.

.

Did you make it larger, to account for shrinkage?

_________________
Vive la Marque !!

All you forgot are some Wicks so that you can light it as a big candle.Super job,I shall be very interested to see a block cast this way.

Hi,

That looks great.
Will you create a silicone mould now out of this in order to reproduce the wax cores for more castings as your wax core will be destroyed each time you cast a block?

Greetings:

minime

I think he must have already done that.Unless he carved the wax out by hand? A silicon mould cannot be made from this pattern.You would not be able to take it apart to get the wax out.This would have to be made up in parts and stuck together.I dont remember anyone ever doing a block this way before.very interesting.

.

Hi,
Yes I know well that making a silicone mould of the finished wax block as it is now is not possible but it could well be made in different sections and then glued together what makes the process much faster.
Dongo in Italy was producing liquid cooled generator housings in a lost foam process where the generator housing was glued together as styroprene foam part from several parts, then filled and compacted in casting sand and later on casted with aluminium.
The styroprene just evaporated when the hot aluminium was filled in the form.
The lost foam casting method is used sometimes for cylinder heads or even engine blocks. Those parts later on have a surface structure grain like if they were made in styroprene. That system is fast in series production however it also has some disadvantages on very thin wall thickness as the gas created by the evaporating styroprene can cause porosity and leaks which require a leak proofing after treatment of the finished part. Actually the finished part is put in a special 2K like liquid under vacuum which penetrates into the porosity of the metal leaving it leakproof after curing. However this process is not cheap for series production.
Greetings:

minime

but today we have 2011 , and we have " Rapid Prototyping " (3D printer) . You must not glue anything , it comes in one piece . The Koux blocks are made this way .

This is a great idea but with a serious flaw as the quantity of resin required to hold the sand together makes too much casting porosity when heated.

Another way to do it is to actually produce the pattern equipment and sand cast from it in the traditional manner. People have had some success in the past by doing it this way apparently.

You are prefectly right Lazarus !
To produce Molsheim blocks with 3D-printed cores is a dauntingly attempt.
Besides, "Rapid Prototyping" say it all! It is a quick way to produce a prototype (in the best case).
Which also explains why production models after all are manufactured in "conventional" ways.

If 3D-printed cores are such a blessing (BTW, this process is known for over 20 years by now), why isn´t everyone using it? Are foundrymen hopelessly traditional ? Well, I didn´t get the impression when I visted the GIFA foundry fair in Duesseldorf last June ...



As written above: perfectly correct, Greg !

I am glad that you prefaced your comment with "some". An old family friend Peter Just,worked at the foundry producing Bugatti blocks and told me that the failure rate was in the order of 2 out of five.Because of the thinness of the sand making the water space between bore and wall,if the cast iron rose higher on one side of the sand to the other,then the weight of the cast iron would push over the sand wall.The result of course was a scrap block.It was in an attempt to cure this exact problem that Bugatti designed blocks with plates on the side of the block.This allowed a far better and stronger sand core,well supported and far less likely to fail.I think that if I were going down this road today of making T35 or T37 blocks for myself,I would cast the side wall open.A nice aluminium side plate with the Bugatti oval badge and a large number of square headed 5mm screws around the edge would not upset me at all.

With the 21 century luxury of 3D computer modelling and CNC machining, it is possible to improve the pattern making process, allowing much closer tolerences for fitting the cores into position more securely. It takes a lot of the skill out of it - but thats progress.

This makes no difference whatever.If the foundrymen allow [ for one reason or other ] the cast iron to rise higher one side than another of a 5mm thick sand "wall" the weight of the castiron will break the sand.If the sand is impregnated with more resin to compensate and make it stronger then the bubbles caused in the melt by the boiling resin will cause blowholes in the part.Early Bugatti blocks, by design,are and have ever been a nightmare for the foundrymen.