Heat bed

[Gotrek]

My heat bed does not seem to be able to go higher than 79F so the ABS does not want to stick to the bed

[Toy]

Generally, the hotbed can be heated up to 70 ℃ in about 2-3mins, and it will takes a long time to reach higher temp.
And here is a post about the hotbed temp, hope it's helpful:
http://www.geeetech.com/forum/viewtopic ... 163#p29163

[ADVALL]

It is likely you bed is out of specification. The cold resistance specification is 1.0 to 1.2 Ohms and if higher than this you bed cannot draw enough current to reach ABS temperatures. A common failing even of new beds!!!!!!!