What Z-corp ink is made of

Hi Fernando,

... pulsing is mostly a problem with high-volume-hydraulics - when working with thin elastic tubes and small volumes per collapsing area there isn't so much pulsing, as the length and elasticity of the tube to the outlet acts as mechanical filter too.

For really high-precision pumping i'll have some other designs with ferrofluidic or magneto-rheological peristaltics, where the forcing of the transported volume is really 'soft' and the feedrate adjustable down to volumes of pico-liters per minute ...

My development in the last years was directed mostly to micro- or even nano-dimensions, so it's a complete different view

Viktor

Heheh, I see we have an expert!

WOW! The print quality is amazing, probably as good as z-corp.

I seem to have hit a hurdle on my epson though...

I am in the process of doing initial writing for a community-oriented project for a Z-Corp style 3D printer based on the work of Graham Stabler (the indoorflyer.co.uk guy). I have been exchanging emails with him on the design on his parasitic printer controller for the print-table and current plans involve getting mostly-universal coding together for the Arduino platform.

I will be posting a small message here with the wiki is ready. Scorch, if you do not mind, will it be possible to take some of your existing work over there once things are ready?

Sure, you can copy anything you like that I have posted here. I could write a little on the new WIKI if you would like. Please reference "Scorch" or the Reprap forum as the source for anything you feel is unique.

Has graham printed anything with his setup? I would love to see him print something 3D with his setup. (his setup seems to be nearly complete but no results have been posted)

You might want to check out this web site:
[www.sci-spot.com]
I like the simplified approach he took to returning the printer to the home position and adjusting the height of his print media. I found the page difficult to follow but from what I can gather he uses used a relay to reverse the poles on one phase of the paper feed stepper to reverse its direction of travel (I think a similar approach could be used on a paper optical encoder controlled paper feed). I also think the image of his circuit is wrong. Despite the sites short comings the info has made me think quite a bit about the way I will move toward automation.

Scorch

@Scorch

I have a question: do these Epson printer come with 2 or more cartridge heads?
The reason why I ask this is that I'm starting to have good results with Methymetacrylate (MMA), commonly known as plexyglass.

The way to get rapid polymerization with this monomer is to precisely measure the ratio of catalyzer and accelerator.

To have the accelerator (a liquid) mixed together in the cartdridge and the catalyzer (Benzoylperoxyde, BPO a solid commonly used as catalyzer for 2 component resins) in the powder bed would be the first solution allthough I don't recommend it. This is because the catalyzer in the powder would dry up and degrade, plus the ratios are difficult to calculate. Also a lot of BPO would get wasted.

The second solution i have imagined would be to have 2 cartdriges (like different color cartridges). Color A would have MMA and the catalyzer, wich would be printed along with a solution from cartridge B with MMA and the accelerator. This way we would be sure that the mix would be perfect.

The powderbed could be made out of acrylic powder, wich is used in nail laker and can be bought in ebay or beauty shops. If you don't need clear objects, you could use sand, marble or clay dust as a medium I guess, any type of inert filler would do.

The different colors on the Epson printers are all integrated into one assembly. In the single assembly each color has unique printing ports. Since each color has its own set of print ports Keeping the catalyzer and accelerator separated until they are printed would not be a problem.

One problem, I have not been able to get anything other than Epson ink to print from an Epson printhead. I am still working on it...

Fernando do any of those chemicals dissolve any sorts of plastics? Can they be dyed for color printing?

BTW anyone know where to get some linear slide rails cheaply? I am having trouble finding some for my printer's new y axis.

@Scorch
Thats perfect then! Now i'm thinking how I could get you some samples in the easiest way possible so that you could test if this thing prints. Could you give me the reference numbers of the refillable cartridges you use? A website where they sell them would be best. I could then fill a batch and send them over to you by post. They are safe to transport if sealed air-tight.

