1/8 Porsche 935/78 'Moby Dick'

[ScratchBuilt]

Hello everyone,

Still here! The last couple of weeks have been particularly busy for me - as the new racing season gets closer, everything starts happening at once and the pressure starts to build - not the best frame of mind to be in for modelling at this stage of a project. However, I have been making making progress...

I decided it was time to stop working on the cardboard panels and start making some foam patterns for the fibreglass - once I've convinced myself this will work, it should kick-start the whole project. First up was the front cockpit bulkhead / firewall section:





The blue foam is 50mm thick, so I added a couple of 10mm white sections to give it some extra width. It should taper from about 150mm at the dashboard to around 110mm at the front edge, but I can lay-up to the full width and trim it to suit later on.

As I only have a small hand-held hot-wire cutter, the only way I can get accurate profiles is to cut and tape cardboard patterns either side of the foam sheet. Of course, this makes it very slow-going - it's not as quick as marking a line on a sheet of styrene and running a knife across! Then, because it's slow it's hard to get excited by the shape you're creating - but I have to keep telling myself it's important: once the fibreglass is added, things will soon change.

With the basic shape finished, I could start adding some of the main details - not easy when you're limited by the number of suitable photos. One of the big details is the channel in the middle of the bulkhead for the steering column:



...and then to bulk-out across the top. All of this will be hidden behind the basic dashboard panel eventually, so there's room for some artistic licence. The fuel tank will cover most of the bulkhead anyway, so I'm not too worried about missing some of the small details - I've got to be realistic about what I can achieve at this stage.



I've added a little fine filler to plug some of the gaps and even out the different texture between the blue and white foam, plus some fine fettling with emery-cloth to take off some of the hard edges:



In a similar manner to the front bulkhead, I've started on the pattern for the left-hand front inner wing:



Again, this is oversize so it gives me the ability to trim it to suit once I have the mk2 chassis ready. I'll have to add a flat panel to the back to close off the inner wheel-arch, then apply some filler, etc, There's also some extra detailing required for a few cut-outs, strengthing ribs, airjack mounts, etc, but this can be added at a later date to the basic panel.

Finally, the sills. I was originally going to make these as a one-piece section with both the front and rear parts of the door opening on the one mould, but I decided against this. I've got to give myself the ability to adjust the shape to suit the mk2 chassis, and this approach should also allow me to use the same moulds for both the left-hand and right-hand sides of the car. Again, more cardboard patterns required:



...and with the inner section too:



The outer section is wide enough to allow me to lay-up over the full size, then mark and trim it to shape. The fine detailing around the door latch, etc, can be built-up with styrene strip. The smaller inner section has a small chamfer running along the top edge - the masking tape makes it hard to see. These fibreglass sections will cover the existing tube-frame sill stucture, so I can join them together and reinforce the chassis at the same time. On the inside of the cockpit there will be some extra panelling to cover some of the tubing - but until I have the chassis ready, I can't guess at this!

I'm hoping that next Saturday should see me making a start on laying-up some fibreglass - it'll be the first 'normal' weekend I've had for four weeks. I can get the front wing panel ready during the next few evenings, and maybe also make a rear inner wing too - we'll see. Once I have some actual panels I can trim and offer-up to the chassis, I'm sure my confidence will increase...and then we're in business!

Back to Stoneleigh - you're right, Ian: no 917's! Three 956 / 962's, two 908-03's, the RS61, a couple of rally-spec 911's, and that's all I saw. A 934 or 935 of any description would have been great to crawl under and get some reference photos, but no luck. The Porsche Club GB used to have a big annual meeting at Brands Hatch which was great - I spent a happy morning poring over David Piper and Mark Finburgh's 917's back in 2004 - but I believe for the last few years it has been held elsewhere. Maybe next year...

So, next Saturday it's the Sebring 12-Hours, so no prizes for guessing what I'll be listening (and maybe even watching) while I'm working. It doesn't start until early afternoon UK time, so I should be able to get some fibreglass on first-thing, then see what happens through the day. I'm supposed to be going to Silverstone on Friday as we've got two or three cars testing, so I've only got four nights to get everything ready...

Have a good week,

SB

[nugundam93]

nice update! we're definitely with you on this build, no need to unnecessarily rush things.

[modlman17]

Great to see this one underway. It's off to a great start so far. Have you looked at Gunnar Racing's website for info on the 935? They recently restored the Swap Shop Moby Dick. Here is a link to some photos http://www.gunnarracing.com/project/935/935-Intro.htm that may help you. They may also help you with detail shots of any areas you need. I've asked them questions before and they have always replied. I look forward to watching this build progress!

Rob

[ianc911]

Looking great so far, and nugundam's right; no need to rush! Thanks for posting,

ianc

[Joe Blyth]

I'm really looking forward to watching this build! Great start!

