No, that would work fine. I have a friend building a RepStrap with that concept. You'll also notice that there aren't many examples of designs that move the table in all 3 axes. If you split it between the head and table you're slinging around less stuff in general, because no axis is carrying the weight of both of the others (if that makes sense).by Kyle Corbitt - Mechanics
I thought I'd crowdsource a dilemma I've been having. For my high-temp extruder I've been trying to bore a 3mm hole through a 1/4" threaded rod. There's not much clearance, so the hole has to be exactly straight on with the bolt. I've tried several methods of trying to keep the bolt straight on with my drill press, including clamping it in a vice (wasn't quite vertical), drilling a 1/4" hole iby Kyle Corbitt - Mechanics
I think that other machines do this sometimes. It is a legitimate strategy. I'm not sure if the opto endstops currently default to open or closed, but worst case you would just need to buy a little "OR" gate transistor and wire it in with the two. Best case, you just wire them in series and it works right. If I were designing an opto endstop I would set it up this way, so people would be ableby Kyle Corbitt - Controllers
Lampbus Wrote: ------------------------------------------------------- > My Dad & i were discussing ways to reduce FFF > warping. he came up with the idea of welding lots > of little spheres together by surface melt, not > total melt. This means the thermal expansion is > limited to the skin, not the volume. > > We couldnt think of a good way to heat just the > skinsby Kyle Corbitt - Plastic Extruder Working Group
Joshua Merchant Wrote: ------------------------------------------------------- > It's not that hard to design containment systems, > like a vacuum on the milling head, etc. I think > the main considerations should be cost, speed, > complexity, and materials and equipment used. Haha, for the record I've never seen a milling setup that didn't produce a certain amount of dust/scrap, nby Kyle Corbitt - Plastic Extruder Working Group
Hey everyone, It has been officially approved by the SRS. I'd love to have as many interested people as possible show up, just let me know. Kyleby Kyle Corbitt - Washington, Seattle RepRap User Group
SebastienBailard Wrote: ------------------------------------------------------- > Right now, what do you think of what's at > ? > > Do you guys like the general feel, or should we > start looking at a video or music library-like > approach? > > I like the fact that since it is a wiki, we can > use it for development of future RepRap versions, > and other projectsby Kyle Corbitt - Administration, Announcements, Policy
You're ordering PTFE tape from McMaster? It ought to be available for cheap in most hardware or plumbing stores, assuming you're in the U.S. or some other western country.by Kyle Corbitt - Mechanics
Interesting, just came across this story in Hack a Day: While it is less than ideal, getting a laser diode that can etch black spraypaint may be easier than trying to get a working milling head. Both processes are messy - milling gets fine dust *everywhere*, but with etching you need to work with potentially hazardous chemicals.by Kyle Corbitt - Plastic Extruder Working Group
Joshua Merchant Wrote: ------------------------------------------------------- > I'm still curious as to whether anyone has an > objection to replacing the 1/8" thick PTFE bar > used as bearings on the stages with the 0.003" > thick PTFE tape. Is there any reason it would be a > problem? By all means, try it and report back whether it works. It has been a long time since I haveby Kyle Corbitt - Mechanics
liam Wrote: ------------------------------------------------------- > Hello. I am new to pcbs. I am working on > something, where I need to develop a pcb design > for interfacing several devices. Hopefully, > someone here knows the blackfin controller and the > surveyor bot. What I need to do is design a pcb to > house the blackfin, an IMU sensor, and an ADC > converter. I haby Kyle Corbitt - Plastic Extruder Working Group
You can buy a shaft coupler from the likes of McMaster that will couple two different-sized shafts like that generally using set screws. You'll want to cut a flat into the screw before using it first, or the set screw might slip.by Kyle Corbitt - Mechanics
Demented, Interesting. Do you have any pics of parts you've printed with this setup? Kyleby Kyle Corbitt - Mechanics
Hmm, if Nophead couldn't get it to work that could be a problem. Perhaps it can be fine tuned by finding the best position for the heatsink on the steel barrel - too low and you risk wicking away all the extruder's heat, but too high and the melting point of the plastic moves up into the high-friction steel barrel. That should be pretty adjustable in this design. Attached is an illustration.by Kyle Corbitt - Mechanics
sid Wrote: ------------------------------------------------------- > okay buying the pcbs from the rrf store costs > what? ~$4/pcb ? > And its tinned, lacquered and silkscreened > As long as I can't do that at home for less, I > don't think twice Agreed. However, I think the goal is to make printing circuits just as simple as clicking "buy" in the RRRF store is right now, and aby Kyle Corbitt - Plastic Extruder Working Group
