Ru Wrote: ------------------------------------------------------- > I know there are also lego counterparts. IGUS > 'enerygy chain' also springs to mind, though that > is for a slightly different purpose it has the > same structure. > > The overhangs are the difficult bit... you could > perhaps use some scaffold supports to hold them > up, but I for one do not fancy removiby Joshua Merchant - Mechanics
Quite interesting. I seem to remember having a K'NEX toy with similarly shaped plastic chain links . We can probably print similar chain links with a simpler design (to reduce overhangs) and thicker walls (to reduce the risk of breaking the chain). It would probably be interesting to use a mold with a tree so that you can cast a bunch of them at once (possibly cast them out of metal in the futurby Joshua Merchant - Mechanics
Did you guys also find that the 80mm long vertical bearing arms are too short to reach the stage and still screw into the vertical bearing supports? My Z-rails are 3/4" thick, my vertical base is 1/2" thick, my teflon bearings (for sliding on the rails) are 1/4" thick, and my Z-stage is 1/4" thick. That's 3/4+1/2+1/4+1/4= 1 3/4" = 1.75" = 44.45mm. On a vertical bearing arm, the distance betweenby Joshua Merchant - Reprappers
Forrest Higgs Wrote: ------------------------------------------------------- > This seems like a lot of trouble and extra > complexity to go to just to avoid having to peel > off some fuzz off your print. Not if you plan to use your print as a pattern for a metal cast - the quality of the parts, which could be improved by having a proper anti-ooze, could be quite important in metal pby Joshua Merchant - Mechanics
I'm just wondering what stopped Zach at RRRF from using a larger chip (than the ATmega644P). There are a lot more options that have more pins and memory, etc. The biggest one is the ATmega2560 with 100 pins (86 max I/O pins), and a bunch more of the other stuff (see for a list of the various chips). It is $17.97/unit at Mouser, though, so perhaps not that one specifically, but the ATmega640 isby Joshua Merchant - Controllers
Forrest Higgs Wrote: ------------------------------------------------------- > Ask Adrian. > > The flat strip idea looked great till I started > wondering how you mill a flat slot into the > extruder barrel to seat it. Maybe it's time to start considering the possibility of casting the nozzle? Alternately, you could just mill it like you would mill the normal hole, except aby Joshua Merchant - Mechanics
To keep the stages on straight paths over the rails, there are bearings with springs that keep them up against the rails (doc is here ). I bought the suggested McMaster part (can be found here ; actually, I bought the replacement part, as that specific part is discontinued), which is a pack of extension springs, each of which measures 4 inches from one end to another. One works on the X stage,by Joshua Merchant - Reprappers
Forrest Higgs Wrote: ------------------------------------------------------- > Here's the comment that Adrian made... > > "Forrest: the previous one leaked, as it says. The > problem is getting the crossing point in the > middle of the flow." Did it leak because the wire wasn't precisely in the middle of the flow, or because the wire didn't seal the wire hole? If it's because itby Joshua Merchant - Mechanics
What's wrong with the various(?) water-soluble polymers? I stumbled upon polyvinyl alcohol , which "is a water-soluble synthetic polymer" with "excellent film forming, emulsifying, and adhesive properties". Perhaps one of our thermoplastics will stick to it? I'm not sure how difficult it will be to extrude this without decomposition, unfortunately. Then again, I can't figure out what it decomposby Joshua Merchant - Plastic Extruder Working Group
There is a minor flaw in the Cast Circuit Board (CCB ) creation that I described. I was imagining a single piece of copper for the entire board. This, obviously, is not desirable (the whole point of a circuit board is to connect certain parts to other certain parts, not to connect everything to everything). Edit (before posting): I should note that I did come up with a solution down near the endby Joshua Merchant - Plastic Extruder Working Group
aka47 Wrote: ------------------------------------------------------- > Josh > Have you considered > > or viks nearly Ponoko ready (might actually be > done by now I know vik has been doing a lot with > it, check with vik) > > Raps > And cut out the middle steps, save time and > expense... > aka47 Kinda off topic, but I suppose it's my fault. Anyway, I did see tby Joshua Merchant - Plastic Extruder Working Group
If I understand your post, what you're looking for is here: The McWire CartBot doc page links to it, under the Files subheader in the Intro header. The DXF files are in the src and sticker-src folders. Either I'm missing something and you're asking a different question than the one I'm answering, or you're just so excited that you missed it . Good luck, and post pictures.by Joshua Merchant - General
It might be feasible to cast the boards; that is, cast the copper circuitry and then pour the circuit board (dielectric/insulating) material around the copper. I imagine we could first RepRap a "pattern" for the copper circuit (perhaps with the help of support material, if/when we get that working; it is not necessary, however). The mold for the copper would be made from the RepRapped (thermopby Joshua Merchant - Plastic Extruder Working Group
So did we ever find a good support material? I found the Paste Extruder documentation , but I can't seem to find any posts/blog entries about testing it as a support extruder.by Joshua Merchant - Plastic Extruder Working Group
Ru Wrote: ------------------------------------------------------- > The arduino diecimila has a jumper to select USB > or other power source. I power mine solely from > USB though; the alternate supply is only really > useful if you want the system to run whilst > disconnected from a PC. Which isn't practical for > a reprap right now. Alright, good to know. > But when you saby Joshua Merchant - Controllers
