I got tired of waiting forty or more minutes for my PCB heated bed to get to 110, so I decided to do something about it. I went to the home improvement store and got a 8mm x 300mm slab of granite and asked them to cut it to 200mm square. (I actually had to ask them to cut it to 7-7/8" because you say mm and they just give you a dumb look.) When I got home I put it on my smooth top stove (which has a burner big enough to accommodate this) and heated it to 150, using my IR thermometer to measure the temp. I removed it with a set of pliers, set it on a board for transport, gently laid it on my naked bed, and turned the bed on. I held my glass about an inch over the stone and slowly lowered it to the surface of the stone to give it time to heat up without busting. Within ten minutes my bed was at 110. I slid the glass back until it was offset from the stone about an inch, lifted one end of the stone with a knife, grabbed it with a pair of pliers, and slid it out from in between the stone and the glass being sure note let the glass crash down onto the bed. Clipped the clips and I was ready to go. https://reprap.org/forum/read.php?4,230266,230266#msg-230266 Tue, 14 Jul 2026 21:56:39 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?4,230266,231694#msg-231694 https://reprap.org/forum/read.php?4,230266,231694#msg-231694 The heater pad is a mains powered silicon pad with the 100K thermistor built in.
The Mosfet that normally controls the power to a 12 volt pad is used to operate a solidstate relay. The solidstate relay switched the mains power on and off as needed.
Very simple upgrade, uses a lot less power from the 12 volt supply so there is ample power for all the other 12 volt items.]]> regpye Reprappers Thu, 01 Aug 2013 05:17:52 -0400 https://reprap.org/forum/read.php?4,230266,231006#msg-231006 https://reprap.org/forum/read.php?4,230266,231006#msg-231006 bryanandaimee Reprappers Mon, 29 Jul 2013 23:24:19 -0400 https://reprap.org/forum/read.php?4,230266,230964#msg-230964 https://reprap.org/forum/read.php?4,230266,230964#msg-230964
Like the second PCB idea, hadn't arrived there yet. They are rather cheap. Been considering witching to AC right out of the wall, but just don't like the idea. I might be willing to do it with the second one since it would be removed for printig and away from the printer.

I guess I will either have to switch my i2 to single plate bed with PCB standoffs or put up with it until I get around to implementing the i3 upgrade I have sitting in wait. But, I just fixed about four issues with one fix and my i2 is running pretty damn good now. I was upgrading to i3 to solve some of those issues.]]> appdev007 Reprappers Mon, 29 Jul 2013 19:56:39 -0400 https://reprap.org/forum/read.php?4,230266,230944#msg-230944 https://reprap.org/forum/read.php?4,230266,230944#msg-230944 -------------------------------------------------------

> Or even better, a heat lamp, a hot air gun and a
> space heater all at once. Hmm, maybe a fresnel
> lens matched to the heat lamp. Perhaps just a
> second HBP board that you could lay on top to
> speed the heating and then take off for printing.
> Propane torch anyone?

Acetylene! Acetylene! That's what I use when I want lots of heat fast. :)

BTW, drilling a hole horizontally into the granite might make it easier to pick up.]]> Yvan Reprappers Mon, 29 Jul 2013 18:03:38 -0400 https://reprap.org/forum/read.php?4,230266,230903#msg-230903 https://reprap.org/forum/read.php?4,230266,230903#msg-230903
I wonder if appdev007 could get similar results with a hair dryer or hot air gun without the hassle/danger of carting a hot slab of granite around.

Or even better, a heat lamp, a hot air gun and a space heater all at once. Hmm, maybe a fresnel lens matched to the heat lamp. Perhaps just a second HBP board that you could lay on top to speed the heating and then take off for printing. Propane torch anyone?]]> bryanandaimee Reprappers Mon, 29 Jul 2013 15:21:16 -0400 https://reprap.org/forum/read.php?4,230266,230846#msg-230846 https://reprap.org/forum/read.php?4,230266,230846#msg-230846 bryanandaimee Reprappers Mon, 29 Jul 2013 11:59:35 -0400 https://reprap.org/forum/read.php?4,230266,230676#msg-230676 https://reprap.org/forum/read.php?4,230266,230676#msg-230676
Maxx, wow, five units is a very low number. If the price is not crazy that is not bad at all. Maybe I should call this guy...]]> Yvan Reprappers Sun, 28 Jul 2013 21:57:52 -0400 https://reprap.org/forum/read.php?4,230266,230604#msg-230604 https://reprap.org/forum/read.php?4,230266,230604#msg-230604 Maxx Mayhem Reprappers Sun, 28 Jul 2013 15:15:17 -0400 https://reprap.org/forum/read.php?4,230266,230535#msg-230535 https://reprap.org/forum/read.php?4,230266,230535#msg-230535
I put an insulator on top of my bed while preheating too. Its a cloth diaper!

