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# A call for help/ideas to develop the Heated Bed

Posted by casainho
 Re: A call for help/ideas to develop the [[Heated Bed]] Build Platform January 30, 2010 01:59PM Registered: 12 years ago Posts: 581
[www.dealextreme.com]

22mm width film on a 30 meter roll for \$5 dollars. That's over 6 meter^2 of kapton for 5 bucks. You will not beat that price.

repraplogphase.blogspot.com
 Re: A call for help/ideas to develop the [[Heated Bed]] Build Platform January 30, 2010 06:32PM Registered: 12 years ago Posts: 52
[www.dealextreme.com]

24mm width film on a 33 meter roll for \$4.20. That's almost 0.8 m^2 of kapton for less than 5 bucks... I think I beat your price ;-) \$5.30/m^2

BTW - 22mm * 30 meters = 0.022 * 30 = 0.66 m^2 [unless my math is off] \$8.08/m^2 for the roll you found - still not a bad deal.
 Re: A call for help/ideas to develop the [[Heated Bed]] Build Platform January 31, 2010 12:35AM Registered: 12 years ago Posts: 581
 Re: A call for help/ideas to develop the [[Heated Bed]] Build Platform January 31, 2010 02:47PM Registered: 12 years ago Posts: 356
Since I understand after reading wiki of Makerbot, they are just doing heated bed for the 60ºC - to use PLA. They simple didn't mention a values for PLA or ABS... since ABS requires 120ºC, looks to me that their solution may not be good for ABS.

I added a link to RepRap Heated Bed wiki page for the one on Makerbot site. And I made just the same on Makerbot page, a link to RepRap :-)

Looking at this video I see a heated bed at 70ºC and using acrylic. Acrylic bends at values like 120ºC... but may be ok for 70ºC. But we need 120ºC for printing ABS.

Things I don't like:

- they are using extruder to control heated bed, and explaining the changes to hardware, firmware and software. This gives even more confusion! I prefer a stand alone and isolated solution from actual tested and working system.

- they are using a thermistor and that requires calibration, meaning that information will vary over temperatures values that users will report. I prefer to use the max. 150ºC calibrated from factory IC.

Things I like:

- Raftless Skeinforge plugin: "zaggo (01/16/10): The Raftless script not only switches off the raft, but let you slow down the printing of the 1st layer's perimeter loops. This helps a lot when printing complex (i.e. not rectangular) shapes without a raft."

That's something I am being doing by hand :-( -- I need to test this plugin.

I sent a message to the author of the plugin to thanks. I also add this information and link to RepRap Heated Bed wiki page.

I didn't bought yet the electronics material for the heated bed. And that's true that my heated bed of 15mm thickness takes a lot to heat... :-(

Yesterday I went to a near city shop (Lanema.pt) that sells plastic, aluminium sheets and gears :-) -- you know, I was looking for plastic to print and also PTFE for extruder. Aluminium for heated bed and gears for a new extruder as NopHead one :-)

The aluminium sheet I bought were of 6mm and at home I saw it was bended, although it was not bended before guy cut it in the size I asked. They also sell machined sheets (more expensive) however I was afraid they would also bend it when on cut.

The only plastic they sell of 3mm diameter is POM. I simple didn't know what was that plastic, they did offer a sample of 4 meters. They sell it at about 10€ for 1kg.

At home I could extrude it, however I verified that at an higher temperature than ABS. It was at about 135ºC (if my thermistor is correct calibrated).

It doesn't stick to kapton tape on hot bed at 120ºC like ABS. I used an electric insulation tape and it did stick, however on second layer it started to warping very much in a way that I had to cancel the print. On wikipedia I can read this about POM:

Disadvantages of acetal based plastics:

* Very high thermal expansion

So maybe the problem of warping is because of that very high thermal expansion. Maybe if I had a heated bed (and also chamber??) more strong that could hold 200ºC, then I could print using POM.

I wrote a blog message about POM here.

Edited 1 time(s). Last edit at 01/31/2010 02:52PM by casainho.

