This doesn't sound like it's about the RepRap electronics. I can't be of much help but I did notice that the Make blog recently had a pointer to "Introduction to I2C": Perhaps that will help.by JohnWasser - Controllers
Google Error Not Found The requested URL /_MJygcN77k8I/R3IQ3hqJ6CI/AAAAAAAAFMY/SS5pSEnA2Xs/1+(31).JPG was not found on this server.by JohnWasser - Mechanics
You know that the center of the arc (I,J) is R distance from both the current position (call that x1,y1) and X,Y (the destination point). Find the points where a circle of radius R around x1,y1 intersects a circle of radius R around X,Y. Those two points are the possible locations of I,J. It's not clear how you pick which of the two to use as the center of the arc... You can draw a clockwiseby JohnWasser - RepRap Host
Spam from the FUTURE! (or at least 15 time zones ahead of me)by JohnWasser - General
Or try if you want the episode described as: Material: Plastic Electronics & Captive Breeding 04092008 The thin, flexible world of polymer electronics, and captive breeding of endangered animals, from tigers to vultures. Quentin and guests discuss. Duration: 28mins | File Size: 13MBby JohnWasser - General
The term "symbolic link" is Unix/Linux speak for what Windows users would call a "shortcut" and Max OS X user would call an "alias". Another way to do it is to make a copy of the desired version of the file and name it with the desired name. andy hall Wrote: ------------------------------------------------------- > I do not know what > "create a symbolic link to the appropriate file >by JohnWasser - RepRap Host
The info in the .swf file says it's 407.29 MB but the directory listing and download results show it as 23.0 MB. I suspect the copy on the server is incomplete. Extruder assembly.swf 29-Aug-2008 16:09 24.0M Extruder assembly1.swf 29-Aug-2008 16:08 3.1M Extruder drive assem..> 29-Aug-2008 16:09 23.0M darwin.swf 29-Aug-2008 16:08 2.1Mby JohnWasser - Reprappers
Kyle Corbitt Wrote: ------------------------------------------------------- > I'm a bit confused - why all the effort to cast > roller chain? I agree. My best guess is that somehow the Ladder Chain discussion in another topic spilled over into this Bicycle Chain discussion.by JohnWasser - Mechanics
Type3Singularity Wrote: ------------------------------------------------------- > Why is there a need for a circuit board on the > RepRap at all? Shouldn't it be possible to control > the motor and sensors almost directly from a > computer in software? To control the hardware you need driver electronics and communication. If you want the hardware to work with Window, Mac, and Linuxby JohnWasser - General
Looks great! Bicycle chain is certainly widely available around the world. It will be interesting to see how nice a roller chain sprocket one can print on a RepRap. It has got to be easier than printing molds and casting timing belt sprockets.by JohnWasser - Mechanics
I think the springs are bent before being tempered. That might make it hard to bend a new hook without breaking the metal. Perhaps you would be better off finding some shorter springs at your local hardware store.by JohnWasser - Reprappers
So it looks like the maximum chain pitch one can fit into a Darwin is about a 1/4" or 6mm. It will be interesting to see if a RepRap can print a working ladder chain link at that size.by JohnWasser - Let's design something! (I've got an idea ...)
Just saw this go by on the Make Magazine blog (http://blog.makezine.com/archive/2008/08/make_your_own_potato_plas.html?CMP=OTC-0D6B48984890). Make plastic from potatoes: Make better plastic from Hylon VII high-amylose potato starch: Note: This version requires a high temperature autoclave or running a pressure cooker WAY beyond normal pressure: "First you need to remove the safety blowout vaby JohnWasser - Plastic Extruder Working Group
Ladder chain uses only one kind of link, sort of like a roller chain "half link". The side plates are offset so the narrow end of one link fits between the side plates of the adjoining link. The wide end has a simple bar across it and the narrow end hooks over the bar of the adjoining link. The bars fit between teeth on the sprockets. I think an octagonal (or even square) square bar would worby JohnWasser - Let's design something! (I've got an idea ...)
eNano Wrote: ------------------------------------------------------- > > o-arduino-compatible-microcontrolador It says "Arduino Diecimila compatible" but the picture shows a board with a serial port instead of a USB port. Here is another source:by JohnWasser - Controllers
As I suggested here: it seems feasible to me to print out links of ladder chain that can snap together. aka47 Wrote: ------------------------------------------------------- > 6mm Servo Chain (aka 04B1 roller chain) in steel > is more cost effective but still not something we > can churn out from a working Darwin. > > Some design effort put into printable drive > belt/chain woby JohnWasser - Let's design something! (I've got an idea ...)
