Isn't the main reason for getting an aluminium bed that it will be the SAME TEMPERATURE all over (on account of its great thermal conductivity)? Unlike the PCB. I think ultimaker people use a glass bed on their aluminium plate so presumably glass makes a better print surface.
I don't know if there is a "main" reason for getting an aluminum heated bed. In my opinion it is sturdier than PCB. All of my kickstarter heated beds for the micro are Aluminum heated beds. Saves on space, and I am designing it for use with PEI or Kapton tape. I really really like PEI, all you have to do with it is rough it up now and then and wipe it off with alcohol.
I have an Alu bed with kapton heater and haptic sheets on my pro1 and it is mostly ok. Mostly as abs is still painful and it needs glue or a perfectly cleaned kapton.
If you know of pei sheets .... Tell me. it can make my pro1 a real badass printer. Anyhow I have build talk sheets ... But I still have not got the courage to try them, since the first time I did I ruined it at first print (low head)
Just to update: 80° C for XT sem to be enough to get it stick to the PEI aluminium, 70° C have been too low, maybe i'll try 75° C next time...
I have to say with this PEI alu plate printing is really cool now!!! With my profiles it is like "print something? Ok, will do it" load model, slice it, upload to OctoPrint, start print. PushBullet pushes me a message when finished (I use a hacked script where the print is considered finished when the bed reaches 30° C again on cool down). I go to the printer and get the part... Next print same procedure... No bed preparation no nothing... Just printing... That is so cool. So far I have only tried XT which sticks good at the right temp...
How about ABS, and does it seem like the PEI coating will be there permanently? Or atleast worth the money?
As I told, only tried XT yet... The coating does not show wearing, but only printed about 10 prints... 50€ (including taxes) for the plate is not so much compared to other build plates, the glass is about 25€ (without taxes) plus shipping, a build tak is about 18€ but that the 304x304 and you have to cut it... So I am pretty pleased with what I got for that price, it has also the "clip step" so the bed clips are lower then the actual build plane which I perfect for your Dual Titan head design...
Well I was thinking 75 PLUS shipping.. I wish everyone would just use USD, you know because we are the best hahahaha... we suck...