SnailRacer Wrote: ------------------------------------------------------- > I wonder if a set of 1/4" steel waterjet RepStrap > parts would be much different in price than the > plywood ones from Ponoko. > > Any particular reason for steel? Waterjets can do just about any material known to man (except for tempered glass or something like that, I think). Of course, laser cuttiby Kyle Corbitt - RepLab Working Group
Great work as always. I'll definitely have to test this new version out.by Kyle Corbitt - RepRap Host
Joshua Merchant Wrote: ------------------------------------------------------- > Aye. I figured I would order the encoders with the > rest of the equipment, but then try just using the > DC motors without encoders. I hope you're talking about the extruder here, and that you realize that you will absolutely without question NEED to put encoders or some kind of feedback on all three axesby Kyle Corbitt - Controllers
Ru Wrote: ------------------------------------------------------- > Making objects 12 times bigger is likely to mean > build times on the order of several days! And > keeping the reprap running that long without a > fault is going to be tricky, to say the least. > Having it break after a mere 24 hours, for > example, is going to ruin the part, and waste a > lot of time. >by Kyle Corbitt - Reprappers
Joshua Merchant Wrote: ------------------------------------------------------- > I have finite funds and no income (and will remain > in this state beyond the time it takes to get the > RepStrap up and running). This explains why I've > been so savings-oriented. > The specific cost to be cut is about 12% of the > current total. Spending a couple days on it, out > of a coupleby Kyle Corbitt - Controllers
To me, the goal is to start with something that *works* and try to reduce cost and complexity from there. It will be no fun trying to determine whether your persistent encoder error is coming from a flaw in the extruder design or a loose bolt in the encoder geartrain assembly. It also seems a bit nonsensical to gear motor output down by a huge factor in the GM3 gearbox, then back up for encoderby Kyle Corbitt - Controllers
Sure, that's possible. But your gear train adds another place for backlash to happen and inaccuracies to build up. I'm sure it's been done before, but the normal solution is just to buy a higher-resolution encoder. It's not *that* much more expensive, and much less of a hassle.by Kyle Corbitt - Controllers
Very nice - looks like their answer to Google's purchase of SketchUp. Seems to be a more powerful program, but perhaps harder to use as well... definitely worth a look. Let us know how well it works!by Kyle Corbitt - 3D Design tools
I could summarize, but this is pretty good on its own, so I'll copy in the whole email: "It all depends on what you want to cut, how accurately and how fast. The highest pressure pumps you can buy in a store are pressure washers, which rarely break 3ksi of pressure (as opposed to our smallest pump, which makes 40ksi) Abrasive is a huge benefit for speed for harder materials. You can certainly cby Kyle Corbitt - RepLab Working Group
@Steve I like it, but some kind of casing may need to be devised to keep them from twisting apart - looks like they're good at resisting tensile forces, but not torsional ones.by Kyle Corbitt - Mechanics
Joshua Merchant Wrote: ------------------------------------------------------- > It looks like a closed-loop system would be > cheaper. > Would it be feasible to replace the cartbot > stepper motors with GM3's > > oducts_id=43 monitored by the Magnetic Rotary > Encoder > > ducts_id=80 and controlled by the DC Motor Driver > > ducts_id=69? > The total cost foby Kyle Corbitt - General
One of the members of my robotics team happens to be an engineer for one of the largest waterjet-making companies in the world. I've toured the factory, and designed dozens of parts that he has cut on these machines. Waterjet cutters require a pump that can produce incredible pressures, and components all along the way that can withstand that kind of pressure as well as a mixed abrasive. That'by Kyle Corbitt - RepLab Working Group
Oh, sorry, I was out of town for the last week and still haven't caught up with everything that has been posted. Mods, feel free to delete this thread.by Kyle Corbitt - General
Hey all, Thought I would let you all know about an interesting opportunity that just came across my radar. A company called Big Blue Saw is having a promotion on August 6th for their machining services in which they'll laser- or waterjet-cut a part up to 9x9" in size out of 1/8" plastic or aluminum. You have to pay shipping. Details can be found on their site at . This is a pretty limitedby Kyle Corbitt - General
Sounds good. Now we just need someone to try it! For now, no one has tried printing anything large enough to bump up against the envelope of the machine though, I think.by Kyle Corbitt - Mechanics