Forrest Higgs Wrote: ------------------------------------------------------- > Why not just use a regular wood auger type drill > bit? My guess is that because they are designed to pull material toward the drive motor they would not work properly in reverse. Perhaps a long auger could be ground down to make a shaft on the other end.by JohnWasser - Mechanics
I think that, generally, that message would mean that some other program was using the port. Since only one program can use the port at a time the exerciser gets and error. Sometimes a program will open a port and then forget to close it again. The easiest way to fix this kind of problem is to re-start the system.by JohnWasser - RepRap Host
Richard B Wrote: ------------------------------------------------------- > 4.Does the controller require any flashing like a > PIC? (Arduino im talking here) or is it all > uploaded via the usb connection. The Arduino comes with a boot loader programmed in. You can upload new programming easily via USB and don't need a separate programmer. (For those that need the space taken up by tby JohnWasser - General
Check the spam bucket. Sometimes spam filters have false positives.by JohnWasser - General
Adding the tags for code ('code' and '/code' in square brackets): +------------\ /------------+ | \ / | | \ / | | \ / | | ----- | +-------------------------------------+ +-------------+ \ / \ / \ / \-----/ That looks likeby JohnWasser - Paste Extrusion Working Group
.+-----=-----------=----------= .| | | .| | | .| | | .| | | .| | | .| | | .| | | .| |-----------| .+-----^-----------^----------=by JohnWasser - Mechanics
I would not include laser cutting under the die cutting heading. Neither would I include broaching or bandsawing. I'd say that if it's not a shaped blade cutting a shape into or out of flat stock then it not die cutting.by JohnWasser - RepLab Working Group
$30 plastic welder toy from The Discovery Channel. Runs on four C cells. It's not clear from the product description what the underlying technology is. My best guess is that it's a very low temperature glue gun but perhaps it's an ultrasonic welder! Too bad all the Discovery Channel stores in the local malls closed up shop last year. Product Detail: Discover the power to make and create witby JohnWasser - Plastic Extruder Working Group
brucew Wrote: ------------------------------------------------------- > I sent an email to Wendy from plastics unlimited > and got an answer on prices of plastic from them. > > Clear Plex > > 3/16by JohnWasser - Massachusetts, Boston RepRap User Group
Reprapper Wrote: ------------------------------------------------------- > It is because people will actively make decisions > to avoid having to learn a new system. If that were the case there wouldn't be any Windows users switching to Apple. > If they invest the time and effort to learn how to use a > commercial 3D printer, will they want to switch to > an alternative that doesby JohnWasser - General
In normal operation (while making stuff) the software has no need to determine which end stop has been hit. If it happens during normal operation something has gone terribly wrong and the machine shuts down. At startup it is not unreasonable to have the human operator determine which endstops are activated and correct the problem manually. Again, if the software sees the end stop signal on itby JohnWasser - Controllers
Purchase a 1/4-20 threaded coupler, usually available from the same place you get 1/4-20 threaded rod. It's a very long hex nut for connecting two pieces of threaded rod. Mount that in the drill press vice so the 3mm drill does down the center of the hole. Clamp down the vice. Put your threaded rod into the coupler and lock it down with a 1/4-20 hex nut. Drill the hole.by JohnWasser - Mechanics
The old eBay link is no longer valid but an eBay search for "zenbot" turned up a current auction: $550 + $40 shipping. (Doesn't include Dremel 300, stepper motor drivers, cables, power, or software) Travels: X-6.00 Y-8.0 Z-2.75 Table size: 9.575 X 13.5 Footprint: 12.125 X 13.5 HDPE frame and Baltic Birch plywood table. Looks like it MIGHT be self-replicating, except for the plywood tableby JohnWasser - General
I would go with the hex bolt or put a hex head on all-thread with a hex nut and epoxy. Then to drive the hex head you can fabricate a coupling from a 1/4" drive socket and some epoxy putty.by JohnWasser - Mechanics