jonnybischof

You can do it with this plugin: http://wiki.ultimaker.com/CuraPlugin:_TweaktAtZ I must admit I never got it to work, but it's supposed to be easy...

I built my firmware with the robotfuzz Marlinbuilder. My configuration.h says: //#define PIDTEMPBED and #define MAX_BED_POWER 255 So I guess PID is deactivated and duty cycle is 100%? That's definetly not what it's doing... My high bed temperature comes from the large temperature drop that I have between the thermistor and the bed surface (10mm thick Basalt stone in between). The drop is about 20K in the center of the bed and goes up to 35K in the corners. That's not pretty but it worked, if only for a short time... /edit: That's for ABS (Orbi-Tech Premium ABS, black). I haven't tuned it much because it doesn't work at the moment... /edit: If I'm using the standard firmware that comes with Cura, is there a possibility to trigger the heatbed output with a GCode command? I'm building a custom HBP controller, but I need some kind of feedback from the printer to tell me when it's done printing... If that doesn't work, I'll just abuse some other signal but it would be a little more elegant to have a dedicated "flag" output.

Gotta love the Swiss army knives... Before my HBP upgrade I used a fixed blade that has no handle (5.11 boot knife) and is therefore very flat. It's very easy to pry off the part with that one, but usually leaves marks on the part. With the HBP I just have to wait for the bed to cool down, then the part pops right off the plate (Problem is, at the moment the heater doesn't work...)

I don't do anything myself, that's what Marlin does. The Multimeter (don't have time to take out the Scope right now) shows anything from 0V to 19V, looks like it switches the output on and off in about 1 or 0.5 Hz frequency. My own controller will definetly not use PWM for the heat-up sequence, that would be utterly stupid to do... When it comes to holding the target temperature, there will be some form of PWM, but very low frequency in the single Hertz or even below 1Hz range.

The ideal temperature setting depends on more factors than just the filament which is used. Probably the most important factor is the printing speed. But then there's also the type of hotend used, temperature sensor tolerances and more. Also, there may be differences between different batches of the same filament type of a manufacturer. Imho, such a list doesn't make much sense...

Hi community I've just had this problem for the second time: I start up my UM1, go to control settings and set 130°C for the heated bed. This takes 10-15 minutes which is why I don't just start the print, no need to heat the filament that long without actually extruding. But then after about 110°C the temperature starts to drop again instead of rising. From that point, the darn thing just doesn't work anymore. The controller does tickle the MosFET sometimes, but by far not enough to actually heat up the bed. I have printed 2 parts without issues at 130°C stable bed temperature, but now that it doesn't work "anymore", even shutting the machine down and restarting it doesn't help. I guess I have to cool it all the way down and retry. This takes about 2 darn hours for God's sake... Anyone knows that issue? I am working on a custom heatbed controller but it will take at least a month until I'm finished with it so I need Marlin to work for the time being... I'm using a robotfuzz custom firmware, didn't change anything except selecting the UM1 with heatbed and correct thermistor. /edit: Some more info: I'm using an IRFB3004PbF MosFET instead of a relay (this is a very rugged and high efficiency part, not the cheap stuff). My Multimeter tells me the UM electronics put 19V (o.O why not go to 48V so no one can use it at all...) on the control signal. The FET has a maximum VGS rating of 20V. Not much air, but it's definetly not a MosFET issue because it works fine some times (up to 110°C no problem...) Anyways, as long as the actual temperature is below the target temperature, the heater should be switched on 100% and not just some 10% PWM or whatever it is Marlin is trying to do here...

I wondered myself whether this is a bug or a feature? Imho this really sucks. The inside skirt makes no sense at all but always messes up the first layer. Using retraction for the first layer however might be problematic. I imagine that the filament wouldn't stick well after having been taken off the platform for retraction and put back. However if there were no inside skirt, there would already be considerably less of a mess on the first layer. I guess we have to live with what's left, usually it wasn't too bad until recently when the inside skirt came. Oh, and also I think the inside brim is more a pain than a help because if you have small holes (like for M3 screws) they will be completely covered up and you have to search for them and pry the brim out. I would suggest solving the problem with introducing a rule for inside skirt / brim: Use an inside skirt / brim only if the surface area of the "hole" is greater than X mm2. Ideally, put "X" into the expert settings and set it to 0 by default. I don't find a better word for the "hole": I mean the inside opening of the part where there's going to be a skirt / brim.

