solar metal printer

well, it has been a long time since I have posted anything to this blog so I will give something of a update on my current projects. I have been working on a solar printer using a fresnel lens prefocus and lenses from a rear projection tv as final focus. they are being attached to a inverted delta printer to provide the movement axis. I have several spools of mig wire to feed into the melt zone and some nickle and titanium wire to test if the temperature is sufficient to melt them. When I get successful print or verification of failure i will post again.

initial fail

well, i just finished disassembling the projector and found that the lcd is reflective and not pass through so that kills that as a idea. next im going to have to remove the screen from one of my other junk devices that I know are backlit lcd's. I have a bunch of old automation direct touchscreens with blown flourescents I know I can use, the less good part of it is the reduced resolution. I had very high hopes of extreme resolution from the projector, but such is life.

new ideas

Ive been working pretty steady on several different projects but may start another new one after seeing more posts about uv curing projects. I must say how much ive been impressed by Junior Veloso's work on the bottom projection system, and I recently found http://mrsec.wisc.edu/Edetc/nanolab/3D_print/index.html
which also gives a reletivly complete uv resin formulation. This got me thinking about doing something similar but using closer to a contact print design.

I happen to have a projector where the light in it has burned out and the cost of a new bulb is greater than the amount I paid for the whole thing. So, it has been in my storage for a couple years waiting for me to come up with a use for it. My Idea would be to remove the HD lcd from it and put it in the bottom of a Square/rectangular column, place uv led's under it and have the print surface on piston like rig with very fine indexing to raise the print platform. Im expecting in this instance to get a print area around 1-2" but with a extremly high resolution. I also have several other old b/w lcd screens that are a lot larger but much lower resolution. I could even see scavenging a large (say 52") HD tv screen and being able to print some rather large and yet highly detailed objects resonably quickly. I see a posible methoud where you convert your slices into a MPG video and have near continuous pull of the Z axis (actualy very small moves each frame).

I don't know if anyone has even tried anything similar to this but I Believe it will be my next major project. The one drawback to it is the cost of the uv curing resin.
If someone can come up with a cheap resin this would be a potential game changer.

copyright and patent

It was recently blogged about US law and 3d printing, after reading the entire paper I had two questions, both of which i emailed the writer, hopefully I will get a response soon. Those questions were about copyright vs patent in the law. specifically if someone posted a design somewhere i.e.thingiverse and then later a company filed for a patent for the same device, and received the patent, would it supersede the copyright or would the posting of the device automatically invalidate the patent due to not being unique or original.

After pondering this for a bit something else came to me, the copyright's that are put on things in thingiverse are (other than as a record) worthless, they have no real meaning since copyright cannot and should not be applied to physical objects, and we as makers do NOT want to change that.
really.
think about what it would do. right now a patent has a very short shelf life of about 12 years (i believe though for some reason 7 seems to come to mind) but a copyright is life plus 90 years or so!!!!

companies have been trying to get patent length extended for years and they have also tried to apply copyright law to patentable objects, so far thankfully none of these have panned out for them.

now, this doesn't mean that i think people should stop posting things or putting a gpl license on them, on the contrary, if i understand patent law then we need to post MORE things, the more we can prove non patentable the better. But also note. once something is posted it cant be patented ever, even by the original poster.
years ago back when i was a kid my uncle made a gold panning device, he made the mistake of selling a few of them before he patented it. results: patent rejected, item already exists for sale.

now, I have no references to quote and IANAL and neither do i play one on TV so don't take any of this as legal advice. not that any of it was actually intended as advice, just as a HMM moment.

mk5 and mendel

Well, ive been working for the last month or so to get dual mk5 heater cores printing on my mendel with very limited success. My biggest issues are excessive loading of the filament through my bowden cable. I can get pla to run through it at REALY low speeds but if I try to extrude over about 10mm/s it jams and strips the filament in my wades extruder. Ive been wondering if the hobbed bolt i made was the cause so I ordered some from ebay about a month ago but have yet to recieve them.

One of the issues I have with the pla is probably filament swelling leading to excessive backpressure but so far I havent found a solution to that. The 1/8" stainless pipes I tried initialy as filament guides seemed to transfer heat too far up their length causing real bad back pressure and when I tried to shorten one of them I made it too short and the ptfe tubing swelled and deformed between it and the upper filament guide section. I currenty am trying a stock makerbot barrel and nozzel assembly and with it I can get the 10mm/s or so feed rate with some reliability though i had to add two heat sinks instead of the standard one. I beleve this is at least partly because the mendel carriage encloses and retains the heat better than a standard makerbot open air design.

x axis mods

I have been working on getting my mendel printing more reliably and have changed the orientation of the x axis motor. The main design puts way too much drag on the axis to print. or at least on mine. Also working on installing makerbot mk5 hot ends so have redesigned the print carriage so the mk5 head can fit between the rods. right now im printing it on my makerbot. Im also considering a mod of the x-z connections to widen the spacing of the rods, right now im concerned that the heat from the extruder may cause issues with the carraige regardless of the new design.

hot end experiments

I have been working on some new hot ends for a while, I purchased several kits from makergear of the Noophead style and have one of them installed in my makerbot right now. then wouldnt you know it but makerbot releases their mk5 extruder and completly changes the course of my expiriments. after looking at their design (i have one hot end on the way and parts for 3 more) I started working on fabbing some equivelents for my mendel.

I will probably post pictures of each test one of these days but the one that im fealing the most confidant about was pretty simple. take a section of 1/8" schedual 40 stainless pipe, turn down the end to 3/8" and thread it 3/8-24. then using one of the aluminum blocks from the makergear kits I drilled it out with a Q bit and tapped it to 3/8-24.

my first test used a single resistor but it could only get to 130C so i have fabricated a new one with two resistors. I have a fealing that im going to have to drive power to each seperatly with my current set up since its a gen2 pwm board so i doubt it can handle the current draw of both resistors in paralel. I may try just applying 12v directly to one and triggering the other with software.

I will post more later, hopefuly with pictures.