---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]
 Re: A call for help/ideas to develop the [[Heated Bed]] Build Platform January 31, 2010 02:54PM Registered: 12 years ago Posts: 356
buzzard192 Wrote:
-------------------------------------------------------
> [www.dealextreme.com]
>
> 24mm width film on a 33 meter roll for \$4.20.
> That's almost 0.8 m^2 of kapton for less than 5
> bucks... I think I beat your price ;-)
> \$5.30/m^2

I bought a few time ago that 24mm kapton tape from Deal Extreme and I am being using it - it works great! :-)

---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]
 Re: A call for help/ideas to develop the [[Heated Bed]] Build Platform January 31, 2010 03:04PM Registered: 12 years ago Posts: 134
Here is where I saw the official makerbot solution:

[wiki.makerbot.com]
 Re: A call for help/ideas to develop the [[Heated Bed]] Build Platform January 31, 2010 03:34PM Registered: 13 years ago Posts: 478
Interesting link thank you goinreverse

Bodge It [reprap.org]
=======================================

 BIQ Sanguinololu SD LCD board BIQ Stepcon BIQ Opto Endstop BIQ Heater Block PCB BIQ Extruder Peek clamp replacement BIQ Huxley Seedling BIQ Sanguinololu mounting BIQ standalone Sanguinololu or Ramps mounting Print It Stick It Cut it

My rep strap: [repstrapbertha.blogspot.com]

Buy the bits from B&Q pipestrap [diyrepstrap.blogspot.com]
How to Build a Darwin without any Rep Rap Parts [repstrapdarwin.blogspot.com]
Web Site [www.takeaway3dtech.com]
 Re: A call for help/ideas to develop the [[Heated Bed]] Build Platform February 04, 2010 03:36AM Registered: 13 years ago Posts: 289
Hallo to all,
my idea is to wrap an alu sheet (200x2oox8) [cgi.ebay.de] with teflon-film.
The sheet must be isolated by thick silicon-washers and kapton-tape from the bed.
The teflon-film is fixed by easy springs around the sheet and i will heat it up by a ceramic-heater-element like this [www.conrad.de].
Maybe controlled as second extruder from the extruder controller???(i`m an old mechanican!)
Erich

Edited 2 time(s). Last edit at 02/04/2010 04:05AM by chris-nobody.
 Re: A call for help/ideas to develop the [[Heated Bed]] Build Platform February 04, 2010 02:14PM Registered: 12 years ago Posts: 356
chris-nobody Wrote:
-------------------------------------------------------
> Hallo to all,
> my idea is to wrap an alu sheet (200x2oox8)
> [cgi.ebay.de]
> 200433808600&ssPageName=STRK:MEWAX:IT with
> teflon-film.

Today I bought another 150x150x6 aluminium sheet and it is bended :-( The one I bought with 15 thickness is the best one and the one that works until now.

> The sheet must be isolated by thick
> silicon-washers and kapton-tape from the bed.
> The teflon-film is fixed by easy springs around
> the sheet and i will heat it up by a
> ceramic-heater-element like this
> ENT-12-V-150-W.
> Maybe controlled as second extruder from the
> extruder controller???(i`m an old mechanican!)

The heater and his controller should let us control the temperature with some good resolution.

I still think that is much more easy to use an Arduino as standalone controller for heated bed, that means there is no need to mess with a working extruder. Heated bed can be controlled independent of extruder.

Look at the simple schematic on Heated Bed page.

Maybe on a complex system you want the printer in synchronization with heated bed... but I guess this is not the case for now.

Edited 1 time(s). Last edit at 02/04/2010 02:19PM by casainho.

---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]
 Re: A call for help/ideas to develop the [[Heated Bed]] Build Platform February 04, 2010 03:00PM Registered: 13 years ago Posts: 289
Hi casainho,
your are right with an independant controller.It is easier for an old man.
i`m still waitin for my print parts.I will recognize your comments.
Thanks Erich
 Re: A call for help/ideas to develop the [[Heated Bed]] Build Platform February 05, 2010 04:48AM Registered: 14 years ago Posts: 204
Just to inform you guys, I made my own prototype like a week ago, Im currently milling it flat with a dremel holder, and Im working on a second prototype, which I intend to sell too.

