Hi Bob,
Re the loss of head travel with the fitting of the gas strut, I have attached a picture of the head at its lowest position with the gas strut at the end of its stroke. It shows a 4mm std length tool fitted via a finger collet and as you can see its some way above the table, 50mm in fact. A 10mm std tool is 35 mm above and even a 10mm long series would be 15mm above.
As I mentioned previously its not a problem if the work piece is vice mounted or packed up from the table plus I would imagine it would be just about ok with a collet chuck. I used the 220-250 strut as recommended which has a 220mm stroke but I see on the SGS website the 6mm struts are also available with a 240, 260 and 300mm stroke.
I have only roughed it out in my head but it could be worth having a measure up i.e. head travel top to bottom, mounting positions for the strut top and bottom and required stroke length. It would mean an extension bracket that gives a mounting position above the head but that would be easy to do.
Just thought I would mention it in case you would prefer to keep the full travel of the head, I am going to look into changing the strut on mine.
