Quiet heater for enclosure?

[bertho 6]

I built a heated enclosure for my UM for printing ABS.

See: http://www.vinland.com/blog/?p=191#more-191

Temporarily I have been using a stripped down hair dryer as a heater but it is very noisy. What suggestions do you have for a heater? About 500W is required.

 

[jonnybischof 60]

I thought the heat generated by the heated bed was sufficient to keep the chamber warm enough.

Keep in mind that if your motors are inside the printer (means: If you didn't convert to direct-drive), then you have to be careful not to heat up the chamber too much. If your motors get too hot, they will fail.

It's better to put the motors outside if you want to enclose & heat the build chamber anyways.

Now, a quieter heater...

The heating element itself shouldn't generate any noise. Only the fan does. If you swap the fan for a standard PC cooling fan, you should get much less noise. Note that the fan mustn't get hot or it will fail, too. I doubt that using a 500W heating element is necessary - there are other components inside the printer that shouldn't get too hot, too.

50 - 60° C air temperature is about the maximum recommendable level. And it doesn't take that much to get there.

 

[zoev89 73]

In my enclosure I reach to 40 or 45 degrees measured at the top of the printer without an additional heater element. The heated platform of 240x240mm at 110 degrees warms it up to that level.

 

 

[bertho 6]

Thanks for your comments.

My motors are outside the enclosure.

I am currently running a 400W heater and the heat-up time is marginal. Once at temperature it properly cycles.

Using a regular PC fan has two problems:

It is not intended to be used at 70C.

A PC fan has large air volume but low pressure. The hairdrier heater coil relies on a high airflow to keep the coil temperature safe. High pressure is needed to force the air through the small opening in the hairdryer.

 

[meduza 191]

I am doing a similar build, i fitted a 300W heater cartridge in a hole drilled trough the center of a CPU cooler and hope that will be enough to get enough heat in the printer.

 

[analog-kid 0]

You may be able to salvage the motor and turbine from an old vacuum cleaner or use a smallish squirrel fan. A vac motor would be loud and have a lot of air flow so a rheostat could limit it to an appropriate level. You could reuse the blow dryer heater or maybe use a toaster or toaster oven heater. Or make your own heating element with a transformer and some Nichrome wire. Just a few ideas from a cheapskate

[bertho 6]

Eric:

The cartridge heater sounds like an interesting option. I have lots of various shaped heatsinks. Then a low rpm rather large bladed fan to keep the air moving. There are metal boxer fans that might be acceptable. I could always otherwise put the fan motor outside and have the shaft inside with a metal blade fan.

You got many interesting projects in Youimage! Jag är från Värmland men bor i Florida.

Analog Kid:

The vacuum cleaner does not sound like a good idea to me it is big to start with. I like the idea of the toaster oven hear elements. I even have a few laying around from another project.

 

[analog-kid 0]

Yes, a full size vac motor would be nearly as large as the entire ultimaker! An external motor with shaft driven fan would be very cool!

[meduza 191]

Bertho: my thinking is to limit the upper temperature of the cpu cooler to be lower than the ignition point of most materials involved, and temperature controlling it even if it means longer warm-up time, i actually have fitted a PT100 in it (i do not like the idea of glowing wires when the printer is left unattended) and instead insuring a lot of air cirkulated in the chamber with crossflow fans.

If you are passing Stockholm on a visit home to Sweden, give me a shout and i show you around at Stockholm Makerspace

[bertho 6]

Eric,

I have a separate PID temperature controller and sensor for the air temperature. The heater block / section has an independent over temperature cutoff if the fan or controller fails.

 

[meduza 191]

Quite a similar setup to us then, but if you use glowing wires like a hairdryer, nichrome or a toaster element like @Analog Kid is suggesting, then it will not help you since the cutoff will not be active until the printer is actually on fire, thats what i meant

 

[bertho 6]

The fail-safe cutoff is in the heater section and kept cool by the airflow at the inlet. If the fan fail or airflow is blocked the heater section will get very hot and the fail-safe will cut off power. This will happen quickly before there is any damage to the printer. It is a standard safety feature of hairdryers.

Bertho

 

[meduza 191]

I'll would at least put wire mesh in front of the heater outlet and inlet then, so it is impossible to touch the heater wires with anything, regardless of how extreme a print fails inside the printer.

Anyways, i am using a 300W version of this embedded in a CPU Cooler: http://www.ebay.com/itm/390997010772

 

[gr5 2,210]

Bare metal heating elements glowing red hot seems a bit dangerous even with a grid - isn't it quite possible for some filament to fall down and go through the grid and then act like a fuse to bring fire back up to your part?

 

[bertho 6]

There is no red hot filament in my case. Th hairdrier heating coils do not glow. The heater is also placed high in the printer so no plastic can fall down on it.

 

[gr5 2,210]

There is no red hot filament in my case. Th hairdrier heating coils do not glow. The heater is also placed high in the printer so no plastic can fall down on it.

 

Well then that sounds reasonably safe. But if you heat the coils without the fan might it then get too hot? Are you thinking of powering the coils with house AC power? Or with some DC power supply?

 

[bertho 6]

Yes, if the fan fails the heater will overheat. That is why there is a built-in safety thermostat in hairdriers that will temporarily open the circuit. There is also a secondary fail safe link that if it gets even hotter it will permanently melt and disconnect power.

A 500W power supply would be very expensive. The heaters are AC powered from the mains.

 

[aviphysics 9]

I think I would take a look at those little office space heaters. would still need to supply a better temperature controller, but they are otherwise pretty much built for the job.

[duesentrieb 0]

Hi,

right now I am useing a very simple enclosure for my Ultimaker. It´s kind of a heat tent on top and all sides closed workes very fine with a heated bed. Improves print quality a lot. Also changed to direct dirve, which works like charm. Getting very accurate parts with great repeatability.

Working on another printer and it will get a closed heat chamber. I will use the following setup:

1) Electric room heater, 230V, 750W, sth. like this: http://www.amazon.de/Konvektor-Heizung-Elektroheizung-2000-W/dp/B009NEEQ2W/ref=pd_sim_diy_6?ie=UTF8&refRID=0DWEB50X44AQBSVBAZZQ

(Has 2000W, but two coils. If I use this one, then I will only use the 750W coil. There are cheaper and weaker ones, but this one got a metal housing. Won´t give me problems with melting plastic... This defvice in it´s original state is safe, you can´t touch the heater wire etc. Got a CE mark, but be careful and know what you are doing if you modify it)

2) Solid state relay to controll the heater with the standard Arduino based PCB.

3) 12V radial fan like this one: http://www.ebay.de/itm/Querstromlufter-Motor-links-12-V-X-Fan-DF43300-L/400782210311

Foehnsturm gave me the idea with his cross flow fan approach and I used it as crossflow fan for quite a time. It´s made of metal and it´s possible to keep the motor out of the heated zone. Ideal solution. I think this type of fan is also used in kitchen ovens, but not 100% sure. On the package it says it´s actually made for heat management. Perfect.

4) Safety switch, which automatically switches off the whole printer, if the temperature inside the chamber is higher than 120°C.

Building this solution requires working with 230V mains. All on your own risk. I won´t take any responsibility. Don´t do it if you do not have the required skills and knowledge. Safety first!

Won´t fit into a standard Ultimaker, but maybe an inspiration. Also be carefull with the material for your enclosure and also the one the Ultimaker itself is made of. It might catch fire! Especially if you have an Ultimaker original made of wood.

Hope this gives you an idea.

All the best,

Philip