Building a Heatbed for K8800

Vertex Delta
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I have flashed the firmware with Arduino IDE 1.6.8 with original,included U8glib - now display problems are fixed :slight_smile:!

I guess I will report the problem somewhere

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@SurviKnows, where did you find the schematics for the K8800 board?

And, can you share your .stl for the supports?

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Here you go :wink:

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:see_no_evil:
Sems it was to obvious to look at that Place…
Thanks!

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@SurviKnows
This looks great! Can you please give us the information what parts are needed and probably were to get them? Is a second Arduino required or does the K8800 board all the magic? Thanks!

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From my playground:

  1. power supply 12/24V, ~200VA
  2. MosFET shield (I used this one, it has an opto coupler as input, seems happy with 3.3V outputs) https://de.aliexpress.com/item/1-st-ck-3D-Drucker-Teile-Heizung-Controller-MOS-Modul-MKS-MOSFET-Bord-Heatbed-Extruder-30A/32831612566.html?spm=a2g0s.9042311.0.0.42164c4dJuOJAH
  3. some kind of head bed (Kossel >=200mm diameter)
    maybe this one will fit… https://de.aliexpress.com/item/3D-Drucker-Heatbed-Aluminium-Heatbed-mit-kabel-f-r-Kossel-Delta-Plus-Pro-DIY-Auto-Nivellierung/32837491920.html?spm=a2g0s.13010208.99999999.266.6a783c004fXBMW
  • You don’t need an additional Arduino if you recompile Marlin with the receipe from @SurviKnows
  • attach MosFET shield to K8800 mainboard

I already did steps 1 and 2. Instead of Kossel headbed I used a silicone headbed (160mm) directly glued to the K8800 glass bed. Problem hereby is the major temperature difference betweeen center and outside of the bed ( >20°C difference).

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Thank you for sharing this information.
I think that the BIQU heat bed will not fit into K8800.

So I ordered the MOSFET some NTC and this bed:

3D-Printer-Heat-bed-PCB-Round-MK3-Heat-bed-220-x-3mm-Aluminum-dual-power-12V

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Which Arduino Board should I choose when recompiling the software?

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If I’m not mistaken, all of the Velleman 3D printer boards are programmed as “Arduino Mega 2560” boards.

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Hi all,

sorry I am on parental leave, so there are some more important things to be done than 3d printing :wink:

Are there still questions regarding the heat bed?
The K8800 can be programmed as Mega2560 without issues - just keep my comments about the Arduino IDE version in mind.

Overall my solution works but I am not to happy since the auto bed leveling quite often does not work correctl (nose is ramped into the bed). One reason might be that the spacers are not perfect, expecially when the heat bed is at >60°C they might get to soft so that the bumps are not detected.

Maybe next week, latest christmas I will play around with an inductive sensor and replace the standard bed leveling solution. Might be the best approach with an aluminium heated bed…

IMG_20181209_1500022
IMG_20181209_15000223492×4656 816 KB

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Hey do you still need the supports? I can share the .stls but as I have written I am not totally happy with the current solution

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@SurviKnows yes please share your .stls on Thingiverse then I can share mine from your photo reverse engineered ones as remixes.
I’m still waiting for my heated bed from China.

Did you change the deltaheight in the firmware? Maybe that fixes the issue.
Should that inductive sensor not be perpendicular to the bed? Can it be closer to the nozzle?

Congrats and all the best to your little maker!

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Here you go: https://www.thingiverse.com/thing:3284276

Jepp you are right, the sensor should be as close as possible to the nozzle.
Anyway, in Marlin you can fill in the x & y delta and it will automatically include it in bed leveling.
With some tweaking, it might be possible to get closer but due to delta setup there are some limitations.

My new mount is a bit better:

IMG_20181214_115609
IMG_20181214_1156094656×3492 965 KB

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Yes this looks much better.
Thanks for sharing the stl and as promised here is my remix:

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Connect the ADC8 aka PK0 directly to the NTC or like here
heiz_schem
inspired by the K8800 schematics for the hotend thermistor??

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Hey,

I follow these report for a view day`s! That’s great! I also build an heatbed application for the Delta.

Yesterday I scratched one of the Piezzo´s. but before I had good results by the autoleveling. My heatbed construction is quiet heavy, so I use some springs to get the weight from the Piezzo´s. And its getting just in touch with the Piezzo´s when the hetatbed is pointed. I realizing also that the best sensitivity is not to pull in the center of the Piezzo´s. quiet a bit to one side.

So can someone put a detailed picture form electronic parts and assembling on the Board, please!

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Heatbed%20spring%20construction
Heatbed%20spring%20construction4608×3456 875 KB

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@bibo yes this look quite heavy.:weight_lifting_man: What kind of heatbed are you using? I can see some insulating material but what is that in between that and the the metal parts? Can you show your setup from different perspectives?

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Just lurked a bit around - what’s about using HPL (high pressure laminate) for the spacer?
It’s temperature resistant up to 180°C and easy to cut…

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@shelxle: I use a MK2Y heatbed 120W, an ATX powersupply and a W1209 termostat layout. Isolation 12 Zoll Hotbed Thermal Pad Isolationsschaum.

So i bought a Hotbed Mos V1.0 NTC 3950, but thats not installed. can someone help me with informations, please?

Where did you solder the cabels exactly. And do you use some aplications between Pins on Vertex board and Sensors ( like a pullup/down´s)?

Connect the ADC8 aka PK0 directly to the NTC or like here[quote=“SurviKnows, post:1, topic:29826, full:true”]

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