Expect some articles at [blog.arcol.hu] soon.

As for the selling I plan to sell it at 100EUR if there are more then 18 buyers, or 150EUR if less (+shipping of course), I can ship inside EU.

The next prototype is almost the same what nophead had, with magnets and such. Also I plan to sell everything (ie power supply, etc), just plug in and play. It will be a drop-in replacement bed for Rapman bitsfrombytes machines. The overall weight will be around 7kg total (from which the power supply is 2.7kg).

If you are interested drop an email to preorder [at] arcol [dot) hu.

No obligation with this email, just Im curious how many people are interested into a ready made solution.

Sorry to not provide pictures and such, but Im working on the articles, hopefully I can publish it at this weekend.

Best regards,
Laszlo

Mendel build log: [blog.arcol.hu]
 Re: A call for help/ideas to develop the [[Heated Bed]] Build Platform February 05, 2010 05:34AM Registered: 12 years ago Posts: 356
khiraly Wrote:
-------------------------------------------------------
> Just to inform you guys, I made my own prototype
> like a week ago, Im currently milling it flat with
> a dremel holder, and Im working on a second
> prototype, which I intend to sell too.
>
> Expect some articles at [blog.arcol.hu] soon.
>
>
> As for the selling I plan to sell it at 100EUR if
> there are more then 18 buyers, or 150EUR if less
> (+shipping of course), I can ship inside EU.

It's a bit expensive, I think. But at same time I think is a god option to buy a ready to plug system that just works :-)

Wouldn't be possible for you selling just the mechanical part? probable the aluminium + heater? (I would prefer to use my own cheap PC PSU and Arduino electronic control circuit). Leaving the cost for PSU for client can be good since you PSU is heavy! and everyone can find locally a PSU and cheap.

And yes, you need to put more pictures and details. I am curious to know if you insulate it under.

And what about electronics control? can we see the temperature value? the system needs to be attached to Extruder board or not?

Since I already started to build my own heated bed, I think I am not interested to buy another, however I am very happy that someone provides it for community! good luck ;-)

---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]
 Re: A call for help/ideas to develop the [[Heated Bed]] Build Platform February 05, 2010 07:17AM Registered: 14 years ago Posts: 204
> And what about electronics control? can we see the temperature value?

As ABS requires the highest temperature, Im not attaching any control circuit to it, Im simply using resistors which are the right value for ABS printing.

If I would include electronics, it would be way too expensive(SSR costs about 20EUR, an arduino board 30EUR more, so it would boost the price another 50EUR for almost no gain).

Also there are so many electronics, that I think the best way is to integrate the functionality into the main electronics, and not provide a yet another control board for the heated bed.

Also keep in mind, that 330mm * 330mm *6mm aluminium sheet is not cheap, also custom machining makes more expensive.

There could be some price changes, as I advance the manufacturing, and select aluminium sheets, but the above prices seems to be about right with almost no profit on my end.

I try to publish every detail, so if somebody want to replicate at home, Im not against it, certainly if he has access to a cnc machine and can get free aluminium sheets.

Laszlo

Mendel build log: [blog.arcol.hu]
 Re: A call for help/ideas to develop the Heated Bed February 05, 2010 07:21AM Registered: 14 years ago Posts: 204
> Today I bought another 150x150x6 aluminium sheet and it is bended :-(

Keep in mind, that there are many kind of aluminium sheets:
AlMg1
AlMg3
AlMgSi1
AlSiMgMn, etc, etc.

Some of them are really soft, and prone to bend.
Adding Si makes it more rigid, also adding Mg makes a bit
harder, but not as much as Si.

So if you got AlMg1, Im not surprised it is bended...

Try to mill it flat with the machine itself. Just dunno how to attache a dremel to Mendel, as the carriage is really tiny. (No1. what I would like to change in Mendel design).
 Re: A call for help/ideas to develop the [[Heated Bed]] Build Platform February 05, 2010 07:27AM Registered: 14 years ago Posts: 204
> It's a bit expensive, I think

The bfb bed is 330x330mm, it is more than four times bigger, then your 150x150 aluminium sheet...

