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tommyph1208

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Posts posted by tommyph1208

  1. I use a 24v 400W PSU from China cia eBay. It adjusts down to 19v, same as the UM power supply, and can drive a 12v reprap heated bed PCB very nicely direct from the existing MOSFET. Draws around 350W during warm up with everything on full. Very neat, no relays, fast warm up and dead stable temperature if you make Marlin use PWM for the bed.

    Andrew

     

    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...

     

  2. As long as the PS has enough watts. Allow 70W for UM. Add the HB Watts and go at least 50W more than that to be sure and you should be right. 24V is more common for HB's though and if you go to 24V for UM you may need a better 12V reg inside UM or at least provide better cooling for the current one.

     

    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?

     

  3. 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?

     

  4. 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

     

  5. I have also wondered about that.

    I thought that the bronze bushing has less play then the ball bearings (on my UM1)

     

    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?

     

  6. 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?

     

  7. 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...

     

  8. 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 :)

     

  9. Thanks for the suggestions, will try to find some computer fans lying around and replace. I already got some feet dampers and it's raised roughly an inch off the ground.

    Computer fans can plug in without modification? (I'm an electronics noob) Soldering anything is not recommended for me...

     

    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?

     

  10. 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?

     

  11. With Christmas coming up it was time for a new thing for the nephews. They still like money so that's what they're getting. Last years little puzzle didn't last long so I hope this will take a minute or two at least. I tried to put in "traps" to get them stuck and missing the right exits, who knows if it'll work hehe.

     

    Are you going to share this one as well? My old man is nuts about those kinds of mind bending puzzles, so I thought I would have a look at yours and possibly find inspiration to make another more complex one...

     

  12. Alright... Does the coin have a lot of individual "hilltops", i.e. areas where the printhead needs to travel to without extruding?

    The coin I did went fine as long as the printhead could just keep moving around and extrude.. but when it got heigh enough that it needed to print the highest points of detail (the hilltops I'm referring to) it all went to crap...

     

  13. On an other subject, but still playing with light, I have tried to print a small medal. It came out a bit like watercolor painting, and I really like the result with the light behind.

     

     

    The original model is really thin and is 12cm wide. I have scaled it down to 5cm to the diameter in Cura so the actual thickness of the building has also been decreased from the original design (around 0.8mm thickness for the front tower, nearly 0mm for the back). Even the cloud on tho is clearly visible.

     

    This printer is amazing!

     

    How do you guys print these?

    I tried printing a self designed coin some time ago.

    Printed it laying flat, but found that all the raised individual details resulted in a lot for travels and it ended up being of really poor quality despite the printer being nicely tuned and printing other objects nicely...

     

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