1. Got a question or need help troubleshooting? Post to the troubleshooting forum or Search the forums!

heatbed and bed leveling

Discussion in 'Mods and Upgrades' started by CAMBO3D, Jul 5, 2013.

  1. CAMBO3D

    CAMBO3D New Member

    Joined:
    Feb 20, 2013
    Messages:
    642
    Likes Received:
    296
    boro glass will take care of minor inconstancy in leveling. However if your pcb bed is warping bad (ie causing your boroglass to lean and not stay level.) that's another issue. remember your setting your glass on top of a surface that is not flat, and changes as temperature changes.

    If you dont want to change up to a kapton heater, just get rid of the pcb heater. level out the birch ply and place the boro on top of that. You will be limited to pla but at least you can print. something worth trying till you get a better heat bed.
     
    2 people like this.
  2. Mastermind1776

    Mastermind1776 New Member

    Joined:
    Mar 30, 2013
    Messages:
    10
    Likes Received:
    5
    Hey Cambo, for your heated bed mod using the solid state relay and independent voltage source, what are the main reasons that you did not use a cheaper mechanical relay as opposed to the fairly pricy solid state relay?

    -David


    Sent from my iPhone using Tapatalk - now Free
     
  3. CAMBO3D

    CAMBO3D New Member

    Joined:
    Feb 20, 2013
    Messages:
    642
    Likes Received:
    296
    When the heatbed is heating. The ramps/arduino board is running a pid routine on the heat bed. Meaning, it switches the power to the heat bed on and off at a rapid rate to keep the temperature where you set it. You'll notice on the board that the led flashes constantly during the heating routine. That is the PID routine doing its thing.

    A solid state relay is best for this application because there are no moving parts to wear out and won't introduce electrical noise into the wiring. A standard relay would wear out prematurely and introduce electrical noise when it is constantly switching on and off. You can use a standard relay but I wouldn't use the PID method for your heat bed if your using a standard relay. There are other options in the firmware for heating the heatbed that are more suitable for a standard relay. The downside of that is it doesn't do as good of a job of maintaining set temperature as the PID method.
     
  4. CAMBO3D

    CAMBO3D New Member

    Joined:
    Feb 20, 2013
    Messages:
    642
    Likes Received:
    296
    For you guys that want to do this mod. Its a simple mod. I'll draw up a wiring schematic and post it shortly.
     
  5. Mastermind1776

    Mastermind1776 New Member

    Joined:
    Mar 30, 2013
    Messages:
    10
    Likes Received:
    5
    Thanks for the input Cambo. :) A schematic would be much appreciated.

    -David
     
  6. Leon Grossman

    Leon Grossman Active Member

    Joined:
    Feb 20, 2013
    Messages:
    226
    Likes Received:
    123
    Kapton with aluminum is a good choice. I don't know that the 3D printed parts to constrain the aluminum were a good choice, though. I'm thinking of the Replicator's habit of having the printed bed supports sag while printing as a good example of not using printed plastics as your go to material for the hot parts of your printer.

    That said, I'm very happy with the 110V Kapton heater/aluminum spreader combination on the heat bed of the i3.
     
  7. CAMBO3D

    CAMBO3D New Member

    Joined:
    Feb 20, 2013
    Messages:
    642
    Likes Received:
    296
    Here is quick drawing with some notes.

    SSR heatbed wire diagram v1.png
     
    6 people like this.
  8. Melody Bliss

    Melody Bliss New Member

    Joined:
    Nov 17, 2013
    Messages:
    276
    Likes Received:
    81
    Cambo, what gauge wire are you using for the hookup? Do we know what the amp draw is of the heater?

    If we're drawing less than 10 amps, then 18 gauge should suffice but I'm a big believer in going overboard in wire gauge when it comes to safety. I'll probably wire up 14 or 12 gauge. I doubt we're drawing more than 17 amps (14 gauge) or 23 (12 gauge)
     
  9. CAMBO3D

    CAMBO3D New Member

    Joined:
    Feb 20, 2013
    Messages:
    642
    Likes Received:
    296
    on the control side of the ssr I used 22awg...load side was whatever my heat bed came with, which i think was 18awg. Load side will vary though depending on how much current your heat bed uses so pick a gauge that will handle your heat bed current.
     
