IR heat lamp heated ABS build:

As we all know, ABS warps on unheated plates. I tried it anyway (on tape), and got some warp.



I used a 250 watt IR lamp ($6 or so) and with it about 8 inches away from my thick aluminum plate it heated it to 90-100C.

My first print at 230C extrusion and using the lamp had minimal warp.



I got a filament jam though, and not sure why. Don't think that should happen at 230C at the 10-15mm/sec I was printing at, so maybe it was unrelated.

I tried again at 240C, just in case I had cold extrusion, and that didn't jam. I am getting a messed-up top layer though. I believe the heat from the lamp, combined with the hotter extrusion temp, is making it too stringy.



In conclusion - I think you can make this work in a pinch to print ABS, but it seems better to have the part stuck to a hot plate without the filament being heated to much as it is being deposited - which the lamp seems to do.

But if you wanted to try this, I would suggest using it to pre-heat the plate to 105C (checked by IR thermometer), then start printing, and remove the heat before you do the top layer.

Oh yeah, it is not really good to heat wood over 100C, so have a fire extinguisher nearby, and don't leave it unattended.

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[www.matter-replicator.com]

Good idea, how well do you think it would work on a larger print?

I think it may be useful in conjunction with a normal heated build plate.

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[www.matter-replicator.com]

What if you try to shield the extruder from the heat? It looks like that the extruder assembly is getting a good deal of the heat from the lamp.
This could lead to insonsistent filament supply, explaining the less that optimal surface finish on the top layer.

Exactly what I wanted to write yesterday, but didn't.

Try to use a more directional light, or make some kind of box with an adjustable 'light nozzle' which then is focused on the area?
And try to exclude all other variables like filament width variation. I had the same looking prints with filament that didn't have a constant width.

Really curious how you go on with this. But for me, personally, I have built a 3mm acrylic 'box' with just two simple parts, one long piece bent into a shape that makes a roof and two walls, like an upside-down 'U' and then one more plate to the front so you have a shape that you can just place over the front of the printer.

This already works like magic for me.




Ralf Wrote:
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> What if you try to shield the extruder from the
> heat? It looks like that the extruder assembly is
> getting a good deal of the heat from the lamp.
> This could lead to insonsistent filament supply,
> explaining the less that optimal surface finish on
> the top layer.

Interesting; as you already said, in conjunction with a heated bed, I can imagine this method eliminating warp (almost) completely.
If you add a heat insulated chamber around it, so that the part is evenly held at an elevated temperature, you might eventually print extremely large parts perfectly after working out the top layer problems...definitely worth a try!

On my larger printer I was considering using an ir lamp to heat the build chamber and give it light, but I wasnt sure how efficient it would be.

Any updates on equipping your printer with an IR light, aduy? Considering Stratasys' hold on the heated chamber patent, an IR based solution might be a possibility to circumvent that. After all, plastic is absorbing IR light readily, so what we are heating is not the build environment, but the object itself.

Great idea.
Test using a Halogen lamp to heat the part directly or indirectly via a heated chamber.

I am a little bit against using lamps with visible spectrum parts because if one was to implement a chamber temperature control, the constant flashing would drive the operator insane. But as a makeshift test, yeah, why not?

These here seem to be IR-only:



Heat control might be a little bit tricky. As you don't heat the air directly, you can't just put some thermistor in your chamber. I guess for each plastic type (since different plastics and different colors absorb IR to a varying degree) you are printing, you need some kind of "measuring piece" with a hole, into which the thermistor has to be inserted. This way, you should be measuring actual material as opposed to ambient temperature that might be off by a lot.
But that is only theory. I have not empirically proven my concerns, yet.

Edited 1 time(s). Last edit at 12/21/2013 11:10AM by uGen.

By the way, if every printed part of a printer in an IR build chamber is covered in aluminium tape or foil, theoretically, one could also use plastics with a relatively low softening point since aluminium reflects up to 98% of IR radiation. This could possibly also be used to direct the radiation to hit the object from all sides for optimum heating. I don't know yet how all these theories play out in practice, but I would love to test an IR chamber ASAP after the holidays.

i would think it better that someone could slightly see the ir light. that way it would be known it was on, and some safety precaution would be taken to protect the cornea of the eyes.

if the ir was not heating the surroundings aluminum would work ok, but it likely will get quite hot. perhaps aluminum and then insulation

Ceramic infrared heaters warm objects not the air.
Objects in front of the IR lamp will warm up.
The back side of the object won't warm until the heat is conducted through the object.
Thin <1mm transparent/translucent plastic objects will pass some radiant energy.

PVC or polyethylene, peak absorption is around 3,500 nm.

Ceramic elements operate in the temperature of 300 to 700 °C (570 to 1,290 °F) producing infrared wavelengths in the 2,000 to 10,000 nm range.
Most plastics and many other materials absorb infrared best in this range, which makes the ceramic heater most suited for this task.

... water and glass (which are colorless) are virtually transparent to short-wave radiation, but are very strong absorbers of long wave radiation above 2.
[www.infraredheaters.com]

I was thinking of a Halogen bulb with a dimmer switch with a fan to circulate the warm air, so the light is always on vs. flickering on/off.

I tested PP with a black Watlow radiant heater, it didn't warm the plastic significantly.