@Gene Hacker
I have not tested all plastics but I'm sure MMA doesn't solve PP, PE, PET. I'm making all my tests in plastic vials. The only doubt I have is Polystyrene which gets easily dissolved by many types of solvents. I will make a test and get back to you here.
You can add colorants to this resin without any problem. This is acrylic chemistry and there are a wide range of dye type colorants that could be solved in the MMA. Adding solid colorants, pigments, is a different issue as I would expect them to clog the fine nozzles.
Edit: And of course you could add pigments to the powder bed if you want the whole body to be one specific color.

Edited 1 time(s). Last edit at 07/11/2008 05:18AM by Fernando.

@Gene Hacker
MMA will solve Polystyrene. I took some PS foam and poured MMA drops on it and saw that distinctive liquefying happening.

FYI epson cartridges are made of polypropylene.

Grat! I was worried for a while that they could be mado of some PS copolymer.
PP would be perfect for this approach.

Does anybody know if only Epson makes the cartridges for their printers? Does anybody else fabricate these consumables?
Edit here's the answer to that question:
[en.wikipedia.org]

Something like this would be really usefull for larger prints:
[www.color-sun.com]

Edited 1 time(s). Last edit at 07/12/2008 05:23AM by Fernando.

I have gone down this Epson print head path because I thought the piezo head would be able to print a variety of liquids. My personal experience has been that it is difficult to get the Epson print head to print anything other than ink that comes in an Epson compatible cartridge.

I tried matching viscosity and surface tension by mixing water, glycerin and liquid soap.
Water: base material
Glycerin: used to increase viscosity
Liquid soap: used as a surfactant (as suggested by mycroftxxx)

To match the properties I used a syringe as a makeshift zahn cup. I first timed the Epson ink as a baseline. When I timed the water and glycerin mix in my makeshift zahn cup. It was obvious that I needed something to decrease the surface tension (the liquid dribbled out of the syringe rather than flowing smoothly). The liquid soap worked great.

I think I have a recipe for a mixture that matches as well as I can achieve using my method. I tried my recipe but it did not work in the Epson print head.

I think the odds of getting ether the MMA catalyzer or accelerator to print from an espon head are slim. Getting them both to print would be shocking.

@Fernando
I am willing if you still want me to give the MMA a shot. I have cartridges so you don't need to spend extra money on that (I have some empties that I have not tainted with anything else). I would like to test any samples in my makeshift zahn cup before I tried printing so getting them in any small vial would be better than in an inkjet cartridge for me.

Scorch

This is from the SOFTWARE forum:
>Re: STL Slice & Dice - Help Wanted!
>james Wrote:
>-------------------------------------------------------
> I've placed some python code in svn at
> trunk/users/vasile/stl2gcode. It takes an stl
> file, converts it into povray format, slices it
> into png-formatted layers and then outputs gcode
> for each layer.

The program still needs a little work but it produces png files of layers sliced through a stl file. The images in the png files are what will be needed to print 3D parts on a modified printer.

Scorch

I was digging around the forum here. Saw this thread. Read what you guys are using.

I was a real world sculptor before I went digital CGI. I gotta tell ya if Zcorp is using a Gypsum to make parts. They are not using Plaster of Paris.

We use this stuff called Ultra Cal 30 in the sculpting biz to make our molds off of our clay sculptures. It's just like Plaster only it's better. It doesn't get as hot when it cures. It picks up detail from our sculpts better. Less bubbles/pits, and it doesn't shrink as much as Plaster does.


I'm willing to take a guess that is probably what Zcorp is using. That or Hydrocal, but Ultracal 30 is much better than both Hydrocal and Plaster.

We yell at Newbies who ask if it's ok to use Plaster of Paris to make molds off of theyre sculpts. We hate it so...

I hope this is true, cause that Evil Scientist Lab Sugar Fab RP Machine looks like it could be an easy reconvert to make a homemade Zcorp like machine.

