You know, the STRATASYS link is a list of patent applications, not granted patents. Based on recent experience at my job, the patent office is making it a lot harder to get patents that are not very non-obvious. Just because STRATASYS says that they want to patent it, does not mean that they will succeed. You know, some of the ideas, like '20080317894' the extrusion tip cleaning assembly, soby fdavies - General
It may be mechanical backlash. When the extruder is cool, if you put your finger in the tip, will it wiggle back and forth any? fdaviesby fdavies - General
I belong to the Houston Hackerspace, txrxlabs (txrxlabs.org). We have a Makerbot cupcake and a Mendel (built by me). We have an open-house meeting on Friday nights starting at about 7:30 if anyone wants to come by and see a working mendel and discuss 3D printer issues. It is at 2010 Commerce st., a few blocks from Minute Maid Park in downtown Houston. In fact, on March 4, we are having an opby fdavies - Texas, Houston RepRap User Group
I belong to the Houston Hackerspace, txrxlabs (txrxlabs.org). We have a Makerbot cupcake and a Mendel (built by me). If you have not got a good meeting location, post a message on this thread and I will ask the other members if you can meet at the hackerspace (2010 Commerce st., a few blocks from Minute Maid Park in downtown Houston. We have an open-house meeting on Friday nights starting at aby fdavies - Texas, Houston RepRap User Group
Oh, some more things: In the file 'process_g_code.pde' you can turn on an echo by changing line 95 from " byte SendDebug = DEBUG_INFO | DEBUG_ERRORS;" to "byte SendDebug = DEBUG_ECHO | DEBUG_INFO | DEBUG_ERRORS;". When I did this (recompiling and downloading the firmware into the sanguino, of course), I could see what the Sanguino was receiving on its serial port from send.py. You would havby fdavies - General
I changed the firmware (FiveD_GCode_Interpreter 20100806) in the Sanguino in my Mendel so that it replies to M101 and M103 with 'ok' rather than an error message. I did this by making the following changes in the file 'process_g_code.pde' Original: /* //turn extruder on, forward case 101: ex->setDirection(1); ex->setSpeed(extruder_speed); break; //turn extruder on,by fdavies - General
I have some PLA 3mm filament that has been sitting around for some months. I tried printing with it and discovered that the extruder was dribbling. By this I mean that when the stepper stopped, the PLA kept coming out. When the stepper started again there was a significant delay, presumably as the void created by dribbling was filled. I would occasionally see the tip blow a bubble with a tinyby fdavies - General
I have successfully printed ABS mendel parts on an unheated acrylic bed. I did have to print some of the bigger mendel parts several times. I discovered that I got better results with the uncolored ABS than with the black ABS. The temperature of an unheated bed still makes a difference. If you have problems with the raft lifting and the bed is cold to the touch, you should try to warm it up sby fdavies - General
I agree with nophead that microstepping does not reduce torque. I think that the confusion revolves around confusing holding torque with stiffness (torque per step). If I run a stepper motor without microstepping, and it is not moving (not stepping), it has a certain stiffness. By this I mean that if I grab the shaft and try to turn it (put torque on it), it will turn a little bit. The is a cby fdavies - Stepper Motors, Servo Motors, DC Motors
This can happen if a stepper motor skips a step. If the head catches on something it can cause the motor to skip a step. There is usually a distinctive noise as it does it. Try holding the top of the extruder (not the top part) to make the motor skip so that you know what it sounds like. fdaviesby fdavies - General
I have added the following page to the wiki about scavenging sensors: fdaviesby fdavies - Controllers
That looks like a nice piece of hardware! See if you can figure out how to power the unit before you take it off of the motor. If you can get a data sheet based on a part number, you could figure it out that way. Otherwise, there may be one or more large polarized (electrolytic) capacitors on the board. If you find one, it is probably on the power rail. This may suggest how to power it. Ifby fdavies - Controllers
Let's see if I can remember... 1. Incrementing 'PHASE' by 256 will take the stepper motor through one full cycle (4 steps). Of course, if you just increment PHASE by 256, the motor will not move. The jumps must be smaller. 2. Each pulse that the arduino receives on pin ADC4 (PC4) is supposed to move the linear stage by one optical encoder increment (this is one quarter of the line-to-line sby fdavies - Controllers
Sorry for the delay in replying. I would suggest starting by getting the optical sensor and strip from a non-working inkjet printer. I would go to garage sales or recycling centers and get two or three. Do not get laser printers, since they do not have the right optical components in them. Start taking the printer apart and you will soon see a grey plastic strip close to the shiny metal rodby fdavies - Controllers
I am printing Mendel parts on my repstrap. While they print I am getting together all the other hardware that I will need. It looks like 5/16 threaded rod will do for 8mm studding. I have a lot (my wife would say a ridiculous number) of old inkjet printers acquired at garage sales. I discovered that many old HP printers have 8mm rods in them to serve as linear bearings. The 6 rods that I haby fdavies - General Mendel Topics
I am working on a Z axis mechanism (very half-baked for now). In the course of doing this, I came up with a nice little clip for 608 bearings. More details in the wiki at Bearing_clip_01 Thanks, fdaviesby fdavies - Look what I made!
