 1mm deep, maybe less, but it shows what a tricky thing it can be to get the shapes to work well together.

The other side might have been OK - certainly I recall looking at the 275 GTB in the next bay of the paddock, and it was much nicer!

I think that as we will be going from a fairly flat bootlid into the tail, I'd envisage a much less severe 'kick up' to the tail - somewhere between the 275 and the Lusso. The one on my tape drawing was/is certainly too severe.

As ever, things will evolve as they progress.



Al

[Pandora]

another find on the 'phone - a prime example of a 'narrow arse dragging on the ground', (courtesy of Shapecraft for Ian Walker racing)

Not even my favourite tail lights can safe this one!



It's many 'problems' include the rear panel being too crowded, the lights too big, the arse too narrow, the same transition problem as the 275 above, and the whole tail too low. Apart from that, it's fine.

Al

[Barry]

Just came across this photo on my phone from when I met up with Steve and Ian at Goodwood.

Whilst I think it shows pretty much what Steve is after in many ways, and is indeed a very nice rear end treatment, I photogaphed it as it clearly shows what I'm keen to avoid - if you look at the exact point of transition between the rear flank / wing and the kick up of the Kamm tail, the transition is awkward - the 2 surfaces jarr, rather than flow together - it might if you were to put a slick of filler across this transition it might be just 1mm deep, maybe less, but it shows what a tricky thing it can be to get the shapes to work well together.

The other side might have been OK - certainly I recall looking at the 275 GTB in the next bay of the paddock, and it was much nicer!

I think that as we will be going from a fairly flat bootlid into the tail, I'd envisage a much less severe 'kick up' to the tail - somewhere between the 275 and the Lusso. The one on my tape drawing was/is certainly too severe.

As ever, things will evolve as they progress.



Al

Do you mean about level with the rear lights? That certainly looks odd to my eyes.

I did speak with Steve during the week: I gather we're waiting for his homework . Steve, if you think you're not going to be able to do it this coming week, let me know and I'll pop up there: it's no problem .

[Pandora]

yes, level with the centre of the light, through up to the edge of the bootlid - it just doesn't flow. The bodywork man must have used the wrong tree stump.

Yes, steve is late with his homework, so I have been busying myself with decorating, roofracks and buildign what appears to be the Hilton for bunny rabbits! I've built a nice table for my chassis to sit on when it arrives too.

Save me Steve!

[Barry]

Definitely agree Re: the Ferrari, I wonder why they just didn't start the blend a little higher up. I guess at the time it just wasn't a priority, either that or it was judged to be perfectly acceptable as is was.

Anyway, don't worry, either Steve or I will save you from the bunnies! I was saying to Steve in the week that I'm really keen to get on to the next stage, and can't wait to have a play with the foam .

[210bhp]

As Russ said to me

"Whoda thowt ouwt as beautiful would a come out a mill i'Bowton"



Regards
Mike

[Pandora]

You have to be careful - one day you are admiring Chevrons, the next, you go out and buy this little lot......

http://www.flickr.com/photos/44645707@N ... 144610516/

Who'd do that? Yup!

bargain too - £100! was very pleased to get them out the way 2 months later for a modest profit. Seemed a good idea at the time!

Al

[210bhp]

Nice one Al

The thing is that your perspective can be skewed because you are always looking at something close up. Sometimes you have to stand back, way back.

The Chevron is one of the most beautiful cars on the track when viewed from a distance.

Regards
Mike

[Pandora]

I feel I am now at just about the right distance from those panels. Dunfermline to Gala, yup, that's about right, LOL

[steve wright]

Sir, the dog ate my homework.... Actually a 356 consumed the only time I've had this month. This lightening business has got serious, but I will get to it in the next couple of weeks (he says with not a hint of hope in his voice )

[Macaulay]

Yeah it's about time you got someone with some design skills and a hands on approach,
Al's getting this sorted from the ground up, it's gonna be alright.
I think you are going in the right direction with a slightly longer tail, it's easier to get a nice flow on the car.
And also making the wheel arches wider to accommodate some wider tires will give you more room to
give the design a bit of shape. It was very constricted before imo, as everything should be as small as possible,
trying to stay as close to the already constructed frame to emphasize/keep the smallness of the car.
I am sure this more "loose" approach will give the car what it needs.

