thereza

Thanks for the suggestions. It's worse with Kapton, it's level but depending on which software I use I have to manually tweak the first layer height. netfabb prints the first layer way too low and cura seems to print a bit high. I've not tried brim, I'll give it a shot. What causes it, and why would a slower fan help? And why would it be worse on the heated bed than just the blue tape? I want to understand the phenomenon so I can better figure out what things to try and why. Thanks, Reza

So I was using blue tape without much problems, though I had some parts that would curl up at the corners. I've switched to a heatbed that I've tried with both kapton and blue tape. The initial adhesion is great, but now the curling is much much worse than without the heatbed -- which was what the heatbed was supposed to solve. What could be causing my problem? Should I just rip out the heatbed?

I can't get netfabb to support the heatbed that I've added. I've even tried to add the M140/M190 commands to the header/footer of the gcode, but netfabb keeps adding M104 S0 commands to turn off the heatbed all over the gcode. Is there some way to force netfabb to work with my heatbed? thanks, reza

I'm just wrapping up my heat bed using an external power supply and wanted to share one little tidbit. You'll need to remove D2 or D3 (depending on where you've connected the heatbed) in order to avoid having the external power supply keep the ultimaker board powered while it is off. you'll just not be able to see the indicator light turn on on the ultimaker board which you can't see anyhow. -r

Hi, I've connected the heat bed to the 2nd temp input but just read that it should have been the 3rd. not wanting to move and resolder the temp sense resistor, i wanted to see if this is the required change in software to make it work with the second temp sensor.. this is from pins.h. So change #define HEATER_BED_PIN 4 #define TEMP_BED_PIN 10 #define HEATER_1_PIN 3 #define TEMP_1_PIN 9 to #define HEATER_BED_PIN 3 #define TEMP_BED_PIN 9 #define HEATER_1_PIN 4 #define TEMP_1_PIN 10 Is there anything else that I would need to change? Reza

btw, any chance you can incorporate these replace entries automatically as checkboxes in the config dialog?

actually, it wasn't that hard to figure it out assuming that bridge rotation is turned on. in gcode_small.py : --- ../Cura_RC4_orig/Cura/cura_sf/skeinforge_application/skeinforge_plugins/craft_plugins/export_plugins/static_plugins/gcode_small.py 2012-05-21 01:51:12.000000000 -0700+++ ./Cura/cura_sf/skeinforge_application/skeinforge_plugins/craft_plugins/export_plugins/static_plugins/gcode_small.py 2012-10-12 22:36:09.805801800 -0700@@ -70,6 +70,7 @@ self.output = cStringIO.StringIO() self.layerNr = 0 self.parsingAlteration = False+ self.bridgeLayer = False def getCraftedGcode( self, gcodeText ): "Parse gcode text and store the gcode."@@ -123,10 +124,17 @@ self.output.write(';TYPE:SKIRT\n'); elif line.startswith('('): self.output.write(';TYPE:WALL-OUTER\n');- elif line.startswith('('):+ if (self.layerNr == 1):+ self.output.write(';TYPE:LAYER0-WALL\n');+ elif line.startswith('('): self.output.write(';TYPE:WALL-INNER\n');+ if (self.layerNr == 1):+ self.output.write(';TYPE:LAYER0-WALL\n'); elif line.startswith('('):- self.output.write(';TYPE:FILL\n');+ if (self.bridgeLayer):+ self.output.write(';TYPE:BRIDGE-FILL\n');+ else:+ self.output.write(';TYPE:FILL\n'); elif line.startswith('('): self.output.write(';TYPE:CUSTOM X\n'); self.parsingAlteration = True@@ -137,4 +145,8 @@ elif line.startswith('('): self.output.write(';LAYER:%d\n' % (self.layerNr)); self.layerNr += 1+ self.bridgeLayer = False;+ elif line.startswith('('):+ self.output.write(';BRIDGE-LAYER\n');+ self.bridgeLayer = True; along with this config .. I get this fix to the bridging problem and

I've finally had a chance to look at the code, and have since upgraded to Cura_RC4 (btw, I noticed you fixed some of the divide-by-zero errors that I had found but never submitted patches for in RC1). I can't find the infill.py file anymore; did that code migrate elsewhere? Thanks, Reza p.s. your code still works amazingly, and NETFABB is still A WORTHLESS PIECE OF S*IT. I just upgraded that as well, and it is just junk. thanks for the hard work!

it seems as if many sections in the generated code are prefixed with the type of section, such as ";TYPE:FILL" -- why doesn't the bridging section have this behavior? I know the code knows that it needs to bridge as it fills the bridged section differently. Any idea where that code might live? Also, can you point me to section of your code which handles the replace.csv -- I can have a go at modifying it to enable conditionals. given the complexity of SF, the replace.csv might be the best place to implement a lot of features if it was more robust.

And I forget, but will those commands disable the fan during bridging? Is there some way to enable it for the bridge? Thanks, Reza

I want more control over the fan - I think it makes a big difference in the quality of the print. I want to combine some suggestions from users from your posts, but they seem incompatible.. ;TYPE:FILL M107 ;TYPE:FILL ;TYPE:WALL M106 S255 ;TYPE:WALL ;LAYER:1 ;LAYER1 M106 The M106 commands get inserted before the LAYER:1 which defeats its purpose. I just removed the manually. Would it be possible to add conditional commands like IF (LAYER<1) then do this substitution? Thanks, Reza

@thedudevt the only thing I don't like about your design is the large thermal mass the aluminum presents. It will take longer to heat and cool. I am thinking of adding a thin piece of aluminium to the top of my build (or glass) -- whichever I can source cheaper really.. I finished wiring the board into the ultimaker - though I've not tested it yet (I will do so in stages), but I'm confident that it should work. I just added another 4 photos to the same album as my last post ( https://picasaweb.google.com/1129126825 ... PX36KvqwE# ) showing the power supply hookup and thermistor hookup.

