yet another Ferrari 1/8th F40 Engine

[Codger]

Malc may certainly have the definitive answer and you may be right. I was not present at foundries when molds were created. But I did see blocks and heads as raw castings exposed from burnt sand in their boxes when they were received for machining. We ran PPAP tests on them for QC.

[Toftdale]

Sometimes if the internal labyrinth is too complex it is necessary to make this structure first out of a ceramic,  then mould your wax around this.  After casting you are left with the metal casting with an internal core of ceramic,  this can then be removed in a pressurised vessel containing a caustic liquid.  - Andy PS, I Also agree this is stunning work.

[Malc2]

Agree with Codger, for the inlet manifold sand castings would be used for the cores and most probably the external shape also.

Lost wax is too expensive for this application. Even Ferrari (or their suppliers) have to work down to a cost!

When the castings are cool, they go in to a huge shaker which literally shakes the sand out.

The core sand is held together with a resin when the cores are made, which if done correctly burns off with the heat when the molten aluminium is poured in to the core box, so when the whole lot is cool the sand 'should' just fall out with a little persuasion. The burning resin is the horrible acrid smell you get if you have ever been near a foundry that makes this type of part!

 

The wrinkling/crazing you can see in the manifold end view (the one with the red lines superimposed) of the external surfaces is caused by poor tooling maintenance or old tooling.

 

The block looks like a high pressure die casting.

 

Malc.

[Malc2]

3 hours ago, nick said:

I'm working up to 3D printing full-sized intake plenums in magnesium for the guy providing me with all the data and photos so I may need to pick your brains in that case for the bits that can't be seen.

Just a bit concerned about making a fairly expensive, full-sized working one rather than a model! Obviously I will be meticulous with wall thicknesses, radii etc anything else I should bear in mind?

regards,

Nick.

The best advice I can give you would be to work with the casting supplier from the start, as he will be able to advise you on the best way to make core box tooling which could affect the design of the part (draft angles/core split lines etc).

 

Malc.

 

[nick]

13 minutes ago, Malc2 said:

The best advice I can give you would be to work with the casting supplier from the start, as he will be able to advise you on the best way to make core box tooling which could affect the design of the part (draft angles/core split lines etc).

 

Malc.

 

Malcolm,

               I’m probably not casting it at all,  my first choice is getting it printed in magnesium directly. I’m just concerned about getting the 3D shape robust enough from a design perspective.
 

We ultimately want to modify it to mate with alternative throttle bodies too. The first version will just be a repeatable replica of the original as they are unobtainable.

 

Later ones will feature a potentially different pitch on the tubes to accommodate different throttle body tubes. 
 

if that proves too costly, my second option would be to get it printed in casting resin that just gasses off under heat, which is where my interest in lost wax casting comes from. 
 

it’s an ideal component to make this way as there are no critical dimensions really, everything mates via silicon hoses so there is margin for error. 
 

it’s only got to take about 2.5 bar so should be perfectly possible. 
 

why are we bothering? If you can find one at all, they sell for £10,000 - £12,000 a pop
 

regards

 

Nick
 

 

[Jo NZ]

The rough external finish gives it away as a sand casting. Lost wax usually has a very smooth finish - it follows the surface finish of the wax.

Lost wax (investment) castings are  (sometimes) cast in a sandbox, but this supports the ceramic shell.  The ceramic is added on as a slurry, forming a coating which is  oven baked to fire the ceramic  and melt the wax out of it.

Edited July 15, 2021 by Jo NZ

[Malc2]

Sounds interesting!

I hope it all works out OK, I would be interested to find out how it goes when you get the full size parts made by which ever process you end up using.

Are the changes to the throttle bodies to improve the engine performance or because the original Ferrari parts are too expensive for the project?

 

Malc.

[nick]

33 minutes ago, Malc2 said:

Sounds interesting!

I hope it all works out OK, I would be interested to find out how it goes when you get the full size parts made by which ever process you end up using.

Are the changes to the throttle bodies to improve the engine performance or because the original Ferrari parts are too expensive for the project?

 

Malc.

Thanks for your help and support,

 

The guy I'm working with builds replica racing Ferraris, when I say replica, everything is Ferrari, he takes Ferrari parts and builds replicas of period racing vehicles, in this case an F40 LM, but some things you simply can't get anymore. I'm not sure what he has in mind for the modified version, but it will be interesting!

 

Regards,

 

Nick

[Jo NZ]

The investment casters that I worked with 25 years ago are micro-metalsmiths. Not too far from you in Yorkshire. I remember driving through Slingsby and past Castle Howard to get there….

