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billdempsey

Heated Bed updated information?

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Hey, does anyone have any updated information on the best way to add a heated bed to an Ultimaker. I have no plans to do PVC, but I want a heated bed so really large flat PLA prints don't curl up at the edges. Since I'm thinking about a different leveling method for the print bed, I figured now would be a good time to swap in a heated bed, too.

Basically, I'm looking for a parts & supplier list, plus basic instructions. EDIT: In the U.S., please.

Somewhere, I also read that you need a bigger power supply (like 400+ watts) for the Ultimaker if you want to connect the heated bed to the outputs of the main board. Anyone know where to order a replacement brick that outputs 450 watts or so?

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The only link I have on hand right now is this one:

http://flashgamer.com/arduino/comments/ ... -ultimaker

Can't quite remember who it was that did that write up (or if it's recent and good. Haven't read through it all yet), I found the link over at the google groups. A tip would be to search there as well since I think more info is available there on that subject than here (yay community segmentation!).

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Thanks for posting up those links.

Just curious if there's any reason NOT to solder in the 4.7k resistor prior to completing the heated bed build.

I've got a buddy coming over who's soldering skills are far better than mine, but I haven't finished machining the aluminum bed yet. I'll probably still need to do some prints w/ the blue-tape method before this project is completed.

 

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Bill,

I started a pretty lengthy disdcussion on the Google group about HBP before I built mine. It was a discovery process for me as I took the advice of others and found my own solution borrowing form the ideas of others. The thread is fairly lengthy at this point, but I think there is a lot of good info there. The thread is recent enough to still be current, I think almost everything there is still relevent.

Basically for my HBP, I am using a thermistor connected to the UM board to sense the temp. This requires adding a resistor to most versions of the PCB. I have an SSR (solid state relay) connected to the heater output terminals of the UM board. The relay switches an Omega (brand) self adhesive 120VAC heater. The heater is stuck to the bottom side of a 1/4" mic6 (cast and machined alum too plate). I have the aluminum set up to accept interchangeable glass plates (std window glass 3/32") which are clamped there with black document clips. In this setup, the heater power is isolated from the UM, so there aren't any issues with the UM PSU being too short on wattage, or dealing with replacing it with a larger one. I bought a power input module and a std computer power cord to plug into the wall. The input module is fused. This set-up gets up to 70C in about 4-5 minutes and once there, holds a steady temp.

There are more details on specifically which items I used in the Google discussion.

I understand that alot of people will say that using AC power to control the HBP is dangerous. If I was dealing with 240?VAC like the power mains are in Europe, I would agree. SInce you're in the US, the risks are lesser. I don't see this being any riskier that using a toaster oven.

I think my last post over there in the Google thread expresses my disappointment in the HBP. Although my bed functions very well, it is not the panacea for print sticking that I believed it to be before I built mine. I admittedly need to experiment some more with it. Most of my prints are smaller and I have been using blue tape on the glass but not heated recently. I have recently read that blue tape heated works very well, and that a glaze of hair spray on the glass can solve the non-stick issues.

Edit: Disclaimer: I am not claiming to have the best setup for the HBP. Only one that makes sense for me and holds temp well. With some more experimenting, it will probably have the utility HBP's are made up to have.

One observation about the new bed is that the printing surface is dead flat compared to the acrylic sheet that comes stock. This was a vast improvement. Coupled with a widget to fine tune the Z home switch, I can print a plate of Cura planner objects in confidence without being there at the start of each piece. Also when I changed the bed out, I went to a 3-point leveling system that also helped immensly for bed leveling. The aluminum is stiff enough it doesn't need 4 points, and 3 points is geometrically simler to level.

I just noticed a couple days ago your interest in my hot end that I posted on Thingiverse. I am proud to tell you that I am still running the nozzle as documented there. It has never jammed. If not for changing between nozzle diameters, I would have never touched it since installation. With the .4mm nozzle, I can print up to about 100mm/sec. Since I usually keep it under 60mm/sec this is fine. Higher speeds beat the UM up uneccesarily and machin time is not that critical to me. If your'e still interested in trying out a nozzle, we can work something out If you want to discuss that or the HBP, I'll PM you my number.

I need to add some photos of my mods, and get my Z switch adjuster up on Thingiverse.

