howto control my self build heated bed with Cura

[roald 2]

hello,

i have made a self build heated bed for my ultimaker original, and connect all the electrical components like the scheme

i have also selected the option heated printer bed (self build) in the configuration wizard and set it to 70 Celsius degrees

but when i hit the button start print in cura the relay don't switch and the bed stay cold?

 

 

 

[drayson 74]

Hi!

Have you modified your Marlin firmware?

If not, it can't work as the UM can not interpret the code.

There is a Marlin builder available linked in this forum - just use the search function (writing via smartphone so unfortunately can't post the link)

[gr5 2,004]

This works great:

http://marlinbuilder.robotfuzz.com/

After you download the hex file, you can upload it to the UM with Cura "expert" menu.

 

[roald 2]

oke i have build the marlin firmware and change the options ''template'' , ''choose options'' , and ''heated bed temperature sensor''

the rest i don't change. and load the HEX file in cura.

now cura display the the bed temperature but the relay don't switch and the bed stay cold

 

[gr5 2,004]

1) Your circuit diagram looks good but you don't need that diode as there is already one on the board - in fact you can see it in the picture just above - next to the FET.

2) Well something is of course wrong. I would disconnect your 2 wires, get out the volt meter and measure the voltage where you connected the brown and blue wires - see if it clicks on to 19V as expected. Also that red LED should come on.

Be very careful with power on your UM with no fan! IC1 - the 12V regulator - can get very hot pretty quickly. It's the one that you were supposed to "lift up" into the air flow. I recommend keeping the UM on for no more than 30 seconds at a time (and off for a minute) or you can keep touching IC1 to see how hot it is. When it gets too hot to touch (150C) it's time to cut power.

One possible failure mode: you put the diode in backwards and 19V was sent across it and it damaged the fet. Seems unlikely - I think it would blow up that diode first. Or maybe you didn't screw down the blue and brown wires properly. Or many other things.

 

[roald 2]

1 i have remove the second diode

 

2 i disconnect the brown and blue wire and measure 19V on the contact and the led light up

 

but still no relay switch!!

 

[roald 2]

 

• [*]RELAY, PCB, SPDT, 12VDC, 10A

[*] Product Range: OMRON - G2R Series

[*] Coil Voltage: 12VDC

[*] Contact Current: 10A

[*] Contact Voltage VAC: 250V

[*] Contact Voltage VDC: 30V

[*] Contact Configuration: SPDT

[*] Coil Resistance: 275ohm

[*] Relay Mounting: Through Hole

[*] SVHC: No SVHC (20-Jun-2013)

[*] Coil Current: 43.6mA

[*] Coil Type: DC

[*] Coil Voltage VDC Nom: 12V

[*] Contact Current Max: 10A

[*] Contact Voltage AC Nom: 250V

[*] Contact Voltage DC Nom: 30V

[*] External Depth: 13mm

[*] External Height: 25.5mm

[*] External Width: 29mm

[*] Mounting Type: PCB

[*] No. of Poles: 1

[*] Nom Operating Power: 530mW

[*] Operating Temperature Max: 70°C''

[*] Operating Temperature Min: -40°C

[*] Relay Type: Power

 

 

 

this are the specifications of my used relay. today i disconnect the two wire's brown and blue from the motherboard and connect those wires from the coil to a 12V battery loader and again no switch!!

do i something wrong? or is it broken? and when it is broken can someone advise me witch relay i must chosen?

i always order at webshop Farnell

 

i appreciated all your good helps guys

 

[aaronalai 2]

Hey Roald, I messaged you in a chat window but misunderstood the problem. I downloaded the .brd files for the 1.5.7v build of the Ultimaker Shield, and I would have to say wiring wise everything looks good. I don't think you could have ruined your relay coil by putting it a the Hot Bed terminal output, even at 20 volts that's only 72mA going through your coil. If you hooked it up to a functioning 12 volt battery and you still don't get the device to turn on, I would check the model number again against the data sheet. I downloaded this datasheet: http://www.omron.com/ecb/products/pdf/en-g2r.pdf and it looks like coil excitation with AC current is a very popular item, do you think it's possible you simply purchased the wrong relay.

Edit: Also, if you look at page 4 of the datasheet, it indicates that the coil can be supplied with voltages 170% larger than the nominal value, so if it really is a 12 DC coil then it should be able to withstand 20.4 volts.