updated posted here: viewtopic.php?f=6&t=970 for those following this thread

@rewolff I agree with the enclosure issue, but I plan on modifying it to allow for more air to flow over the FET. Also, that's when it's on full power. I would imagine the power output would drop significantly when the board came to temperature. @thedudevt I can't tell how you've mounted your PCB and if you have glass over it or print directly onto it? I've finally made a bit of progress with my build. I was surprised how easy polycarbonate is to work with -- i'm used to acrylic which melts when you try to drill, etc. Anyhow, I made the polycarb holder for the heating element. I overlapped the heater by 1" and followed the contour of the acrylic bed otherwise. Aligning the holes didn't go as well as I would have liked, and I ended up drilling some of the holes much larger and using washers to compensate. I wasn't sure how the heating PCB was intended to be used. I think i mounted it upside down, but I didn't like all that lame 'keep away from children' crap written on the visible surface. Also, the pads to attach the power cables were way small and I used a knife to scratch off more of the soldermask to allow for a bigger soldering area. The thermister is attached via katpon tape (not sure how others have done this). There is a short bit where the wires are also attached to the PCB, but I hope they can tolerate the heat (I will find out shortly). I also have the wires simply running down into a hole. I don't expect them to get caught on anything, though the wire carrier looks good. My current issue is that now my build surface area is reduced and I need to adjust the location of the limit switches so it doesn't bang into anything. I've posted pictures here : https://picasaweb.google.com/1129126825 ... PX36KvqwE#

some implementation details can be found here: viewtopic.php?f=6&t=970

I checked, and the part is http://www.st.com/internet/com/TECHNICA ... 002690.pdf which is a pretty bad-ass component. Using it in that configuration will burn about 1.6W on the fet, and the fans should adequately cool it. I also understand this stuff (i design and build medical equipment). I also built an open-source cnc mill controller board and wrote the firmware for it ( http://reza.net/cms/index.php?page=rstep ) -- but thanks for the concern When I have more time, I'll resume work on it, but the project is kinda in stasis. Reza Reza

i don't know why you wouldn't be able to connect the GNDs together. Especially if they are both switching/isolated supplies. hopefully they have the stp55nf06l mounted and everything becomes quite simple.

this is annyoing.. this is what they have listed in the BOM Part Value Device Package Library mounting side pcb rs-componentsnumber (if available) Supplier Partnumber Q1 STP55NF06L IRF512 TO220BV transistor-power top 485-7721 STMicroelectronics STP55NF06L they show both the STP55NF0L and the IRF512. The former is good, the latter is not going to work.

i just checked and the STP55NF06 part quoted (i'm not sure if it's on my unit or not, i'll check later) goes up to 50A @ 60V with a very low on resistance. If that's the case then nothing needs to be modified, just connect the 12v supply to the heater bed to the ultimaker and share the grounds as said earlier..

I was thinking of doing something like that as well originally, but rewolff has a good point. if it has fet it has on it, then the 19v is always on and the gnd switches on and off. If you want to use it, then you'll have to use a p-channel fet in this configuration (see photo) the main advantage of replacing the part is that you get the benefits of cooling it from the fan - otherwise you will probably need a heatsink on the fet

I like your idea better than what I had in mind, but 7A will not work -- it will need one that can handle >10A. I've got another fet lying around that is rated much higher and can switch off 5v, but it's a SMA part, so it will be an ugly replacement.

Hi, So I am making some progress with my heated bed build. So far, I've gotten: PCB heatbed - http://reprap.org/wiki/PCB_Heatbed This mosfet: http://www.datasheetcatalog.org/datashe ... B603AL.pdf a 10k thermistor a 12V @ 20A power supply from http://www.ebay.com/itm/110840547570?va ... 1497.l2649 and a sheet of kapton film http://www.ebay.com/itm/280813434730?ss ... 113wt_1193 I just ordered some 3/8" polycarbonate http://www.amazon.com/dp/B000G6QQ7Y/ref=biss_dp_t_asn I plan on making a mount out of the polycarbonate for the PCB (polycarbonate should easily handle the required temp), temp sensor will connect to the bottom of the PVC (I will probably have a big chunk of the bottom cut out so the PCB can heat and cool more quickly). The mosfet will be inline with the power supply, and connected (along with the thermistor) to the ultimaker control pcb -- thus it will not drain any current from the ultimaker. And I'll just cut a piece of kapton to fit on top. I can switch to glass if it doesn't work well, but I happen to have a ton of kapton film that i can't use for my original application so I'll try to use it here. Hopefully it will not be too difficult to calibrate it all. Anyhow, let me know if anyone has any thoughts. i'll post build progress here..

mine went form OK to screaming - contacted UM and they replaced it. New one is way quieter.

I purchased a PCB-based heated bed and was planning on starting my build. I had a couple of questions. 1. why don't people use acrylic for the bottom-side of the heated bed? It doesn't melt till it hits 160C, and the bed only needs to be 70C. 2. can the board that comes with the ultimaker handle a heated bed? I measure 1.3Ohms resistance in mine, which could draw a ton of power quickly. Or should I make a separate implementation using a PID temp controller (like $24 for one these days + cheap thermocouple probe). 3. what kind of power supply is reasonable? thnx reza

I'll try again, but for my prints, but Stnd w/ Stnd PLA just did not work at all. I tried cura rc4, and it did an amazing job and the interface is so simple. Volumetric prints are def. the way to go. I just feel like I wasted money on netfabb. Reza