I was just trying to illustrate that it doesn't make sense to use repraps in place of conventional manufacturing. The resources that were spent making the vast amount of repraps would be much more efficiently used in a regular manufacturing assembly line. I agree entirely with Mike's statements. I don't need that many combs either. -Samuelby Samuel - General
True, I did kind of overlook the possibility of self assembly, but I had presumed that the figures Zach gave were pertaining to the current gen of reprap. And on that presumption I based my calculations. Personally though, I think that the reprap, though a very few will get to the high-level of clothes production, will for the most part be marginally limited in capability. Also, I think that theby Samuel - General
Sean, Nice thoughts, I can't really disagree or comment on any of them. It seems that there are several markets that would develop through the conjunction of the internet and the reprap. 1) Custom rp companies. Both web and local. The web companies would try and take advantage of volume and lower the price, but in the end may be unsuccessful at beating the locals, unless they aren't in an areaby Samuel - General
Other questions related to figures, are what the relative costs, time, and upkeep are. By my figures, 17 generations of repraps at a multiplication rate of double per generation, that would be 131072 repraps. These all require some minimal human assembly. Also, multiplying by the projected target price of $400, that many repraps would cost $52.4 million. I have no similar figure for a comb-makinby Samuel - General
Indeed, repraps would be great for making molds. Presuming you can make decently sized objects in metal, a reprap could indeed make certain parts of the manufacturing equipment. It would probably reduce the cost of the regular machines due to the decreased time of development. By giving the engineers a tool like a reprap, they could make test versions of the assembly line much more quickly than bby Samuel - General
Reprap is definitely good for custom design, so both A and B make a lot of sense. However, custom products are rarely cheaper or faster than manufactured ones. Mass production is very efficient. It can make bulk orders for materials in advance, allowing that to be cheaper, and can utilize machinery specially designed to be the absolute best at what it does: make the same thing over and over. A loby Samuel - General
Thanks, nophead. So, then, any other ideas on how to reduce the cost of motors? I had been hoping to try and get a cheaper motor, possibly a micro-stepping stepper, and use a positioning system, such as shaft encoder or linear encoding, to make up for the lower precision. This site claims that micro-stepping doesn't help much for precision. Thus the need for positional encoder. -Samuelby Samuel - Mechanics
I don't think the purpose of the RepRap is to overthrow the current manufacturing system. It will always be cheaper to manufacture items in bulk, and faster as well. I think the real philosophy behind the RepRap is the fact that it is designed to replicate exponentially. The RepRap is good for personal design and testing, not personal manufacturing. If you're trying to make something and have anby Samuel - General
From what I remember reading, stepper motors aren't too precise when it comes to micro-stepping. They tend to lose steps along the way, and eventually it will add up to error in the print. Frequent end-stop calibration may help, and perhaps it's not much of a problem, but I think that we should have at least some form of position encoding other than step-counting. It may be that the motor isn't oby Samuel - Mechanics
Just based on the fact that this method was used in all of the printers I've looked at, I can presume that this method is: -Cheap to manufacture and assemble -Accurate enough for high resolution photo printing, and -Fast Personally, I think that if anything is good enough for regular printers, it has a possibility of being a good choice for the RepRap. They are very fast, printing a page in aboby Samuel - Mechanics
During a visit to Office Max, I happened to pass some of the time browsing the insides of all their desktop printers. One thing that I noticed was that they seemed to use a plastic strip along the length of the shaft to encode the position of the motor. It had very fine alternating lines of black and clear. I've done a bit of research, not much, and these are a few pages I've found. Presumingby Samuel - Mechanics
It was certainly a very slick design. I like the way he used the rails. It seemed like it would be so easy to just loosen a screw and adjust something, or replace a part. And that doesn't seem to be at the expense of too much reliability. From my experiences, machines with moving parts need to be designed as sturdily as possible, but simply, so that you can quickly adjust or replace injured pieceby Samuel - General
Actually it's the other way around, nophead and Zach. Unipolar motors have more wires, which can be tied together and then it can used as if it were a bipolar motor. Not the other way around. Very confusing, I know, but still important if you're trying to decide whether you can buy a motor or not. Because we use bipolar on the RepRap, we don't have to worry too much, because either unipolar or biby Samuel - Reprappers
I'm very interested myself in having a reprap capable of making custom ic's, but it seems that it will be hard to have a good reason to fab our own resistors, etc. My reasons being that the materials required are going to be diverse, used in small quantities, and especially in the case of the transistor, hard to find or expensive. I think that the reprap should probably just consider tape reelsby Samuel - General
I've thought a lot myself about ways to extend the reprap's functionality, allowing it to reproduce more of itself. About layering transistors, I've begun to wonder whether that's really such a good idea after all. Yes, you could fabricate all of the chips and logic required, such as the pics, but they would be very large, and impossibly slow. And would probably cost more than just ordering a manby Samuel - General
Speaking of houses, I had seen somewhere a device that was almost exactly a giant rp, that was designed to lay concrete in a stream to make a wall. I just looked it up, and I found an article discussing it. It has a link to a video on youtube that shows it in action. The tool head they use is really interesting, and might be an inspiration to future heads for the reprap. I'm not sure how theyby Samuel - General
The words "suction cup" were probably poorly chosen. I was trying to think of the best way to describe the part of the tool head designed to suck off the solution, before it spread too much. It doesn't necessarily have to have a seal, though if you need to absolutely prevent any liquid from getting past it, you could have a cloth border, to soak up any stray liquid. The wikipedia page described uby Samuel - General
Alternatively, you could try and keep the solution contained, say in the tip of a tool head. Then you wouldn't have to worry about large tubs of solution, or moving a circuit board up and down. It would probably work like a syringe head, slowly pumping the solution onto the board just where you wanted it. Encircling the syringe would be a suction cup feeding to the pump, drawing off the solution,by Samuel - General
You might have to be careful. If the bus bar is also submerged in the plating solution, it could get plated as well, and that might cause some problems. It might grow in the wrong ways, and end up connecting the wrong things, if possible. If this is just for circuits, you could try and plate the traces on the bottom side of the board, while somehow applying the current through the bus bar on theby Samuel - General
I'd kind of like to clear up a few things about the motors, so that we can tell whether a particular motor is a good alternative to the official, slightly expensive choice. So here are some questions: 1) What are the suggested specs on the motors? Things like shaft diameter, holding torque, bi/unipolar, voltage, resistance, etc. It would be nice to know what the minimum requirements for the motby Samuel - Mechanics
In the Darwin, how much of the precision is dependent on the motors, and how much is dependent on the gears/rods, etc? If we wanted more precision, could we get it by using a fancier driver to run our stepper motor at 1/8 step, or more? It might not matter how precise the motor is, if the gears and rods to which it is attached do not have the same precision. Could a cheap 200 step/revolution motby Samuel - Controllers
What are we actually looking for in a 3D modeling tool? Are we looking for something simple that can be modified, or something that is already capable? The most capable open source multi-platform tool is probably blender, but I doubt it would be easy to modify. Also, I haven't gotten MeshLab to work, but it seems to only open preexisting files.by Samuel - General