Polyimide Heater Comparison

[@DWIT3D]

That is very surprising... great comparison and a good indicator to raise bed temps higher than we might think for the standard heater to obtain "real" temperature required!

[@MapleLeafMakers]

either that, *OR* you never really required those higher temperatures in the first place, depends how your prints are coming out now I guess :D

[@3dexperiments]

Very interesting results, I did not expect there to be that much difference.

[@MapleLeafMakers]

Neither did we

[@Mehecanogeesir]

It makes sense - the thermistor is deeper into the plate, so it measure the temperature closer to the surface. Thus, instead of heating the bottom of your bed to 100C and waiting/hoping for the best, this sensor lets you know when your entire plate is reaches 100C. Meaning the bottom of the bed must be greater than 100C at the time of meeting the desired bed temperature. I would be curious how far above 100C it goes (if it truly does, I'm just speculating), and how it would compare to a larger bed like a 350mm Voron. Thanks for the video about a new advancement!

[@MapleLeafMakers]

We're looking forward to seeing larger heaters of this style too. Not sure how far (if at all) the heater overshoots the target temperature, maybe we'll check this out in a follow up video

[@Mehecanogeesir]

@@MapleLeafMakers Thanks so much! I'm looking forward to more about this as well. I believe in Mainsail, it shows how much power the heater is applying to the bed as a percentage. If the firmware is only lowering the percentage after heating up vs gradually lowering the percentage as it nears the target temperature, I would think it'd overshoot. Which leads to my curiosity about larger and thicker beds for safety reasons. Best wishes!

[@chadblows]

That's a crazy difference

[@MapleLeafMakers]

It sure was. Thanks for watching!

[@nhchiu]

Thanks for the great video and showing the results so clearly! Sorry I have two questions: 1. Is the printer enclosed during the 15min heat soak process? 2. Do you think it's the type of heater that make such huge difference or it's simply the position of the thermistors? Thank you!

[@MapleLeafMakers]

1. The printers weren't fully enclosed. panels were on, and doors were closed, but the tophats were off. 2. I think it's mostly the thermisor placement. We have a regular silicone heater with a similar screw-in thermistor in the LDO Trident 250 Kit and look forward to testing that theory.

[@yusky03]

If you heat it up too fast the bed will warp. That is why the 100w heater on a spec voron is limited to 60% duty cycle. "#max_power: 0.6 # Only needed for 100w pads" I am sure the situation would be worse with a thinner than spec bed. On the v2 it states... "## Adjust Max Power so your heater doesn't warp your bed. Rule of thumb is 0.4 watts / cm^2 ."

[@mashiori9020]

I'm still running the 150w 220v heater on my 6mm bed from the 0.0 to 0.1 upgrade and bed is doing just fine, hopefully it goes to 0.2 without much issue

[@thePavuk]

I would believe that it's for normal sized beds, not these small. 120mm of 8mm aluminum wouldn't bend so much.

[@Invaderjason123]

Would be interested to see this for a 2.4 as the 10 minutes or so wait for bed to reach 110 can be a bit annoying sometimes.

[@MapleLeafMakers]

A very quick and non-scientific test says the 300mm bed fares a little better, but still close to 10 degrees below the target.

[@marcosramirez385]

I have a keenovo 100w heater with a ssr on my v0 with a mandela buildplate that someone sujested I lower to 60w in klipper.

[@MapleLeafMakers]

it's a popular rule-of-thumb to keep the heater wattage at or below 0.4W / cm^2 to avoid potentially warping the bed. I have never seen bed thickness mentioned along with this number, and a thick bed should be more resistant to warping. We haven't noticed any effect after a dozen or so heating/cooling cycles, but of course your mileage may vary.

[@nathanielhudson6574]

@@MapleLeafMakers I'd really love to see somebody test the 0.4W / cm^2 theory. I've heard it said as fact many times, but haven't actually seen any actual data. What happens if you give a bed a full watt per cm^2 and cycle it over and over? Do we see warping?

[@MapleLeafMakers]

Good idea!

[@deathcube2006]

I know it would be really expensive, but I would love to compare to nickel plated copper heatbed, much more thermal mass than aluminium

[@MapleLeafMakers]

Oof that would be neat but very pricey indeed....

[@Zettymaster]

i mean, why the nickel plating? we ARE going to put a heater and magnet foil on it anyways, so everything that would matter just needs to be cleaned before assembly

[@ZenExMachina-dl2zt]

I have one in an LDO V0.2-S1 kit that I am building. How would I go about collecting data in a way similar to what you presented with your graphs?

[@MapleLeafMakers]

We just put a piece of non-reflective tape on the bed surface and hit it with an infrared thermometer -- Set the bed to 100C and start a timer.

[@troyj3292]

The dilemma I see is managing printer profiles if one bed is actually 20C lower than another if you have multiple printers.

[@MapleLeafMakers]

Ya we deal with it constantly switching between various sizes / printer configurations. Profiles help.... mostly....

[@Sttreg]

Wait, so you are telling me when the thermistor read 100 on a normal bed, it isn't even close to that on the surface? That's huge, and could explain a lot of adhesion issue. Heating the bed first and then the tool head isn't enough as you showed with your time measurement.

[@MapleLeafMakers]

That's exactly what this test demonstrated! We were as surprised as you!

[@Zettymaster]

so what we learned is: 100W is more then 60W... shocker i know having the thermistor at the place that actually needs the heat makes it report the correct temp. again shocker. in all seriousness though, i would love it if keenovo just had a hole in their heaters and we could thread a thermistor in the middle

[@MapleLeafMakers]

The good news is that the latest trident kit we got from LDO had the hole you are talking about! The bed is even tapped for one of these thermistor's. Hopefully more manufacturers embrace the idea!