Figured I'd post my build and get some feedback, maybe give others some ideas. This will be my first 3D printer, I'm excited to get it going.
I made a silicone insulting pad for my heated bed from a tube of silicone. I used the borosilicate glass plate I ordered on ebay for the printer as the base of the mould. Gave everything a nicer slathering of vaseline and I think it worked out pretty well. After it was done curing I took it out of the mould and siliconed the rough side to the bottom of the heat bed PCB and left the smooth side that was against the glass exposed. It took a long time to cure, about a week. I aesthetically ruined part of the smooth side that was against the glass by trying to take it out too early.
As I'm sure some of you have found out, the graphic smart controller doesn't fit nicely onto the Hadron. The rotary encoder hits the gantry, so I removed it and mounted it beside the LCD recessed far enough to clear the gantry.
For the heatbed electrical connections I needed something low profile to fit between the heated bed and the aluminum plate, but that could handle the high current. I used pins from the large 4 pin molex connectors found in computers. on the female end I stuck a Q-tip and let the shrink tube shrink around it, then pulled out the Q-tip to leave an insulated socket to stick the male pin.
For bed levelling I didn't want any wobble, so I machine some brass hardware to try and help. I used #6-32 threads because they have a major diameter of ~3.5mm, the largest which would fit through the holes on the aluminum plate. I slightly drilled out the holes on the PCB headbed to fit snugly on the brass shaft portion above the threads, so there's no play there. I also used conical springs, so that almost the entire spring is compressed, and the part that isn't compressed is on the thin end of the spring nearest to the heat bed. This makes the spring more stiff laterally and because the uncompressed area is nearest the heatbed, gives the heatbed the least amount of leverage to laterally effect the uncompressed part of the spring. I also just had them lying around and I like to convince myself that my junk parts are probably better than buying new stuff anyway. Finally clamping the bottom of the brass bolt thingies between two nuts on the plate, as the corners of the plate are slightly rounded from face to face on the ends, pulls the brass bolts out slightly towards each corner, if that makes sense. The bed can still compress, but it's very stiff and feels very solid.