Matt

 

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Soldered in the resistor and picked up a 25A SSR to go between the UM boards heated bed output and an extra 650W power supply I had. Just in the process of machining a piece of "optically-flat" aluminum a friend found for me to fit the PCB. Also scored some 220mm wide polyimide tape from Protoparadigm. Almost there.

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Just finished machining the plate and wiring up the heated PCB.

Can anyone point me towards the firmware source code that would apply to the heated bed control ? I'm not crazy about the thermistors that I received and I'd like to make sure that if it fails (ie. resistance goes to infinity or zero), the heated bed shuts off vs. going full-on.

 

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You can grab the source code from https://github.com/Ultimaker/Marlin if you don't already have it.

The heating stuff is all in Marlin/temperature.cpp - primarily the manage_heater() function. It handles both the extruder(s) and the heated bed. You will also see the interrupt loop that reads the values... it appears to have a max temp error case, that is intended to disable all the heaters... but the code is pretty complex, with the various #ifdef's... you'll need to check against what's defined in configuration.h and configuration_adv.h and follow it all through to totally convince yourself that it's working right, I'm afraid.

 

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If you are a competent and experienced c coder - definitely look over the firmware. It's well written code for the most part and easy to read (the parts I've looked at).

Also don't be discouraged by all the steps to build your own Marlin. I was nervous it was going to be very complicated but google told me everything I needed to know and I think it took less than an hour. I found not one, but a few places that gave me step by step instructions for installing the compiler, getting the source, editing the config files and getting my own custom Marlin build. This was necessary anyway at the time because at least then (early january when I added my heated bed) Daid's page didn't work right for heated beds. Daids marlin builder page was *very* helpful in createing a configuration.h file - I was able to diff Daid's versus the default to see what I might want to mess with:

http://daid.eu/~daid/marlin_build/

 

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An hour? I don't remember it taking that long. Perhaps it's because you're building on Windows. :-p

Marlin is a great example of what open source collaborative coding can achieve, but I think there's a pretty steep learning curve. I don't find it easy to read, overall (And I've been a professional developer for 30 years, starting a few years before I wrote my own BIOS in C and Assembler at the age of 15, so I'm not exactly a newbie when it comes to C).

I mean it's easy enough to get a superficial sense of what's supposed to be going on, but the multiple code paths to support lots of different hardware and ways of doing things make it a bit of a pain to actually prove that it's doing what it claims to be. And frankly, some bits of it are flat out voodoo, like the recursive defines that make the menu structures work (clever! But a bit impenetrable), or just complicated like the planner/stepper or temp code. I've found plenty of bugs already, including one pretty fundamental one. And as Daid, points out there are things that are incomplete or slip through the cracks.

That said though, it's a great asset to us all, and I'm excited to be getting to contribute to it :-).

 

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I assume you are just making fun, but just in case - I meant an hour to read instructions, install the compiler, download marlin, figure out what the instructions meant (where's the bloody open project and build project commands?), read every variable in configuration.h and all the comments and change a few things, and then build it and download onto ultimaker. The actual compile was trivially quick.

 

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Hey guys, I wan't to share my progress in adding a Heated Bed to my Ultimaker. I find it hard to find the right information for adding a HB and it seems that everyone has his/her own approach. There are many options like the kind of heater (silicon, kapton, PCB), powersupply (12, 24, 230 V) etc. etc. My solution probably doesn't make the choice for a HB more easy but maybe it has some useful information for you.

At first, I wanted to attach the Heated Bed directly to the UM PCB and I almost go all the parts. Then, when I was about to solder the resistor and other parts to the PCB I decided to take another approach and build the Heated Bed as a separate system. I'm not super skilled with electronics and I don't want to destroy the PCB (using my 230V heaters), spent 200,- on a new PCB and be back where I started from... After all, controlling the Heated Bed with the UM PCB needs parts from which it's not very clear which these should be, and also a lot of topics report about problems varying from bad temperature readings to blown up MOSFETS.

So, to make the Heated Bed as a separate system I've gathered the folowing items:

- Digital Temperature Controller:

http://www.tjskl.org.cn/products-search/czab7db1/220v_digital_thermostat_temperature_thermostat_switch_wh7016c-pz23367ad.html

If you search for the item numer, which is WH7016C, you'll probably find a lot of sources in your own country. It comes with a temperature sensor. Range up to 100 *C. I bought it for 19 euro's.