If you want to talk about accelerating the setup time of the Ultracal 30. You add Potassium Sulphate into the water.

You can also you mix in another Gypsum called Terra Alba into the Ultracal to speed it's set time up.

Warmer water also helps to speed it up.

As for how much Potassium Sulphate. That I don't know I can ask around. Same goes for the finely ground Terra Alba. The water/binder in the Zcorp machine is yellow looking. I will also ask about this to see if anybody has any idea as to what it might be.

Edited 1 time(s). Last edit at 07/17/2008 05:31PM by makeit.

Hmm, interesting!
On a quick search, the prices I found don't seem too expensive either:
[www.plaster.com]
At 26$ for 50 pounds it's ranks at 0.52$ per pound.

@makeit: Some more questions for you. How fast can you make this plaster harden, best case scenario? Would your guess be it could be applied in layers as per Scorch's device and retain enough hardness (not break into slices)? It doesn't need to finish rock solid, just hard enough that you can manipulate it and that in a later step it can be impregnated with some kind of resin. Is the end result porous enough to adsorb resin?

Edit: I have read this thread on a forum which contains some specifics about this material, what it's made of, the various mixing proportions with water etc...
[www.sculpture.net]

It's actually a mix of 85% Plaster of Paris (Gypsum, CaSo4 * 1/2H2O), 10% Portland cement and 5% sand dust.

Edited 3 time(s). Last edit at 07/18/2008 04:24AM by Fernando.

Dry strength is 6,000 psi VS Plasters 2,400 psi.

The layers bond better against each other in Ultracal.

Time for cure is 25-35 minutes, but this machine is doing micro thin layers so who knows.

I buy mine from a local pottery shop, and thats where you should look too since you might have one near you and that will make it even cheaper. I buy 100 pound bags around 45 bucks.

As far as impregnating it with a resin. I guess so. It is porous. I mean we use it to cast latex in it, and it pulls the water out of the latex and that's how we makes mask. You can mold the ultracal finished part in many different flexable materials and make cast copies from that mold in resin, silicone, or urethane so...

I'm not worried about the part that comes out, cause you can always mold it to make it in the material you want. I notice you guys are very concerned about that.

Yeah we want to be able to do finshed parts as well as molds. Both things are a very good thing to be able to build.
The strength of the dry product is impressive, if in layers we can achieve half or a third of that i would be more than happy. You can always add extra toughness afterwards with very cheap resins. The end result should be very resilient indeed!

I think the only issue here may be if the inkjets can achieve enough wetting to create an uniform layer. I wonder if blanketing the dry powder with wather through an inkjet will make it bond enough.
Best case scenario is if we need 1 or several passes to bond 1 layer.
Worst would be if 1 pass delivers to much water so that the plaster starts to crumble or flow.
I really need to get myself an inkjet printer!!

Found this on the net- after this is Zcorps patent on binder and powder.

0021] The first adhesive may be at least partially soluble in a fluid applied to the granular material during three dimensional printing. The at least partially soluble adhesive may include or consist of polyvinyl alcohol, sulfonated polyester polymer, sulfonated polystyrene, octylacrylamide/acrylate/ butylaminoethyl methacrylate copolymer, acrylates/octylacrylamide copolymer, polyacrylic acid, polyvinyl pyrrolidone, styrenated polyacrylic acid, polyethylene oxide, sodium polyacrylate, sodium polyacrylate copolymer with maleic acid, polyvinyl pyrrolidone copolymer with vinyl acetate, butylated polyvinylpyrrolidone, polyvinyl alcohol- co-vinyl acetate, and combinations and copolymers thereof.
[0022] The granular material may include a filler. The filler may be inert. The inert filler may include or consist of plaster, terra alba, bentonite, calcium silicate, calcium phosphate, magnesium silicate, magnesium phosphate, aluminum oxide, aluminum hydroxide,
limestone, dolomite, wollasonite, mica, glass fiber, glass powder, cellulose fiber, silicon carbide fiber, graphite fiber, aluminosilicate fiber, mineral fiber, and combinations thereof.
[0023] The inert filler may include or consist of an organic filler such as starch, modified starch, maltodextrin, cellulose, polypropylene fiber, polyamide flock, rayon, polyvinyl alcohol fiber, sugars and sugar alcohols, carbohydrates, and combinations thereof.


