Circular 220mm heated bed for 220V?

Hey guys!

I'm working on a Delta, as I've posted in a previous topic. My delta will have a 220mm circular build surface, and I really want a heated bed.

But I've come across a problem. My base is to small to fit a Duet and a power supply that can power a heated bed and all the other parts. So I would have to enlarge the frame like the Atom 2.0 heated bed option does, to make for a larger base, but I don't like this option. I would rather buy a heated bed that I can power on AC and control from the duet with a relay. This saves up a lot of space. But I can't find any 220mm bed that is suited for 220V AC, only 300mm silicone heaters or 220mm 12/24V beds. Does anyone have option to find/make a 220mm 220V heater/bed? I can't come around a solution...

Thanks,
Andreas

Check for Keenovo heaters on Amazon and eBay. They will do custom sizes, but I would suggest going with a 200mm heater for a 220mm bed.

Why a 200mm heater?

Give yourself some space for mounting the bed.

I have an aluminium plate wich is 260mm in diameter, so I think I will still have enough space if I go for a 220mm heater to, no? Or what do you mean? The print space needs to be 220mm, the glass and aluminium plate are bigger. Is it better to go with 200 or 220?

You said that your printer has a 220mm build surface. To me, that meant the diameter of the plate and not the build area. Since the actual plate size is 260mm, you could go with a 250mm heater and still have a margin around the edge from the heater for mounting. Doesn't really matter that the heater is larger than the build area. In fact, that might even be better.

Edited 1 time(s). Last edit at 12/08/2016 02:43PM by ElmoC.

i found one on aliexpress "silicone heater bed 220v round"

You can order a silicone bed heater to whatever size, voltage and power you want from Shenzen Ali Brother Technology via Alibaba. They made me a 230V 350W 300mm one. The cost was around $35 AFAIR.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Another option to help you get more room:

[www.thingiverse.com]

Quote
dc42
You can order a silicone bed heater to whatever size, voltage and power you want from Shenzen Ali Brother Technology via Alibaba. They made me a 230V 350W 300mm one. The cost was around $35 AFAIR.

Hi can you explain me a concept?
I have a 24V 270W silicone bed and it take several minutes to go to 100°
How can I solve this issue? what kind you suggest me?
and how do you connect a 230V without damage risks?
If I have for example a 230V and 350W, what is the current ?
For example in my case I have 270/24=11,25A
Surely the basis of my reasoning there are gaps of knowledge but can you explain me how can I feed a 230V bed with a 24V power supply ??
Or If I can rephrase my question!!
What coupled bed +power supply you suggest me to gain temperature (100/120°) ASAP ?

Quote
mdcompositi

Quote
dc42
You can order a silicone bed heater to whatever size, voltage and power you want from Shenzen Ali Brother Technology via Alibaba. They made me a 230V 350W 300mm one. The cost was around $35 AFAIR.

Hi can you explain me a concept?
I have a 24V 270W silicone bed and it take several minutes to go to 100°
How can I solve this issue? what kind you suggest me?
and how do you connect a 230V without damage risks?
If I have for example a 230V and 350W, what is the current ?
For example in my case I have 270/24=11,25A
Surely the basis of my reasoning there are gaps of knowledge but can you explain me how can I feed a 230V bed with a 24V power supply ??
Or If I can rephrase my question!!
What coupled bed +power supply you suggest me to gain temperature (100/120°) ASAP ?

You don't feed a 230V bed with 24V. You feed it with 230V. You want a heater that is the same voltage as your mains.

As for the current, a 350W heater running on 230V would use 1.5A.

To control the heater, you can use a Solid State Relay.

I can get my 400W heater to 100+ in about a minute.

sorry for hijackin the thread but what i am reading are very impressive.

i just installed my 270mm x 350mm 220v 600w heater in bottom of an 8mm aluminum 6061 ( i think). if you dont mind asking what kind of precautions did you took to protect the dc boards from a 220v leak- short ciruit..

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Delta Printer
Duet 0.8.5 firmware 1.19

Quote
mdcompositi
What coupled bed +power supply you suggest me to gain temperature (100/120°) ASAP ?

First tell us the size and construction of your print bed, and what sort of printer it is.

Quote
Gaou
sorry for hijackin the thread but what i am reading are very impressive.

i just installed my 270mm x 350mm 220v 600w heater in bottom of an 8mm aluminum 6061 ( i think). if you dont mind asking what kind of precautions did you took to protect the dc boards from a 220v leak- short ciruit..

See [duet3d.com]. That page is written for the Duet series of controllers, but the precautions listed are applicable more generally.

Edited 1 time(s). Last edit at 12/11/2016 01:43PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42


First tell us the size and construction of your print bed, and what sort of printer it is.

