Looks like I'm about to move to Glouster/Cheltenham. I've got a placement year in Tewkesbury. Which seems to make me closer to the majority of you RepRappers.by TheFallen - United Kingdom RepRap User Group
Fair enough, good luck battling your way through those library functions.by TheFallen - Controllers
I never got the hang of pointers, although I did avoid them like the plague. One thing I'd recommend with C is to get your head round data types and data structures. They are both awesome and powerful tools! Massive board there, that must have cost a lot to get fabbed up. On another thought Wouldn't it have been better for you to make seperate boards for each major function? A Stepper board, a Cby TheFallen - Controllers
I got a Motherboard and the Opto Isolators and the second it went over the £20 I got charged VAT which was an unpleasent suprise as the Post Office then added a £8 handling charge on top. Not a nice thing at all. I'd definately recommend not getting the PCB but the kits, it's worth the money rather than the hassle of finding the parts.by TheFallen - Controllers
I used to use it at my old school, it's quiet sticky but I don't think it conduct through the sticky side, and it holds up to soldering extremely well, however it fails in that it's not the most robust of things, it needs to be stuck down well otherwise it just peels.by TheFallen - General
I'd love to go, but same as Demented Chihuahua, it happens right in the middle of exam time Oh and I'm going to HOPE so I haven't got much money anyway!!!by TheFallen - General
I guess it'd be like a more accurate version of the L297/L298 combo, an upgrade for more complicated models/versions of rep-rap. See the joy of reprap is that it almost makes hardware like software, self-updating. You don't have to start from scratch, you can simply upgrade the old files/parts with new parts. In this case, the old standard stepper motor drivers are replaced with ones that areby TheFallen - Controllers
I've been playing around with the SLA7052's and I have to say, they're very nice...by TheFallen - Controllers
One book that deals a lot with nano replicators is Charles Stross's Glass house.by TheFallen - General
3 meter USB cable, but why? To be honest, you can get pretty much all the electronics on the Arduino, thats around 20 GPIO pins. And cost wise I was referencing the first post, I2C is complicated, however RS232 is pretty much standard on almost all uCs and requires the minimal of code.by TheFallen - Controllers
I have to admit, I always use Octopart, it's a search that seems as powerful as Google (or do they use a Google API?) And it gives you helpful links to both datasheets, manufacturers and pricing. Not to mention, a pretty picture!by TheFallen - Controllers
To sense the current across the stepper motor coils you need two 0.5 ohm resistors, something we don't have in the UK, or at least in in any of the main electronics suppliers. The resistors need to be around 1 watt and carbon film NOT wire-wound. Rapid sell some nice 1 ohm resistors that can, when soldered in parallel can replace the 0.5 ohm resistor. And aboutby TheFallen - United Kingdom RepRap User Group
Joe, search for 1ohm resistors, two of them in parallel with give you the 0.5 ohms required for the L298 sense resistors. It's easier and cheaper than using the 5 0.1 ohm resistors as green arrow has done...by TheFallen - United Kingdom RepRap User Group
See I agree, I'd be using 5V as my standard for the boards, least thats how I do it for all the RepRap boards I've designed, although these are mainly for the Arduino trunk.by TheFallen - Controllers
Rapid's search is great for part numbers, damn useless for anything else. I think I posted up a parts list from rapid with the associated codes in it.by TheFallen - United Kingdom RepRap User Group
Oh a though you can use 2 1ohm Resistors rated at 1 watt in parallel to get the 0.5 ohm sense resistor for the l298. That saves you 5 0.1ohm resistors in series.by TheFallen - United Kingdom RepRap User Group
It's nice, I tried to make one based on the L298/L297 combo, I've included the brd file and sch. Please download and have a poke around.by TheFallen - Controllers
put stuff in them? I get loads for my electronics supplier here in the UK, I put project parts in them if I'm shelving the project for a little while...by TheFallen - Controllers
Personally, I'd go with simplicity over cost. No exclusively but I think it's far better to simply have DIR and CLOCK seperate for each motor, with 3 motors thats only 6 pins, 6 pins for an entire cartesian movement system. Okay, then add 6 pins for the limit sensors, 2 for each axis. So we've used 12 of the Arduino's 14 digital pins, and we want to leave pin0 and pin1 open for USB/Serial communiby TheFallen - Controllers
I've just had a look at the Arduino again, the 6 Analog sensors can be used, as rudimentary digital sensors. This can be done though if commands, like if(anaIn > 100) limit = 1; if(anaIn < 100) limit = 0; That way anything above 2v gets counted as a high and anything below 2v counts as a low. (assuming the analog input scales 0-255 and Vref = 5v). This should then free up 6 digital i/oby TheFallen - Controllers
Arduainas? Arduinos surely? as in Check here: MAKE: WE Podcast 1: With PDF: MAKE: WE Podcast 2: With PDF: Also RepRap forum thread here: Personally Arduino doesn't provide enough grunt for RepRap. I think Wiring , which is essentially the granddad to Arduino is a far better option.by TheFallen - General
Heh it seems I've made a mistake, anyone know where I can get 0.5 ohm resistors?by TheFallen - United Kingdom RepRap User Group
tbh, to do that all you need is some way of depositing some etch-resist on the PCB, hell, even the current HDPE may prove suitable here, quite simply, more testing needs to be done.by TheFallen - Mechanics
PowerPoint would be a bad idea, but it wouldn't be a bad idea for it all to be consolidated into pdfs. I think it'd als obe a good idea to get it all sorted on the Wiki front.by TheFallen - General
Here's my attempt at neatening the parts list up for the V1.1 board, it has Rapid codes so it can all be bought from there, I'll try and do the same for Farnell/RS, and for some of the other boards as well. Any feed back is welcome.by TheFallen - United Kingdom RepRap User Group
Actually my general take of Maplin (UK's Radioshack) staff is that they're idiots. They've told me things that were obviously wrong many times over. I'm sure there are some good ones, but I'm yet to meet them. The main problem is the variable resistor/diodes. As the person above wants to get the right ones, and the UK has different shops, who sell different componants.by TheFallen - United Kingdom RepRap User Group
I think when you look at it like that it's easy to get disheartened, probably to recognize that that's the projects eventual aim, not something we're aiming for by 2008. I'd count something like Darwin as a reprap, a device that can print a fair chunk of it's own parts, meaning you have to only buy the bare minimum. Just the ICs, Motors, wire, metal rod. It's be nice to be able to print copperby TheFallen - General
The Way I saw it was that a repstrap is something that's been bashed together out of odds and sods to make the parts for a reprap like Darwin. Repstraps would, unique to the maker, although they'd all share similar properties (3 axis control, a plastic extruder/miller etc). Once you've made your reprap you could simply bin the reptsrap as it would not be as accurate, nor as useful. I mean, the bby TheFallen - General
The chip is an Allegro SLA7052M. Have a look here: Essentially most of the components are internal, it's a uni-polar driver, and it seems most people don't have these. I can't remember whether it can be converted easily. It just needs a Vref, sense resistors, smoothing cap and inputs. I am using different motors than the "official" stepper motors sold/used by most reprappers. I got them for frby TheFallen - Mechanics