By Jupiter

[metalmad]

Absolutely Beautiful 

[Mayhugh1]

I just happened upon your build. I went to the beginning and started reading and couldn't put it down until I had read it completely through. I'm awe struck. A really impressive project and excellently written up as well. I loved the photos and text associated with your casting process - Terry

[Jasonb]

Those cast manifolds do look the part

No that you have found a suitable foundry do you think you may be getting more parts done that way which you had previously intended from solid provided the piggy bank allows it? Or will you just use it where it would be hard to do from solid unless parts were joined together.

[Roger B]

Splendid     

[Jo]

Its only six Weeks until the GMES show Mike, we are expecting to see the Jupiter there 

Which reminds me... was I going to take anything this year as they didn't invite me to

Jo

[Jasonb]

Maybe as you run them down so much they did not invite you?

I got an invite

[Vixen]

Wow! Thanks for the encouraging comments. 

Jason, Lost wax casting has it's place. It is ideal for making highly detailed small items like boiler fittings, or higher volume runs of intricate engine parts. I am thinking of Bruce Satra's Morton and P&W engine castings or the RR Merlin castings used by Terry Mayhugh. If you read Terry's Merlin build log, he tells how he needed to straighten warped castings and having to spot the fastener centers off the casting to ensure good visual alignment.

I consider lost wax casting to be the weapon of last resort. I would prefer to carve an intricate part from a solid billet whenever possible. Sometimes a part is impossible to carve, rather than simply difficult and that is where the lost wax casting process comes in. However lost wax can be an exercise in frustration, time and expense, but if there is no other way.....

Jo I have displayed at the GMES show for over twenty years and have the pile of their little brass plaques to show. They invited me again this year, provided I brought my own tent and removed the display each night. They could no longer provide any insurance cover. I plan to bring the Jupiter and the Mercedes W165 engines. I will be sharing a gazebo tent with Mike Cole.

Mike

[Vixen]

How do the words of that John Denver song go; "Some days are diamonds, Some days are stone".

The Jupiter project can be a bit like that and "Some days are stone"

I have had a few frustrating days with the Jupiter, trying to cast the investment wax for the induction manifold which connects the carburetors to the Induction Spirol. I have never attempted anything this big before. The first couple of attempts were a disaster. I find I am not getting complete filling of the mold cavity, probably due to premature cooling of the wax before it had flowed completely round all three tubes. It could be a trapped air pocket or the wax is cooling too quickly before all the molten wax has been injected. The wax is crumbly and crystalline which again suggests chilling. Maybe I need to find a way to heat the silicone mould before injection. The front side, which is not visible, is almost perfect but the rear face, which can you, see is flawed.


Here are the three soluble wax cores waiting inside the mould cavity for the hard wax injection


The mould box still clamped up after the red wax injection


The first disastrous attempt

It is very expensive in time and materials, I need to sort this problem quickly. I will start by adding some more air vert holes and if that does not work, to inject the wax from the opposite side to get the hottest wax flowing against the part you see. I have also got a different type of injection wax to try. The problem is it's a three day cycle, The yellow soluble wax cores are made on the first day and the hard wax injected on the second and the cores are dissolved out on the third.



The second attempt was a little better but still incomplete filling

I made some changes to the procedure. I changed the injection point to the other side, so the hot molten wax will flow over the problem side first, I already added the three small air vents but the biggest change was to use a different kind of wax with a lower melting point and less fillers than the red wax. It is not so strong due to the absence of any fillers but it worked well enough, as you can see.in the photos. The green wax casting is not perfect, but it is adequate to cast from. The yellow soluble wax was dissolved out overnight in cold water. If you look, you can see the white and black plastic inserts I used to economise on the amount of the expensive soluble wax consumed each time.


Things look promising when I open the mould box


I warmed the mould over an old oil filled radiator, I could only go to a few degrees above ambient because any higher and the soluble wax cores start to melt, and there could be thermal expansion problems with the silicone moulds. Any way, the mould was warmer. I also changed the type of wax, the red wax was high temperature melting (and cooling) which I suspect was being chilled by the mould. I found some lower temperature green wax, with less filler materials, which was much more fluid when ready to inject. That, together with the additional air vents and injecting the wax from the other side of the mould all paid dividends. I have one usable green investment wax, not perfect, but usable. It's in the cold water tub at the moment dissolving the three cores. Tomorrow I will be able to inspect the complete wax. You may notice one of the bolt flanges broke off during removal from the mould. It was a clean break, so I can repair that easily in the morning. I have discovered that LiquidPoly plastic kit glue will solvent weld investment wax almost invisible.








I have just enough materials left to have one more attempt to try and improve the wax model. I will send the best one to the foundry and have the other in reserve in case there is a foundry disaster. Hope I will not need it !!!


Gotta go, got a hot date with a sexy   wax model

[petertha]

I admire your tenacity, those are complex pieces. What 'dissolves' the inner core yellow wax & leaves the shell wax unaltered?

[Vixen]

The soluble "wax" is formulated to be just that, ie. soluble in cold water. It needs to be kept in an airtight container. The shell wax formulation is different and completely unaffected by water. Both melt below the boiling point of water and both become a solid at room temperature. Both are expensive consumables on the road to a metal casting. The different wax formulations are died with colour to help identification.

Mike

[petertha]

The soluble "wax" is formulated to be just that, ie. soluble in cold water.

Interesting. I had no idea that was even available. Can you provide me a brand name or supplier (its completely unrelated to casting).

Back to your project, apologies if you addressed or answered this somewhere already. But would a 3D-printed hollow part (essentially the part itself) serve the same purpose as the 2-part wax core process if it was printed in casting wax? I have 3D cad experience but limited 3DP experience aside from a few plastic knick-nacks made for me at Shapeways. I see specific waxes being offered as a material selection for jewelry & the like.

[Vixen]

Hi petertha,

In Reply # 86, I gave details of suppliers in UK and USA where you can obtain Freemans Jewelers Sol-U-Carve wax. There are alternative brands, but this is the one I used.

There are many roads to heaven and as many ways to produce an investment wax. Of course it is possible to create a 3D model of the part and get the likes of Shapeways to print a wax for you.

A number of print houses will also provide the complete lost wax castings process, limited to small items. You send the 3D model file together with the money and they send back the metal casting.

Some people say you can print a PLA model on your home printer and go for lost PLA instead of lost wax. It sort of works, but I have yet to see a quality casting using this method

My 3D modeling skills and home computer power are limited, so I chose to make physical master models, moulds and cast my own investment waxes. I still need to employ the services of a lost wax investment foundry to do the final stage of casting the aluminium.

Mike

[90LX_Notch]

I am beyond impressed with this thread.  Great stuff Mike; keep it coming.

-Bob

[Art K]

Mike,
Those parts look great, like everyone else I lack all the terms saying how phenomenal those wax castings look. Still following along.
Art

[Vixen]

Thank you all for following and your kind comments

The Induction Manifold investment wax has arrived at the foundry and is "in process". I have my fingers crossed waiting to see what emerges.

Mike