- Kapton Heaters:

http://www.omega.com/ppt/pptsc.asp?ref=KHR_KHLV_KH

I've got two KH-508's from the company that I work for. If you order directly from the site, of course you could/should get just one with the right size. BUT, since they are 115 V, I'll use two in series to use 230 V directly from what comes out of the walls in Holland. Size is 20 x 12,5 cm, comes with 3M adhesive back.

- Aluminium plate:

http://www.aluminiumopmaat.nl/

This is a Dutch site which provides custom made aluminium plates in almost every size (graag gedaan). So you don't have to buy like a square meter... I've got 26 x 24 x 0,3 cm. The 24 cm side is the same as the acrylic platform, so it fits onto the screws. The 26 cm is for holding the two 12,5 cm heaters which leaves 0,5 cm space on the sides. Prices for the plate was 4 euro but shipping cost 18 euro (hahaha shit). I found this part to be the hardes to find for a low price...

Furthermore some parts like, power switch, wiring and probably a safety bi-metal switch. So, maybe needles to say, but I will attach the adhesive heaters to the aluminium plate. Drill holes, a little bit bigger than the screws and attach them using a rubber bushing for insulation and expansion of the plate. Then somehow attach the temperature sensor to the board and connect everything to the temperature controller.

I'm still waiting to receive the last parts so when I've got them, I'll post again!

To be Continued

 

 

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Hey all, I've finished building my Heated Bed upgrade and wan't to share some pictures with you:

Heated Bed Upgrade

Heated Bed Upgrade

Heated Bed Upgrade

 

The kapton heaters with adhesive back stick to the aluminium and the thermistor is clamped against the heater (for best temperature reading). I've attached the bed using the same screws and some heat-resistant rubber bushings. For now, the temperature controller is attached with an elastic band but I'll have to print a nice casing for it. I've calibrated/adjusted the temperature with an external thermometer and when printing the temperature varies with only max 2 degrees.

 

I'm VERY happy with the result and the prints are super straight with a nice finish because I print directly on the aluminium plate. I've tried blue tape but it adheres so good that I had to rip the tape appart to get the print of. For the first layer I set the bed to 80 degrees and from the second layer on I use 68 degrees (using PLA from Formfutura which is a little bit more gummy at the transition temperature).

 

Can anyone advise me about using fans or not? I don't see a lot of difference if I put the fans on or off. Fans off gives results just as good so I would like to take the fans of the head. Unless it better to use them??

 

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I'm glad you are happy.

For layers that take more than around 20 seconds you shouldn't need the fans. But when you have layers that can print in 2 seconds - for example the antennas on the top of the ultimaker robot - then fans help a lot. With my fans on at 100% I can print 5 second layers no problem. If I print much faster (say 1 second layers) it looks like crap even *with* the fan. I have been meaning to test with the fan on and the fan off. Will test that eventually.

Sooo - don't throw away your fans just yet. I'm sure you will have plenty of parts in the future where the top most layers print in under 5 seconds.

 

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I find the dual fans are a necessity for small and/or thin features. I designed a wine glass that's a single wall joris print and with no-fans, it's just a stringy mess not even resembling a wine glass, with a single fan, the fan side turns out ok, but the opposite side is riddled with holes. I'd like to see a plugin that adjusts the fan speed to be inversely proportional to the layer time. I'd also like to see some more nozzle-centric fan-ducts (that don't grossly increase back pressure on the fans. If anyone's played with the new Replicator 2, you know what I mean.

I'm loving my heated bed, but as soon as I have time, I'm going to machine a new one out of cast MI-6 rather than the horribly un-flat T6.

 

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I too have the same problem with my UM. I can not print the model I desire because it has a 3 mm massive basis and is 16,5 X 16,5 X 20 cm. high.

What would happen if I don’t install a hot building plate but rougher put my entire UM in a heated environment up to 70 degrees? The bottom part with the wiring and motherboard would not be in this environment but cooled separately. Could all the other parts including the spool of filament handle this?

 

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Stephan - first of all know that I had troulbe with warping - I got a heated bed - but now I don't use it because I found other simpler solutions. So what exactly is your issue? Do you have a photo? Is it warping of the corners? Or something else?

 

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