How much was your aluminium sheet?

(Im just curious no offense at all)
 Re: A call for help/ideas to develop the Heated Bed February 05, 2010 07:53AM Admin Registered: 14 years ago Posts: 13,530
... milling an Aluminium-sheet really flat with a dremel should be nearly impossible ... better try to roll it flat with some steelrods.

What mechanical setup for milling do you have?

Viktor
 Re: A call for help/ideas to develop the Heated Bed February 05, 2010 08:01AM Registered: 14 years ago Posts: 204
> ... milling an Aluminium-sheet really flat with a dremel should be
> nearly impossible

Seems to work fine for me.
Im using a dremel, a dremel right angle attachment 575:
[www.dremel.com]

And 1mm thick cutting disks (420).

It is noisy as hell, but works fine.

And also I designed a dremel holder for my machine too.

I will publish a blogpost about it at the weekend with some nice photos.

Edited 1 time(s). Last edit at 02/05/2010 08:02AM by khiraly.

Mendel build log: [blog.arcol.hu]
 Re: A call for help/ideas to develop the Heated Bed February 05, 2010 08:08AM Registered: 14 years ago Posts: 204
Oh, and Im actually milling steel/iron. Its still the first prototype.

I would expect aluminium is much easier.
 Re: A call for help/ideas to develop the Heated Bed February 05, 2010 09:11AM Admin Registered: 14 years ago Posts: 13,530
... maybe we have different views for flatness

With my CNC-mill and a 500Watts-millhead and a 6mm-cutter i can mill a flatnes with maybe 3 microns local (20x20mm) and 10 microns global accuracy over a 300x300mm area.

When i last milled with a dremel-type millhead on the same machine the accuracy was around 20 microns local and nearly 100 microns global ...

Viktor
 Re: A call for help/ideas to develop the Heated Bed February 05, 2010 09:18AM Registered: 14 years ago Posts: 204
For printing, I think 0.1mm flatness error is perfectly fine. But I will report anyway how it will turn out the whole story.

The current flatness error is about 1-1.5mm.

Edited 1 time(s). Last edit at 02/05/2010 09:19AM by khiraly.

Mendel build log: [blog.arcol.hu]
 Re: A call for help/ideas to develop the Heated Bed February 05, 2010 09:27AM Admin Registered: 14 years ago Posts: 13,530
khiraly Wrote:
-------------------------------------------------------
> For printing, I think 0.1mm flatness error is perfectly fine.

... OK, we HAVE different views

I'm building a XYZ+rot-setup with an desired accuracy near to 1 micron for paste-dispensing or laser-sintering with a laserspot of 10 microns diameter - here 20 microns error in flatnes is a catastrophe ...

Viktor
 Re: A call for help/ideas to develop the Heated Bed February 05, 2010 01:12PM Admin Registered: 15 years ago Posts: 7,864
When the layer height is only 0.25 to 0.4mm 0.1mm is quite a big error when printing without a raft.

[www.hydraraptor.blogspot.com]
 Re: A call for help/ideas to develop the Heated Bed February 05, 2010 02:08PM Registered: 14 years ago Posts: 204
> When the layer height is only 0.25 to 0.4mm 0.1mm is quite a big error
> when printing without a raft.

With my current bed, I could only print using raft, and in that case I needed to be around when it started, because I have must to level the bed using the three nuts while it started to print the raft.

I hope I can avoid at least this issue.

However the dremel is already running 12 hours, and only about 1/3 is finished of the table...
And I think I should mill another 0.1 mm from the top of the bed.