--------------------------------------------------------------

Zcorps patent on the liquid binder and powder. ( I like the gelatin, rabbit-skin glue, soy protein mixed in water binder listing. Wonder if the build powder used for that one is White Corn Starch.)

1. An article, comprising;

a product of a mixture of a plurality of particles comprising;

an adhesive; and

a filler;

wherein said mixture of a plurality of particles further comprises a first fibrous component and a fluid that activates said adhesive to form an essentially solid article composed of said plurality of particles;

said adhesive substantially soluble in, and said filler sparingly soluble in, said fluid;

the article further comprising adjacent layers, each layer comprising the product of the mixture of particles and having a contour with an edge, and a final shape of the article being defined by the edge of each of the layers, wherein either a portion of the edge of a first layer is offset from a portion of the edge of an adjacent layer to form an article having an undercut and/or overhang, or a continuous first layer is provided with a discontinuous adjacent layer to form an article having a cavity.

2. The article of claim 1, wherein said mixture comprises a second fibrous component.

3. The article of claim 2, wherein said first fibrous component has a mean length of about 60 microns to about 200 microns.

4. The article of claim 3, wherein said second fibrous component has a mean length of about 30 .mu.m to about 100 .mu.m.

5. The article of claim 4, wherein said first fibrous component and said second fibrous component are selected from the group consisting of polymeric fiber, ceramic fiber, graphite fiber and fiberglass.

6. The article of claim 5, wherein said first fibrous component and said second fibrous component are a polymeric fiber selected from the group consisting of cellulose and cellulose derivatives and substituted or unsubstituted, straight or branched, alkyl or alkene, monomers containing up to eight carbon atoms.

7. The article of claim 1, wherein said filler is an organic compound.

8. The article of claim 7, wherein said filler is an organic compound selected from the group consisting of sugars, sugar alcohols, organic acids and urea.

9. The article of claim 7, wherein said filler is a carbohydrate.

10. The article of claim 9, wherein said filler is a carbohydrate selected from the group comprising acacia gum, locust bean gum, pregelatinized starch, acid-modified starch, hydrolyzed starch, sodium carboxymethylcellulose, sodium alginate, hydroxypropyl cellulose, and hydrolyzed starch.

11. The article of claim 9, wherein said filler is maltodextrin.

12. The article of claim 11, wherein said filler is maltodextrin having a dextrose equivalent of 10.

13. The article of claim 1, wherein said filler is a polymer.

14. The article of claim 13, wherein said filler is a polymer selected from the group consisting of polyethylene glycol, sodium polyacrylate, polyvinyl alcohol, polyvinyl pyrrolidone, sodium polyacrylate copolymer with maleic acid, and polyvinyl pyrrolidone copolymer with vinyl acetate.

15. The article of claim 1, wherein said filler is a protein.

16. The article of claim 15, wherein said filler is a protein selected from the group consisting of gelatin, rabbit-skin glue and soy protein.

17. The article of claim 1, wherein said filler is an inorganic compound.

18. The article of claim 17, wherein said filler is an inorganic compound selected from the group consisting of sodium silicate, plaster, bentonite and salt.

19. The article of claim 1, wherein said adhesive is a water-soluble polymer.

20. The article of claim 19, wherein said adhesive is a water-soluble polymer selected from the group consisting of polyethylene glycol, sodium polyacrylate, polyvinyl alcohol, polyvinyl pyrrolidone, sodium polyacrylate copolymer with maleic acid, and polyvinyl pyrrolidone copolymer with vinyl acetate.

