alternate source for 12x12 kapton film heaters

[Frank]

I could swear I saw a posting for an alternate source for 12x12 kapton film heaters similar to the ones used on the A1.
I've searched here, but couldn't find it..
I have a spare for the original 12x12 heater, but I'm looking for one that has a little higher resistance to keep
from overloading the power supply..

Frank Pirz
Media Conversions LLC

[Rick H]

I have been looking for the 200 watt heaert replacement for a while.  I have several 400 watt samples. I would be glad to trade for some 200 watt versions. 

[RepRapper]

Hey guys, 

i can offer you silicone- or kapton heaters for A1 with 24V or 230V. Those are High Quality replacement. i recommend silicone. 

If you are interested, feel free to send me a mail. 

[Frank]

First: A question I was going to ask at the end of this note.
Is there a preference for Polyimide (kapton) over Silicone in a heater?
personally I like the kapton heater. I'm backing up the one I have now
with 2 1/8in thick layers of pellet stove gasket. the first layer gets carved
up to accommodate the wiring, the second provides a full layer of insulation
between the heater & the bed. The silicon rubber heaters (see below)
that I bought are a lot thicker than the kapton ones TL supplied.
it's going to make my bed assembly even thicker. not something I really want to do.

I sort of answered my original question. my starting point was reviving my search for an 8x16 bed heater:
qubd - http://store.quintessentialuniversalbuildingdevice.com  - look under heated beds
http://store.quintessentialuniversalbuildingdevice.com/category.php?id_category=19
I chose to use 2 of their 12v Silicone Rubber Heater Bed 200mm x 200mm (8"x8")
http://store.quintessentialuniversalbuildingdevice.com/product.php?id_product=61
I used two of them in series to driven by a 24v supply. power consumption & current
are within limits for the smoothie board controller and the PSU. (24v 17a = 408W)

So I went back to qubd to see what they had for 12x12.
24v Silicone Rubber Heater Bed 290mm x 290mm (12"x12")
http://store.quintessentialuniversalbuildingdevice.com/product.php?id_product=60
would seem to do what is needed in an A1 without exceeding the power supplies rating.
at $60 + shipping it's a bit expensive, and although advertised as 12x12
it's really 11.5x11.5 and I need to be able to print out to the edges.
[it's why i was designing a 8x16 printer...]

In an earlier note (now lost) someone suggested heated beds from aliexpress.
with the further suggestion to search for both silicone & polyimide heater
Kapton is a brand name so polyimide will net more searches.

searching for: "silicon rubber heater 24v 300mm" [also check the "1 piece" box]
turns up 9 matches (not all are square and several are from the same vendor)
[search for "24V 300W Silicone Rubber Heater Bed 300MM x 300MM" ]
with price points of $20,$28 and $35 with shipping between $15/lot and $18/lot
I could get 2 of the $20 units shipped to me for $58 (cheaper than the qubd unit!)
[2 because if works as advertised I'm going to retrofit the other one to my original printer #45]
Rick H - 200w will take a lot longer to heat up.. 300w is within the capabilities of the A1's PSU..

I'm not happy about having to use silicone rubber instead of kapton, so I searched
again for polyimide heaters using "polyimide heater 24v" I got  34 results
but none that were 300mm square. I did find one that was 100mmx300mm
[search for 300mm*100mm Polyimide film Heater 106W 24V]
I could run 3 of them in parallel to get a 318w 24v heater. they are $20 @ with free shipping.
I also searched for "polyimide heater 12v" but nothing showed up in the right size & wattage.

searching for "3d printer bed heater 24v" gets 199 results, the most promising is
"24V 300W  Heated Bed Plate" - which nets a 300x300 silicone heated bed 24v 300w
for the reprap/prusa/mendel - similar to the one above.
you can also find "Reprap TAZ 5/TAZ 4 LulzBot TAZ 3D printer 24v Silicone Heater 360W 24V "
which is slightly more (20%) power and closer to the PSU limits...

SO..back to the question I started with..
am better off using 3 kapton heaters pieced together or a single silicon rubber heater???
why are there always so many choices???

[Glenn Beer]

I have one of the silicon rubber heaters, works fine. That it is 1/2 inch smaller isn't a problem. 

It works out to being 1/4" smaller all the way around. And you need some space around the edges for mounting the glass anyway.