Ru Wrote: ------------------------------------------------------- > pe cord (Dyneema) doesn't stretch > > From (but a > brief googling will get you a more reliable > reference!) > > Under tensile load, UHMWPE will deform continually > as long as the stress is present - an effect > called creep. > > So you might not want it as a continuous load > bearer... tby Kyle Corbitt - Mechanics
Doing good work there, slade. Remember to post the files as you finish them!by Kyle Corbitt - Reprappers
VMware might be a good solution. I have it working in vista with no problems. Not sure how well it lets the guest OS access ports, etc. though, which is necessary for RepRap.by Kyle Corbitt - RepRap Host
That's a lot of text! Sounds like you have some interesting ideas - maybe you should try building a prototype and reporting back to all of us how it works? I'm interested, but you've got quite an elaborate plan and it would be easier to visualize with a working model. Good luck - innovation is like currency around here!by Kyle Corbitt - General
Bearings don't move - I think they're just round because you can get brass bar like that. EDIT: had this thread open a while before I responded, whoops. Forrest got there first.by Kyle Corbitt - Mechanics
Nothing like doing the research! Looks like the RRRF encoder has a whole slew of output options. Check them out at . I've never heard of SSI - sounds interesting. I'm a little concerned that the EM radiation from the motor could interfere with the magnetic sensor, but I don't know... is there anyone out there with experience in this field that could give us a better opinion? Looking at the dby Kyle Corbitt - Controllers
This is still a research project. Many of your questions cannot be easily answered because no one actually knows. If you're looking for a kit-type project that will work out of the box, pick up a Fab@home or wait another 6 months That being said, I'll do my best to sort out your concerns. First, I don't think anyone has actually gotten a seedling working well, so you'll be taking your chanceby Kyle Corbitt - General
Lampbus Wrote: ------------------------------------------------------- > Quadrature is unlikely because it is attached to a > motor - and the printer knows wich way it is > running the motor, just not how fast. (speed > varies with load, direction (usually) dosnt) > > Quadrature is only useful where the controller > dosnt control the speed or direction. Like in a > mouse.by Kyle Corbitt - Controllers
Nice. I don't know that this will really be easier to use than the BRL-CAD interface (it's still using text to define visual objects, which always takes creative thinking), but I wonder if this could be used as the basis for a BRL-CAD GUI written in Python. Python is easier to code than C, which I assume is what the majority of BRL-CAD packages are in.by Kyle Corbitt - RepRap Host
snoop911 Wrote: ------------------------------------------------------- > So the question is: do you want to use the printer > as part of a repstrap? > > Definitely. I tore down the printer some more > yesterday, and found another motor (its used to > move the print head across the paper > (width-wise)). Haven't found ITS sensor, but if > its a stepper motor, I couldby Kyle Corbitt - Controllers
Anyone know a good source for these silicon pieces? I'm worried that if it's too thick it will make extruding unpredictable, because you've got this relatively cold and thick thing applying pressures to the extrusion from all kind of weird angles... but we'll see.by Kyle Corbitt - Mechanics
snoop911 Wrote: ------------------------------------------------------- > Reprap (Darwin) uses a stepper motor controlled by > a PIC, so where does the Magnetic Encoder get > used? > > I was thinking of using my printer parts (pwm > driver ic, and the optical encoder / motor), but > is it perhaps better to go magnetic and buy the > Magnetic Rotary Encoder board? >by Kyle Corbitt - Controllers
Arthur Wrote: ------------------------------------------------------- > Looks well done, functional and cool. But how > come the surface isn't smooth like the little cup > and statue in the video? The video is low quality, and the apparent roughness of the extruder part surface is vastly exaggerated by the camera flash. I've handled Stratasys-made parts before, and they are actuallyby Kyle Corbitt - Reprappers
Larry_Pfeffer Wrote: ------------------------------------------------------- > Exposing an entire layer at once (many voxells in > parallel) is attractive, but isn't the only way to > go. One could imagine a raster-scan system, based > on two tilting mirrors to "paint" each layer. If > the light source were of sufficient power, that > approach might be competitive on speed.by Kyle Corbitt - General
With all due respect to fernando - and I certainly understand that he knows things that I'll never understand in my life - I don't think he's got the problem quite whipped yet.by Kyle Corbitt - General