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Trick Laser Aluminum spreader having the opposite effect?

Posted: Tue Feb 02, 2016 7:41 pm
by shentheory
So it just came in the mail yesterday - pulled off the glass and cleaned it, put the heat spreader on the HBP and clamped the it down with the glass on top. To my utter surprise it's actually taking MORE time to heat up.....
With a goal of 100c, it's taken about 10min to go from 80c to 85c. I live in Atlanta and it's so currently the ambient temp is not an issue at all. It get's up to 60 in about the same time as without one, but once it has to climb high for like ABS temps, it's significantly slower. I feel like i'm taking crazy pills :P am i missing something? seems like taking it off would almost be better. any help/tips/advice would be appreciated.

Re: Trick Laser Aluminum spreader having the opposite effect

Posted: Tue Feb 02, 2016 7:47 pm
by IMBoring25
Yes, a heat spreader will slow heat-up. It's more mass that has to be heated to temperature. The point of the heat spreader is to make the temperature distribution across the bed more even.

Re: Trick Laser Aluminum spreader having the opposite effect

Posted: Tue Feb 02, 2016 7:52 pm
by Xenocrates
You've added additional thermal mass without adding more power. So it takes longer to heat. The point of a heat spreader is the even out your surface temperature, which allows you to get consistent adhesion at potentially a lower temperature. If you want faster heating, go ahead and add a towel to the top while you warm the printer, or use an enclosure/heatgun/heatlamp/higher voltage supply

Re: Trick Laser Aluminum spreader having the opposite effect

Posted: Tue Feb 02, 2016 8:55 pm
by Outsider
Mine takes a bit longer to heat up also. I much prefer that to the un-even heat distribution that I had before. I have a PEI coating on my aluminum. I am printing PETG at 230 and the heat bed is set to 80 now. I have not had a single bed adhesion failure since I installed the disk. Before that I had a couple of cold spots that would always let go.

Re: Trick Laser Aluminum spreader having the opposite effect

Posted: Tue Feb 02, 2016 9:50 pm
by bvandiepenbos
shentheory wrote:So it just came in the mail yesterday - pulled off the glass and cleaned it, put the heat spreader on the HBP and clamped the it down with the glass on top. To my utter surprise it's actually taking MORE time to heat up.....
With a goal of 100c, it's taken about 10min to go from 80c to 85c. I live in Atlanta and it's so currently the ambient temp is not an issue at all. It get's up to 60 in about the same time as without one, but once it has to climb high for like ABS temps, it's significantly slower. I feel like i'm taking crazy pills :P am i missing something? seems like taking it off would almost be better. any help/tips/advice would be appreciated.
yes, it will heat up slower, but like others already mentioned, the entire print surface will be more even which helps print adhesion.
It would be a good idea to do a PID auto tune for the heated bed now that you have heat spreader, that might help heat up a bit. At the very least PID tune will keep temp more stable.

My experience has been the heat spreader makes my machines heat up a bit quicker, although one machine is running at 13.8 volts and the other is 24 volt, that may be why?

The heat spreader has a plastic film on one side, make sure that side is down against hpb.

If your machine has a "meanwell" type psu instead of a ATX psu I would turn up the trim pot to up the voltage from 12 volts, you can probably get around 13.4 volts. Even the small increase in voltage will help reduce heat up time.
Measure the voltage before and after you adjust it, just for reference.
Note: If you do increase voltage you should PID tune the hot end also.

A towel does help, or a large glass lid from a cooking pot works good.

Re: Trick Laser Aluminum spreader having the opposite effect

Posted: Wed Feb 03, 2016 7:44 am
by Eaglezsoar
bvandiepenbos wrote:
shentheory wrote:So it just came in the mail yesterday - pulled off the glass and cleaned it, put the heat spreader on the HBP and clamped the it down with the glass on top. To my utter surprise it's actually taking MORE time to heat up.....
With a goal of 100c, it's taken about 10min to go from 80c to 85c. I live in Atlanta and it's so currently the ambient temp is not an issue at all. It get's up to 60 in about the same time as without one, but once it has to climb high for like ABS temps, it's significantly slower. I feel like i'm taking crazy pills :P am i missing something? seems like taking it off would almost be better. any help/tips/advice would be appreciated.
yes, it will heat up slower, but like others already mentioned, the entire print surface will be more even which helps print adhesion.
It would be a good idea to do a PID auto tune for the heated bed now that you have heat spreader, that might help heat up a bit. At the very least PID tune will keep temp more stable.

My experience has been the heat spreader makes my machines heat up a bit quicker, although one machine is running at 13.8 volts and the other is 24 volt, that may be why?

The heat spreader has a plastic film on one side, make sure that side is down against hpb.

If your machine has a "meanwell" type psu instead of a ATX psu I would turn up the trim pot to up the voltage from 12 volts, you can probably get around 13.4 volts. Even the small increase in voltage will help reduce heat up time.
Measure the voltage before and after you adjust it, just for reference.
Note: If you do increase voltage you should PID tune the hot end also.

A towel does help, or a large glass lid from a cooking pot works good.
If you use the whole pot you can cook some crabs while waiting! :lol:

Re: Trick Laser Aluminum spreader having the opposite effect

Posted: Wed Feb 03, 2016 10:19 am
by barry99705
Eaglezsoar wrote:
bvandiepenbos wrote:
shentheory wrote:So it just came in the mail yesterday - pulled off the glass and cleaned it, put the heat spreader on the HBP and clamped the it down with the glass on top. To my utter surprise it's actually taking MORE time to heat up.....
With a goal of 100c, it's taken about 10min to go from 80c to 85c. I live in Atlanta and it's so currently the ambient temp is not an issue at all. It get's up to 60 in about the same time as without one, but once it has to climb high for like ABS temps, it's significantly slower. I feel like i'm taking crazy pills :P am i missing something? seems like taking it off would almost be better. any help/tips/advice would be appreciated.
yes, it will heat up slower, but like others already mentioned, the entire print surface will be more even which helps print adhesion.
It would be a good idea to do a PID auto tune for the heated bed now that you have heat spreader, that might help heat up a bit. At the very least PID tune will keep temp more stable.

My experience has been the heat spreader makes my machines heat up a bit quicker, although one machine is running at 13.8 volts and the other is 24 volt, that may be why?

The heat spreader has a plastic film on one side, make sure that side is down against hpb.

If your machine has a "meanwell" type psu instead of a ATX psu I would turn up the trim pot to up the voltage from 12 volts, you can probably get around 13.4 volts. Even the small increase in voltage will help reduce heat up time.
Measure the voltage before and after you adjust it, just for reference.
Note: If you do increase voltage you should PID tune the hot end also.

A towel does help, or a large glass lid from a cooking pot works good.
If you use the whole pot you can cook some crabs while waiting! :lol:
Aww, man. I have a hard enough time boiling water on my stovetop! :D