So, what am I missing?

[FatFreddie]

You want the head about half the slice thickness off the table (I'm assuming sli3er has used 0 for the first layer height) - this squashes the first layer down firmly.

The head needs to go on the Z axis - I assume that was a typo :-)

You can use some masking tape to print on - maybe on some MDF - cardboard might be ok but the first layer height is quite important.

If the part is small you will need a fan (start after the first layer is finished) otherwise the build up of heat will melt the object. This can just be a desk fan or you could blow on it :-) Alternatively you should be able to tell Sli3er to dwell between layers but a fan works better. Alternatively print several objects. The problem is lost plastic oozing out during the dwell.

Good luck - when it's working it's better than watching TV :-)