anon4321

There are some ingenious solutions for the probe. I was thinking of simply having the probe magnetically attached or manually clipped to the head only during measurement. Then the probe can't impact the head weight during printing very much. Someone came up with a way that through a series of moves of the build plate to the extreme Z causes the probe to lower and then a second series of x/y movements cause the probe to raise. Each position is maintained with magnets and springs. I mean c'mon.... someone had their head in the game with this solution: http://www.thingiverse.com/thing:89146 Although, if it were me, I would just have the lever on the build plate controlled by a servo so you don't need to have the extreme Z movements and there wouldn't be the risk of the mechanism causing issues at the extreme Z if you are printing something near the volume limit. But still, that is some amazing out-of-the-box thinking and with the exception of a few pieces like the magnets and switch and springs, a 3D printable solution.

That dragon model gets my vote for the next challenge. I'll unofficially declare Joerg the winner of the previous challenge.

Python code to generate circle gcode for UM1. NOTE: someone needs to check my calculations especially around the extrusion amount. #!/usr/bin/python filament_diameter = 2.89 build_area_width = 205.0 build_area_depth = 205.0 rings = 10 wide = 0.4 thick = 0.2925 / 2 temperature = 230 bed_temperature = 60 base_dia = 180 pi=3.1415927 center_x = build_area_width/2.0 center_y = build_area_depth/2.0 filament_area = (filament_diameter / 2) ** 2 * pi head = ''' M107 ;start with the fan off G21 ;metric values G90 ;absolute positioning M82 ;set extruder to absolute mode M107 ;start with the fan off G28 X0 Y0 ;move X/Y to min endstops G28 Z0 ;move Z to min endstops G1 Z15.0 F9000 ;move the platform down 15mm M140 S{bed_temperature:.2f} ;set bed temp (no wait) M109 T0 S{temperature:.2f} ;set extruder temp (wait) M190 S{bed_temperature:.2f} ;set bed temp (wait) G92 E0 ;zero the extruded length G1 F200 E3 ;extrude 3mm of feed stock G92 E0 ;zero the extruded length again G1 F9000 ;set speed to 9000 ;Put printing message on LCD screen M117 Printing... ;Layer count: 1 ;LAYER:0 ''' loop = ''' G0 F9000 X{x:.2f} Y{y:.2f} Z{z:.2f} G2 F1000 X{x:.2f} Y{y:.2f} I{r:.2f} E{total_mm3:.2f}''' tail = ''' ;End GCode M104 S0 ;extruder heater off M140 S0 ;heated bed heater off (if you have it) G91 ;relative positioning G1 E-1 F300 ;retract the filament a bit before lifting the nozzle, to release some of the pressure G1 Z+0.5 E-5 X-20 Y-20 F9000 ;move Z up a bit and retract filament even more G28 X0 Y0 ;move X/Y to min endstops, so the head is out of the way M84 ;steppers off G90 ;absolute positioning''' total_mm3 = 0 body = '' cross_section = thick * wide z = thick for i in range(rings): dia = base_dia - ((wide * 2) * i) circumference = pi * dia r = dia/2.0; x = center_x - r y = center_y mm3 = (circumference * cross_section) / filament_area total_mm3 += mm3 body += loop.format(**vars()) print head.format(**vars()) print body print tail.format(**vars())

0.15mm layer.

HA suck it you UM2 elite bastards! (I'm joking)....

LOL, my gcode needs a little work.... Unless I just invented the gcode spirograph....

Why no UM1 love?!?!?! We can do circles too!

I'm interested to see the bed from UM for the original. I have V2 from Jason HK but it does lack stiffness in both the aluminum and then the glass. I believe his V3 is a mm thicker.

some interesting stuff here: http://gtocs.blogspot.com/2012/04/garys-diy-cnc-touch-probe.html Wonder if we could miniaturize and 3d print something then clip onto the nozzle head for measuring.

I've been thinking about this on and off. One problem with the electrical probing or even mechanical probing with the tip is anything stuck on the tip will lead to inaccurate measurement. Ideally, you would level the bed just before print with everything at temperature The problem for me is that the nozzle seems to weep plastic even if it is retracted. So it will almost always be difficult to use the nozzle in the measurement. BTW, Antiklesys , marlin has "mathematical" leveling if you can give it the distances to the nozzle at various points. It uses the measurements to adjust the platform through the Z axis to check the platform and nozzle in "virtual" level. It obviously needs good Z accuracy. Here is an extreme demo:

BUT I AM EMOTIONAL !!!! j/k no problem. I was largely wrong anyway as others pointed out that the remaining instructions correctly cause a 0 distance to be used. I stole the gcode from the leveling wizard and print the big square. Then measure it with calibers and adjust so that it is like .25mm (for first layer squish for bed adherence and a tiny amount of shrinkage) and adjust a necessary. Then I know when the gcode calls for .3mm first layer, it is very near .3mm regardless of the actual tip to bed plus all the thermal expansion and whatnot.