The thing is, I specifically bought the Basalt plate because there is no need to use any interface material (Kapton, Glue, whatever) with it. The Basalt material is not exactly like glass, it's porous and not 100% mirror flat. That's what the seller says anyways. I have a huge stock of Kapton tape (like 3 or 4 Rolls) but found it nearly impossible to get it on the platform cleanly. It's really hard to put a string of it on the plate exactly in parallel to the other, without them overlapping or having a gap. And gluestick is no option in my opinion, I don't want to waste tons of gluestick while printing. I'm planning on making a little 3D printing factory with 3-4 printers which will be running almost all day. Depends on whether the things I'll design will be sellable or not (I'm still in the planning phase). If you say you heat the platform to 70°C, does that mean that your thermistor says it's 70°C or did you measure the actual surface temperature of the platform to be 70°C (meaning the temperature set in software is probably higher)? I think the cooling fan significantly drops the surface temperature on my bed. But I didn't complete my experiments yesterday so I'm not sure about that yet. I will probably be using ABS for any "commercial" prints because they have to be long time stable (30 years and more service time -> storage products like specialised boxes and holders / stands). I hope ABS will stick better because there must be absolutely no warping. I'll do more testing (with ABS mostly, and with the IR thermometer) tomorrow - today is a busy day :(

Actually, I have almost never re-levelled my bed and never had any problems with it I guess it depends on how thick you need your initial layer to be (that's not the raft, I'm talking about the first layer of the model!). I usually left it on 0.2 to 0.3mm, always worked fine...

There's one advantage the IR thermometer will have versus a TC: With the IR I can measure any point on the HBP and determine whether the temperature is even across the bed. I suspect there will be a significant temperature drop on my 2kg Basalt bed from the center to the edges. But I hope that if I heat it up longer than just what it takes for the thermistor to reach target temperature, it will eventually even out. By the way: I'm doing the first test prints with my HBP right now. Don't get it to stick yet, but I guess I'm just doing it wrong for the moment. Doing some experiments...

Got myself an infrared thermometer, but of course I left it at home and can't take a measurement today. I'll report back as soon as I have some measurements. I've heard that about 50°C is the point where it starts to hurt your fingers. But actually I have never given it much thought myself...

I was worrying about this competition for some time now, but just like you wrote - I wanted to participate but did not even get around to putting my printer back together until now. So now I've still got my printer next to me with the work-in-progress HBP staring at me reproachfully... I'm sorry I couldn't participate! I guess I'm speaking for lots of people here. Looking forward to the next competition, though. But please give us a bit more time, like 5-6 weeks

Bin immer noch nicht dazu gekommen o.O Habe mein Heizbett noch immer nicht fertiggestellt - daran arbeite ich aber gerade. Momentan habe ich keine Anwendung für das Filament, und da es scheinbar nicht ganz problemlos in der Anwendung ist, werde ich es erst testen, wenn ich auch tatsächlich etwas Nützliches damit drucken muss.

https://www.igo3d.com Ich habe gelesen, dass iGo3D der offizielle Vertriebspartner von UM in Deutschland sei (Quelle: http://www.3d-drucker-world.de/ultimaker-2-in-deutschland) Im Shop ist der UM2 gelistet, Lieferzeit steht aber ebenfalls 6-8 Wochen. Muss es ein fertig zusammengebauter Drucker sein, oder könntest du dich auch damit anfreunden, ein Kit zusammenzubauen? Den Original UM als Kit haben sie soweit ich weiss vorrätig, und beim Zusammenbauen lernst du die Maschine gleich kennen und kannst zudem Transportschäden ausschliessen. Mein Original UM läuft seit August ohne zu zicken und bis gestern ohne irgendwelche Upgrades oder Modifikationen. Die Druckqualität ist bereits im Originalzustand sehr gut und kann bei Bedarf weiter verbessert werden.

Have a look at this page: http://marlinbuilder.robotfuzz.com/ Builds you a custom firmware with just a few clicks. Just made one for my HBP today - seems to work fine but I haven't tested the printhead or movement yet, just heated the bed. I noticed some differences, for example the Ulticontroller beeps differently (much better, less noisy) and the menu is slightly different. You'll definetly want to do some calibration prints first and see if everything behaves as intended. You can select dual extruder + heated bed, but you'll have to see for yourself if it works - I don't have a dual extruder...

The firmware is only a few kilobytes in size (The one I've built recently was 288 kB). It's just as slow as anything else, but less data = less time. A Gcode file can be several Megabytes (biggest one I've had so far was 20 MB -> The Colonel from Thingiverse). We are intending to do just about the same thing in a few weeks but we're using a Cortex M3 MCU which is a little bit faster than the Arduino - didn't take that into account before...