[ScratchBuilt]

Hello everyone,

As things turned out, I didn't go to Silverstone after all - one of our drivers cancelled, so I wasn't required. Still, this meant that I could advance my plans for the weekend's fibreglassing...

Before getting to the messy bit, here's a few shots of the mould I made for the rear wheel-arch - hopefully it gives a good idea of why progress hasn't been too rapid recently. I started with a rectangular block of foam, then took two slices off one side to match the lines of the chassis; next, another cut was made to separate it into a top and bottom half, and a final cut across the top surface created the curve of the rear window frame:



The top half of the block was then sliced length-wise to create the inner face of the panel:



Finally, a curved section was cut from the inner part of the top block to create the wheel-arch:



The time-consuming part comes when you remember that for every cut I make, I have to produce two templates to attach to the block to guide the hot-wire. The various pieces of foam were fixed together with double-sided tape, and some gentle shaping with emery cloth gave the wheel-arch a more rounded profile.

So, the first job on Friday night was to cut all the pieces of fibreglass cloth to lay-up on the moulds. I was only going to add two layers at a time, and started with the lightest 0.6oz cloth - this is fine enough to lay as a single sheet over complicated moulds without it wrinkling and lifting. The moulds were all given a generous coating of vaseline as a release agent (messy), and I then mixed up the resin and hardener and started the lay-up. In all, about 1 3/4 hours work to put on the first two layers.

The two Friday layers were joined by two more on Saturday morning, this time with heavier 1oz cloth; then, two final layers on Saturday night - another of 1oz, with a final covering of 0.6oz to finish off:



The main bulkhead section was...awkward! I haven't removed it from the mould yet, but I suspect it's going to fight me all the way. I'll probably have to re-make the mould for an easier lay-up - there's too many changes of direction, too many folds and creases. There's no reason why I can't make it as a multi-part panel - unlike the 908, all the fibreglass here is supposed to be steel, so it will eventually be painted - so I can add detail and reinforcement with styrene and green-stuff, and it will all be covered up!

Here's the other four parts after being prised off the moulds:



...and after a first trim, with a quick wash and scrub-up...the front wing:



Rear wheel-arch:



Door sills:



Finally, it feels like I've started the project! Now I can work out where all these bits need final trimming to shape, and see if it will all work when combined with the chassis. I doubt if any of these pieces will make the final build, but they should help me to avoid problems later on. I'll attempt to remove the bulkhead section tomorrow night and see how it goes...

More next week!

SB

[John18d]

SB - thanks for another installment - just out of curiosity, what type of foam is that? - John

[puffyrs]

Looking good.

[ScratchBuilt]

Hi John - the blue foam is what's left of a single sheet of insulation I bought a couple of years ago when making the 908. Technically I believe it's known as 'expanded extruded polystyrene', but it should be easily available from DIY suppliers or insualtion specialists - I've always just asked for a sheet of 'blue foam' and that's what I've been given! Hopefully I have enough left to make all the other panels...

I spent about half an hour removing the front bulkhead panel from the mould tonight - it has stayed in one piece (I wasn't sure that it would...) and I didn't have to destroy the mould in the process! So, now for some trimming and to see if I can build a car...

More on Sunday,

SB

[ewestra]

Can't wait to see this coming together. Great job scratchbuild really a great job.

Eric

[ScratchBuilt]

Hello everyone,

Well, the front bulkhead panel came out okay - I was a little worried that it might have a few weak spots caused by a patchy lay-up, but it seems strong enough:





I think for the mk2 version I'll separate the channel for the steering column and make this a glue-on part - it'll make the lay-up much easier. Fine detail can be added with greenstuff, styrene, etc, so I don't have to include this in the moulding.

So, time to start trimming the test-pieces and fit it all together. Firstly, here's the front bulkhead in position:



You'll notice that I've trimmed the panel to fit around the lower chassis tubes - on the original 935-78 the Porsche engineers simply chopped the bodyshell to a line, built it into the frame, and then filled in the gaps. However, it's easier to fill small gaps with fibreglass when they're full-size than when they're 1/8, so I want to keep the gap-filling to a minimum!



Adding the front wing panel was simple enough - just a little re-trimming and adjustment to fit it around the roll-frame A-pillar. An inner wing panel will probably be required too, but that can wait for the mk2.



You can also see how I've trimmed the sill panels to fit around the frame - the smaller piece covers the chassis from the inside, while the main doorframe will attach to the outside. The joint between the two can be filled, and styrene detailing added to create the door seal lip, etc. The whole of the rear bulkhead area will have to be panelled eventually, but this will be a combination of flat sheet cut to size, and a few moulded parts.

