Hi,
i noticed that the heatbed is not insulated at the bottom. On my mendelmax i used alot of wadding to keep the heat where it should be.
Is there someone who has already done such a thing on his mighty z ?
I would expect that the heatbed could reach the desired temperature much faster.
Hi,
i noticed that the heatbed is not insulated at the bottom. On my mendelmax i used alot of wadding to keep the heat where it should be.
Is there someone who has already done such a thing on his mighty z ?
I would expect that the heatbed could reach the desired temperature much faster.
Yes, I have. Dropped heating times by a significant margin. I used the 3mm cork pads available. Just need to trim a little.
How did you fix them to the bed ? Is cork so heat resistent ?
Thank you for the information
I think 2-3 layers of kapton tape also should insulate heat
How did you fix them to the bed ? Is cork so heat resistent ?
Thank you for the information
I just replaced the screws holding the heated bed with longer ones and used those to hold the cork bed in place. Ideally I want to get either some aluminium or FR4 cut to sandwich the cork and push it hard up against the bed. Even still, it makes a significant difference now and hangs a little.
The cork is only warm to the touch.
just now i measured the time from switching mighty z on to the start of the print.
it took about 6:30 min to heatup the bed, after 9:30 min the extruder reached it's temp
and the print started (with z-abs).
i will buy some cork and measure the time again to get some insight about the time saved !
so i did measure the time with 3 sheets of 4mm cork under the heatbed & a cold start:
after 5:40 the heatbed reached it's temperature.
after 8:30 the print started.
you can place the sheets right under the heatbed, without fixing them, they rest on the two metal arms directly under the heatbed.
you need to leave some space to be able to calibrate the platform and also cut the sheet so that the magnets & the pins are not covered.
so there is still a small gap between the cork sheet & the heatbed, but the gap was much larger when i tried
to fix the sheet using the 4 screws the heatbed is mounted on the alu plate like wilsonj suggested.
interesting result but after an initial "enthusiasm" of that being a ~12% shorter time, if you take into consideration that an average print is 4-5hrs long and many of them can be 10-30 hours long, then a 50-60sec in time saved is really very small and negligible.
BUT the insulation has another role too, so another thing that would be very useful if you were able to measure is to find one of these cheap watt meters and print twice the same let's say 5hr print, and measure what difference the insulation will cause in power consumption due to the lesser heat loss
i ordered a energy-measuring-tool & will do some tests
i did some measurements (see attached pictures).
i printed something that took me about 1:31 minutes with a cold start.
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first with 3 x 4mm cork plates under the bed:
1:31 minutes consumed 0,187 kWh
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second print, the same also with cork plates BUT i put the "hood" on (see attached pictures).
1:31 minutes consumed 0,171 kWh
within the heatup phase i kept the hood of because i have to remove filament from the nozzle
before the raft is build.
--------------
i still have to print without the cork plates & measure the consumpion
it seems that printing with a hood saves about 10% of energy.
Images:
I do not think that bottom insulation is useful because heat moves up and not down.
If you save some time heating up, you have to wait some more time to cool down the plate and remove the item.
An improvement for the heat plate would be to have a more even temperature also in the perimeter , the corners have a lower temperature that affects printing of large items.
I do not think that bottom insulation is useful because heat moves up and not down.
If you save some time heating up, you have to wait some more time to cool down the plate and remove the item.
An improvement for the heat plate would be to have a more even temperature also in the perimeter , the corners have a lower temperature that affects printing of large items.
If you don't think heat radiates from below the plate try putting your hand on it.
I have not said that heat do not radiates , I just said that it is not very useful .
Your reply is not funny , it is unusefull as isolating the plate bottom.
Take a look at the image of my avatar, I'm shure that seeing in colors you'll understand the concept.
I have not said that heat do not radiates , I just said that it is not very useful .
Your reply is not funny , it is unusefull as isolating the plate bottom.
Take a look at the image of my avatar, I'm shure that seeing in colors you'll understand the concept.
I wasn't trying to be funny!
Have you actually tried insulating the underside of your hot bed ?
I have machines with insulation and without. The one with insulation heats up quicker, period. And stays warmer longer, reducing reheating times in between prints.
As you obviously have access to FLIR equipment, perhaps you could show a picture of the top of the bed and bottom for comparison ?
I'm no physicist, but I think radiation is quite different to convection, which is what your avatar appears to be showing btw.