tommyph1208

Thank you for that little recap of Ohms law The wiki actually says: "Running 24V on the 12V terminals will heatup the heatbed to 100 degree in only 2 minutes (Your printer controller will regulate the power to the heatbed in order to get your preset temperature.)" But nothing about it going up in smoke though... So it might actually be worth a try if the 30% loss makes it too slow? Just had a quick look at my standard UM PSU and its rated at 120W... that + the 260W for the heated bed and then overshooting to land somewhere around the 65-80% of total PSU capacity gives me at a 20V PSU between 475 and ~585W

I bought my printer second hand, have no warranty whatsoever... I absolutely agree about driving the HB through a relay rather than directly through the UM board, but as I see it this really shouldn't have anything to do with whether you could ALSO drive the UM from that same PSU? As Ownen mentions; As long as the PSU current is somewhere close to the standard UM one (19-20V) and has enough power that you can drive both units from it, it should work right? Question sort of remains though about exactly how many watts the HB will draw from the PSU if 20V is supplied to its 12 or 24V port, and what will this off value mean for its performance, (heat up time, likelihood-of blowing-up etc.) Also, I am still uncertain about the possibility of the PSU momentarily dropping from the 20V to something lower when the relay kicks on the HB... like: How much of a drop, how long to recover, and what will this do to the printer mid print?

Hoping that someone stumbles upon this thread

Maybe try checking your nozzle, both inside and outside... I saw a post somewhere of a super macro shot of a nozzle tip that had been beaten up quite badly, a little chunk had been chipped off etc. The guy who posted it had then sanded/polished it back down for a nice even round nozzle exit hole and it had improved his print quality significantly... Alternatively you could try buying a new nozzle somewhere, they aren't that expensive...

Yes I heard horror stories about that and definately don't feel like trying out my luck ith direct 24V to the UM... I have no problem withusing a relay... Regarding the curret used to power the heatbed; I have this quote from the RepRap wiki (http://reprap.org/wiki/PCB_Heatbed): "It has dual power mode optimized for 12 or 24V but you can also use everything in between (16V, 19V what have you) (Your printer controller will regulate the power to the heatbed in order to get your preset temperature.)" Does this basically refer to PWM mode of heating? Which is not what I will be using with a relay...? Or am I completely off? The wiki also mentions all sorts of other options, like: "With 15V on the 12V terminals will maintain approx. 115 degree Celsius without regulation" and "Running 24V on the 12V terminals will heatup the heatbed to 100 degree in only 2 minutes (Your printer controller will regulate the power to the heatbed in order to get your preset temperature.)"

So you can turn your 24V China PSU down to run only 19V? But how come the UM wiki specifically state that you should not run a heated bed directly from the UM PCB? Are you not worried about that? All these contradicting information get me seriously confused...

Thank you for the insight Owen I read somewhere that the alu heatbed I have should really function anywhere in between 12 and 24V (it has points for those two levels of current to be soldered onto it) I think I would be most comfortable with not feeding more than the default current into the Ultimaker PCB, having to replace/heat manage a bunch of components that might or might not cope with that... Any idea what would happen by powering the 24V port of the HB with just 20V? And what about the voltage fluctuations I mentioned? I read somewhere that someone had measure a 24V PSU dropping to 21-22 V when the relay kicks on the heated bed (rising again afterwards), If I got, say a 20V PSU, it would perhaps momentarily drop to 17-18V, maybe even lower... How would that effect the printing UM?

So... Just to revive the never dying dscussion on heated bed upgrades for the UM1 I wanted to ask a few questions in relation to this... First of all, I am no big expert when it comes to electronics, so bear with me if something is way off... I have this heated alu bed lying around: http://reprap.me/front-page-show/alu-reprap-heater-board-mk3.html And I was talking to a friend of mine about doing a heated bed upgrade for my UM1, and the possibility of using the same PSU for both printer and the heated bed... I've read enough on different forums and websites to come to the conclusion that I should not attempt to connect the heated bed directly to the UM Electronics, but instead use the heated bed output of those to control a relay sitting in between the heated bed and a 12/24V power supply... I'm not a big fan of adding more cables, weight etc. to the printer and would therefore really like to make do with just one Power supply... So I guess my qustion boils down to: Is it possible/recommendable to eg. get a 20V power supply with enough watts to run both printer and heated bed, but connect them seperately to the PSU? (UM electronics directly, Heated bed through relay) My friend was worried about voltage fluctuations when the relay kicks the heated bed on and off, and how these would affect the rest of the printer... Any input on that? Has anyone done something similar?

