Sunday, November 26, 2006
Sorry for my lack of posting lately. It's not that I haven't been working. I've just made very little progress. Nonetheless, little progress is still progress. Here we go:
I've rebuilt my Stewart platform with more careful measurements. It's the same thing, but level-er.
Beyond that, I've been trying to get a syringe drive working. The plastic plunger has been replaced with a square metal one with a hole bored down the middle -- square so that it can fit through a square hole, preventing it from turning. Matching the square hole to the syringe has been a problem. I'd tried making that part out of polymorph, but it doesn't stay soft long enough for me to do a good job, so I made it out of plasticine and cast a mold of it. This was an adventure in of itself -- I first tried making a wax version then casting a mold of it, which accomplished nothing more than the destruction of both the original and the mold. But finally I managed to cast the part itself. It works.
I've tried to build a rough stepper controller for the stepper motor in pure digital logic with no luck. It continues to resist my attempts to decipher it's sequence -- I have one that sort of works, only sort of, it often jams, stalls, or reverses direction(!!) That's not right! I'd build it in a pic, but I've since realized my PIC programmer is about 14 years too old to program the pics used on reprap.org. I'd order a newer PicStart+ but microchip's site demands Internet Explorer, which I do not have and cannot have on my operating system of choice. I'd complain to Microchip about their awful site but their (not an) e-mail complaint support also requires IE! Someone should fire their webmaster. Out of a cannon.
Sorry to hear about the Internet Exploder problem you're having. I'd noticed that. You might want to see if you can get a PicStart+ on Froogle.
I'm using a melabs USB programmer for PICs that I bought from Randy at glitchbuster. The bundle costs about $120. I've had mind for about 6-8 months now and am completely satisfied. You can bounce rocks off it and it is pretty much idiotproof, something I need badly.
For programming I'm using Oshonsoft's PIC IDE Basic compiler. You can get that bundled for about 70 Euros and it is worth every penny, imo.
I'm using a kit version of this with current protection and a MAX232 serial interface rather than the transistors.
Does it have enough power to push anything other than water?
Unless it's changed, I've been using that for programming my PICs...
2 out of 5 PICs have given me problems, but I can't say if it was the PIC in the first place, the programmer/prigramming, or the ULN that they were attached to (which has been replaced as well). The other 3 work just fine, and they've all taken their programming on the first try.
(The one slight modification I made to the design was to the rs232 connection; I split it into a pair of 3pin connectors with one of the connectors matching the pinout of the reprap comms board, allowing me to use the same cable for both.)
I've been running it on a machine that boasts 'y2k compliance', so it's old enough to have a good serial port.
Hmm! That looks interesting. My head was about to blow up wondering how I was going to program the pic for the pic programmer until i realized that it was programming that pic. Duh. I'd forgotten pics were in-circuit-programmable.
Do you have schematics for your version? I have a MAX232 but lack the zener's.
As for strength, the strength is currently zero because a) It's not mounted on a board, b) My motor controller doesn't work. I'm working on it! :)
Lots of possibilities!
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