Just got a new Power Expander from Denmark. Looks like all the components is on the board this time 
After dinner im gonna test it out.
Works 
First picture is just a plate picture from top 
i like that the plate have rounded corners. Was one of many requests i had. dont like the mk3 normal plate that have a sharp corner.
Second picture is how i did the mounting. I found a very special Loctite glue for plastics among other things that could take alot of heat and is working very nice dont need to make a big blob it is sitting there like a beer in my hand.
Last picture is well my solution for a Quick release. and how i solved where to place my Electronics. Power and wires for the termistor on the same Cable. The Epcos NTC 100k termistor is soldered smack in the middle of the plate bottom side.
In the back you see the Vertex PSU. In the front i have placed a 24V 340Watt PSU from Meanwell. Between the 2 i have a Electronics box that i made with the Power expander and 2 LM2596’s in. As you can see i have reused the original fan hole sins i have the fan placed more directly on the controller board.
First test : It took 45 sec to reach 50C and 3,33min to reach 100C i looked with a thermal cam that i borrowed to see how even the heat is and it looks very even over the plate wish is nice.
Did the math for the plates. They will end up at $41 + shipment. Close to the double ($16,8) of what a mk3 plate from reprap.me goes for. Well considering i didnt order a huge quantity. Just 10 plates as a first test i think it is fairly ok. Wish it would have been possible to order a larger amount but sins i dont know the demand and other things. I might aswell put my finger up and see where the wind blow 
If i could have come up to 200 units the price tag would have dropped like a stone and not be totaly far from what the plates goes for at reprap.me.
Marlark, from where do you ship these heated beds? Can I contact you outside of the forum?
Erik
Im located in Höör, Sweden. and you can reach me at teddyhq at hotmail dot com
The first plate have been sold this morning to Eero so going to ship that so he should have it tomorrow.
@Raby : Didnt notice your question until now so i just messured the resistance on the 12V and 24V circuit on the plates for you.
24V = 2.6 Ohm
12V = 1,5 Ohm
[quote=“Marlark”]@Raby : Didnt notice your question until now so i just messured the resistance on the 12V and 24V circuit on the plates for you.
24V = 2.6 Ohm
12V = 1,5 Ohm[/quote]
Thanks. It means you’ll need about 220W in 24V and only 100W in 12V which respectively is more and less than the original MK3. As the bed is larger, I would have expected a higher resistance : are the tracks wider than in the original design?
They are a litle wider but not much you can almost not see the dif. You dont happen to know a formula for calculating heating time. was considering the time to heat if using 24V on the 12V path. I read on the reprap forum that it would take less time to heat up on a normal mk3 bed doing that.
If i havent already said it … anyone that want one can now send me a email on teddyhq at hotmail dot com. I have been looking up shiping costs today so now i know what the local post company in sweden wants in term of fee’s.
[quote=“Marlark”]was considering the time to heat if using 24V on the 12V path. I read on the reprap forum that it would take less time to heat up on a normal mk3 bed doing that.[/quote]Indeed but it will suck 16 A (almost 390W) from the power supply ! And your reaching the limit of the Mosfet (20A). You’ll also need to recalibrate the PID to avoid too much overshoot. And use 2.5 mm² wires.
An original MK3 takes about 2 minutes to reach 50° and 5 minutes to 90° with a power consumption of about 140W/24V. At 220W/24V it should already take less time.
Well i did time it to 45 sec to reach 50C and 3,33min to reach 100C with the setup i use atm. So i should be very happy then
Besides, the Power Expander (buy it at reprap.me?), what power supply do I need?
I’m not an electronic expert…
Should I:
- Replace the existing 15v power supply with a more powerfull one
Besides driving the printer, I have the IKEA LEDs running directly on it,
and a voltage convertor (15v -> 5v) to power the RaspberryPi - Add another power supply (???Watt, 12/24volt?)
Thanks for your inputs!
Erik
Got your bed Erik?
Probably best to put in another PSU. Your going to need it. I use a 24V 340W wish is a litle overkill but on the other hand i have a litle leftover i can use for something else in the future. Think there is in a previus Post convo with Raby that you need a minimum of 220Watt on a 24Volt PSU for this bed.
There is Another thing that could be used if you dont want to go for a PE and that is a solid state relay. I Think Eero is using that for his setup. Dont think it realy matter wish of the 2 you go for. (Example : Solid state Relay link)
Best Regards
Marlark
Not yet Marlark, but I’m trying to see what else I need to buy so I am prepared when it arrives :).
Prices seem about the same for the extra PSU so I’ll order this url=http://meanwell.nl/products/Meanwell-SP-320-24—PSU-enclosed-24V-13A__SP-320-24.aspx[/url] 320Watt from Meanwell too.
Thanks for the valuable and quick feedback!
Erik
On 12V you will need 90W
On 24V you will need 221W
That’s the minimum I calculated with the resistance Marlark supplied. 250W would normally do the job for 24V, but 320W will be as good, just more exspensive
Hi Marlark,
I’m also interested to buy one. I have send you a email
Yupp you got an email in return Have still a couple left.
Marlark,
After reading the wiki, and searching around, the one thing i dont understand is where the thermistor goes and how its connected to the motherboard. Would you mind showing a pic or two of that?
Thanks