Heated Bed Problems

[tpulti-bt 0]

Hi there,

we finally managed to install our own version of a heated bed. Primarily we wanted to avoid the upbending problem, but unfortunately it still persists. We tried different alluminium beds (normal and sandblasted) and we tried glas but without success so far. We read something about having to use Kapton tape with an aluminium bed, but 3M Polyimide (Kapton) Tapes cost a fortune.

Does anyone here have a functional setup? If so, which material do you use at which temperature? Do you use any kind of tape? Do you extrude at a specific temperature?

Thanks for your help in advance

Regards

tpulti-bt

[dingo 0]

Hi,

Are you printing PLA or ABS?

I also had small warping with PLA, but only minimal. I printed directly on a glass plate.

For PLA you need a bed temperature of around 50° C. I print first few layers without fan, that it sticks good to the bed, then I had no more warping...

Be careful when using a fan on a normal glass plate. My glass broke this way, due to the different temperatures on the glass.

Now I use a special glass, temperature resistant to 800° C and no problems...

For ABS the bed should be around 100° C and you need Kapton that it sticks well to the bed.

Its just a trial and error thing. Test a few bed temperatures and switch the fan on/off to get a feeling.

Overall the heated bed added a very big value to my Ultimaker!

Regards

Tristan

[joergen 1]

we finally managed to install our own version of a heated bed. Primarily we wanted to avoid the upbending problem, but unfortunately it still persists. We tried different alluminium beds (normal and sandblasted) and we tried glas but without success so far. We read something about having to use Kapton tape with an aluminium bed, but 3M Polyimide (Kapton) Tapes cost a fortune.

Does anyone here have a functional setup? If so, which material do you use at which temperature? Do you use any kind of tape? Do you extrude at a specific temperature?

The recommended/consensus PLA bed temperature is 70C, fans off for the first couple of layers. Glass or kapton work pretty good, but bluetape is also OK (don't print the first layer too close (compared to cold), otherwise the blue tape gets embedded into the PLA, and impossible to remove). prints will pop off at exactly 35-40C. lower bed temper is possible, but makes it more difficult to get the first layer to stick.

ABS has a recommended bed temp of 110-120C, I prefer to start with 115C, and then drop it to 110-111C after the first 2 layers.

About glass plates breaking:

The glass plate will break if you don't take the expansion of the glass while heating up into consideration. the easiest work around is heating up the bed with glass to temp, and then attaching any clamps to hold the glass in place. if you clamp it right from the beginning, it has no room to expand other than up (buckle), and any additional stress will cause it to fail. the same applies to the coo, down phase, relief the clamps and stress first, and let it cool easy. I print on pretty thin glass panes (2.2mm), and nothing broke so far.

[tpulti-bt 0]

Ok, thanks for your answers, we'll try that. Let's see how it works out