The nearest measurement is 2cm and the resolution is 0.3cm. The real question is the repeatability. You could overcome the above by mounting the sensor at say 2cm and then do something like when the measurement goes from 2.1 to 2.4 assume it is at 2.4cm and use that value, The problem is will it repeatedly and reliably go from 2.1 to 2.4 at the same distance? There is always slop in repeated measurements. If the slop is +-0.005 cm, it would work. If the slop is 0.1 cm (1mm), probably won't work. resolution and repeatability are usually related with repeatability being defined in the minimum resolution or half of it If that is the case for this sensor, 0.3cm or +-3 mm or even +-1.5mm isn't going to be good enough when your first layer is on the order of 0.3mm So it is a good idea but I doubt that sensor has the resolution and repeatability required.

I looked up the regulator. One of the few things you can get at RadioShack... http://www.radioshack.com/product/index.jsp?productId=2062600 It seems that it has internal thermal protection so is it possible it is overheating? I believe the 12V is only used to feed the Arduino. However, if you modded the UM1, did you hook anything else up to the 12V line? Fans? LEDs?

Hmmmm, I have seen some behavior similar to this. If I turn off the power, like in an attempt to abort a print but don't disconnect the USB then reestablish the 19V power, I get the MINTEMP error. Nothing seems to clear it except removing ALL power including the USB power. Even unplugging the USB with the 19V on won't reset it so it appears locked into this state. I believe that without the 19V power, the 5V power "sags" and puts either the Arduino or the TC amp into a weird state. I think the MINTEMP error really causes a fit in the firmware. I've seen really weird behavior if the machine is started in the MINTEMP state. Like the controller display filling with blocks (try disconnecting the TC from the amp and turning on the machine). So given all this, is it possible that you are intermittently losing 19V power? Could the jack be "iffy" becoming temporarily disconnected due to vibration? How about the power brick? Is the line side solidly connected? If it isn't that, you might get the same behavior if the 12V regulator is going bad.

Save Tool Path is the same as save gcode and requires that the model be sliced before it is enabled. I believe slicing requires a lot of floating point calculations and that is something the Celerons are not particularly good at..

Unlike other motors, steppers use current for holding torque when not moving so will also generate heat when not moving. You should be able to test this. Without filament in the second extruder, try turning the gear during a print then with the power off. During the print, you will probably feel a lot resistance because even though it isn't in use, the driver is enabled and the stepper is powered. Steppers can take a lot of heat so you might want to just leave it alone. If it really bothers you, you can dial back the current. NOTE: Others including myself have damaged drivers while adjusting them !!!!!!!!!! DO THIS AT YOUR OWN RISK. See http://wiki.ultimaker.com/Electronics_build_guide You don't need to use a multimeter, Just use the information above to determine how to reduce the current and then just reduce in small increments WHEN THE POWER IS OFF. Be careful and note that the drivers get HOT. Make sure you replace the fan/electronics cover after adjusting. I would unload all filament and try to match the force required to get the second motor to skip against the first and then adjust a little HIGHER so you don't skip steps on the second extruder causing bad prints. GOOD LUCK! HEED THE WARNINGS!

Check also that the Bowden tube is secure at both ends.

Do you have a BOM for the non printable parts for the four leg configuration shown?

Good points Jonny. I didn't think about the reduction in resolution that reducing the max PWM would cause. 255->101 makes the granularity quite poor for the 12V mode.

Hmmm, I wonder if marlin supports a maximum PWM for the heater outputs that could be used to reduce the avg power delivered to the 12V cartridge.

Awesome stuff Joerg. Meshmixer support definitely seems like the key to cleanly printing this. Thank you for the extra pics. Don't worry about sharing the stl. This is more of a "try it yourself, learn by doing" type contest so I'll give meshmixer another shot.

LOL.

That is brillant!!! Whoever designed that is a genus.

Cool. that is what this idea is all about! I like seeing people try different ways, tools and materials. Please clean off the supports and take a picture if you have time.. I'd like to see the underside. How much and in what direction did you rotate it? I tried to install meshmixer but unfortunately it doesn't like running as a non-admin user under windows. How do you like the XT? I was thinking about using it to print a new head and sliding blocks and was wondering if it would standard up to a heated chamber.

Jonny, are they truly 24V cartridges and not from UM? If so, you should know that the UM versions are 18V so a true 24V may take longer to heat up and might not be able to hit high temperatures or maintain a temperature as well as the UM version.