What's the other 93% made up of? You may be right, it may be the trace substances in the formula, but it could also be the other 93% of stuff in there. The temperature sensitivity of the adhesion sounds more like a mechanical property change than a chemical reaction.by patbob - General
REPRAP SQUAD Wrote: ------------------------------------------------------- > Is this thread dead? Yes, pretty much, nobody seems to respond. I suspect it might not be the thread that's dead so much as the area. > Anyone interested in getting a group > together pls get ahold of me. If you organize something, I'm interested. I had to put my bootstrap machine on hold indefinitely butby patbob - Oregon, Portland RepRap User Group
Is anyone going to Orycon this weekend? I ran into the program director a while back and he said he was planning on having a signup-panel "track", in other words, he was going to set aside a room and let members sign up and hold any panel they wanted. If iit didn't get cut, I was thinking it might be interesting to hold a oanel for reprap & 3D printing in general... but I'd need more than jby patbob - Oregon, Portland RepRap User Group
I see what you're thinking, and "dessicant" isn't the proper term for it because by definition, that implies water. Also, many dessicants work without physically touching the material being dried. The work by sucking moisture out of the air, which gets replaced by moisture coming out of something else. Hopefully this helps you understand why people weren't connecting with what you were tryingby patbob - General
@galaxyman7 You could try spraying the bed with adhesive to hold the paper down. Elmers makes one that can be used for making a temporary or permanent bond. The temp bond is like the sticky on a postit.. it might be just enough to hold the paper down but still be releasable when starting from an edge. Don't know how the heat would affect the glue though.by patbob - General
Dark, you've mentioned your idea about some sort of dessicant effect before. Any chance you could explain what you're thinking there? The nylon needs to be very dry as it is or it forms steam bubbles, ruining the extrudate. The extrusion temperatures should drive most of the remaining moisture out... so I'm not seeing how a dessicant would affect things further, especially one that's being expby patbob - General
You might try clay-coated inkjet paper. The clay might be porous enough for it to stick well, yet it would dissolve in water.by patbob - General
There are risks with nylon that are not present with the other plastics. The concern expressed here is simply to ensure you've educated yourself (which you obviously have), and are sufficiently safe. The concern is also expressed for others who might be reading this thread. The last thing any of us want to hear, is that someone hurt themselves because they weren't even aware there were additioby patbob - General
Good advise, and exactly what I was doing. Since I couldn't get electronics I could understand and had documentation, and the stuff I did want was still not available a month later, I boxed this project up and decided to pursue other hobbies for a while instead of start a new one. If we had an active users group going, I would have found someone there to help me navigate what I didn't understanby patbob - Oregon, Portland RepRap User Group
I'd be interested in such a recurring users group meeting. I don't have much to offer the group yet, since I had to take a break when I got stuck on the electronics end of things though.by patbob - Oregon, Portland RepRap User Group
I'm not up on colored plastics, but don't they mix pigment with a resin to achieve color? If so, how about using CMYK pigments and a single natural color resin filament. Mix them in the extruder hot end. Just need the single filament drive. Since pigments would be lower volume, might be able to use some sort of syringe delivery mechanism for them, which might simplify the entire head. The prby patbob - General
If I understand you right, the answer is yes, but why bother? You're halving the applied voltage to the windings that way and thereby limiting the possible torque. The microstepping controller chips (such as the AllegroMicro's 3967) already do an H-bridge with regulated directional current through the windings.. which is sort of the same thing without the voltage limit.by patbob - Stepper Motors, Servo Motors, DC Motors
> Will I have problems of diffraction? Diffraction is an edge effect -- as light passes an edge, it diffracts. The higher the ratio of edge to area, the worse the issue becomes. Diffractionwise, you're better off using a larger iris further from the focus.. but that may not give the best results. Worst case, experiment. > For the atmosphere you can use a glove box or just > glass paby patbob - Powder Printing and Selective Laser Sintering
Conductive pens have been around for ages for circuit repair/alteration. However, aren't they pens more like paint pens or markers? As I read it, the innovation here was that they produced a conductive ink that had the corerct consistency to be applied using a ball point as an applicator. That would make using one in a X-Y plotter to draw circuits a lot easier.by patbob - Developers
As you can see cdaringe, we're a really active RepRap users group Best bet is probably to organize a gathering yourself. Maybe talk to lokkju and see if the BrainSilo hackerspace would be interested in hosting? Last summer when I tried, there wasn't a lot of interest, but maybe there is now.by patbob - Oregon, Portland RepRap User Group
