After a bit of testing I discovered a couple of interesting things.
The 4mm inductive probe had a better detection range on a single sheet of thin aluminium than when I doubled the foil or used thicker foil.
I also found that you can extend the range of the probe by simply taping some foil around its end. (see image)
So I did the following...
Powered up the probe and adjusted the foil until the probe did not detect it. Next I taped the foil down at that position.
I placed a sheet of foil on a flat surface a placed a sheet of 3mm glass on top of it, I then folded the foil over the edge of the glass and trimmed it so there was a small overlap, the foil was then taped to the glass.
Next I placed a sheet of microwave cling film over the foil and taped it into place. This is to prevent the foil from possibly causing a short circuit when placing it against the heater PCB.
According to some web sites this cling film is safe to be in contact with food up to 120C so I think it should handle the heat okay.
I now clipped this onto my heater PCB. Note the glass faces up and the foil side face down against the heater PCB
This method allows the 4mm probe to be about 1.5mm above the 3mm sheet of glass. I have been using it for bed leveling and it works great.
Happy printing
Edited 6 time(s). Last edit at 05/30/2017 12:26PM by SouthT.