Technically, that should work (if the card and USB are separately hooked up to the MCU). But I don't think this is supported by the firmware because that's not so trivial and uses some of the MCUs memory...

Just realised it took me 5 months until I got my heated bed working o.O I finally ditched the idea about using power resistors and went with a silicone heater and Basalt bed from qu-bd (shipped around the world for about the same price as the parts...). The HBP is heating up to 80°C as I'm typing this. Takes quite some time because the thermistor reading is way off the actual platform surface temperature (it shows 72°C but I can still touch the surface). However I hope that if I just wait some more minutes, the plate will be evenly heated up. So far I'm just going to test the heating up and cooling down processes. I guess it will take at least half an hour for the plate to cool down from 80°C to 30°C. I'm not yet ready to print on the thing as I'm still building the clamps to hold the bed in place and haven't adjusted the endstops yet. But so far, it's looking really good. Guess I'm gonna have to get an infrared thermometer - I can still briefly touch the plate (though it's really hot by now) with the thermistor having shown 80°C for about 3 minutes. /edit: Cooldown-update: Cooldown from 80°C to 46°C takes 22 minutes... without any active cooling measures.

Haven't tried it yet (my UM1 heated bed upgrade is just cooling down from the first time heatup right now), but if you print with the heated bed turned on, the parts should "pop" off the bed as soon as it's cooled down after printing. Did you print on cold glass?

Beim Elektronikhändler (mouser, farnell, digi-key, distrelec) gibt's sowas auch recht günstig. Meistens aber nur in grösseren Mengen. Beim Trocknen muss man sehr vorsichtig sein. Das Silica-Gel ist giftig! Ich habe gewöhnliche Aufbewahrungsboxen gekauft und werde die einfach mit einem Dichtungsband abdichten. 100%ige Luftdichtheit (gibts eh nicht) ist vermutlich gar nicht notwendig und evtl. sogar schlecht fürs Filament. In einem anderen Thread hier im Forum hat jemand von einer komplett zerstückelten Rolle Filament berichtet, welche seine "Trocknung" wohl nicht wirklich gemocht hat. Je trockener das Filament, desto brüchiger wird es wohl.

Gut zu hören. Viel Spass mit dem UM2!

I wouldn't use a stepper motor here at all. A simple geared motor should more than suffice. And you don't need a controller for a DC motor. You could use a complete H-bridge driver which would enable you to change the motor direction (necessary if you want to be able to switch colors). But then again you can even control that without the use of any programmable IC. It's also cheaper because it's simpler. If you need a week to program and debug the product (usually it takes more even for small projects), then you lose time = money. If you have a simple circuit that you just need to put together, you have a simple product that's probably going to work right away. No software bugs, no programming hardware needed. But anyways, I think that's too many details for the moment. On this stage of development, you have much more important problems than electronics details... Tell me if you need help with the electronics, but consider the major mechanical challenges first - no use making an electronic circuit if you can't make a working mechanical prototype...

Wenn man mit Cura das "First-time setup" für den UM1 macht, dann gibt es dort unter anderem einen Testablauf für die Endschalter. Ich habe keinen UM2, aber vielleicht wird das dort auch gemacht? Wenn ja, würde ich einmal diesen Endschalter-Test durchführen. Es klingt zwar eher nach einem Software-Problem, oder einer fehlerhaften Verkabelung, aber der Test ist zumindest beim UM1 schnell gemacht und beantwortet die Frage, ob der Fehler bei den Endschaltern liegt oder nicht. Ansonsten kann ich dir beim UM2 leider nicht weiterhelfen, da ich ihn selber noch nie gesehen habe...

Awesome!! Is that a toothbrush? Very curious about the final results, too..

You could simplify that into an analog circuitry without the need of an MCU. I guess that's what they use on the 3Doodler, too, because there is no space for an Arduino platform. And the price tag wouldn't be 99$ anymore with the Arduino already taking 30$. But, if you use an Arduino or whatever MCU platform, you can have much better control over the heater. In most cases that's probably not necessary, it just depends on what you want to do. The analog circuit is actually not much more than some operational amplifier comparing the NTC voltage against the pre-set reference voltages (which resemble for example 200°C) and then switch between "higher than" or "lower than" target value. Connect that output to the heater, put in some hysteresis, and that's it. Use a simple switch to select between 2 or 3 reference temperatures.. /edit: About the difficulty level for the electronics: I'd classify that as a good project for beginners. You need to know (teach) Ohm's law and some Op-Amp basics. It can all be breadboarded and hand-soldered, no programming skills or good layouting needed. If you're not going into detail on the expo, you can just show the kids that there isn't more electronics in there than just about 10 simple parts.