Ru Wrote: ------------------------------------------------------- > I think its a plan to allow the reprap to be > powered from a 12v only source, like a car > battery. Oh. How... thoughtful? > There's nothing to stop you making use of > existing 5v lines if you have them though. Right. The ATX 20 pin Molex connector has 4 +5VDC wires/pins (see the diagram here ), and the +5VDC raby Joshua Merchant - Controllers
I don't quite understand how all the Generation 2 boards are powered. I have a classic ATX power supply that I want to use, and I'm building my Arduino from this . The doc says "You generally only need to connect a wire from black (ground) and yellow (+12V) to the RepRap." This doesn't quite make sense to me, as the wiring for the power (Step 1 in the PhysComp tutorial) has a 5VDC regulator (by Joshua Merchant - Controllers
I don't have much time to respond to each comment and post about all my new ideas, but here are a few points: I noticed that no one posted any comments whatsoever about the proposed optical encoder. Any reason? At the current point, these look like they will be the best balance between cost, durability, and performance (at least at the beginning and for me). If the current steppers are so overpby Joshua Merchant - Controllers
Kyle Corbitt Wrote: ------------------------------------------------------- > Welding is cool and useful, but there is still a > need for a rigid but reversible joint. If nothing > else, snapping two parts together is usually > faster and easier than setting up up a hot glue > gun-like device to do the same thing. It would be easier and faster once you get it running if you haveby Joshua Merchant - General
Ru Wrote: ------------------------------------------------------- > I'm going to be terribly pessimistic about this. I > suspect if you want high quality gears, you're > going to have to use milling/lathing to make them. > I'm opento dissent on this one, but I think it > would be very difficult to print very high quality > gears. Nop has made progress with quality, so I don't thby Joshua Merchant - Controllers
Forrest Higgs Wrote: ------------------------------------------------------- > Depends on how long the production run is and how > complex the object is that you want to > manufacture. The shorter the production run and > the more complex the object the better the > economics of using 3D printing look. True, and that's why I included such exceptions in the rule, but most of thby Joshua Merchant - General
Plastic welding could be an alternative (or rather, candidate) to the standardized joint proposed earlier. Possibly even CNC'ed. With a proper setup, the machine could build small objects, automatically store them (setting them aside, stacking, whatever), build more small objects, etc, then retrieve them and weld them together into larger pieces which couldn't otherwise be built by the machine.by Joshua Merchant - General
There's also the fact that a RepRap is an RP device, and RP stands for Rapid Prototyping. Not manufacturing. Prototyping. Though there are some instances where a technique similar to RP is used in manufacturing, prototyping methods are usually more expensive and less efficient per unit than mass production manufacturing methods.by Joshua Merchant - General
I downloaded Informative Graphics' free viewer . I had to calibrate the measurement tool (apparently it did not have the original scale data; is this normal?). I used the distance between big circles in the corners. The centers of these circles form a rectangle, and I calibrated using the length of the shorter side of the rectangle as 18cm, which I measured with a ruler from the printed page (thby Joshua Merchant - General
Ru Wrote: ------------------------------------------------------- > Sure, but a stepper/stepper driver combo is > usually more expensive than a cheap DC > gearmotor/DC driver/encoder. > But then the cheap homebrew servos simply aren't > anywhere near as good in a huge range of roles, > though they do happen to work very well as the > power behind an extruder. Hence my caveaby Joshua Merchant - Controllers
I started cutting my plywood (instead of acrylic) pieces for my McWire today and I've run into some trouble with the X and Y stages. The PDFs in the stickers folder of the McWire downloadable files are all fine except the two for the X and Y stages. When I print them with 1:1 scaling the right and bottom sides get cut off by a bit. I've tried a lot of printing manipulation using Adobe Reader's prby Joshua Merchant - General
I looked again and it looks like the 120by Joshua Merchant - General
Ru Wrote: ------------------------------------------------------- > you may not need parallel supporting rails on the > stages. > > So I apply the brakas, and turn the drive shaft 45 > degrees to tilt the stage. I then release the > brakes. What keeps the stage at 45 degrees? The brakes on the bolt motor. Obviously, this would put stress on the connection between the bolt andby Joshua Merchant - Mechanics
Forrest Higgs Wrote: ------------------------------------------------------- > Um... did you miss the part that they can only be > operated at a maximum temperature of 120C? That would work for some thermoplastics (like PCL). Unfortunately it's just under polyethylene's requirements. The specs do however say that the device is "Rated up to 392by Joshua Merchant - General
Yeah, I think rapid prototyping is something that should be localized. Stratasys has the right idea, selling the machines instead of just RP'ed objects. The whole point of rapid prototyping is that it's rapid. Waiting a day or more for an object because it has to be shipped is just silly. By the way: Forrest Higgs Wrote: ------------------------------------------------------- > I find it tremby Joshua Merchant - General