Couldn't you just replace the fan with a more expensive silent one? There are like a billion of them around...

Apart from the material being too thick for the 3 mm. bowden tube and hot end of the UM, it has been reported that you need to print extremely slow with flexible material (10-20 mm./s.), disable all retraction and add a little bit of oil to the bowden tube to remove some of the friction from the rubbery material

Alright... See now that makes sense... So its the fast rotation of the long X and Y axis that make the bronze bushings more suitable than ball bearings... Thank you for clearing that up

That might be it... I dont know... Hoping that someone with intense knowledge of the design decisions that went into the UM1, will pick up on this thread. Seems counter intuitive though that the extrusion head itself has ball bearings, while the XY slide blocks that its attached to has the bronze bushings? In the end they move in exactly the same way right?

So... I have disassembled my entire UM1 with the intention of giving it a neat Glossy White paintjob (for that all-important WAF) as well as make an E3D hotend, and possibly a heated bed, upgrade... I did not assemble the printer myself, and so the exact parts and way they are all assembled has not become fully apparent to me before now... During disassemble one thing that puzzled me was why exactly Ultimaker has opted for the linear bronze bushings in the XY slide blocks, rather than (linear)ball bearings as everywhere else on the printer? Seems to me that ball bearings ought to work slightly better/provide slightly less friction?

What is the upper limit for layer height? 0.25 mm. sounds like a lot to me...? I never printed above 0.1 myself, though I'm aware you can go higher than that for fast low quality prints

Heated bed? Did I miss something here? There is instill no official Heated bed upgrade for the UM1 right?

Screw is definately damaged, can you find a replacement and then try tightning it as gr5 suggested?

does the gcode have an "retract an awful lot error"?

Sounds like you have no power running to the printer at all, do you have an ulticontroller? If so, can you use it to eg. move some axis? The ulticontroller can run on usb power alone, while the rest of the printer needs the power supply...

How is the dual extrusion upgrade working for you?

Panels should also effectively hinder any sudden drafts of cool air... or maybe even worse: curious fingers

So, just to clarify... You are printing a bunch (from the size details provided in the picture I'm guessing 9?) of trees in a single print run...? How does these print? One layer at a time for all models or finishing an entire model before moving on to the next? If its the first, possibly the blobs could have to do with the start and end of travels between models, finishing an entire model before moving on to the next should effectively mimmick the print quality you get from printing just a single model in a run...

This is awesome... I've been contemplating building acrylic sides myself and even altered the original laser cut drawings to get some laser cut acrylic panels with engravings (files in this link: https://dl.dropboxusercontent.com/u/1259814/Ultimaker%20Acrylic%20side%20panels.rar) I ran into the same problem with the standard, (as well as the donut type) fan duct sticking outside the frame when homing the printhead (or printing at the left edge of the build plate) Thanks for sharing

Did you try printing stuff with support? Either automatically generated by Cura, or you model some into your models yourself... Removing support and getting a nice surface finish is not always easy, but it might be a solution for you in some cases

You should be able to just replace the plug of a standard PC fan with the one sitting on the UM main board fan (they aren't soldered but kept in place by small "hooks" you have to push out with a screwdriver or similar) I did this with the printhead fan and it worked flawlessly... of course you should check the recommended voltage/amps of the fan you are replacing it with. It should roughly match the specs of the original... I don't know what those are, but maybe it says on the fan itself or possibly its marked on the electronics board where the fan is connected?

So... Another feature request for Cura I havent been able to find a hotkey for scale and rotation of objects in Cura? I use 3d modelling tools like Maya and Max, and the Unity3d engine when making games... All have hotkeys for rotation and scale on E and R repectively (counter intuitive I know, like: why the hell is rotation not on R? but thats how it is per default and I as well as many others have gotten used to it) I find myself pressing those keys all the time while manipulating object in Cura, where they do absolutely nothing... So my question is: would it be possible to include those hotkeys in cura or maybe even better, a menu for setting up hotkeys for yourself?