1 Topic by Photog

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Topic: safe temperature for bed on SD3?

I installed glass on top of my aluminum and kapton bed. I've found that in order to get the temp of the glass up to 105 celsius (measured by IR thermometer), I have to get the actual heated bed temp to show up as 125 celsius in Repetier-Host.

My questions:

1) Is it safe to be running the bed heater at 125 for long times? Solidoodle default config has it running at 95 celsius.
2) When it says 125 celsius in R-H for bed temp I'm actually at about 105c near the center of the glass plate, 108c at the exact center of the glass plate, and 95c near the outer edged of the glass plate. What can I do to improve the heat and make it more even throughout the surface?
3) Should I even really be using a temp this high for my glass plate? I'm trying to solve my warping issue on large prints.

FYI I tested the max and was able to get her (the heater) up to about 140 celsius before I gave up with waiting, took about 25 minutes to get to that temp. I think the newer SD3's are shipping with more powerful heated beds because I've heard of other people's only getting up to like 90 max here on the forums...

My SD3:  Clear plexiglass case, case heater, X axis stabilizer, Z axis stabilizer, thumb screws, filament guide, heatsinks on all motors, extruder fan, controller fan, heatsinks on motherboard, Y rod pillow block, USB and Power on/off switch, fully calibrated including trimpot tuning. Am I missing anything?

2 Reply by 2n2r5

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Re: safe temperature for bed on SD3?

Photog wrote:

I installed glass on top of my aluminum and kapton bed. I've found that in order to get the temp of the glass up to 105 celsius (measured by IR thermometer), I have to get the actual heated bed temp to show up as 125 celsius in Repetier-Host.

My questions:

1) Is it safe to be running the bed heater at 125 for long times? Solidoodle default config has it running at 95 celsius.
2) When it says 125 celsius in R-H for bed temp I'm actually at about 105c near the center of the glass plate, 108c at the exact center of the glass plate, and 95c near the outer edged of the glass plate. What can I do to improve the heat and make it more even throughout the surface?
3) Should I even really be using a temp this high for my glass plate? I'm trying to solve my warping issue on large prints.

FYI I tested the max and was able to get her (the heater) up to about 140 celsius before I gave up with waiting, took about 25 minutes to get to that temp. I think the newer SD3's are shipping with more powerful heated beds because I've heard of other people's only getting up to like 90 max here on the forums...



Long story short is that IR thermometer is not accurate. Use a thermocouple if you have doubts that the bed isn't the right temp. 125 is way too hot and you WILL burn out your mosfet or heated bed. With glass and hairspray you can probably get the print to stick at ~85-90 with no problems. Also, the glass will lag behind when you heat up the bed. You will need to let it heat soak for 5-10 min to come up to temp.

If you are still getting warping then try an enclosure. (cardboard box works for now)

There are a few topics on what is best getting even heat distribution. Flat ceramic tile wins out by the looks of it.

SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.

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3 Reply by Photog

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Re: safe temperature for bed on SD3?

2n2r5 wrote:
Photog wrote:

I installed glass on top of my aluminum and kapton bed. I've found that in order to get the temp of the glass up to 105 celsius (measured by IR thermometer), I have to get the actual heated bed temp to show up as 125 celsius in Repetier-Host.

My questions:

1) Is it safe to be running the bed heater at 125 for long times? Solidoodle default config has it running at 95 celsius.
2) When it says 125 celsius in R-H for bed temp I'm actually at about 105c near the center of the glass plate, 108c at the exact center of the glass plate, and 95c near the outer edged of the glass plate. What can I do to improve the heat and make it more even throughout the surface?
3) Should I even really be using a temp this high for my glass plate? I'm trying to solve my warping issue on large prints.

FYI I tested the max and was able to get her (the heater) up to about 140 celsius before I gave up with waiting, took about 25 minutes to get to that temp. I think the newer SD3's are shipping with more powerful heated beds because I've heard of other people's only getting up to like 90 max here on the forums...



Long story short is that IR thermometer is not accurate. Use a thermocouple if you have doubts that the bed isn't the right temp. 125 is way too hot and you WILL burn out your mosfet or heated bed. With glass and hairspray you can probably get the print to stick at ~85-90 with no problems. Also, the glass will lag behind when you heat up the bed. You will need to let it heat soak for 5-10 min to come up to temp.

