Well flammability is really the problem here. MMA is a volatile liquid with very low viscosity. So you need to work in safe conditions, no open flames and such. I could imagine a way of reducing volatility at the cost of increasing viscosity. Something along the lines of dissolving PMMA powder into MMA monomer could have the desired result. Agree on your description of the advantages of Acrylicby spota - Polymer Working Group
Hey Viktor! In the near future I will be able to give a formulation for Acrylic resin here that works on the same photoinitiators I sent you. The difficulty now seems to be able to work with the same commercial resins, as their composition is not specified most of the times. That's why for the Acrylic resin composition I will be using mostly the pure compounds, not commercial mixes. I can get 1by spota - Polymer Working Group
Hmm, interesting! On a quick search, the prices I found don't seem too expensive either: 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 rockby spota - Powder Printing and Selective Laser Sintering
Not with the photoinitiators discussed here. As far as I'm aware of, Urethane chemistry is based on 2 molecules that react together to form a polymer chain. As such, they don't need a catalyzer that could be triggered through UV. Unless you modify one of the 2 constituent molecules to be triggered by UV, I don't see how this could be done.by spota - Polymer Working Group
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: Something like this would be really usefull for larger prints:by spota - Powder Printing and Selective Laser Sintering
@Gene Hacker MMA will solve Polystyrene. I took some PS foam and poured MMA drops on it and saw that distinctive liquefying happening.by spota - Powder Printing and Selective Laser Sintering
@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 Hackerby spota - Powder Printing and Selective Laser Sintering
@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 cartdrby spota - Powder Printing and Selective Laser Sintering
mimarob Wrote: ------------------------------------------------------- > > how about gelatine? to wobbly? Doesn't set fast enough. Agar is better in that respect and is less wobbly. It works fine for "cold" deposition. But for molten plastic, you need a support material that sticks to it so that it prevents warping. The best candidate, IMHO would be the same plastic, deposited in supportby spota - Plastic Extruder Working Group
Glycerin is very safe. You will find it in any Pharmacy and it can be heated up to over 200by spota - Plastic Extruder Working Group
Wow... It'll take ages to write! As for Steve's suggestions: DTF - deposited thermoplastic fabrication: I like it better as a replacement for the "forbidden word" as it doesn't specify that we have to use a filament. Maybe somewhere in teh future there will be other extruder designs that use pellets or whatever? EMM - extruded material manufacturing - Even more general than the previous. I liby spota - General
Interesting! Have we attracted somebody's attention that early? Okay, let's call it Reprapping or whatever.by spota - General
I'd agree that self replication is a great feature RepRap has that F@H lacks. It just allows for an eventual cheap and exponential distribution model of our equippment. I'd also say that working with an open-source/GPL license is another key feature of this project that makes people want to work on it. It certainly does that for me. FDM may or may not be where it's at. I consider it to be a veryby spota - General
Yup, I agree more or less. Those are the beacons we would be expecting. There's a related post by Steven DeGroof showing the google trends and I think the biggest news, appart from the pikes we face when getting digged/dug/dugged is that we seem to gather a solid amount of returning traffic. As of lately, I have also witnessed some very interesting new techniques being submitted to discussion herby spota - General
I'm sceptical about the cutting edges being tempered steel. Theres Vanadium steel, Carbide, Carborundum. How would you machine those?by spota - General
Heheh, I see we have an expert!by spota - Powder Printing and Selective Laser Sintering
I wonder if the drillbits aren't a unsurmountable problem as well? Think of the technology needed to machine a drillbit, the precision involved. Plus there is a chicken and egg problem that arises there also: you need a hard drillbit to machine the next, less hard drillbit, making drillbits that are less hard after each generation. Also, ther eis a lot of knowhow involved with the operating ofby spota - General
Different types of resins for different types of applications indeed. I think the inkjet is easier for me to build on, plus I have a 1liter bottle of Methylmetacrylate plus Benzoylperoxide lying around wich I don't know what to do with, so I will try this. The more viscous resins would be perfect for persitaltic pumps. That pump would work well with filler charged resins too, wich is a great advby spota - Powder Printing and Selective Laser Sintering