21. The article of claim 19, wherein said adhesive is a water soluble polymer that is a carbohydrate.

22. The article of claim 21, wherein said adhesive is a water soluble polymer that is a carbohydrate selected from the group comprising acacia gum, locust bean gum, pregelatinized starch, acid-modified starch, hydrolyzed starch, sodium carboxymethylcellulose, sodium alginate, hydroxypropyl cellulose, and hydrolyzed starch.

23. The article of claim 1, wherein said adhesive is an organic compound.

24. The article of claim 23, wherein said adhesive is an organic compound selected from the group consisting of sugars, sugar alcohols, organic acids and urea.

25. The article of claim 1, wherein said adhesive is a protein.

26. The article of claim 25, wherein said adhesive is a protein selected from the group consisting of gelatin, rabbit-skin glue and soy protein.

27. The article of claim 1, wherein said adhesive is an inorganic compound.

28. The article of claim 27, wherein said adhesive is an inorganic compound selected from the group consisting of sodium silicate, plaster, bentonite and salt.

29. The article of claim 1, wherein said fluid is added in an amount effective to form a solution of said adhesive.

30. The article of claim 29, wherein said fluid further comprises a humectant.

31. The article of claim 30, wherein said fluid further comprises a humectant selected from the group consisting of a polyhydric alcohol and urea.

32. The article of claim 31, wherein said fluid further comprises a flowrate enhancer.

33. The article of claim 29, wherein said fluid is a non-aqueous fluid.

34. The article of claim 33, wherein said fluid is a non-aqueous fluid selected from the group consisting of methyl alcohol, ethyl alcohol, isopropyl alcohol, acetone, methylene chloride, acetic acid and ethyl acetoacetate.

35. The article of claim 1, further comprising a printing aid to reduce distortion in activated material.

36. The article of claim 1, wherein said fluid is an aqueous fluid.

37. The article of claim 1, wherein said mixture of said plurality of particles comprises:

adhesive in an amount of from about 10 to about 50 percent, by weight, of the total weight of the mixture;

filler in an amount of from about 0 to about 80 percent, by weight, of the total weight of the mixture;

fiber in an amount of from about 0 to about 30 percent, by weight, of the total weight of the mixture; and

said fluid comprises a humectant, in an amount of about 0-20 percent, by volume, based on the total volume of said fluid, a flowrate enhancer in an amount of about 0-10 percent, by volume, based on the total volume of said fluid; and dye in an amount of about 0-0.1 percent, by volume, based on the total volume of said fluid.

38. The article of claim 37, wherein said mixture comprises a second fibrous component in an amount of about 10 percent, by weight, of the total mixture.

39. The article of claim 37, wherein said mixture of said plurality of particles comprises:

adhesive in an amount of about 30 percent, by weight, of the total weight of the mixture;

filler in an amount of from 60 percent, by weight, of the total weight of the mixture;

fiber in an amount of about 10 percent, by weight, of the total weight of the mixture; and

said fluid comprises said humectant, in an amount of about 5 percent, by volume, based on the total volume of said fluid, a flowrate enhancer in an amount of about 2 percent, by volume, based on the total volume of said fluid, and dye in an amount of from about 0-0.1 percent, by volume, based on the total volume of said fluid.

40. The article of claim 39, wherein said mixture comprises a second fibrous component in an amount of about 10 percent, by weight, of the total mixture.

41. The article of claim 1, wherein said particles each comprise said filler coated with said adhesive, said mixture self-adhering when activated by said fluid.