I did some experimentation with induction heating a while back: and . The advantage of Induction heating is that the RF coil does not have to touch the item heated, and that the item heated can get quite a bit hotter than the RF coil. In order for induction heating to be a 'killer ap', it would have to allow a simpler extruder head structure somehow. If you could have a simple copper wire wiby fdavies - General
I have had good results using a stainless steel tube as the thermal transition. I described it here: . Please note that the TO-220 heater part of that design did not work very well. I have since gone with an aluminum body type resistor like nophead has been using. I found a stainless tube which is barely thick enough to put a 10-32 thread on. This means that the thickness of the stainless atby fdavies - General
I have slightly modified your main script file so that it will run with Octave. I have attached the resulting file. F Daviesby fdavies - General
I spotted some water bottles (pictured). I live in the Houston, Texas, area, and found them in my local grocery store. The website (primabottle.com) says that the bottles are made of 'ingeo' from Natureworks. Interestingly, I have been printing with PLA from Ultimachine, and they say that it is 'ingeo' from Natureworks. I think that these bottles may be made from PLA! Now I need to empty onby fdavies - General
Cool! I am glad that someone is working on this. F. Dsviesby fdavies - Look what I made!
Here is a pencil box that I just made. Thanks, F Daviesby fdavies - Look what I made!
WIll current be flowing through the water? I have done a bit of dabbling with simple electrolysis, but have never seen noticeable forces between the wires immersed in the electrolyte. Also, descriptions of electrolysis tanks do not mention having to compensate for such things. So, would it be magnetic forces between the wires that control the position of the floating part? That might work, buby fdavies - Mechanics
My repstrap uses stepper motors and optical feedback on both the X and Y axis. The stepper motors are microstepped. I do this by driving them with a PWM (pulse width moduled) waveform) that makes a sinewave. I have put details on a wiki page. fdaviesby fdavies - Controllers
I have a repstrap that has a glass plate as the print bed. I have not printed directly on it, though. I have printed these ways: 1. ABS on plexiglass sheet taped to the glass at the corners. The plexiglass has to be at least 1/4" or the ABS will bend it considerably. 2. PLA on foam board taped to the glass. This was marginal. The slight warping that PLA does was enough to overcome the stiby fdavies - Reprappers
If you have a complicated part (not a primitive), then you run the solid editor on a part (the solid editor is a plugin). You can then get the X, Y and Z coordinates of two vertices. If the measurement that you are interested in is parallel to one of the axes, simple subtraction will give you the answer. This is probably not as easy as you had hoped, but it can be done. I am not aware of anyby fdavies - 3D Design tools
If you lift the front lid of the printer (as if to change the cartridges), you will often see a grey plastic strip. It is grey because of the large number of tiny stripes. You should take apart the printer to get it, and you should use the sensor from the same machine. The data sheets for the sensors imply that the exact spacing of the stripes is important, and I have seen different spacings oby fdavies - General
Some kind of simple position measuring system, like the opto strip and quadrature sensor that can be scavenged in yard sale inkjet printers, can cover a multitude of sins, like slipping cables, and certainly the nonlinearity caused by cable winding onto a drum or cable stretching. fdaviesby fdavies - General
I am glad that you are working on the polar idea. I think that it has a lot of potential. fdaviesby fdavies - Polar Machines, SCARA, Robot Arms