Hmmmm... I see this resin printing calls for more experimentation. I wonder if for Epson printers the liquid has to be hidrophylic... I will soon take a vacation and I should be able to look into it. First I will see what's the best solution as a printing resin. I suppose acrylic is the way to go. I will get me an used Epson printer and try to print some stuff (itching that ever present experimeby spota - Powder Printing and Selective Laser Sintering
Although you have to pay to read the complete article, bollocks!....by spota - General
@Scorch I have been thinking along the same lines, try to reduce the viscosity to the lowest possible values. There are two solutions I see here: 1) Find the safest thinner possible for Polyester resins. The logical choice for a thinner would be Styrene (viscosity 0.7 mPa-s). 2) Forget about Polyester and work with Methylmetacrylate and/or Butylmethacrylate, which have an extremely low viscoby spota - Powder Printing and Selective Laser Sintering
Impressive demonstration! I wonder if the Epson piezzoelectric cartridges would work with UV-resins. They have the consistency of syrup, so maybe they would clog the very fine nozzles, what do you think? Also, for this setup one could consider air drying resins, which should be easier to get by than UV photoinitiator mixes, although they are slower at catalyzing. Another very easy option would beby spota - Powder Printing and Selective Laser Sintering
@Viktor No worries, mate. i myself am extremely busy now, changing jobs as well, wich leaves me very little free time for much else. So, whenever you have time, have a go at the initiators I sent you and post it on the forum, as I will always be checking. To bad about the silicone being UV opaque! That would really have been a great application. Did you see what happens if lightly heated? Maybeby spota - Polymer Working Group
Hello Nishant, You can try Hydroquinone which should act as a radical blocker. Very low doses around 0.01% could be effective. Work upwards from that dose to increase potlife. Do you know if your resin mix is sensitive to metal ions? If yes, adding EDTA would also reduce the sensitivity of the resin mix. Good hunting!by spota - Polymer Working Group
Hey all! @Viktor: I am very curious about what will happen with these catalyzers and the silicone resine. it would be a very interesting application if the same photoinitiators work. Please keep me posted on that! As with the other idea you have, that's called live-polymerization. This is a very hot issue these days in polymerization chemistry. I'm a little green on that subject so I cannot tellby spota - Plastic Extruder Working Group
Holddd your horses, Zach! Those links you sent me are for some really expensive stuff! Here is a list of lamps with more reasonable prices: Here's an online shop with the germicidal kind: Click on the GERMICIDAL - COMPACT FLUORESCENT (can't link directly here) And under ULTRAVIOLET - BLACKLIGHT BL350 - FLY KILLER they have the blacklight model. Actually I got mine from a regular lighting shopby spota - Plastic Extruder Working Group
I understand. I'm not so familiar with FDM printing strategies, but I do get from your explanation why grip is important. And I agree that the best candidate for support material in that case is the same polymer. Maybe a combined approach to the support role could be applied: use agar or similar for the gravity support material and columns of polymer for specific points where grip and warp avoidby spota - Plastic Extruder Working Group
That much? That's quite a tall bill! What you are looking for is a remedy to shrinkage, I don't know if any support material can give you that. Bodies, when cooled down will try to shrink. If you don't let them, which requires some serious tension bearing devices, they will become tensioned. IMHO, a "sticky" surface is just not a good enough device to maintain and counteract the tension created iby spota - Plastic Extruder Working Group
On the bacteria issue, adding some antiseptic to the mix would also do the trick, like soap or bleach. I only tried with PP over the agar. It stuck very lightly, indeed, but not enough to require heavy force to remove it when cold. The question being: how much would it be necessary to stick?by spota - Plastic Extruder Working Group
Melting the gel in the microwave is very easy! It also accepts a lot of fillers. So far, sand-dust or clay dust have had the best results in respect of adding better mechanical stability and thermal resilience to fused polypropylene. I think this stuff really is ideal as support material for the FDM process. The only point to be solved is how to deposit it, be it by creating 3mm rods solid enouby spota - Plastic Extruder Working Group