The rear wheelarch needed quite a lot of trimming to get it to fit, but it has proved that it is possible to make it work:





I moulded a return for the lower edge of the rear window frame, but I think for the mk2 I'll trim this off and mould the complete roof and frames in one; I'll have to adjust the mould to make sure the angle of the panel lines up with the window.

Of course, once I've made the 'original' 911 panels (or what's left of them!) I'll then have to add all the extra aero parts. The rear side windows will be extended to include air ducts each side, for example. The door sills will be reinforced and the outer 'running boards' will then have a secure mounting. I'm planning to make the main nose, tail and engine cover as removable parts, so the sills should give me somewhere to hide some magnets (must remember to try using magnets!)...but a solid base is important, too.

I think I'm reaching the point where I make the go / no-go decision...and right now it's certainly looking like a 'go'. Making the mk1 version has given me some good ideas and identified a few things that can be improved. In some ways the 908-03 can almost be considered the result of work going back to when I started the first 917 back in 2004, whereas the 935 is quite a different concept - I'd rather spend a bit of time and effort now trying out a few ideas, than get three years down the line and think of all the things I should have done differently! I don't really want to spend another three years making another Moby Dick to get it right...

So, I'm going to spend some time looking at what I've done, making a few notes and sketches, and making sure that I know what I want to do. I know that I want to re-position the rear cockpit bulkhead, and to modify the sill structures, for example. I'm pretty sure that the angles of the roll-cage A-pillars will have to be modified, too - but it might be easier to make these to suit the roof and pillars. Another thing to investigate is the layout of the pipes for the oil and water systems - some of the chassis tubes were used to carry the fluids from the coolers at the front of the car to the engine at the back, so I need to make sure that certain tubes are in the right place to give me a chance of making the connections!

There are plenty of challenges here, that's for certain!

That's about it for tonight; I'm not sure if I'll post an update next weekend - it could be that there won't actually be much to show! We'll see...

Have a good week,

SB

[ianc911]

Great progress! Your Mk I is better than my finished products!

ianc

[eyckles]

Hi SB,

Again as always your updates are amazing. Cant wait to see what comes next.

Best regards,
Lesley

[Shovel]

Mark

[ScratchBuilt]

Hello everyone,

Although the Easter break is usually a good opportunity for me to spend a few days getting down to some solid modelling, this year I spent three days with the FF2000's at Snetterton - so that was Plan A out of the window. However, my lack of recent updates has not been due to inactivity - after spending a few evenings working out how the oil, fuel and cooling systems were supposed to work, then deciding what I wanted to change on the mk2 chassis, it was time to start cutting tubes again!

I started with the outer perimeter frame for the main cockpit section - I felt it would be easier to build 'up' rather than 'out', as I did with the mk1.



Once again the lego jig is being put to good use to hold everything in place. All the joints are securely pinned, many by using a small length of stripped-out wire sheath pushed into the end of each 5/32" tube. This gives a much tighter fit than my normal method of gluing in a length of styrene tube, and grips the copper wire particularly well:



At the back of the frame I've introduced two 'sockets' to give me a better location for two of the upright tubes later on:



I felt this method would be better than trying to pin the into the middle of a regular joint between the two horizontal tubes. I'm still trying to build as much strength into the tube frame as I can, so little things like this should all help.

With the outer frame complete I added the internal bracing:



There's still some shorter cross-tubes to add in later, but I need to position these to suit the seat mounting, etc.

Next job was to create the rear crossmember which supports the front end of the gearbox. The mk1 version was quite basic, but for the mk2 I'll obviously be increasing the detail. It started as a simple frame of 3/16" square tube:



I've added short lengths of 1/8 tube inside each leg so that I can pin all the joints together - as well as the engine and gearbox hanging off this frame it also helps to locate the lower suspsension trailing arms, so it's got to be strong. To help, the lower tubes which support this crossmember have been reinforced with 3/32" brass:



It all goes together like this:



The long tubes running between the crossmember and the front of the chassis are pinned at both ends and contain more brass tubing:



I might regret this later when I find I have to drill into these, but the mk1 chassis showed just how flexible the styrene tubing would be over this length. The gearchange mechanism is mounted onto these tubes, and some of the seatbelt mounts, but that's about it. Again, strength is the priority.

To start building up the detail I've added two 0.5mm plates to the box-section frame, front and back. These will be filled with more styrene strip and greenstuff to eventually get the required shape:



There's some more chassis tubes to connect to this frame, plus I need to incorporate some mountings for the front of the gearbox - more drilling and pinning, I think. That's all on the 'to-do' list for this week...or next week!

So, that gets me up to date. I haven't posted for a couple of weeks as it's taken a while to get into the frame and actually have something to show. I know some of this is going to seem like going over old ground again, after the mk1 chassis build, but hopefully you'll see the differences and improvements. I'm not racing again until the middle of next month, so I should be able to get back into the routine of my regular Sunday-night updates....

Have a good week!

SB