42. The article of claim 1, wherein said mixture comprises a first and second polymeric fibrous component.

43. The article of claim 42, wherein said filler is a water-soluble polymer.

44. The article of claim 43, wherein said adhesive is a water-soluble polymer.

45. The article of claim 44, wherein said fluid is an aqueous fluid.

46. The article of claim 45, wherein said filler is maltodextrin.

47. The article of claim 46, wherein said adhesive is selected from the group consisting of selected from the group consisting of polyethylene glycol, sodium polyacrylate, polyvinyl alcohol, polyvinyl pyrrolidone, sodium polyacrylate copolymer with maleic acid, and polyvinyl pyrrolidone copolymer with vinyl acetate.

48. The article of claim 1, wherein each layer of the article is adhered to an adjacent layer of the article via adhesive bonds provided by the activated adhesive.

49. The article of claim 1, wherein the first fibrous component is a reinforcing fibrous component restricted to a length about equal to a thickness of the layer.

50. The article of claim 49, wherein the mixture further comprises a second fibrous component, to provide dimensional stability.

51. The article of claim 50, wherein the second fibrous component has a length less than half the length of the first fibrous component.

52. An article, comprising;

a product of a mixture of a plurality of particles comprising;

an adhesive;

a filler; and

an aqueous fluid that activates said adhesive to form an essentially solid article composed of said plurality of particles;

said adhesive substantially soluble in, and said filler sparingly soluble in, said aqueous fluid;

the article further comprising adjacent layers, each layer comprising the product of the mixture of particles and having a contour with an edge, and a final shape of the article being defined by the edge of each of the layers, wherein either a portion of the edge of a first layer is offset from a portion of the edge of an adjacent layer to form an article having an undercut and/or overhang, or a continuous first layer is provided with a discontinuous adjacent layer to form an article having a cavity.

53. The article of claim 52, wherein said mixture comprises a first fibrous component.

54. The article of claim 53, wherein said mixture comprises a second fibrous component.

55. The article of claim 54, wherein said first fibrous component has a mean length of about 60 microns to about 200 microns.

56. The article of claim 55, wherein said second fibrous component has a mean length of about 30 .mu.m to about 100 .mu.m.

57. The article of claim 56, wherein said first fibrous component and said second fibrous component are selected from the group consisting of polymeric fiber, ceramic fiber, graphite fiber and fiberglass.

58. The article of claim 57, wherein said first fibrous component and said second fibrous component are a polymeric fiber selected from the group consisting of cellulose and cellulose derivatives and substituted or unsubstituted, straight or branched, alkyl or alkene, monomers containing up to eight carbon atoms.

59. The article of claim 58, wherein said filler is a carbohydrate.

60. The article of claim 59, wherein said filler is maltodextrin having a dextrose equivalent of 10.

61. The article of claim 58, wherein said filler is a polymer.

62. The article of claim 61, wherein said filler is a polymer selected from the group consisting of polyethylene glycol, sodium polyacrylate, polyvinyl alcohol, polyvinyl pyrrolidone, sodium polyacrylate copolymer with maleic acid, and polyvinyl pyrrolidone copolymer with vinyl acetate.

63. The article of claim 62, wherein said polymer is a carbohydrate selected from the group comprising acacia gum, locust bean gum, pregelatinized starch, acid-modified starch, hydrolyzed starch, sodium carboxymethylcellulose, sodium alginate, hydroxypropyl cellulose, and hydrolyzed starch.

64. The article of claim 52, wherein said filler is an organic compound.

65. The article of claim 64, wherein said filler is an organic compound selected from the group consisting of sugars, sugar alcohols, organic acids and urea.

66. The article of claim 52, wherein said filler is a protein.

67. The product of claim 66, wherein said filler is a protein selected from the group consisting of gelatin, rabbit-skin glue and soy protein.

68. The article of claim 52, wherein said filler is an inorganic compound.

69. The article of claim 68, wherein said filler is an inorganic compound selected from the group consisting of sodium silicate, plaster, bentonite and salt.

