Dual-head, plastic/wax printer, for voids and support?

Has anyone tried using wax as a temporary supporting material for complex 3D plastics printing? A forum search doesn't turn up any mention of wax.

As far as I know, wax melts at a lower temperature than most plastics, so wax could be used for structural support when building complex 3D shapes with voids or overhangs.

Once the part has been completed, it would be gently warmed until the wax runs off, leaving only the complete plastic part. The wax can then be reused to printing more parts.

,

It seems feasible to build a two-nozzle printer that can extrude both plastic and wax, and it can then use whichever material is needed at the moment.

Probably the big question is, would the wax interfere with bonding of the plastic? I would assume that it would have no effect, since the usage intent would be for the wax to form a semi-solid bead that does not liquefy and flow away from the contact point where it is applied. But, the plastic may need some time to cool or need forced-air cooling, so that just-applied plastic does not liquefy the wax that will next be applied.

By using wax as a space-filler, complex plastic mechanics with gears, levers, and axles may be printable in one pre-assembled process, possibly going so far as to be inside an enclosed unopenable gearbox, with only weep holes for the wax to drain out when completed.

,

Oh, insanity mode now. How about printable rubber/latex parts inside the printed plastic and wax mold? This would allow 3D printing of pre-assembled valves and pumps with internal pre-gasketed seals.

The question here, is if the chemicals in room-temperature vulcanizing rubber/latex would be compatible with the plastics and not soften or melt the plastic parts.

Heat-vulcanizing of the rubber may also be possible, if the temperature can be kept below the melting point of the plastic components.

,

(I am just a hobbyist and have no experience in this field. But it is an area of interest to me..)

I'm really excited to do a wax printing extruder... which would be necessary beforea dual head design. Wax would allow for more detailed investment metal casting. There is some work being done on piezo heads that will allow for this but it's very recent.

I'm convinced by the UP! printer processes and results that we don't need separate material for support, it can be done through a combination of the right material and software to create nice breakaway supports.

I think the dual head things will realy show their worth when we have a conductor in one extruder and an insulator in the other.

i was thinking about a dual head for wax after seeing bodgits post about the dimension printers but i was thinking solenoid for opening and closing the wax nozzle and deemed it to expensive, now i'm considering going in adrians direction and mocking a pen full of machine oil beside the extruder, perhaps wtih a servo like makerbots pen thing.

What about something like a Quill pen, but with hot wax? or some type of design that uses surface tension to prevent the wax from dripping?

... there was a thread with 'subractive wax fabbing', where a solid block of wax was reduced - a hot tip melted a small volume that was removed with vacuum and caught in a reservoir ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

What about printing a wax mould for metal casting (Eg set clay around the mould, melt off the wax, fill the void void molten metal).

Would this be a feasible method for 3d metal printing?

abs completely vaporizes by around 1500c according to this on [blog.ultimaker.com]


so you would clay around your abs material. vaporize abs, and fill in cavity with metal of choice. its simply genius!

1 print head though... I think we need several print heads inside the same heater core. that probably is in the works.

Dale Mahalko Wrote:
-------------------------------------------------------
> Has anyone tried using wax as a temporary
> supporting material for complex 3D plastics
> printing? A forum search doesn't turn up any
> mention of wax.

I see two problems you would need to overcome to do this.

First is the inherent difficulty of feeding the wax. Since it is not as strong as plastic, any wax filament would be extremely fragile, so you would need to come up with a completely new extruder design.

Second, and probably a bigger roadblock, is I doubt that you can get either ABS or PLA to stick to wax, so I suspect that it is not suitable for use as a support material. Fortunately this one should be testable before solving the first problem, simply by attempting to print onto a block of wax.

You guys might be interested in the Waxuum, a subtractive toolhead for cutting wax. In prinicple you could run it in reverse and use it to deposit molten wax. It has been noted elsewhere that extruding wax is different from extruding a thermoplastic because wax does not have a broad glass transition. In the words of nophead "it will not work because wax is too runny when hot".

However, what makes wax bad for extruders makes it good for inkjets. Wax is used as a solid ink in some paper printers (Solid Ink) and there are 3D printers on the market that basically use inkjets and molten wax.

OK people.
We can totally do this.
We know how to make inkjets: Scratchbuilt, Reprappable
We know all kinds of ways to make heaters: Hot Ends

Does anyone want to take a hot end and stick it on an inkjet and see what happens? Just don't set fire to your house or send yourself to the hospital with burns from a molten-wax bath.

PS - As has also been noted, the forum search does not work for three-letter words like "wax", use google instead. For your convenience here are some of the other threads:

Reprap wax printing?
Wax-Powder Sintering for Lost Wax Casting
Printing with wax for metal casting?
RepRap using wax for making bronze molds?
Wax Print Heads? casting parts?
Tools for creating non printable parts
Xerography printed Mendel