jcabrer Wrote: ------------------------------------------------------- > An edge card connector requires skills (PCB > etching), and components (edge connectors and > crimping tools) that are not readily available to > RepRap builder at every level. Take a look at your computer's motherboard. The PCB etching skills are the same as needed for etching all the other PCB boards. The coby patbob - Plastic Extruder Working Group
How about using an edgecard connector?by patbob - Plastic Extruder Working Group
Are there any assembly lines that produce any finished goods, of any kind, without involving a human somewhere between the receiving and loading of raw materials, and the moving/shipping of filled crates? How about even a proof of concept of any kind? We're a ways away yet.by patbob - General
I agree that standardizing interfaces is the way to go.. and I think PCs are a perfect example of what we want to do. Not because PCs have standards that never change, but preceisely because they DO change -- they slowly morph over time to meet the new needs of users. As new standards get supported, there's almost always a transition period where systems support both old and new stardards at thby patbob - Developers
I assume you mean to use it for cleaning up the plastic parts you make? The rotary ones work mainly by the parts (or rocks) sliding against each other with the grit between them, so while it will clean up the parts, it'll also abrade the exterior and round off any corners (the pressure is higher on them, so they get abraded faster). Without some chunky media to get inside concativities, creviceby patbob - General
The silicone rubber that says its "aquarium safe" should be relatively non-toxic once fully cured -- that stuff doesn't have any metals or other chemicals that are toxic to vertbrates or invertebrates that will leach out, even at small rates and over prolonged times. However, some food-safe silicone sealant would probably be even better.. after all, who cares if a manufacturing flub poisons a buby patbob - General
vizion Wrote: ------------------------------------------------------- How > easy would it be to go to 32bit floating decimal > for long term scaling? This is off topic, so you should really open a new thread to ask this question. I'll be happy to chime in about mantissa bits and all on such a thread, or drop me a private message.by patbob - General
Thanks for taking the time to elaborate. Now go forth and bring us FEC . BTW, is there any chance you can make the firmware autonegotiate FEC/no-FEC with the host SW, preferably in a way that's backward compatible to old host SW? That way we wouldn't have to fork the FW, and we could prevent from having to have yet another host SW configuration parameter that needs to be understood by each indby patbob - General
Have any of us Portland reprappers acquired electronics yet? I'm hoping to be in a place where I want to get an order in for electronics in the next few weeks, and I figured it might make life easier for all if we tried to standardize on a set of electronics. That way, we could share knowledge, spares, firmware, extra bits, or even swap in borrowed known-working electronics for debugging purposby patbob - Oregon, Portland RepRap User Group
Um.. I'm not a USB expert or anything, but isn't USB is a packetized protocol with CRCs in each packet? If so, you shouldn't be seeing any data errors induced in the USB transmission itself (or at least, not many). Also, I don't think lower baudrates help when using USB. As I understand it, the actual rate of data transmission across the USB wire remains the same regardless of baudrate settingby patbob - General
If the ack turnaround time is the limit, then you want to use the standard solution -- send commands in batches and ack the entire batch. That way, you could increase the throughput of commands sent between acks. This could be implemented in such a way that the firmware remains totally compatible with everything existing today, which would allow exisitng printer drivers to implement it when theby patbob - General
The wiki has docs on G-code that details what the commands all are and what they do and what kind of response you should expect. I believe you just need to connect to the correct serial port at the correct baud rate with any terminal program, then you can type G-code commands at it manually.by patbob - General Mendel Topics
I'm working on it.. but am still a ways away from getting an extruder going for it.. or a printer for that matter It doesn't seem too hard to dry one's own nylon. Besides, I'm trying to use 0.080 inch string trimmer line so even if I have to give up on it, I have a use for the nylon line (can you say "lifetime supply of string trimmer line?" ).by patbob - General
I've been thinking about what's been said on this thread, and about the $30 parts sets themselves, and I suspect they may be a bit premature. Not that they can't be made and sold (and if you can, by all means, please do). But more a philosophical issue of whether $30 will be incorrectly perceived as a low cost of entry by too many people. I'm thinkining the most good might be to make those parby patbob - Plastic RepRap Parts for Sale
I'm no expert since I don't have a printer yet, but the infill I've seen isn't solid. Without going into details, this sounds like it would be a lot of work to use a spiral on some infill layers. What kinds of benefits were you thinking might be gotten by using a spiral infill pattern?by patbob - Plastic Extruder Working Group