70. The article of claim 52, wherein said adhesive is a water-soluble polymer.

71. The article of claim 70, wherein said adhesive is a water soluble polymer that is a carbohydrate selected from the group comprising acacia gum, locust bean gum, pregelatinized starch, acid-modified starch, hydrolyzed starch, sodium carboxymethylcellulose, sodium alginate, hydroxypropyl cellulose, and hydrolyzed starch.

72. The article of claim 52, wherein said adhesive is an organic compound.

73. The article of claim 52, wherein said adhesive is an organic compound selected from the group consisting of sugars, sugar alcohols, organic acids and urea.

74. The product of claim 52, wherein said adhesive is a protein.

75. The product of claim 74, wherein said adhesive is a protein selected from the group consisting of gelatin, rabbit-skin glue and soy protein.

76. The article of claim 52, wherein said adhesive is an inorganic compound.

77. The article of claim 66, wherein said adhesive is an inorganic compound selected from the group consisting of sodium silicate, plaster, bentonite and salt.

78. The article of claim 52, wherein said fluid further comprises a humectant.

79. The article of claim 52, wherein said fluid further comprises a flowrate enhancer.

80. The article of claim 52, further comprising a printing aid to reduce distortion in activated material.

81. The article of claim 52, wherein said particles each comprise said filler coated with said adhesive, said mixture self-adhering when activated by said fluid.

82. The article of claim 52, wherein said mixture comprises a first and second polymeric fibrous component.

83. The article of claim 82, wherein said filler is a water-soluble polymer.

84. The article of claim 83, wherein said adhesive is a water-soluble polymer.

85. The article of claim 84, wherein said filler is maltodextrin.

86. The article of claim 85, wherein said adhesive is selected from the group consisting of selected from the group consisting of polyethylene glycol, sodium polyacrylate, polyvinyl alcohol, polyvinyl pyrrolidone, sodium polyacrylate copolymer with maleic acid, and polyvinyl pyrrolidone copolymer with vinyl acetate.

87. An article, comprising;

a product of a mixture of a plurality of particles comprising;

an adhesive;

a filler;

a first fibrous component; and

an aqueous fluid that activates said adhesive to form an essentially solid article composed of said plurality of particles;

said adhesive substantially soluble in, and said fiber sparingly soluble in, said aqueous fluid;

the article further comprising adjacent layers, each layer comprising the product of the mixture of particles and having a contour with an edge, and a final shape of the article being defined by the edge of each of the layers, wherein either a portion of the edge of a first layer is offset from a portion of the edge of an adjacent layer to form an article having an undercut and/or overhang, or a continuous first layer is provided with a discontinuous adjacent layer to form an article having a cavity.

88. The article of claim 87, wherein said filler is sparingly soluble in said aqueous fluid.

Edited 1 time(s). Last edit at 07/19/2008 02:25PM by makeit.

if the water is depostited on the ultracal powder at the same flow rate of ink on paper. I'm pretty sure it wouldn't run, crumble or flow.

How do you drop the next layer of powder down over the previous one? I know the build tray lowers before each new layer.

Theres a homemade RP machine out there called the Candyfab- Totally looks like the one to study to make a Zcorpclone

Also just found out that 3dmax has a split feature to make 2d images of your 3d model.

I use meshlabs and it works out ok, but it doesn't make the split layers from the absolute center of the model. I need to beg someone to fix that. Come up with a spilt entire 3d model into 2d images function.


Thoughts:
Pump connected to tube
tube connected to the print cartridge
pump keeps cartridge full. (how does it know when to stop so it doesnt over fill it?)

printer prints out plotter files of 2d slice info made from 3d model. Powder acts as support system( )

table drops one layer before next print session- see candyfab machine They used a 12 V one ton automotive jack

[www.flickr.com]

How is the next layer pulled over the previous one? youtube video of zcorp shows layer covering over previous print when arm returns for the next pass. Looks like a roller system of some sort.

Quote

How do you drop the next layer of powder down over the previous one? I know the build tray lowers before each new layer.