Edit2: Also, like gr5 said I wouldn't worry about the diode, from both your drawings and the photographs of your installation, the diode is facing the correct direction and would have only been in parallel with the existing diode on the board, essentially doing nothing.

 

[gr5 2,004]

Roald - you need to invest in a multimeter so you can measure the voltage across the coil and then if that looks good so you can measure the resistance across the contacts. Without a multimeter this is going to be tough to diagnose.

 

[roald 2]

hey AaronAlai, gr5 thank you for answer my questions. i learn every day more and more about the electronics of my ultimaker

today i connect the relay to the 12V battery of my car and it works. after the good results with the car battery i want try it again to my ultimaker port but the tiny contact of the coil broke before.

i also call my colleague today the one who gave me the relay, and he tell me that it should be possible that i can connect the coil in only one way (i'm always thinking i t makes no different)

he also tell me that it is possible to connect 19v on the coil but it reduce the life cycle of the coil.

tomorrow i order a new relay and also a component to reduce the voltage from 19v to 12v to spare my coil.

i let you know if it works.

and yes gr5 i have a multimeter

 

[owen 19]

hey AaronAlai, gr5 thank you for answer my questions. i learn every day more and more about the electronics of my ultimaker

today i connect the relay to the 12V battery of my car and it works. after the good results with the car battery i want try it again to my ultimaker port but the tiny contact of the coil broke before.

i also call my colleague today the one who gave me the relay, and he tell me that it should be possible that i can connect the coil in only one way (i'm always thinking i t makes no different)

he also tell me that it is possible to connect 19v on the coil but it reduce the life cycle of the coil.

tomorrow i order a new relay and also a component to reduce the voltage from 19v to 12v to spare my coil.

i let you know if it works.

and yes gr5 i have a multimeter

 

Hi Roald

I've been using a 12V relay for mine for over 12 months with no problems. Also most relays don't care about polarity. They would only worry about polarity if the used a magnet or had an internal diode or LED.

 

[aaronalai 2]

Hi Roald

I've been using a 12V relay for mine for over 12 months with no problems. Also most relays don't care about polarity. They would only worry about polarity if the used a magnet or had an internal diode or LED.

 

Owen is right, and I don't see any mention of a diode in the datasheet I linked to. I would ask your colleague to test for a 12 VDC output at the terminal screw interface.

 

[roald 2]

oke what do you think about this one ''omron g2r-1a-e 18vdc''

its from the same series and the voltage lay a lot closer to the 19v that i measure on the board.

http://nl.farnell.com/omron-electronic-components/g2r-1a-e-dc18/relay-power-spst-no-18vdc-16a/dp/2103591

 

[owen 19]

oke what do you think about this one ''omron g2r-1a-e 18vdc''

its from the same series and the voltage lay a lot closer to the 19v that i measure on the board.

http://nl.farnell.com/omron-electronic-components/g2r-1a-e-dc18/relay-power-spst-no-18vdc-16a/dp/2103591

 

Yep, that would be better. Just check the contact current is high enough for you. It doesn't hurt to go a bit higher there to make sure.

 

[roald 2]

 

i have compare some datasheets and i think this is the best relay for me:

panasonic ew - ale1pb18 - relay ,pcb, spno 16A 18vdc

http://pewa.panasonic.com/assets/pcsd/catalog/ale-catalog.pdf

i have made this decision about;

*coil voltage 18vdc close to the 19v output on the board

*coil current 22,2mA low coil current the board have enough power to drive the relay

*spst-no contact i dont need no more contacts

*good price

i hope i choice the right one and it will work this time

 

[aaronalai 2]

I'm a little confused by the data sheet, it's been a long day :wacko:, is the "P" identifier indicative of a PCB style with the No tab terminal form factor? If so, I would buy a tabbed terminal relay, especially with your implementation of it.

 

[roald 2]

yesterday i have receive my ''panasonic ew - ale1pb18 - relay ,pcb, spno 16A 18vdc'' relay and implement it

and it switch and everything working well.

problem solved thanks for all the help

 

[drayson 74]

Great to hear!

I just waited to get the confirmation that this relais is working on your side so now I can order the same part for my heated bed...

:mrgreen:

Have fun with it!!!

 

[roald 2]

Great to hear Drayson, that i also can help you with my search to make a better printer.