plunge depth with pycam

Hi , sorry if ive posted this in the wrong area. Spent ages getting the Gravograph Vx86 working, finally did it with help of the guys on this forum, done a couple of nice engraves, noe want to take it a step further.
The collet takes 1/4" tools , so im using a 3mm router and in trying to produce some 5 mm deep bezels for a flight sim that im working on.
Anyway i have a stl model , thats fine and pycam.
now i setup pycam to do its thing and have set the model -5mm below the axis, but once i have loaded the g code into my machine and touched down on the surface the toll moves up , then to the start point , then plunges 5mm down into the material! and it doesnt like it.

Ive set move model z to -5.00 and max step down is 0.5mm .
and its still doing it, whats going wrong ?
any ideas please ive contacted the pycam site but have had no response that makes sense!
i need it to machine surface down , not plunge then cut.

set the model to be at 0.0 rather than at -5 i would think
the top surface should be set at 0 , and then the full depth of cut would be -5.0mm in 0.5 steps

in pycam under gcode make sure you have touch off on startup ticked
and a safe height of a positive value ( default is 25.0mm)

if you can post your ngc file if you have problems we can see whats going wrong

never spotted that thanks, ill give a go tomorrow, slight hurricane force winds blowing out there tonight so stay in stay warm and have a beer!

well tried it with the touch off on startup ticked.
and it was higher than before, so i moved it back down 5mm and then the bottom of the model was on the touch off point , also i got this action will take it out side the z and x work area.

it needs to come down an extra 5 mm so i may just set the shift to -10 . just got back from this and its still wrong!
ive got to recheck what ive done again , but the damn drive belt has gone at the mo so i need to replace that, rubbish its only lasted 20 years!