Mendel build log: [blog.arcol.hu]
 Re: A call for help/ideas to develop the Heated Bed February 05, 2010 05:41PM Registered: 14 years ago Posts: 204
Here is a video, how Im milling it flat:
[vimeo.com]

Mendel build log: [blog.arcol.hu]
 Re: A call for help/ideas to develop the [[Heated Bed]] Build Platform February 05, 2010 06:21PM Registered: 12 years ago Posts: 356
khiraly Wrote:
-------------------------------------------------------
> > It's a bit expensive, I think
>
> The bfb bed is 330x330mm, it is more than four
> times bigger, then your 150x150 aluminium
> sheet...
>
> How much was your aluminium sheet?
>
> (Im just curious no offense at all)

150x150x15 were 15€ on a local shop. After that I bought at the same shop a 150x150x6 and it came bended. The guys do cut the sheet and bend it on that time :-(

I also bought 150x150x6 on another shop and it came also bended. And it's simple to understand that if my printed layer is 0.35mm, a very small bend makes a lot of difference.

But there is a hope!! The Raftless pulgin for Skeinforge let's us define a head speed and extrusion speed, so we can make the first layer as if were raft... like be larger than 0.35mm to avid problems on bended sheet.

I am very happy that someone want to provide this service to community! I am being documenting the wiki about this... and today I used for the first time the Raftless plugin! I will now work on a way to put that plugin available and working for everyone.

So maybe is better that you provide only the aluminium sheet and the heater element. What voltage and wattage were you thinking of, that PSU? what kind of element heater?

And why not a small bed? like the last one of NopHead that makes possible to print the Mendel parts?

How user will be able to choose the 55ºC or 120ºC? or other values for other plastics?

I guess we could do a general heater control box, with input of 5V to 24V, and the same output for heater element. An input for temperature sensor, buttons and the LCD.
For example the extruder heater, it could be controlled with such an heater! The user just needed to start printing when temperature reach the defined value.
Since the output is a Mosfet on/off, the system can control heaters and fans... maybe useful for a heated room...

Edited 3 time(s). Last edit at 02/05/2010 06:47PM by casainho.

---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]
 Re: A call for help/ideas to develop the Heated Bed February 06, 2010 02:54AM Registered: 14 years ago Posts: 204
> 150x150x15 were 15€ on a local shop

So 330x330 piece would cost 72.6+ EUR. Aluminium is not cheap at all.
So 100EUR for the whole thing seems pretty good deal to me. (if I can really make it that low). (and I need to machine it also, which is expensive)

> But there is a hope!! The Raftless pulgin for Skeinforge let's us
> define a head speed and extrusion speed, so we can make the first layer
> as if were raft... like be larger than 0.35mm to avid problems on
> bended sheet.

I think the only solution would be to attache the z limit switch to the extruder head, and it would go above the table and measure the height at every 10mm. So the software than could create the 3D modell of the bed.

> So maybe is better that you provide only the aluminium sheet and the
> heater element. What voltage and wattage were you thinking of, that
> PSU? what kind of element heater?

I thought about a lot, I started with 230/24V transformer, but finally it is more simple to get only a 230/12V toroid transformers, 200W.

From 12VAC we could make 12VDC (I already made such pcb some years ago), so we could feed the pcb from that transformator too.
Also heating the nozzle could use 12VAC.
As for the wiring, with 1.5mm2 everything is fine, as it can support until 20A. And 1.5mm2 is very common, because the houses are wired generally with it.

> And why not a small bed?
Its only a half solution. We could *really* print 25cmx25cmx25cm big objects!

> How user will be able to choose the 55ºC or 120ºC? or other values
> for other plastics?

I plan to support only ABS, as it requires the most heat. If somebody wnat to heat only for 55C, then fine, he/she should use his/her favorite electronics to make the control. It is possible, but by default it will be just fine for ABS.

I should really create a summare blog about all this.

Edited 1 time(s). Last edit at 02/06/2010 05:21AM by khiraly.

Mendel build log: [blog.arcol.hu]
 Re: A call for help/ideas to develop the Heated Bed February 06, 2010 07:46AM Registered: 12 years ago Posts: 356
khiraly Wrote:
-------------------------------------------------------
> > 150x150x15 were 15€ on a local shop
>
> So 330x330 piece would cost 72.6+ EUR. Aluminium
> is not cheap at all.
> So 100EUR for the whole thing seems pretty good
> deal to me. (if I can really make it that low).
> (and I need to machine it also, which is
> expensive)

Ok. I understand now that you are using the Rapman, which have a big area.