I have a custom corexy with a 300x300 aluminium plate (3mm thick) where I attached a silicone bed 24V 270W
I've read your page about how to connect a bed and I sensed (correct me if I'm wrong) that much is related to how the board is designed, how much current can support the tracks of the PCB
I have an ULTRATRONICS that have in correspondence of bed mosfet a 15A fuse
This makes me think that with any type of bed (12/24 or 230 V) must never exceed the current of 15A
with my configuration can reach 100 ° in twenty minutes !!
at this point I would like to be advised by you on what may be the best configuration to use(24 or 230 V I don't know)
In any case double power supply is needed?
.....and what kind of termistors silicone bed of alibrother use ? My bed (bought on aliexpres but don't remember where) had a fake termistor that I replaced with an other....

p.s. crydom SSR are very much expensive!! the cost as much as the electronics board!!

Quote
mdcompositi

Quote
dc42


First tell us the size and construction of your print bed, and what sort of printer it is.

I have a custom corexy with a 300x300 aluminium plate (3mm thick) where I attached a silicone bed 24V 270W
I've read your page about how to connect a bed and I sensed (correct me if I'm wrong) that much is related to how the board is designed, how much current can support the tracks of the PCB
I have an ULTRATRONICS that have in correspondence of bed mosfet a 15A fuse
This makes me think that with any type of bed (12/24 or 230 V) must never exceed the current of 15A
with my configuration can reach 100 ° in twenty minutes !!
at this point I would like to be advised by you on what may be the best configuration to use(24 or 230 V I don't know)
In any case double power supply is needed?
.....and what kind of termistors silicone bed of alibrother use ? My bed (bought on aliexpres but don't remember where) had a fake termistor that I replaced with an other....

p.s. crydom SSR are very much expensive!! the cost as much as the electronics board!!

I recommend a heating power of 0.4W per square cm of bed. Some people recommend 0.5, but that increases the risk that it will reach a dangerous temperature if the heater doesn't turn off. For your bed, that's 360W.

If your PSU has the usual voltage adjustment potentiometer, and it has enough power in reserve (e.g. a rating of 400W or more), and your electronics can take it, you could turn up the voltage to about 28V. That will give you about 36% more power, which may be enough, and the current draw will still be below 15A. Your hot end power will increase by the same amount so you will need to retune the PID. You can wire some silicon diodes in series with the fans to reduce the fan voltage back to 24V.

The Ali Brother heaters have the standard Chinese 3950 beta thermistor.

Yes the Crydom SSRs are expensive. The Auberin one is a much better price.

Edited 1 time(s). Last edit at 12/13/2016 05:35PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42


If your PSU has the usual voltage adjustment potentiometer, and it has enough power in reserve (e.g. a rating of 400W or more), and your electronics can take it, you could turn up the voltage to about 28V

What do you mean when you say "your electronics can take it"??
My ultratronics can take it?

A last question..........
what are advantages/disadvantages about 12-24V DC or 230V AC?
Considering obviously the appropriate safety precautions?

Quote
mdcompositi
A last question..........
what are advantages/disadvantages about 12-24V DC or 230V AC?
Considering obviously the appropriate safety precautions?

The higher the voltage, the less current is needed to power the bed for a given wattage. Therefore, if you want to run a high powered heater on low voltage, you will need a lot of current. This has two consequences. First, the printer electronics has a maximum allowed bed current that it can drive directly. This is typically 11A for cheap electronics and 15A for better electronics. At 12V this gives a maximum heating power of around 130W and 180W respectfully. At 24V, 260W and 360W. If you need to switch more current, you will need a good SSR. Second, you will need much thicker wires to carry the current and a more expensive PSU to supply it.

A mains voltage heater will draw much less current because of the higher voltage. However, because it is higher voltage and is AC instead of DC, it also needs an SSR. But the choice of SSR is much less critical. Also you can use a smaller PSU for the printer because it doesn't supply the bed power.

Driving the bed heater from mains power requires additional safety precautions, especially if the bed is moving. So my general advice for those competent to work with AC mains is:

Up to 200x200mm or 230mm diameter bed: 12V DC heater, or 24V if you prefer or have other reasons to use 24V power.
300x300mm bed: 24V DC heater and electronics with 15A bed current rating
Above 300x300mm: AC mains bed heater
Delta printer with bed larger than 230mm: AC mains heater because it easy to do with a fixed bed, although 24V power is also possible up to about 350mm diameter

Suppliers of printer kits will prefer low voltage heaters for product liability reasons.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

So with my 220mm bed, you do not suggest using mains to power it? I mostly do it because of space issues, and it heats up super fast.

My recommendations are intended as a general guide only, based on what is easiest and cheapest to do safely and effectively. With a 220mm round bed on a delta, you are only just below my suggestion to use mains power above 230mm.

Edited 1 time(s). Last edit at 12/16/2016 02:11PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

dc42, do you use bang-bang or PID with the AC heated bed?

Quote
dc42

300x300mm bed: 24V DC heater and electronics with 15A bed current rating

Ok I'll buy this! 24V 360W
But I have two questions?
Do I have to use also in these case an SSR, just to be safe? Please can you link me here in Europe a seller about Auber relays
The bed that I have now was bought from alibrother and I had a problem with termistor (also using 13 in termistor bed string in marlin)
I had to replace it with a termistor used on e3dv6!!
Is this due to a construction defect?
I measured the temperatures of the two thermistors (alibrother-E3D) with an infrared thermometer and found temperature differences of 20 °

Edited 1 time(s). Last edit at 12/17/2016 03:13AM by mdcompositi.

