The price of $20 for the cable when the Sanguino kit is only $25 seems quite out of proportion. Can anyone confirm Larry's idea that the USB BUB board works with the Sanguino? Jonby jonwise - Controllers
My attempts to build a simple linear stage have been hampered by the screwed rod bought from several local suppliers not being straight. Is it possible to buy threaded material on a RepRap budget that will rotate without a millimetre wobble?by jonwise - Mechanics
I have tried the RM2 motor and it is not a good replacement for the RM3 in the BitsForBytes extruder. It naturally runs much faster and, slowing it down to an appropriate speed, the torque is too low.by jonwise - Mechanics
I am having problems producing a U shaped object because, on the concave side, the shell shrinks away from the fill. Any suggestions for Skeinforge parameters to get round this problem would be appreciated. Jonby jonwise - Skeinforge
To help line up the teeth, I made a cast on a block of wood of a strip of about 60mm of the belt using some spare J-B WELD. When gluing the ends of the belt together, they could be clamped into the mould so they were correctly lined up.by jonwise - Mechanics
Solarbotics tell me the RM2 is not the 12 version of the RM3. To correct my original post, the second motor had not burnt out. It stalled with similar symptoms to the failed first motor but further investigation showed the problem was elsewhere. The HDPE had developed a kink between the extruder drive screw and the channel down to the heater barrel. It has happened twice more and this problem iby jonwise - Mechanics
Is the Solarbotics RM2 the motor I am looking for? It does not mention 12 volts but is described as a more powerful motor for a GM3. Active-robots.com have it on their web site for sale in uk.by jonwise - Mechanics
I have been using the 6v version. Is there a supplier of the 12v version in England?by jonwise - Mechanics
The second motor of my BitsFromBytes laser-cut extruder, a GM3, has just failed. I do have not a record of the time it has been operating but I estimate it is between 5 and 10 hours, running with M108 S120. The gearbox looks OK but the brushes of the motor are worn. Is this a reasonable life for the GM3 motor/gearbox? Any suggestions for a more robust replacement without building a different extrby jonwise - Mechanics
Thanks for the feedback. I am pleased not to have problems with the temperature control. Looking at the extruded filament with a lens I can see a fine black line which is presumably the dust from the bolt and washer which take the load of the pressure roller in the BitsFromBytes laser-cut extruder.by jonwise - Plastic Extruder Working Group
My HDPE products have generally retained the off-white colour of the source filament but recently the results are a much darker grey. Is this a sign that the temperature is too high( I have not changed the setting from 240 Celcius that I have been using since I started)? What else might it be? Jonby jonwise - Plastic Extruder Working Group
I have found that a startup sequence is essential after a reverse drive on the previous extrusion as it takes longer to get the material flowing again compared with just switching off the extruder motor. Getting the parameters correct for a mixture of path lengths is proving difficult. A fixed time for starting and stopping can be determined by experiment provided the extrusion runs for over 30by jonwise - Mechanics
I am in Cheltenham. My RepRap has been working for several months and I would like to chat face-to-face as well as via the forums. Jon Wiseby jonwise - United Kingdom RepRap User Group
Thanks for the new firmware, it promises much improved quality by removing the pauses between commands, but I am having a few problems. The first is that resetting the origin with a G92 hangs unless I insert a pause. The length of the pause needs to be long enough for the endstops to be reached. The 5 seconds in the attached code is not sufficient for general use. Is there a better solution thanby jonwise - RepRap Host
I have also tried a startup pattern reversing to the start point of the line as you suggest. The initial attempts look good but I have not yet had time to get any experimental results. The base material in the photograph is a kitchen chopping board. I would normally add a raft but that would have made it more difficult to see the test results. Jonby jonwise - Mechanics
The tracks in the image below were printed from left to right. The extruder went into reverse at 13mm on the ruler and the ends are 3mm, 4mm ... 9mm long. With a 3mm end there is clearly still lots of ooze. In this run, 6mm or 7mm looks optimal, after which the end is getting rather thin. Jonby jonwise - Mechanics