I will check my ohms, from the end of the wire, but I used large guague speaker wire and it will prob add a little bit of resistance.]]> appdev007 Reprappers Sun, 28 Jul 2013 09:55:32 -0400 https://reprap.org/forum/read.php?4,230266,230438#msg-230438 https://reprap.org/forum/read.php?4,230266,230438#msg-230438 -------------------------------------------------------
> The bad news,
> he really is not interested in selling only one. I
> told him I want a 3-5 minute time to 120C. I
> should have a price next week.( I was up front
> with him that the second machine will not be out
> by next month. )

So what is his minimum quantity?]]> Yvan Reprappers Sat, 27 Jul 2013 23:27:37 -0400 https://reprap.org/forum/read.php?4,230266,230407#msg-230407 https://reprap.org/forum/read.php?4,230266,230407#msg-230407
i turn on preheat, when i set up parts on board, slice them few minutes and it start to run..

i have few sheets of paper under heated, warmup time alot faster with some isolation under bed]]> woo Reprappers Sat, 27 Jul 2013 17:49:18 -0400 https://reprap.org/forum/read.php?4,230266,230405#msg-230405 https://reprap.org/forum/read.php?4,230266,230405#msg-230405 You do have to make sure that you take the cover off before starting to print though.
Mike.]]> leadinglights Reprappers Sat, 27 Jul 2013 17:42:21 -0400 https://reprap.org/forum/read.php?4,230266,230364#msg-230364 https://reprap.org/forum/read.php?4,230266,230364#msg-230364
Anyone else have those numbers for their PCB bed?]]> Yvan Reprappers Sat, 27 Jul 2013 13:22:40 -0400 https://reprap.org/forum/read.php?4,230266,230360#msg-230360 https://reprap.org/forum/read.php?4,230266,230360#msg-230360 It the pad itself heats up in a few seconds and can go above 170C, so I installed a thermal fuse for safety. The setup from bottom to top: insulation, heating pad, 1/8" 6061, borosilicate glass topped with PET.]]> stephenrc Reprappers Sat, 27 Jul 2013 13:11:40 -0400 https://reprap.org/forum/read.php?4,230266,230349#msg-230349 https://reprap.org/forum/read.php?4,230266,230349#msg-230349 Maxx Mayhem Reprappers Sat, 27 Jul 2013 12:33:45 -0400 https://reprap.org/forum/read.php?4,230266,230344#msg-230344 https://reprap.org/forum/read.php?4,230266,230344#msg-230344 sheck626 Reprappers Sat, 27 Jul 2013 12:09:16 -0400 https://reprap.org/forum/read.php?4,230266,230343#msg-230343 https://reprap.org/forum/read.php?4,230266,230343#msg-230343
My PCB Prusa Mk2 bed takes about 15 minutes to reach the same 105-110°. Odd that there is so much variation?]]> Yvan Reprappers Sat, 27 Jul 2013 11:54:05 -0400 https://reprap.org/forum/read.php?4,230266,230266#msg-230266 https://reprap.org/forum/read.php?4,230266,230266#msg-230266
I went to the home improvement store and got a 8mm x 300mm slab of granite and asked them to cut it to 200mm square. (I actually had to ask them to cut it to 7-7/8" because you say mm and they just give you a dumb look.) When I got home I put it on my smooth top stove (which has a burner big enough to accommodate this) and heated it to 150, using my IR thermometer to measure the temp. I removed it with a set of pliers, set it on a board for transport, gently laid it on my naked bed, and turned the bed on. I held my glass about an inch over the stone and slowly lowered it to the surface of the stone to give it time to heat up without busting. Within ten minutes my bed was at 110. I slid the glass back until it was offset from the stone about an inch, lifted one end of the stone with a knife, grabbed it with a pair of pliers, and slid it out from in between the stone and the glass being sure note let the glass crash down onto the bed. Clipped the clips and I was ready to go.]]> appdev007 Reprappers Fri, 26 Jul 2013 23:31:27 -0400