On Sun, Jun 12, 2011 at 10:42 AM, Ed Nisley <ed.08.nis...@pobox.com> wrote:
> On Sat, 2011-06-11 at 23:54 -0700, Mike Payson wrote: > > that is a limitation of the Makerbot firmware. > > As nearly as I can tell, ReplicatorG has become sufficiently > intertwingled with the firmware that it's best to not stray too far from > the beaten path, so I'll continue to use the 2.7 firmware until things > settle down a bit. RepG 24 has 17 different drivers for various > combinations of machines / firmware / configurations and it's not at all > clear what works with what. > True, which is why I recommend avoiding Makerbot stuff all together. I used RepG and Gen3 electronics on my first bot, but I have since switched to RepSnapper & Sprinter on Sanguinololu, and I get far better results. You are correct, though, from everything I hear, RepG is a bad choice to use with anything other than the Makerbot firmware. > I used to like being a beta tester, but I've gotten over it... > The funny thing about this comment is after your first post, I almost posetd a link to your own blog (before I realized it was your blog) pointing out some of the design flaws in the Makerbot stuff. From what I can tell, Makerbot doesn't have beta testers, their philosophy seems to be "ship it, then sell them an upgrade when they complain". I am actually pretty surprised to see that you seem to be a bit of a Makerbot champion, considering how critical you are of many of their technical decisions on your blog. > integrated MCU based driver > > The problem with that is economics: right now, the hardware cost for the > microcontroller(s) and motherboards has run up against the cost of an > ATX system board. In fact, the MBI retail price for the Ardino / > Motherboard / Extruder Controller exceeds the full-up Atom I'm using > with the Sherline. > This is somewhat true if you are looking at one of the boards that uses an Arduino, and is definitely true if you use the overpriced Makerbot electronics, but I have never understood the justification for buying a $65 board just to get the $10 chip on it. I currently run Sanguinololu, which costs about $100 complete including the four stepper drivers. http://reprap.org/wiki/Sanguinololu > There's not all that much horsepower in an 8-bit microcontroller and the > firmware is bumping up against those limits, too. I expect the next > generation will use an ARM or some such, at the economics will > definitely favor a commodity PC and a very cheap analog interface board; > you need pretty much the same stepper drivers for either one. > I never said anything about 8-bit. :-) Like I said, watch for a big improvement in the usability when the next gen electronics ship in a couple months. The cost should still remain under $100 including stepper drivers. (BTW: ARM chips are cheaper than an 8-bit ATMega). All the firmware does is eat G-Code and spit out parts; that's exactly > what EMC2 does with my Sherline mill. I think it'd be a whole lot easier > and less expensive to use EMC2 for motion control than to re-invent all > those functions and jam them into an Arduino. You can certainly get a MiniITX board for around $50 (Though finding one with a Parallel port is becoming more difficult). Then you have to add memory for anouther $25, a hard drive, a dedicated power supply, probably a case of some sort. All told, you are probably going to spend $200 or more on a MiniITX system before you ever think about adding the parallel interface, the stepper drivers, and the dedicated power supply. > Plus, you'd get a much > better user interface, bigger displays, better keyboards, and a much > more stable system for free. > EMC = RepG = RepSnapper. EMC is not the same as the electronics, so you cannot say "Plus, you'd get a much better user interface, bigger displays, better keyboards" since those same points are true of the RepRap today with the host software. I do agree that EMC is more stable, but things are rapidly improving on that front. And of course you don't really get these things for free. Most users will not want to run Ubuntu as their normal desktop OS, nor will they want to reboot into EMC every time they want to make a print, so that means you have to buy each of these items and dedicate them to the printer. Suddenly your $200 is at $300 or more, still without the stepper drivers, parallel interface and PSU. On the RepRap, these things truly are free since they use your existng PC, not a dedicated one. The fact that the "computer" inside the printer is a PC running EMC2, > instead of a microcontroller running something else, is largely > irrelevant. From the outside, you feed either printer with G-Code from > Skeinforge it produces parts; the advantage of using EMC2 is that > developers can concentrate on improving *printing* rather then > reinventing motion control / UI wheels. > You assume the UI model is not going to change. There are developments underway that will change the fundamental way people interact with their printers. It won't be quite as simple as selecting "Print" in your CAD program, but it will be much easier than it is today. One benefit of these changes will be exactly what you suggest... There will be much less need to focus on improving the host, allowing people to focus on improving the printers and the code that drives them. I'd like to do it just to show how it works, but ... not right now. You can print on EMC today. Several people use it already, and I assume the number will continue to grow. But the vast majority of the RepRap community will never switch to EMC simply because their are too many disadvantages to it compared to the current model of integrated electronics (the current model, but not necessarily the current generation). ------------------------------------------------------------------------------ EditLive Enterprise is the world's most technically advanced content authoring tool. 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