[nick]

Anyway first prints of the all new block at 12.5% as it’s all drawn 1:1 

 

it’s hard to see but the proportions of my original guessed version were way out

[Malc2]

It must be a great boost to the project to have actual dimensions to model with.

Block looks great.

 

M.

[nick]

47 minutes ago, Malc2 said:

It must be a great boost to the project to have actual dimensions to model with.

Block looks great.

 

M.

Absolutely it’s made me realise how difficult, if not impossible, working from  just from photos is.
Fusion 360 let’s me render the model in scenes with a virtual camera and virtual lens, so with a 50mm ‘lens’ I’ve been able to position the model to actually match existing photos I have and it snaps perfectly with all the ones of tried. 

 

Doing it the other way around and trying to remove or allow for that perspective distortion in the photos to draw a 3D model simply doesn’t work it turns out. Although photoshop is capable of perspective correction it screws up the proportionality when things are in a different plane, which they inevitably are. The cylinder blocks for example are obviously pushed back from the front face of the block, so the face can be squared up and drawn OK because it’s flat, but the cylinder blocks are then too small as they are further away in the photo, as the 90° vee is non-negotiable if forces the cylinder blocks out of proportion. 
 

I get this now, but it would still be hard to estimate it. 
 

this shot says it all, I found a sectional view in the manual, and the new model just snapped to it perfectly without adjustment

 

 

Nick

 

 

[silver911]

This project...as you know from our PM's Nick...thoroughly intrigues me...absolutely fascinating to watch

 

Ron

[nick]

Still plugging away at this. I have now completed the 'unhanded' parts of the heads, ie the centre sections. I now need to draw the front and rear sections of each head that makes them handed.

 

 

I've got a new printer arriving tomorrow which will allow me to run two  workstreams simultaneously plus its a lot faster than my current model.

 

I've got a high level of confidence that this version is pretty accurate too, so watch this space!

 

Just for fun, I pulled out my old Pocher lump and it turns out it's dimensionally quite accurate, infact my new version may even fit the Pocher gearbox I have. 

 

Regards,

 

Nick

[nick]

Just tripled my production capacity at a stroke, my new printer is twice as fast as my old one, and just seems a hell of a lot better - first test prints, standard issue rooks, 1,000 layers in about 2 hours (which is pretty quick believe it or not) and they look extremely crisp to me. 

 

why?
 

Somewhat counter-intuitively they have gone from using a colour screen to a mono one.
 

These resin printers are basically made out of mobile phone displays with a big, pokey UV lights under them shining into a vat of liquid resin, to cure each layer at a time as the build plate rises out of it. by definition, each pixel of each layer is just on or off, colour doesn’t come into it.
 

The big breakthrough is that we are now seeing custom screens made for this purpose, So they are mono, this means they are higher contrast (sharper), longer lasting, and can handle more powerful UV lamps, which in turn means shorter exposure times per layer (=faster print times) and better results - what’s not to like?
 

And of course the license is cheaper. 
 

Anyone not old enough to understand that joke, please leave the room the room now.

 

regards

 

Nick. 

[albergman]

Really enjoying watching you progress in this "hobby" Nick.   How exciting to be involved in designing a replacement Ferrari manifold for the real-world.   Myself, I'm about to give my filament printer to my son as I haven't printed anything in over a month and he's desperate to start printing stuff.   I'm finally assembling my latest steam locomotive that is 95% printed!   By far though, the most fun of the whole project was learning and designing with Fusion 360.  The whole project has been fun and very satisfying but I can't wait to return to actually fabricating all parts of a model by hand.   How old-fashioned eh??

 

Eternally grateful to you for nudging me into learning Fusion.

 

PS I'll be 83 next week so all you younger modellers can learn it!

 

 

[Jo NZ]

Nick I'd guess an Elegoo Mars 2 Pro? Just bought one myself...

[Jo NZ]

14 minutes ago, Jo NZ said:

Nick I'd guess an Elegoo Mars 2 Pro? Just bought one myself...

On second thoughts a Saturn...

[Sabrejet]

That block is gorgeous: I don't need one, but I really want one now!!!!

[nick]

7 hours ago, albergman said:

Really enjoying watching you progress in this "hobby" Nick.   How exciting to be involved in designing a replacement Ferrari manifold for the real-world.   Myself, I'm about to give my filament printer to my son as I haven't printed anything in over a month and he's desperate to start printing stuff.   I'm finally assembling my latest steam locomotive that is 95% printed!   By far though, the most fun of the whole project was learning and designing with Fusion 360.  The whole project has been fun and very satisfying but I can't wait to return to actually fabricating all parts of a model by hand.   How old-fashioned eh??

 

Eternally grateful to you for nudging me into learning Fusion.

 

PS I'll be 83 next week so all you younger modellers can learn it!