Keep hacking at it! :D

[Barry]

Hello

In a way it seems a shame to edge away from that whole cut down tiny hill climber look. Frankly if we didn't have that roof, we'd have more likely been O.K.

I aways said to Steve that a major frustration that I had was the fact that we had the car looking near-perfect from dead-on side view, and then something truly terrible started to happen as you wandered towards the rear. So, as it happens, the bit you did was spot on, the bits I did: less so .

[steve wright]

Hey Macaulay! Thanks for the observations - you're spot on, and you might be pleasantly surprised to hear we still refer to your sketches more often than you might imagine. You had it right although none of us could've envisaged what a ball-ache the roof and straight-on rear view would be....

[Pandora]

To keep you all up to date with the design progress, I've made a bit of progress tonight. And in the spitrit of 'we are all in this together', I'll show this to Steve here first......

Barry sent up tracings of the profiles we built up on the day we spent on the car recently, and I've started to transfer the info onto a full sized board, currently leaning against my dining room table. Pininfarina this is not!

From the tail panel outline and cross section sketch line, my first task is to create the 'plan' view at a set height (I chose 600mm high based on the make up of the buck, and the wheel arch formation etc). given that I know the width of the tail panel at this height, and how much clearence I want at the wheel arch, I simple join up these points with a smooth curve (yeah, if only it was that easy). Steve or Barry will confirm the width of the wire profile at the trailing edge of the door at 600mm high in due course, and i'll then continue the curve to seamlesly flow into the front....... (This line is shown at the botom of the sheet in the photos below.)

Next is to set out a couple of key longitudinal sections which, combined with the section described above, set out the key points for the various cross sections to intersect with

I started by setting out the centre line from Barry's tracing, then using the one cross section profile I sketched out, I formed the line 400mm out from the centre line, down the bootlid from the rear window to where it intersects with the tail panel (you can see it is pretty much parallel, but lower, than the centre line. It's all pretty easy so far........

Now, the buck 'box' is 1400mm wide, 700 either side of the centre line, and the outer edge is the line on which perhaps the most important longitudinal section lies, the one which has the most shape, and will define the overall shape of the rear arch. I should say, (much like Barry forming alloy on the wheel) long gentle curves are the hardest to control. tight wee radiuses tend to be easier to see where you've gone wrong, so this one has been fun. Below are just 3 of my attempts:


Sections 23 2 13 haunch too far back

I was trying to pull the haunch of the arch back, away from the narrow point near the base of the C pillar, where the arch meets the rear window, but you'll notice that on this early attempt the centre line of the arch appears to be behind the centre line of the wheel, and it looks like the body is getting dragged behind the car. Not good, so onto this:


sections 23 2 13 700 low

This one is better, but really highlights a concern I'd already suspected, and had mentioned to Barry and Steve. If you look at the photos of the buck from dead behind, I thought the rear panel has too much curve to the top edge. It just needs the top to be flatter a wee bit - basically I thought I need to pull the outer top corners up by 1/2" or so, and this profile confirmed it.

If you recall, there has been much debate earlier in the thread about 'droopy bums' / saggy arses etc. My suggestion so far has been to keep the forms at the rear from falling below the strong horizontal line from the door top, and here you can see that the profile drops just too much as it goes to the rear. (these lines will of course not actually be seen on the final shape, but they really show where the bulk of the forms will lie) so, I mucked about with it and got to here:


Sections 23 2 13 700 high

You can just make out the pencil line tracing of the previously 'droopy' line and see how relatively small a change in the line (it's raised by 19mm) makes a big difference to the flow. I think it's much stronger.

It might not actually need a new tail panel made, as I might suggstet we form the kamm tail panel as a whole and simply bolt it onto the existing panel, and loose the discrepancy in the foam carving process.

You'll notice I've also made some progress on the section through the Kamm tail panel

Next job (Unless Steve has any significant concerns over these profiles) will be to start creating the profiles across the car between the rear window and the rear panel. I think I'll need to redo the one at 100mm behind the axle line slightly and then the ones at 300 and 500, after which I'll do 100, 300 and 500mm in front of the axle line.

Hopfully these sections will all pick up on the points I want them to hit from the previous lines, or else that is when you have to start looking for the mistakes you think you've made and it all gets really complicated.

Fingers crossed it all goes to plan!

I'll keep you posted

Al