This got touched upon in another thread. You use a hopper of feedstock, and a counter-rotating roller to push the layer to the desired thickness and compact it somewhat. Or at least, that sounds like the best plan.

Quote

Theres a homemade RP machine out there called the Candyfab- Totally looks like the one to study to make a Zcorpclone

Well... not quite. It was designed and built with some fairly specific goals in mind, and their fabrication method (SHASAM, which deserves a prize for being a splendid acronym) has very limited resolution.

Their printing method also appears to be involve shasam-ing pixels rather than drawing vectors; perhaps I misunderstood their articles though. This isn't a great design decision either.

Lastly, they use a very large build area, which means that it gets pretty heavy when full. For this reason, they don't have a dispensing hopper, and it would be very big, heavy, awkward to fill, require a very strong chassis etc etc. New layers are added by hand. Because of its low resolution, this doesn't cause too many problems.

It is only superficially similar top z-corp type things, In my opinion at least

[forums.reprap.org]

I think this is how the refill layer system works. This setup lets the Plow do a double pass over the new layer to ensure a nice clean unform layer. The first pass happens when it travels over the print area- since it's place before the printer cartridge. The next pass grabs the newly raised powder from the other table that raises up. It drags this new layer of powder over the dropped down build area.

makeit Wrote:
-------------------------------------------------------
> [forums.reprap.org]
>
> I think this is how the refill layer system works.
> This setup lets the Plow do a double pass over the
> new layer to ensure a nice clean unform layer. The
> first pass happens when it travels over the print
> area- since it's place before the printer
> cartridge. The next pass grabs the newly raised
> powder from the other table that raises up. It
> drags this new layer of powder over the dropped
> down build area.

Pretty much exactly how SLS Machines do it. Except that theres two feed pistons either side of the build area, and two overflow chutes outside of those.

A counter-rotating roller picks the material up and pushes it evenly accross the bed and the other feed, into the overflow chute.

The trouble with pulling a 'blade' accross the bed is you'll just tend to 'streak' it. It'll just create a series of long scores accross the bed.

The problem of the leveling device leaving marks, 'streaks', in the powder got me thinking. Vibrating the container would make the powder behave more like a liquid and find it's own level, unfortunatly this isn't suitable if the power needs to be compacted.

Well and the just printed layer would move around...
is that a good idea?

See

'sid

A vibrating part bed is actually not so bad of an idea for levelling out the powder once its been deposited. It will need a good deal of vibration depending on the material used.

Unfortunately, you're also going to be wobbling your 'curing' parts, and also potentially misalign the bed for the next layer of printing. Then theres the problem of constantly shaking a cartesian bot made of cheap steel tubes not designed to withstand forces anywhere near that.

Its a good idea though.

Making the powder behave like a liquid is potentially a bad thing, if it results in the part moving. From my extensive knowledge of cheesecake manufacture, I recall that in a mixture of large and small fragments of the same material, agitation causes the larger parts to rise to the surface.

The top layer could potentially contains some very fragile areas indeed... the beginnings of a part with a flat horizontal surface are going to be a single layer thick for example.

Nice idea, probably doomed.

Got the mix trick for you guys.

4 onces Terra Alba mixed into 50 pounds worth of ultracal 30 powder.

Add 2 onces of Aluminum Sulphate to the proper water volume needed for a 50 pound mix as well. Aluminum Sulphate works quicker than Potassium or Zinc sulphate.


The warmer the water mix is, the quicker the ultracal will set as well.

I think Zcorp is using starch, but then again. I don't see why this system won't work.

Paint the Ultracal with a Forton resin system to strengthen it.

Edited 2 time(s). Last edit at 07/23/2008 12:44PM by makeit.

I think that using a roller to spread a layer of powder is probably the best way to do it. Here's an example: [www.indoor.flyer.co.uk]

Might I also remind you of all the trouble NASA is having with vibrating powders.