lajos Wrote: ------------------------------------------------------- > From the dailymail article: > > BTW easily concealed bullets? Who made that up? Well, the Daily Mail, apparently. Airport security had no issues finding the spent .45 casings I forgot I had in my luggage after a range trip. I'm guessing the Daily Mail is unaware that such things show up pretty easily - they onlyby Have Blue - General
akhlut Wrote: ------------------------------------------------------- > @ haveblue - Perhaps, but I doubt it. No one > really got too upset when you published your 3D > gun-smithing accomplishments to you blog. It was more a rhetorical question - I don't imagine that Thingiverse or grabcad.com (where I think most of those designs originated) will be given takedown notices under ITAR, aby Have Blue - General
woo, I generally just leave the part in the machine to cool. Unless I'm feeling impatient, in which case I just yank it right out of the chamber as soon as the print is done :-) Even in those cases, I haven't noticed any warping (but I did find that the transparent ABSi, a methyl methacrylate ABS, is still pliable at envelope temperatures and does need a full cooldown).by Have Blue - General
akhlut Wrote: ------------------------------------------------------- > Shutting down Defcad is not a political statement. > Wilson may have broken the law. An an arms > manufacturer he should have fully understood the > ITAR rules before publishing his designs online. > His claims under the research exemption are flimsy > at best. Personally, I think he's screwed. I thinkby Have Blue - General
Department of State, actually - ITAR (International Traffic in Arms Regulations) falls under the purview of the State dept, not DoD.by Have Blue - General
uGen, as per your request, here is the readme file.by Have Blue - General
akhlut Wrote: ------------------------------------------------------- > Defdist isn't the first. Haveblue did it a while > ago. Well, I printed an AR lower - it's only by way of the 1968 Gun Control Act that what I printed is by itself a firearm. On the AR lower and the 10/22 receiver I printed, heat is not a concern, so standard ABS works just fine. As for more exotic materials, yes,by Have Blue - General
My Stratasys machines run the chamber at 70 deg C for ABS. As shown, the Mojo (unlike the FDM series and P-class machines) puts all the motion control elements (steppers, belts, etc.) outside the heated envelope, so they can use a lot more plastic for such components. It probably reduces the power consumption as well, since they don't need to heat as large a volume. VDX Wrote: ---------------by Have Blue - General
1.75mm (0.070") is also what Stratasys machines have been using since the mid-'90s, so there may have been a bit of "well, it worked for them..."by Have Blue - General
Kevlar fill sounds neat, but I don't think it would be terribly useful as a 3D printing filament. The benefit of aramid fibers in composite construction is that if the epoxy matrix fails, the Kevlar will still hold together (whereas fiberglass or carbon fiber will break along with the matrix). However, aramids may be less abrasive than other fibers, which would make them well suited for reinforby Have Blue - General
"guns in the hands of citizens means nothing" - I'm afraid I really don't follow your logic given the example cited. From my readings of the event, there were indeed privately owned arms in use. As documented in http://constitution.org/mil/tn/batathen_press.htm, the reporter on the scene noted at least a 12ga. shotgun, a repeating rifle, and a .45 pistol (which must have been a M1911, as I'm noby Have Blue - General
Price really depends on the specific resin - SABIC Cycolac resins ran me over $5/lb. at special sample pricing. Normally, they would have been over $30/lb. for a minimum 55lb. order!by Have Blue - General
rogerw Wrote: ------------------------------------------------------- > isn't the final 'threat' of a democracy suppose to > be the vote not the threat that the masses will > rise up with their guns? > i'm still struggling to understand why you need to > be rise up against the govt? > could you give me some examples where this has > been required before in a modern sense? Iby Have Blue - General
Not to mention that voids within the deposited material could have unintended effects on the burn rate and shockwave propagation.by Have Blue - General
Simba Wrote: ------------------------------------------------------- > I do find that polymers such as metal-filled, > fiber-filled, truly conductive, and magnetic are > still missing. However, I think there is a bigger > win here for reprap. The holy grail of the > carriage mounted granule extruder, which I've > finally come close to solving. This new extruder > will alloby Have Blue - General
It was actually 72 Shore A durometer for the 'STPE-2' elastomer. Hytrel was my first guess as well, but since all of the variants I saw at a first glance were beige in color (and Jan's samples appear to be clear/colorless), it could be a compound from a different maker. Have you looked overseas for sourcing the Kraton? Digging through Alibaba and the like turn up resin prices that are far lessby Have Blue - General
Simba Wrote: ------------------------------------------------------- > Of course, neither am I, but as is always the case > with rep-rappers I would like to - and promise to > - release the plans, sources, and methodology once > there is a final 'product'. Thanks, Simba - that's fantastic! I'm limited to running 1.75mm filament, and my machine requires a fairly high flow rate due tby Have Blue - General
Simba Wrote: ------------------------------------------------------- > Have Blue Wrote: > -------------------------------------------------- > > Simba, what are the specific resins you're > looking > > to extrude? I'm always interested in testing > new > > materials, but knowing specific material > > properties is pretty important. > I will reveal just forby Have Blue - General
Just because there's a patent on it does not in any way indicate that Stratasys, 3D Systems, Makerbot, or any other 3D printer manufacturer will actually license that patent. It would be in their interest not to license the patent, as to do so would be a clear indication that they intend to cripple their equipment. Also, the patent is not specific to additive manufacturing, but also "subtractivby Have Blue - General
Also, it's only a patent application - it hasn't actually been granted. Anyone know of prior art?by Have Blue - General
Simba, what are the specific resins you're looking to extrude? I'm always interested in testing new materials, but knowing specific material properties is pretty important.by Have Blue - General
Don't forget Objet, which is actually headquartered in Israel:by Have Blue - General
Just came across this paper, which covers conversion of a Stratasys machine to print with a low-temperature Tin-Bismuth alloy:by Have Blue - Wire and Thread Embedded Extrusion
I purchased desiccant from Amazon to make my own packs to keep the filament box on my printer dry:by Have Blue - General
You can indeed have clear ABS - you just have to reduce the size of the butadiene phase distributed through the SAN matrix so that light isn't scattered by it. Unfortunately, reducing the size of the butadiene regions also destroys the impact resistance that the butadiene provides. As such, 'clear ABS' is actually MABS - methyl methacrylate butadiene styrene. The methyl methacrylate's index ofby Have Blue - General
destroyer2012 Wrote: ------------------------------------------------------- > I do wonder what plastic they use. Probably it's > not ABS, but some proprietary mix that has good > properties like not shrinking, not being runny, > etc. Their ABS-Plus material is SABIC MG94 resin. It's a high-flowing injection molding rade material, not extrusion grade. Not shrinking is due in largeby Have Blue - General
Actually, I think the only reason that people use PA-747 is because everybody else is... At least in the US, most of this filament is coming from places who make 'plastic welding rod', which doesn't really have the same properties that you'd want in feedstock for a 3D printer. MG47 will cost more, but it's not the only option - I suggest you take a close look at Enviroplas ENV00-P0503N-7000, whby Have Blue - General
My vote is for some sort of injection molding grade resin, not PA-747. MG47 runs far better on my Stratasys than PA-747 due to the much higher flow rate. I'm mystified as to why people keep using PA-747 - it's like trying to push concrete through a syringe...by Have Blue - General
Which ABS resin will be used?by Have Blue - General
Looks promising - just ordered a coil to test out on the Stratasys.by Have Blue - Polymer Working Group