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Designs that do not fit in other categories. Previously named "New RepStraps and Post Mendel"
Hello Robert!
I have done some research to achieve resin mixtures that would be UV cured. My goal was to make both the resins and the UV-lamps affordable, as well as fast curing.
There have been a couple of problems that have been encountered on the way.
Achieving cheap and fast curing mixes produced an effect that's called surface screening:
The top layer cures fast but the bottom layers don't
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spota
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Polymer Working Group
Sorry if I'm a little late to join in on the thread.
I just saw it recently and as a chemist just wanted to confirm what BDolge has said above.
Sadly PLA is not so easy to synthesize as would be desirable. Several of the steps above are cumbersome, some of them are even frankly dangerous. But it is possible to do, specially if done in a bigger operation. Will you m,anage to eat the price of impor
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spota
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Polymer Working Group
SebastienBailard Wrote:
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> I wonder; could one make a slurry of powdered
> bronze and monomer, squirt catalyst on the surface
> to make a hardened slice of the object, put down
> another thin layer of slurry, another squirt, and
> so on?
>
>
>
Definitley a good idea, yes!
The only requisite here would be that the tim
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spota
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Powder Printing and Selective Laser Sintering
SebastienBailard Wrote:
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> There are two kinds, piezoelectric and thermo.
> *Piezoelectric uses a piezoelectric element to
> mechanically push the droplets out.
> *Thermo heats up a resistor. The heat creates a
> steam bubble in the (usually aqueous with thermo)
> ink, and that bubble pushes the droplet out.
> See:
>
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spota
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Powder Printing and Selective Laser Sintering
I've been thinking and this might be the ideal technique to use the "spray-on" catalyzer on top of a layer of liquid resin.
Imagine a surface of resin in a vat that is being filled a layer at a time. after thi sfilling step, the inkjet sprays catalyzer on specific points, initiating the polymerization. neigbouring points would merge together. Newly sprayed points on top of the previous layer wou
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spota
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Powder Printing and Selective Laser Sintering
Hmmmm, inkjet!
That's the perfect technology for my UV-setting resins!
What is the viscosity needed for the ink?
Also, won't it clog easely with resins?
AFAIK, it's based on microbubbles generated by explosive evaporation...
Thats the kind of thing that could cause a monomer to polymerize in the inkjets canules.
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spota
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Powder Printing and Selective Laser Sintering
TheGuy Wrote:
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> Spent my spare 3.5 minutes today tinkering with
> polymer mono filament and an electrostatic module.
> Easily got 7 inches of deflection from 7.5kvolts
> at 80hz. So the extruder head I envision could
> cover at least that much area with minimal
> expense. Picture 2 electrodes at right angles (or
> 3 at 1
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spota
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General
What about using heat resitant cements?
It woul dbe a matter of having the correct molds. Maybe silicon molds would work nicely. Also i'm trying to mix resins that have a degree of flexibility but still maintain an accurate shape. This would be useful as mold material.
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spota
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General
Hey Viktor!
This Waterglass investigation is really cool!
And it has a LOT of possibilities i see. I have been reading up a little on this Sodium Silicate. It really is the ideal sintering composite! Do you have pictures of a final glass sintered with this stuff? Does it look like regular glass or is it more like aerogel?
Now that we have a separate forum for our gooey threads, don't you think
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spota
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Polymer Working Group
ohiomike Wrote (General forum):
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> A major issue with fibers is that they are resin
> hungry materials. If you want flex in the material
> add polyurathanes. Most two part polyurathene
> casting resins sold at craft stores are straight
> chain polyols so they have relatively high
> molecular weights to hydroxide values. The
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spota
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Polymer Working Group
Brian Dolge Wrote (General forum):
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> Have you considered using powdered fibre-based or
> "volume enhancing" laxatives like musilex or any
> psylium based product? As Mike pointed out it
> won't enhance flexibility but it might increase
> toughness by as part of a composite material.
Hey Brian!
I tried this recently. I went
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spota
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Polymer Working Group
ohiomike Wrote (General forum):
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> Try mixing the catalyzer into the flour first,
> partially fill a pan with the resultant mixture,
> and then using a syringe write a pattern in the
> pan with FA, add another layer and repeat. I would
> be very interested to see if you have any
> interlayer adhesion issues and what your sur
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spota
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Polymer Working Group
Hey all!
I will continue my this thread under the Gooey Extrusion sub-forum as it seems a more appropriate place to talk about... well, gooey stuff
See you over there!
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spota
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Paste Extrusion Working Group
Hey all!
I'm happy to inaugurate this sub-forum and I will do it with this matter which is what I'm working on.
To start, i'll explain what Furfury Alcohol (FA) is and why I chose to investigate it. FA is a brownish flammable liquid, of the similar viscosity as water. It is produced from plant waste through chemical reaction with sulfuric acid and is quite a cheap and readily available product.
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spota
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Polymer Working Group
I like the organisation, Seb!
I'm more of a red commie than an anarchist you see
Off to post my first thread in the Goeey part!
Actually, it's a follow-up on that old "Furfuryl Alcohol" tread in general forums...
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spota
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General
RoundSparrow:
I damn agree! Call me obsessive compulsive, but a little order in these forums would do a lot of good and your scheme seems to make a lot of sense.
