SD4 Heatbed Installation (Page 2 of 3)

Cork Tile is cheap and easily shaped to preference.  I may use the glue idea (I have gorilla glue so that'll be my glue of choice).

http://www.amazon.com/gp/product/B0018D … &psc=1

Try an office supply store...Staples or Office Depot.

I'm not so sure cork is such a good idea.  One of the main reasons I started this mod was because the SD4 aluminum bed wouldn't stay flat causing poor conductance to the glass plate.  I am using 3/8" CE Phenolic which is great but am discovering it is almost impossible to keep the PCB heater flat when attached via the corner screws.  The board started with the corners a bit high so I thought the screws would easily pull them down flat but finding that is not working too well - the cork is too soft and doesn't keep it planar.  I think I am going to remove the cork and attach directly to the backboard via heavy-duty 3M double-sided tape.

You'll still be putting glass over it, correct?

You might just try not having the bed home before a print. No matter what there is a risk of the hotend snagging because the distances are so short. I drop mine 10mm before the print head moves.

Did you put that code in the g-code start section of repetier?  Can you share the code?

I purchased an 80A SSR because that and the 25A versions were the only ones designed for 12V (for some reason the 40A & 60A by the same manufacturer (Mager) only go down to 24V.  However, I learned that the FET on the Prinrboard can easily handle the 10A used by the heater so I just replaced the connector and called it good.  Seems to work well enough.  Still took 20 minutes to reach 100C and see 20C lower at the corners.  Kicking myself for not taking an IR image of the stock but with the 6" lower wattage heater I am sure it had to be worse.

Some people here and there told me I can connect directly to the board no problem and it is just slower heating that way, then someone I think at reprap.org linked to a thread where the Printrboard creator was saying yout shouldn't go over 7A for the heatbed connector.
I'll try to find the link.
EDIT: Here it is: http://www.printrbottalk.com/forum/view … 299#p53542

That doesnt look like good even heating, which is weird for a MK2.
Here are similar thermal images here: http://www.soliforum.com/topic/2230/the … ed-setups/

BTW, have you ran a pid tuning after replacing the heatbed?

I am curious to see IR images of the silicone heat pads on mcmaster versus the MK2 now. The MK2 looks like it's performing kinda ok. I think your heat up times should be much faster than 20 minutes from what I've heard, though.

After looking a bit closer, I think my results are actually quite similar.  I am seeing 20C delta on all but the standard SD3 bed and QU-BD+ceramic tile in the report.  I am no worse then that - it just looks worse in my image because I am using a different color scale.  Looks to me that the heater on bottom (standard SD3) provides the best uniformity (15C) thanks to the aluminum spreader but suffers only from flatness and heatup time.  Maybe I should stick with aluminum (but maybe thicker to help avoid warping) and find a higher power heater to help with the heatup time.