RADIANT HEATING WITH INFRARED
[www.watlow.com]

Infrared heater
[en.wikipedia.org]

The Principles of Infrared
[www.drc.co.uk]

Introduction to Radiant/Infrared Heating
[www.deltat.com]

Edited 1 time(s). Last edit at 12/22/2013 09:19PM by A2.

@jamesdanielv: That makes sense - maybe one could add an indicator LED - if the IR contraption sits inside a closed chamber with reflective walls, including the access hatch/door, I don't see any problem with that. Open designs however, might be better off with light bulbs emitting partly visible light.

@A2: Because IR directly heats the object, I thought it could be useful as it might not infringe on the Stratasys patent on heated build chambers. After all, we don't primarily heat the build environment like this. And to "reach around" the object, simply cladding the inside walls of a build chamber with a thin layer of aluminium might help. Of course one could also design some really fancy walls that optimize beam reflection, but I doubt one design would fit all objects like this.
A little bit disappointing to read that the PP didn't really heat up as I have hoped to be able to print exactly that. Can you explain your setup a little bit more? Also, colored filament might react differently to IR, right? So we might need one "sample block" into which the chamber temperature thermistor goes for each different filament and color.
Initially, I didn't have high hopes to find a PWM-controllable dimmer - a cheap one at that. Turns out that my concerns were unjustified: Dimmer and PWM to DC converter. Awesome! Maybe I should really get a medical IR lamp. Even if parts heating is unsuccessful, a little bit of warmth for my back might not be a bad idea

Quote
uGen
A little bit disappointing to read that the PP didn't really heat up as I have hoped to be able to print exactly that. Can you explain your setup a little bit more? Also, colored filament might react differently to IR, right?

Fusion welding (hot plate) virgin medical grade PP.
Watlow sales rep gave me a few radiant heaters to test as an alternative to hot plate fusion welding.
I wanted to eliminate touching the part to melt the surface.
The heater surface was black, the PP parts were a translucent milky white.
Because the PP was translucent it didn't absorb much of the radiant heat in a time span conducive for efficient mass production.
I imagine that a black PP object would absorb the radiant energy more efficiently.

I'm interested in inexpensive PP filament printing, if you find any thing relating to PP please alert me

Wait a minute, what dimensions of PP stock are you talking about? Maybe successively heating single layers works well enough to be viable?

PP seems to be generally available as plastic welding rod. Maybe 3mm is a little bit harder to find, but Orbi-Tech for example is one supplier to consider in Europe.
Judging from some comments from the stone ages of the RepRap project, PP tends to warp quite a bit, IIRC.

There was a video on 3ders.org with someone talking about "advanced materials for 3D printing", including PP.

Although closed roughly 12 hour ago, this Kickstarter project shows some PP printing action in their video.

Quote
jamesdanielv
i would think it better that someone could slightly see the ir light. that way it would be known it was on, and some safety precaution would be taken to protect the cornea of the eyes.

if the ir was not heating the surroundings aluminum would work ok, but it likely will get quite hot. perhaps aluminum and then insulation

I am pretty sure that an IR heat lamp would not cause damage to the eyes, at least not without feeling discomfort first, if you were so close it felt hot.

I'm not an expert, can anyone confirm or deny this?

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What is Open Source Hardware?
Open Source in a nutshell: the Four Freedoms
CC BY-NC is not an Open Source license

I didn't read everything in this PDF on IR-emitting diodes, but what I understood from quickly glancing through is that we don't "feel" or see IR-A radiation on the retina. Thus, we tend to not avert our eyes when we gaze into such a radiation source and are susceptible to overexposure. Furthermore, cornea damage can occur in the same way that skin damage does by overexposure.
Luckily, the Elstein brand IR emitters I found are supposed to emit wavelengths in the range of 3-10µm, which is outside of IR-A. They are also used in terrariums to provide warmth for pet reptiles, so I cannot imagine them being especially dangerous to use, but it doesn't hurt to do a little bit more research before coming to a definite conclusion.

Bump

I have an open design and am going to give the ceramic elements a go as soon as it's up and running.

Wrapping exposed plastic assembly bits with aluminum foil seems cheap and will reflect up to 97% of the IR radiation "shiney side out", though matte foil is estimated at only 70%.
Stainless steel foil is rated at 90% and doesn't conduct heat as well as aluminum, so may be a better IR insulator in the long run.

What do you mean with open design?
Do you intend to print ABS without enclosure and hope the IR lamp will keep the part from delaminating/warping?
How do you aim the lamp to the part? The extruder will always make a shadow or the part will get IR only from one side.
I'd only give it a try as enclosure heater, because it wouldn't flicker visually.

I saw a paper from NASA recently in which they heated a print inside a makerbot (!) using halogen lamps- about 12 of them- to keep the print warm while printing. I don't know how you control the surface temperature of the print and imagine it would be easy to melt the print.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

IR lamps don't need an enclosure, as there's no ambient heat to contain. I don't have an enclosure, hence "open", nor do I want one.

DD, yea, I saw a video of an i3 rigged with surround IR lamps. Controlling the temp would be haphazard at first, but with trial and error and the help of sensor(s) and potentiometers for dialing intensity will be as easy as finding hotend and bed temps for various filaments.