 

 

Hi Frank, you’re very welcome.
 

I’m really enjoying fusion myself now, second time around (I even bought a license!) 

 

During my first attempt at drawing this I was learning fusion at the same time, so spent a lot of time fighting it. Now I have all the things it can do in my kit bag, I’m approaching it completely differently and enjoying it much more. 
 

plus of course I have my new friend Enzo on the other end of messenger so if I need anything measuring or photographing, he generally gets it back to me within an hour. 
 

My biggest take-away is when to use ‘new bodies’ rather than join, for example all of the bolt islands in the head (the blobs on the top sides of the heads) are cylinder shapes with half-spherical bottoms, so by creating them as new bodies it’s easy to tweak them in height so the amount they protrude on the face is perfect, then just replicate 4 of them at the correct pitch, and only then combine with the main body and filet. Easy. 
 

Plus on the first attempt I was working ‘top down’ - I had a good photo of the red Ferrari valve cover, so I drew this first, used it to figure the cylinder head, rather incorrectly it turns out, then used that to do the block, very wrongly. 
 

this time I have the data, so started ‘bottom up’ with block, and it’s going much better!

 

I thought about you setting my new printer up, it has charcoal filters built in and a silicon seal around the cover so it’s supposed to be odourless and quieter! Hard to tell in my workshop next to an old stinky one  

 

thanks for following this nonsense anyway and glad you’re enjoying it. 
 

Nick

[nick]

On 7/14/2021 at 10:49 PM, Malc2 said:

Agree with Codger, for the inlet manifold sand castings would be used for the cores and most probably the external shape also.

Lost wax is too expensive for this application. Even Ferrari (or their suppliers) have to work down to a cost!

When the castings are cool, they go in to a huge shaker which literally shakes the sand out.

The core sand is held together with a resin when the cores are made, which if done correctly burns off with the heat when the molten aluminium is poured in to the core box, so when the whole lot is cool the sand 'should' just fall out with a little persuasion. The burning resin is the horrible acrid smell you get if you have ever been near a foundry that makes this type of part!

 

The wrinkling/crazing you can see in the manifold end view (the one with the red lines superimposed) of the external surfaces is caused by poor tooling maintenance or old tooling.

 

The block looks like a high pressure die casting.

 

Malc.

I stand corrected then gentlemen, thanks for your fascinating experience and input.
 

Every day is a school day, I wasn’t even aware of that technique, in my ignorance I had incorrectly assumed if you couldn’t split a mould lost wax was the only way to go. 
 

In my defence, I’m ageing ex-aircraft engineer and we didn’t cast much building airframes  

 

thanks again,

 

Nick. 

[Jo NZ]

2 hours ago, nick said:

In my defence, I’m ageing ex-aircraft engineer and we didn’t cast much building airframes  

 

Avionics. Always fighting you guys for more space, more power, more cooling....

 

Casting, salt bath brazing, electro-forming. You name it, we tried it! (not always successfully....)

[nick]

Just put the block on to print on the new machine. Print time has gone from 13 to 5 hours, let’s see how it comes out this afternoon. 
 

I’ve also drawn a raft in fusion so not letting the slicer auto generate any supports at all, my theory is this will be strong enough to enable me to print flat - Let’s see how that goes!

 

 

 

Regards

 

Nick

[nick]

That mostly worked then…

 

 

turns out it prints very well like this, but does need supports in a small number of areas shown highlighted in yellow. 
 

 

my drawn-in raft is much more connected, therefore a hell of lot stronger than slicer generated supports and also easier to remove with a razor saw and flat sanding just like old fashioned, traditional resin casings, and leaves no scarring at all.

 

I’ve learnt a lot from this, so may adopt a ‘let it fail’ approach in future to determine where supports are actually needed. 

 

why? Well if you leave it to the slicer software to calculate this, it tends to over produce supports to get the mechanical strength to print, which I’ve solved already, and the downside is you are left with lots of ugly and difficult to resolve scars when the supports are removed, like this earlier version;

 

 

think of it like sprue from Hell.

 

So by doing it this way I can manage the points where support ACTUALLY is needed in fusion by drawing manually and designing in making it easy to remove without scarring. You’ll see what I mean in the next version. 

 

As I’ve got an eye on productionising this, ie not just getting away with getting one good print, but rather having a reliable, repeatable process, this is quite important.
 

like I said, every day is a school day.

 

new printer, we like. 😎👍

 

thanks for watching!

 

Nick

 

 

[nick]

So a little tinkering later, I have crafted support structures exactly where they are needed and designed a way of easily removing them without leaving a mark. This seems to be working well, I'm just experimenting with different printer settings to get the right balance of detail, smoothness and speed now, but looking OK so far.