  10. Mike Kelly

    Mike Kelly Volunteer

    Joined:
    Mar 11, 2013
    Messages:
    6,967
    Likes Received:
    2,276
    do you still have your robo cambo or did you sell it afterall? Thanks for sticking around regardless, it's nice to have someone with your level of experience around.
     
  11. Rodrigo Falcetta Laperuta

    Joined:
    Dec 17, 2013
    Messages:
    4
    Likes Received:
    0
    Greetings folks!!

    I'm having the same problem with my R3D.

    And would like to implement this solution because is is easier than soldering to me.

    Down here in Brazil, temps are way higher and the heat bed stops working, yesterday we got 35C and no A/C on the house, so hot that i managed to print only half of the calibration pyramid.

    I found a Solid State Relay, with the right specs, but what is the right fuse to buy? I'm not an electronics guy, and would like some advice on this.

    Could you, please, share the specs of the fuse?

    Tks
     
  12. Mike Kelly

    Mike Kelly Volunteer

    Joined:
    Mar 11, 2013
    Messages:
    6,967
    Likes Received:
    2,276
    a 15A fuse should be fine. 12v but that shouldn't matter.
     
    2 people like this.
  13. Rodrigo Falcetta Laperuta

    Joined:
    Dec 17, 2013
    Messages:
    4
    Likes Received:
    0
    Thanks for the help Mike! I'll look up the parts...

    This fuse is a ordinary fuse or a specific type? I mean, like that car fuses, or like that glass ones, etc, etc...

     
  14. Patrick Elliott

    Joined:
    Feb 20, 2013
    Messages:
    35
    Likes Received:
    8
    How about a source for your parts? I'm considering upgrading my PLA printer to a heated bed. I thinking of this set, but would like a 24v heat pad. http://r.ebay.com/W4kplB
     
  15. Mike Kelly

    Mike Kelly Volunteer

    Joined:
    Mar 11, 2013
    Messages:
    6,967
    Likes Received:
    2,276
    Any 15A fuse will work, car fuse, glass fuse, etc. Just depends on how you want to mount it. Car fuses are nice because they're easy to swap in and out, though you could go with a glass tube that has leads coming off it.

    Doesn't really matter as all you're trying to prevent is shorting the line and blowing your power supply.
     
    2 people like this.
  16. Rodrigo Falcetta Laperuta

    Joined:
    Dec 17, 2013
    Messages:
    4
    Likes Received:
    0

    Thanks again Mike, will look up the parts down here, and build the solution!

    What is the difference between the method used to heat the extruder and the bed? Shouldn't this problem happens also with the extruder?
     
  17. Mike Kelly

    Mike Kelly Volunteer

    Joined:
    Mar 11, 2013
    Messages:
    6,967
    Likes Received:
    2,276
    The extruder draws lower amps, somewhere around 3A and it has a polyfuse rated at 5A. It's possible the extruder could run into this but I'm thinking it requires less energy to maintain the ~230C than for the hbp to maintain 100C so the HBP is almost continually running at max amps which makes the polyfuse heat up more.

    Bypassing that polyfuse is an easy way to run the build platform without overheating
     
    2 people like this.
  18. Rodrigo Falcetta Laperuta

    Joined:
    Dec 17, 2013
    Messages:
    4
    Likes Received:
    0
    Hummm now I get it Mike.

    Down here in Brazil we are prone to hotter weather conditions.

    So this SSR solution is very appealing to me.

    Thanks again for sharing.
     
  19. srose418

    srose418 New Member

    Joined:
    Dec 15, 2013
    Messages:
    1
    Likes Received:
    0
    what do you recommend in terms of dedicated power source for the SSR. I tried to do the wiring before noticing my bed was heating continuously because I tried wiring through the stock power supply, not realizing it required its own. Thanks in advanced.
     
  20. CAMBO3D

    CAMBO3D New Member

    Joined:
    Feb 20, 2013
    Messages:
    642
    Likes Received:
    296
    that's your choice. chose whatever power supply voltage that your heatbed uses. I used 24v dedicated supply for my 24v kapton heater. you can use the stock 12volt supply if your using the stock heatbed, which is 12v volts..
     

Share This Page