SnailRacer Wrote: ------------------------------------------------------- > According to Carl there is 0.030" lost to the cut > width, and > smaller parts probably should be attached with > small tabs to > keep them from falling into the catch tank if > there isn't a > waterjet stone to be used. Right, but I'm pretty sure that all water jet CAM software deals with the offseby Kyle Corbitt - RepLab Working Group
This is a bit of a spinoff from the thread at , but I was inspired by nophead's old high-temp-extruder prototypes (full story at ) into coming up with a bit of a complicated change, so I thought I'd start a new thread. The primary purpose is to eliminate the PTFE thermal barrier, while simplifying construction. Walking through the new barrel design, starting at the bottom and moving upwards, weby Kyle Corbitt - Mechanics
hyperk Wrote: ------------------------------------------------------- > I'm not sure what it would take > for a RepRap to read gerber files Not much. You can already get gerber->gcode converters easily, and it should be easy to interpolate the lines for additive fabrication. Of course, it will take a dedicated programmer some time to do it right, but the technical hurdles aren't highby Kyle Corbitt - Plastic Extruder Working Group
SnailRacer Wrote: ------------------------------------------------------- > Steel might survive the baggage handling > gorillas. > > Although aluminum is probably more practical due > to weight concerns. Good point. If anyone happens to pursue this route, be sure to blog about it. One intermediate step I'm considering in getting to Darwin is to build a machine like this one, anby Kyle Corbitt - RepLab Working Group
Bruno, if you link to the video I'm sure someone can figure out what the pause was for.by Kyle Corbitt - Reprappers
Interesting. Out of curiosity, does anyone know how they get it to stay on those non-stick pans?by Kyle Corbitt - Mechanics
Forrest Higgs Wrote: ------------------------------------------------------- > I think you'll find that you can't glue PTFE. Can't you get furniture coasters that are essentially PTFE skids attached to a rubber backing? I've used some before, and they seem to be suck together with some sort of adhesive. I'd imagine there's *something* you could find that would work with it, although I doby Kyle Corbitt - Mechanics
I'd like to suggest an area meet-up following the Seattle Robotics Society (website: seattlerobotics.org) meeting on Saturday, August 16. I've contacted the powers-that-be at SRS and am awaiting approval, but my feeling is that this shouldn't be a problem on their end. SRS meetings run from 10 to 12-ish, although the end time is pretty roughly defined. Following the formal presentation, thereby Kyle Corbitt - Washington, Seattle RepRap User Group
Believe it or not, but as of yesterday, a search for the keyword "cuil" on the cuil site didn't turn up _any_ relevant results! I checked for myself. Today it looks like they finally found themselves, but the vast majority of the first page of results is still completely irrelevant.by Kyle Corbitt - General
That's not a bug, that's a feature! We are obviously working on the most awesome open-source project ever... cuil has spoken.by Kyle Corbitt - General
Check your yellow pages for a local metal shop that will sell you scrap on the cheap - most big cities in the US will have these kinds of stores. I usually hit up a place called "Metal Shorts" whenever I need stock metal for small projects, as they're about 40 minutes from my house and can usually give me a pretty good deal on scrap. Just from looking at the design, I could probably get all theby Kyle Corbitt - Mechanics
@Larry: Doh. Good catch with the "pi" thing... that was dumb. I'm afraid the stiff tube idea may lead to more variability in the extrusion rate as the tube moves around - what advantage would it bring? And for what it's worth, I emailed Lou from Fabr to ask about his design. I think it's ok if I quote him directly: "The extruder was a simple design, which seemed to match existing commercialby Kyle Corbitt - Mechanics
Thanks Forrest. Doing some napkin math, assuming 18 bar and a .15cm radius filament (and check me if I'm wrong): 18 bar * ((14.5lbs/in^2)/1 bar) * (4.45N/1 lb) * (1 in/2.54 cm)^2 * (.15cm)^2 ~= 4.05N of force - that's not that much. Just for fun, I'll make some more warrantless assumptions and see how they turn out. Let's say we've got a 1cm diameter drive wheel and the extruder is only 50%by Kyle Corbitt - Mechanics
I know that conventional wisdom around here is that a pinch-wheel extruder won't provide enough force to work, but does anyone have a good reason for this? I've done a bit of research on this concept, going way back to the MkI extruder spec'd at . While an interesting read, the only explanation it gives for including such a gratuitous number of drive wheels is that "A single-wheel pair can onlyby Kyle Corbitt - Mechanics
sid Wrote: ------------------------------------------------------- > Ru, > because neither the extruder not the x- and the > y-axis are lifted by the motor in any way, it > shouldn't be a problem if they are heavier > (physically) > Only thing that makes heavier parts difficult to > move is higher friction, > so by adding some nice bushbearings that's not a > problemby Kyle Corbitt - RepLab Working Group