Zach:
Tattoos, really?? What is your tattoo about? I design tattoos for the love of art, that's why the interest. For now, I have only made some that were tattooed on others, girlfriends mostly. I have one for me all thought up: a Prom
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spota
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General
I have to give credit to whomever told me to try regular flour!
I made a batch 2 days ago and left it to polymerize with straight catalyzer, no blocker.
here are the figures:
4 grams of flour
4 grams of Furfuryl Alcohol
1 gram of catalyzer solution (40% pTSA in a common alcohol sovent)
The result, as I saw them today are a flexible yet tough black polymer. Comparable to, say, shoe sole materia
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spota
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Paste Extrusion Working Group
Found some bulk proiders here:
The cellulose fiber is called SANCEL
it's packaged in 25kg bags
It's the same stuff you can buy at a nutritionist:
only that the nutritionists 250g costs you 6$
I'll try that as a filler too.
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spota
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Polymer Working Group
I will try regular flour and then some fiber food additives like the ones you mention (psylium, oat fiber and other mucilagens), just to learn the effectiveness of these so called water soluble fibers.
Actually I'm very positive that cellulose fiber, wood dust and some other plant derivates will help me as they contain the right kind of fiber. What I was wondering is if anybody had been working
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spota
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Polymer Working Group
Interesting...
Maybe these Alkali silicates will help you lower down the fusion temperatures of your ceramics? this is what in German would be called "Fliess Mittel".
I know that for this purpose Postassium Carbonate, Sodium Carbonate, Lead Carbonate are being used in the glass industry. My chemists gut feeling tells me that Alkali silicates should lower the melting temperatures down to more se
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spota
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Paste Extrusion Working Group
Mike I thought along the same lines as you.
having a vat with the cheap catalyzer I'm developing and printing Furfuryl Alcohol or Furfural threads on top of it, then dropping the layer a level. it would make for a ruff prototyper if we can solve the problem of enclosed volumes in the 3D models.
It's like a SLA (stereo lythography) but without lasers.
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spota
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General
Thanks for all the input.
maybe I should explain a little better what I have tried allready and what I'm aiming for:
I have allready tried starch and it has no effect as a crosslinker. I'm working with a brittle resin, wich os fantastic for hardness, but needs some kind of filler that crosslinks the polymer and has some flexible properties.
Starch cannot do this as it's a crystalline type of m
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spota
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Polymer Working Group
I'm opening this thread to call on anyone that may have worked with fibre powder, be it cellulose, oat husk, coconut, apple etc fibre powder.
What would be a good and cheap supply of this and where could I get it?
I'm looking fos something that has a very fine grain size (50 - 100 micro-meter) so that i can use it as a filler for resins that by itself are very stiff but brittle.
I have found cel
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spota
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Polymer Working Group
Hey all!
Thanx Zach! I also think this could be usefull. I will try and put together a recipy that people could easely work with.
I guess that building a simple circuit board would be th enext step... but I'm not very much of an electronics guy, so maybe somebody has a simple diagram that I can build. Nothing crazy. Just stuff to test resistors, transistors, condensators etc with this type of tr
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spota
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Paste Extrusion Working Group
Hey all!
After 2 weeks spent with a broken ellbow, i'm back on the workbench.
Nothing, i say NOTHING will hold me back
I have had some interesting results while mixing copper powder with this resin.
I mixed around 70 weight% of copper vs the resin mix. The resin polimerzed slow enough so that the copper powder subsided towards the bottom of the polimer.
When braking off the sample, which is 2m
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spota
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Paste Extrusion Working Group
I have read about this a couple of weeks ago.
The tricky part, on top of the painstaking layer per layer dip thingie, is to find out the correct suspenion of clay particles. It can't be to much and not to little, and the clay type has to have the correct platelet-group size.
This is as far as I remember reading, i think from Physorg.com
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spota
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Polymer Working Group
(from builders blog entry)
Hi all!
Today I made some progress on the blocked catalyzer.
As a reminder, the catalyzer is para-Toluene Sulfonic Acid (pTSA), wich is a strong organic acid, in solid form. I have dissolved it in Isopropanol alcohol (a solventquite similar to Ethanol).
This catalyzer, if added in this solved form to Furfuryl Alcohol (FAlc, the actual polymer resin) will cause it to
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spota
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Paste Extrusion Working Group
Hey Viktor!
Good idea! I will try starch as it's pretty easy to get and it's also a standard product.
I don't know how much fiber it contains, but it's worth a try.
Its always great to hear about your sintering efforts. They really seem to be going well!
It seems that glass, having a big thermal inertia is easier to sinter than metal, is that correct?
This would be an interesting result and wou
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spota
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Paste Extrusion Working Group
Hello Mike, nice to hear back from you!
Actually i started with Furfuryl Alcohol and not Furfur Aldehyde because it seemed to be less volatile as in less vapors. But I do have both and I want to complete the same tests on FAld as I'm doing on FAlc.
Yeah, the sealed pot was a stupid idea, I know
Afterwards I remembered you saying something about this in one of your previous posts. I think I wil
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spota
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Paste Extrusion Working Group
Fascinating stuff!
To bad i don't have such powerfull laser sources, it seems that a whole world of sintering possibilities lies there to be experimented...
Anyway, I will keep you indformed with the progresses I make with heat/light/UV activated polymer resins. Let's see if we can get some neat application working at low temperatures!
I'll inform you with mixture proportions soon. I'll also t
by
spota
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Paste Extrusion Working Group