1/4 Scale Cosworth DFV Engine

[JonC]

Hi Mike,

Yes thanks, I am following the Jupiter build and took some useful information from the manifolds you made including the investment casting people, very impressive work I might say.

I may still try the silicone mould method you employed but thought I would try this method first.

Jon

[Vixen]

Hi Jon,

I am very interested in your method  of using 3D printing for lost wax castings. It is a completely different method to the one I used, so I am following along quietly in the background and learning from you.

I can see that 3D printing has many advantages over hand carved masters with the potential to eliminate several process steps towards the production of usable waxes. I am watching and learning from your experiments and experiences. One day, I may even invest in a 3D printer of my own.

Keep posting your progress

Mike

[tghs]

shapeways can provide parts printed in wax,, they will also do the casting,, they also do metal printing.. they are pricey .. 

[JonC]

Mike, glad it's of interest to you. The mould scan easily be rescaled and reprinted as well however the post processing is quite laborious.

I hoping that if it works, it will allow multiple waxes to be produced without distorting or damage. My machining skills are nothing like yours so I'll need quite a few back up castings I'm sure.

tghs, thanks for the info, I'll look them up

Jon

[Vixen]

Jon,

I sometimes  used a company called Sculpteo, they offer a similar service to Shapeways and appear to be marginally less expensive. Both firms specialise in commercial 3D printing in a wide variety of plastics and metal.

Both firms also offer a complete lost wax casing package. From your 3D model to the finished lost wax casting in your chosen metal. Unfortunately, they only offer a complete end to end lost wax casting package, they will not supply the printed waxes to a customer or accept a customers waxes.

Mike

[tghs]

looks like shapeways has dropped the wax only option,, there should be other providers,, I have seen some vids using PLA in place of wax,, there are also some material options for home 3D printers..

[Jo]

.... One day, I may even invest in a 3D printer of my own.

They have come down in price Mike. Surus' new one only cost £70 on fleabay. I expect its quality and capability to be reflected in the price but it is an investment in a learning process... And I already have my first printing order 

Jo

[JonC]

Mine is a £120 Chinese Geeetech printer. It's been excellent.

[JonC]

Jon,

I sometimes  used a company called Sculpteo, they offer a similar service to Shapeways and appear to be marginally less expensive. Both firms specialise in commercial 3D printing in a wide variety of plastics and metal.

Both firms also offer a complete lost wax casing package. From your 3D model to the finished lost wax casting in your chosen metal. Unfortunately, they only offer a complete end to end lost wax casting package, they will not supply the printed waxes to a customer or accept a customers waxes.

Mike

Still getting used to posting

Mike, what about the Covent Garden jewellers you used? Are they still up for casting from customer waxes?
Although I would imagine that materials will be restricted from them, specially in a high grade aluminium

[Vixen]

Mike, what about the Covent Garden jewellers you used? Are they still up for casting from customer waxes?
Although I would imagine that materials will be restricted from them, specially in a high grade aluminium

Jon I have not checked recently but "Just Castings" is their name and that's what they do for a living. You send them your waxes and get the finished castings by return post (after you pay the invoice). If you have a small item and are prepared to wait a few extra days, they will add your waxes to other customer's waxes to save a little on the costs. If your item is large, or you are in a hurry, it may need a complete investment flask by itself. That will cost about £160 for a flask.

BTW you also need to pay for the amount of metal used. They are jewelers, so normally cast in precious metals. I have never bought aluminium by the gram before, fortunately it is a light weight metal, and not intrinsically valuable.

If you are in a hurry and get the wax to them by mid afternoon they will mount the wax and pour the invest the same day. The evening shift place the investment flaskin the burn out oven overnight and it will be at full temperature and ready to go early next morning. The hot flask is then placed on the vacuum caster and the freshly molten metal is drawn into the cavity. By mid morning the casting will have removed from the used investment, the runners sawn off , the casting cleaned and inspected and readied for the customer. Better than a 24 hour turn round. They cast in different metals every day of the week and are very good at what they do.

The aluminium they use, appears to be pure aluminium, not a high strength aluminium ally; so it is rather soft when it is delivered. I have not tried any heat treatment to precipitation harden the aluminium. It is therefore soft and gummy to machine and tapped holes have no great strength.            HE30 T6 is is NOT

Hope this helps

Mike

[JonC]

Thanks Mike, very helpful.

Going to order some red wax soon and see how it goes. Then if all is ok I'll decide where to go for the casting.

Jon

[Vixen]

Jon,

After you have injected the molten red wax and allowed it to solidify; use cold water to harden the wax before you attempt to remove it from the mould. The cold water will also lower the skin temperature of your hands and fingers, making them less likely to leave marks and finger prints on the wax.

Keep us posted with progess

Mike

[JonC]

Mike,

How runny is the wax when hot? Is it like water or more viscous?

Also I saw that you heated it immersed in boiling water. Is it important not to get it above 100 deg ?

Jon

[Vixen]

Jon,

The wax takes a long time to fully melt (heat of fusion or something like that) so you need to be patient, stir it regularly to make sure it has all melted and there are no hard bits left. Take your time and don't rush things. Dont be tempted to directly heat the pan of wax, always use a double water boiler to stop the wax exceeding 100C. The wax is quite runny near 100C  but stiffer at lower temperatures. I used a kitchen thermometer to ensure I had the wax temperature as near to 100C as possible. You need to be efficient and get the molten wax into the mould before the temperature drops and it thickens. As you have seen, I always use an injection syringe pump, I have never tried to pour it into a mould.

The wax also takes a long time to harden in thick sections.

Mike

[tghs]

I used metal syringe as a poor mans wax injector  and used casting wax,, attempts with other wax failed,, some waxes change in qualities if over heated,, just keep the syringe in the molten wax, pump the wax in and out before filling a mold.. pouring also failed..
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