If you are still getting warping then try an enclosure. (cardboard box works for now)

There are a few topics on what is best getting even heat distribution. Flat ceramic tile wins out by the looks of it.

Just ordered a thermocouple. FWIW, tested my IR thermometer on something outside. Weather.com reports my temperature outside as 31 degrees, my IR themometer reported 31.3 degrees. So it doesn't seem to be too far off.

Right now I'm printing with a bed temp of 110c (in R-H), and my thermometer is reporting the glass in the hottest spot is 87c.

My SD3:  Clear plexiglass case, case heater, X axis stabilizer, Z axis stabilizer, thumb screws, filament guide, heatsinks on all motors, extruder fan, controller fan, heatsinks on motherboard, Y rod pillow block, USB and Power on/off switch, fully calibrated including trimpot tuning. Am I missing anything?

4 Reply by dubbsd (edited by dubbsd 2013-12-08 14:00:44)

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Re: safe temperature for bed on SD3?

the IR gun will give a false reading do to the beam refraction of the glass.

Ultimaker S3.

5 Reply by Photog (edited by Photog 2013-12-08 08:26:07)

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Re: safe temperature for bed on SD3?

dubbsd wrote:

the IR gun will give a false reading to to the beam refraction of the glass.

Still waiting to get my thermocoupling.. but I'm still thinking the IR gun is not giving false reading. I tried lowering temps on the bed down to 85c as suggested, filament won't stick to the bed at all. Minimum temp I can get it to stick at is 95c, but get immediate corner lifting after the first couple layers and the print gets moved around. My lines are very flat too so that's not the problem. If I bump bed temp up to 105c I get less corner lift.

What's weird is that I *just* finished my enclosure 2 hours ago, and now with the enclosure I'm still getting warpage on tall prints, and now I'm getting delamination which I wasn't getting before. Thought enclosure supposed to solve that...

I'm using ABS too forget to mention. I also have Slic3r set to lower the bed temp by 5c after the first layer.

I really think for some reason the glass is just not heating up as hot as it should be in relation to the bed. My glass plate is 2mm thick.

My SD3:  Clear plexiglass case, case heater, X axis stabilizer, Z axis stabilizer, thumb screws, filament guide, heatsinks on all motors, extruder fan, controller fan, heatsinks on motherboard, Y rod pillow block, USB and Power on/off switch, fully calibrated including trimpot tuning. Am I missing anything?

6 Reply by ronsii

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Re: safe temperature for bed on SD3?

First off sticking and lifting are two different but related things... the main things that cause lifting are temperature differences... so the hotter you make the plastic the more it will cool and shrink to reach room temp...or enclosure temp, if the plastic is not sticking good to the bed it will lift sooner or later even if it looks like it is stuck on the starting layers the plastic may hardly have any adhesion to the bed then as layers progress and shrinkage starts to pull on the print the first layers will lift, the main fix for this is too ensure that you have good adhesion to the bed by 1.cleaning the bed thoroughly 2.slow the first layers print speed 3.depending on the design add a brim 4.especially if using glass,prime the bed with abs slurry(does not have to be thick even a 5 percent abs/acetone works)

Many people see upping the bed temp as a fix-all and while it may seem to make the plastic at first it has a lot of side-effects with temp deltas on subsequent layers and shrinkage which causes lifting.

The enclosure you made should help because it lessens the temp differences from the time the plastic is extruded until it reaches the case temp... however as you increase the temp inside the case it also increases the bed temp and a few other things causing other issues.

Your glass bed also acts as an insulator so you will have to let it warm up a lot more to get near as hot as the metal underneath it and even then it will not be as hot and the hotter the bed heater underneath the delta across the top will increase as well.

7 Reply by Photog

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Re: safe temperature for bed on SD3?

Ok I let my bed stay at 105c for about 35 minutes. Measured it with IR gun and the glass in the middle of the bed read 80c. Used the thermocoupling, and the glass in the middle of the bed read 63c. In R-H the temp of the bed said 105c.

My SD3:  Clear plexiglass case, case heater, X axis stabilizer, Z axis stabilizer, thumb screws, filament guide, heatsinks on all motors, extruder fan, controller fan, heatsinks on motherboard, Y rod pillow block, USB and Power on/off switch, fully calibrated including trimpot tuning. Am I missing anything?