Strongarm Walking Foot Sewing machine User Manual page 22

If the distance is out, then loosen the set screw on the drive collar using a small, high quality
screwdriver, set the bar to 16mm, then tighten the set screw firmly. Make sure you don't rotate
the needle bar as you adjust it.
Remember the needle must be in its lowest position when you check the height.
Another way to check needle bar height is to put the machine on its back and remove the
retaining ring from the bobbin system. Turn the balance wheel until the needle is just coming
up from its lowest point and the tip of the hook is just in line with the needle. Now measure
the distance between the top of the eye of the needle and the tip of the hook. The distance
should be less than 1 mm.
distance should be
16-17mm
less than 1mm