Quote
Andreas15
dc42, do you use bang-bang or PID with the AC heated bed?

I use PID. RepRapFirmware on the Duet uses slow (10Hz) PID, which is compatible with all types of SSR.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
mdcompositi

Quote
dc42

300x300mm bed: 24V DC heater and electronics with 15A bed current rating

Ok I'll buy this! 24V 360W
But I have two questions?
Do I have to use also in these case an SSR, just to be safe? Please can you link me here in Europe a seller about Auber relays
The bed that I have now was bought from alibrother and I had a problem with termistor (also using 13 in termistor bed string in marlin)
I had to replace it with a termistor used on e3dv6!!
Is this due to a construction defect?
I measured the temperatures of the two thermistors (alibrother-E3D) with an infrared thermometer and found temperature differences of 20 °

Whether or not you need an SSR depends on the bed current rating of your electronics. The cheaper electronics such as RAMPS can't handle 15A, but many of the better boards can. I don't know of a European seller for the Auberin SSRs, better ask Auberin.

Your thermistor reading issue was because you had the wrong thermistor parameters configured in your firmware.

Edited 2 time(s). Last edit at 12/17/2016 04:06AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42


Whether or not you need an SSR depends on the bed current rating of your electronics. The cheaper electronics such as RAMPS can't handle 15A, but many of the better boards cam

Your thermistor reading issue was because you had the wrong thermistor parameters configured in your firmware.

I use a 32bit Ultratronics from reprapworld but in any case I want to keep safely and I will connect anyway an SSR
Can you help me about termistor configuration?what you mean?

I have this

#define TEMP_SENSOR_BED 1 (for termistor e3d that I use now)

I've used also 13 for 100k Hisens 3950 but nothing changed..........

I thought having to edit and recompile firmware to change parameters went out with the Ark - or at least with 8-bit electronics

Edited 1 time(s). Last edit at 12/17/2016 04:29AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42
I thought having to edit and recompile firmware to change parameters went out with the Ark - or at least with 8-bit electronics

Sorry .....what are you saying?? I don't understand.......

Edited 1 time(s). Last edit at 12/17/2016 04:55AM by mdcompositi.

I'm a bit in a dilemma with this one. Or going with an AC bed, or enlarging the whole frame to fit the 350W PSU, or finding a smaller PSU :p I don't know if it is worth all the safety requirements to go AC, but it just sucks to make the frame bigger to fit a PSU clean inside it. It really has to be in the base and I'm also not a fan of adding an extra extrusion under it to fit the power supply. Does anyone know a small(er) 350 or 360W power supply? The LRS-350 (30mm in height) is the smallest that I found, but the width and depth should have to be smaller too...

Quote
Andreas15
I'm a bit in a dilemma with this one. Or going with an AC bed, or enlarging the whole frame to fit the 350W PSU, or finding a smaller PSU :p I don't know if it is worth all the safety requirements to go AC, but it just sucks to make the frame bigger to fit a PSU clean inside it. It really has to be in the base and I'm also not a fan of adding an extra extrusion under it to fit the power supply. Does anyone know a small(er) 350 or 360W power supply? The LRS-350 (30mm in height) is the smallest that I found, but the width and depth should have to be smaller too...

This is just my own personal opinion based on my past experience, but I refuse to use any DC based heater anymore. I had nothing but problems with them not running at the spec wattage and the extremely long heat-up times. I know lots of people that haven't had the issue so I know it can work. For myself, the extra trouble for the safety of using an AC heated bed is less than the trouble I had with DC based one.

Quote
mdcompositi

Quote
dc42
I thought having to edit and recompile firmware to change parameters went out with the Ark - or at least with 8-bit electronics

Sorry .....what are you saying?? I don't understand.......

You said you have 32-bit controller electronics. I am saying that if you use one of the major 32-bit firmwares, which are RepRapFirmware and Smoothieware, you don't need to recompile and re-upload the firmware to make changes, such as changing thermistor type. You just edit the configuration file on the SD card, which is read when the firmware starts up. In RepRapFirmware, you can even do the editing in the web interface without having to remove the SD card, or change parameters such as thermistor type on the fly to see what effect they have.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
Andreas15
I'm a bit in a dilemma with this one. Or going with an AC bed, or enlarging the whole frame to fit the 350W PSU, or finding a smaller PSU :p I don't know if it is worth all the safety requirements to go AC, but it just sucks to make the frame bigger to fit a PSU clean inside it. It really has to be in the base and I'm also not a fan of adding an extra extrusion under it to fit the power supply. Does anyone know a small(er) 350 or 360W power supply? The LRS-350 (30mm in height) is the smallest that I found, but the width and depth should have to be smaller too...

In that situation, my choice would be to use an AC bed heater. Whether you do depends on how well you understand the safety requirements. If you want to use PID to control the bed heater, check whether the firmware you intend to use supports slow PWM for the bed.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].