I guess a table for Cupcake CNC would be nice and cheap (even If I do not have that machine and have another with 200X300). I think there should be a simple and cheap solution for users that do not want to spend much money. For example, Cupcake CNC users VS Rapman users. Cupcake is smaller and cheap, but is for sure enough for some users.

This are just thoughts.

> > But there is a hope!! The Raftless pulgin for
> Skeinforge let's us
> > define a head speed and extrusion speed, so we
> can make the first layer
> > as if were raft... like be larger than 0.35mm to
> avid problems on
> > bended sheet.
>
> I think the only solution would be to attache the
> z limit switch to the extruder head, and it would
> go above the table and measure the height at every
> 10mm. So the software than could create the 3D
> modell of the bed.

I am looking to do that but for milling PCB on my CNC. It's a complicated solution, I guess that milling flat the aluminium is better for this application.

> > So maybe is better that you provide only the
> aluminium sheet and the
> > heater element. What voltage and wattage were
> you thinking of, that
> > PSU? what kind of element heater?
>
> I thought about a lot, I started with 230/24V
> transformer, but finally it is more simple to get
> only a 230/12V toroid transformers, 200W.
>
> From 12VAC we could make 12VDC (I already made
> such pcb some years ago), so we could feed the pcb
> from that transformator too.
> Also heating the nozzle could use 12VAC.
> As for the wiring, with 1.5mm2 everything is fine,
> as it can support until 20A. And 1.5mm2 is very
> common, because the houses are wired generally
> with it.

A big bed is more problematic also because the need of big power.

For a small bed, I was thinking on 12V @ 5A, 60W, which should be enough. And so use a cheap and local PC PSU.

> > How user will be able to choose the 55ºC or
> 120ºC? or other values
> > for other plastics?
>
> I plan to support only ABS, as it requires the
> most heat. If somebody wnat to heat only for 55C,
> then fine, he/she should use his/her favorite
> electronics to make the control. It is possible,
> but by default it will be just fine for ABS.

Good :-)

Yesterday I were talking with Prusjar at IRC and he made good changes to Raftless plugin, it works very good :-) -- Prusjar will send the plugin to Skeinforge author and ask for integration on Skeinforge for future versions :-)

---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]
 Re: A call for help/ideas to develop the Heated Bed February 06, 2010 03:47PM Admin Registered: 14 years ago Posts: 13,530
Hi Khiraly,

... in your 'milling it flat'-video i could see how warped the plate is

Your setup is a good idea, but i think this grinding-discs will reduce in diameter after some way, so you have to adjust regularly or your surface will get wedge-shaped ...

Viktor
 Re: A call for help/ideas to develop the Heated Bed February 06, 2010 07:02PM Registered: 14 years ago Posts: 204
VDX Wrote:
> Your setup is a good idea, but i think this
> grinding-discs will reduce in diameter after some
> way, so you have to adjust regularly or your
> surface will get wedge-shaped ...

Im milling two full days already. Like 30hours in total, and Im not done yet. Im using the 5. disks now.

I think the best method is going end-to-end the y direction, and 0.4mm after each turn toward the X direction.

In that way the bed is flat toward the y direction. It has some elevation towards the x direction, but I can repeat the process, just this time I go end-to-end the x direction...

Its a painfull and noisy process. Hopefully I will finish my aluminium version next week...

Mendel build log: [blog.arcol.hu]
 Re: A call for help/ideas to develop the Heated Bed February 07, 2010 04:23AM Registered: 12 years ago Posts: 387
Quote
VDX
With my CNC-mill and a 500Watts-millhead and a 6mm-cutter i can mill a flatnes with maybe 3 microns local (20x20mm) and 10 microns global accuracy over a 300x300mm area.

In my mind, it's less important that the bed is perfectly flat, and more important that its warping matches the error in the XY frame. So khiraly's solution seems to me to be quite a good one, assuming the dremel doesn't wear down much throughout the operation.
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