In an attempt to reduce the stringing of filament at the end of a line, I have been experimenting with reversing the extruder drive. It is not easy to get a tidy end to the line and some initial experiments suggest that there might be benefit in back-tracking at the end of movement, so for a line from (0,0,0) to (x,0,0) the extruder runs normally to (x-a,0,0) when the extruder is switched to reveby jonwise - Mechanics
Where are with this gcode host software? Looking at the svn trunk revision 2296 today, gcode output is there but is this a good version on which to base developments? I notice that in GCodeRepRap.java there is a comment " * TODO: find a better place for the code. You cannot even detect a layer change without hacking now. " May I suggest that we need some classes representing layers, paths, extrby jonwise - RepRap Host
It is worth checking that you do have rr-logo-green-url.png in the botConsole folder.by jonwise - RepRap Host
Enrique, Thanks for the quick response. I printed a first attempt last night and although my 3D design needs some adjustments the shape was produced despite the warnings. I was intrigued by the complicated fill pattern on the bottom layers which was quite different to that which I have been seeing in earlier products and the extra switching off and on of the extruder increased the ooze problemby jonwise - RepRap Host
I am trying to produce the shape in the image below but slice_shape throws the following error. Do I need to avoid the 'island' for skeinforge to work? The gts file is attached. File "D:\gbs\reprap\skeinforgeNov26\skeinforge_tools\slice_shape.py", line 397 , in getSliceGcode skein.parseTriangleMesh( slicePreferences, triangleMesh ) File "D:\gbs\reprap\skeinforgeNov26\skeinforge_tools\slby jonwise - RepRap Host
Enrique, Thanks for the update. I have tried oozebane using the November 20 version and find there is a problem when there are several short steps near the end of the extrusion. I would be pleased to offer a code correction but cannot see how it is intended to spread the slow-down over existing steps. The gcode below is from the diamond.stl example starting at line 108. With oozebane: G1 X-0.55by jonwise - RepRap Host
Thanks for this. The slow-down still does not complete correctly because on the last move the feedrate goes back up to the original value. I feel I ought to submit a fix rather than just report it but I do not yet have sufficient understanding of the code to do this with confidence. The number of slowdown steps is set to 2 and it is the third which has the fast speed so guess the process is starby jonwise - RepRap Host
Some help understanding oozebane would be appreciated. In the example below using skeinforge from the Nov 6 zip file above, the feedrate drops before the extruder is switched off. Will this not cause a blob near the end of the extrusion? Without oozebane, my gcode starts: G21 G90 G28 M103 M105 M108 S130.0 M104 S220.0 M101 G1 X3.84 Y1.32 Z0.18 F960.0 G1 X9.13 Y1.32 Z0.18 F960.0 G1 X9.13 Y9.88 Z0by jonwise - RepRap Host
> in the 10 seconds or so after the drive stops, I get another 20mm of thread Applying reverse drive to the extruder for about 3 seconds, I get only 4mm of ooze. This feels worth adding to the skeinforge tools. Is oozebane the place for it or is there somewhere better? Jonby jonwise - Mechanics
I have been measuring ooze from the extruder. Using HDPE at 240C, in the 10 seconds or so after the drive stops, I get another 20mm of thread. My initial experience is that the oozebane tool in skeinforge does not cope well with this long ooze. Is this a common experience with the BitsFromBytes Laser-Cut extruder? Is it worth trying reverse drive to the extruder?by jonwise - Mechanics
> ... second and third layers of the raft ... As I understand it, the raft sticks to the base, the product sticks to the raft and to separate the product from the base, the raft material is expendable. Why several layers of raft? Jonby jonwise - Plastic Extruder Working Group
I have just moved to a kitchen chopping board. I do not know the material but it is the common 'plastic' variety. Using HDPE at 240C, I put down a single layer of the Skeinforge raft under the product, setting the nozzle close to the surface to get good adhesion, and it works much better than any other base I have tried. The product can be removed using a chisel leaving the board reusable.by jonwise - Mechanics
Where can I find a compatible set of software for arduino and skeinforge? I have the GCode_Interpreter in reprap-arduino-firmware-1.3 working to extrude a test rectangle. When I create gcode from skeinforge it includes M108 to set the flowrate which is not in the arduino gcode interpreter.by jonwise - RepRap Host
> ... Sharpening the screw was probably the key change .... After more intermittent extrusion, I removed the drive bolt again and cut the thread deeper, to at least 1.5mm, using a small hacksaw. This seems to have solved the problem as I have run on several days since then without needing to adjust the pressure roller.by jonwise - Mechanics