The UV cured dental resins used to adhere fillings to teeth are filled with those toxic components. After polymerization they are considered biocompatible since they have passed the FDA tox tests.by 2shedsJackson - Polymer Working Group
UV cured dental polymers are printable. They just tend to be more costly since they are made for dental applications vs plastic trinkets.by 2shedsJackson - Polymer Working Group
The initiators work over a much wider range than just 355nm +/-1nm but it's unlikely to extend up to 405nm. The sensitivity probably falls off above 380nm to near zero.by 2shedsJackson - Polymer Working Group
Conductive UV cured resins have been around for quite some time. The carbon blacks types are mainly used for static protection. The one in the video looks pretty clear so it might be based on silver or copper since it's not outrageously expensive. I doubt if they will post a conductivity spec since it's made for arts and crafts vs printed electronics, but it will be easy enough to measure.by 2shedsJackson - Polymer Working Group
LinuxCNC runs on ARM. It's been ported to a few ARM SOC's (arm9, 11, cortex A8 and 9) for multi-axis machine control. linuxcnc raspberry pi mcp23017 realtime linux kernel ARM cnc stepper motors Linuxcnc (emc2) running on Pico-SAM9G45by 2shedsJackson - EMC2
EMC2 now supports RTAI for 3.x kernels as well as Xenomai and RT-Prempt . The developer supported Live and install CD is Ubuntu but others use Gentoo, Arch or custom distros.by 2shedsJackson - EMC2
PVA filament for FFF is water soluble and already available.by 2shedsJackson - Polymer Working Group
Photopolymers may be made to shrink, not shrink or even expand when cured. I'm not sure why you're having problems finding them. What did they say when you contacted them about photopolymers with low/no shrink?by 2shedsJackson - Polymer Working Group
Polyester resin may be made to shrink or even expand when cured. The range may be -15% to +5%. It depends on the formula.by 2shedsJackson - Polymer Working Group
What did they say when you emailed them to ask about the UV resin?by 2shedsJackson - Polymer Working Group
As an alternative to the Somos you can use any of the UV through visible spectrum cured photopolymers by They will cure quite rapidly at 355nm and have a few options for small quantities of different formulas with Paypal links for ordering. They also have hundreds of other formulas available.by 2shedsJackson - Polymer Working Group
The newly listed UV and Visible Light Cured photopolymers at cure from the UV spectrum up to the visible ~440nm. They actually have hundreds of formulas but only list a few with Paypal links for DIY and low volume sales. These will cure quite rapidly for your application even using a full spectrum or UV-A reaching aquarium or reptile lamp. A small laser pen from 360-440nm will also work quiteby 2shedsJackson - Polymer Working Group
Bucktown Polymers makes hundreds of different formulas. The older UV polyester is still available at the same price. The UV versions will cure in the UV spectrum up to only ~390nm. The newly listed photopolymers are more DIY friendly, since they are easier to use. Low to no odor, low viscosity and cure in the UV and the visible spectrum up to ~440nm.by 2shedsJackson - Polymer Working Group
The yahoo group is another hobbyist site like this one. I've seen a few projects start and then stall out. [3dprinter.wikidot.com] is the test rig made from Erector Set parts? Reminds me of the 60's. [3dlprint.com] seems the farthest along. has stalled out again as well. If you noticed I mentioned 385-390nm vs 200-365nm for the range of UV.by 2shedsJackson - Polymer Working Group
I posted this in the other thread about visible light cured resins. But in case anyone is only looking for UV cured I decided to make some 385-390nm UV cured photopolymers with a few different monomers and oligomers. They have different viscosities with various strengths and weaknesses. I'll post the Howto on modifying a low cost DLP for use with a low cost UV LED array. DLP + UV LED's for underby 2shedsJackson - Polymer Working Group
I'm not sure what issues you have been facing with syringes or inkjet, I don't have problems with either. But I decided to make some 385-390nm UV cured photopolymers with a few different monomers and oligomers. They have different viscosities with various strengths and weaknesses. I'll post the Howto on modifying a low cost DLP for use with a low cost UV LED array. DLP + UV LED's for under $500by 2shedsJackson - Polymer Working Group
There are some new MEMS Industrial Printheads with ~30pL drops and 16 nozzles for ~$100. I'll try and see about availability for DIY and how to publish specs on controlling them. They might fire at up to 50khz and handle fluids in the 8cps to 20cps range.by 2shedsJackson - Powder Printing and Selective Laser Sintering
I'm not sure of the development at reprap but it's practically a no-brainer using EMC2 and a micro-nozzle or syringe. for example. The problem I have with UV curing is DIY and UV over-exposure. The problem with visible light curing photopolymers is keeping the photopolymer away from light until it cures. No peeking into the printer or storing it in clear bottles. has several patents on theby 2shedsJackson - Polymer Working Group
The issues with thermal inkjet cartridges "TIJ" are: They only work with low viscosity fluids <3 cps They are compatible with fluids within narrow range of surface tension. There is only one older HP Gen1 with open specs. There are many other cartridges available but expect a sh*tstorm of complaints from the makers if the specs get out in the wild. They are only good for a couple of Litre'by 2shedsJackson - Polymer Working Group
There are also some lower melting temp (180°C to 240°C) flexible polyamides under $10/lb that have a Shore hardness of D 40 or Shore A 80-90 similar to Macromelt used for low pressure injection molding that should work fine. What you don't use may just be remelted so there is minimal waste.by 2shedsJackson - Polymer Working Group
Be sure to show people a way of or have a way of keeping the visible light cured resin away from enough light until it is deposited by the printer. Otherwise you're going to get complaints that their container of liquid resin turned into a solid block of resin or kept clogging the dispenser since it started curing before is was dispensed. I've been considering sending some resin fomulas to Chinaby 2shedsJackson - Polymer Working Group
jdoggy72 Wrote: ------------------------------------------------------- > we are looking for > alternate sources for the photo polymer, the > cheapest of which costs $285/kg. They charge $285/kg since they can get it. Similar to $3K/L for aqueous inkjet ink when sold in 30mL plastic cartridges. The cost of raw polymers are <$20/kg in volume. But then you need the formulation experby 2shedsJackson - Polymer Working Group
Photoreactive resins use photoinitiators along with UV to trigger the polymerization. It works kind of like dominoes where you need enough energy to knock the first one over and then it starts a cascade down the line. Some are inexpensive and are used in high volumes in the printing industry. We are talking about open plans for a DIY printer using a photopolymer and a DLP projector since the oby 2shedsJackson - Polymer Working Group
I have a inkjet hardener + powder based design that prints at ~0.5L/hour with only one printhead. I should have open plans for it later this year. Inkjetting water based epoxy also works. Micro valves will work for slightly higher viscosity epoxys.by 2shedsJackson - Polymer Working Group