Hydraulic Outfeed Support

Like most small operations I run a chop saw near the garage door, but when the workpiece is long one needs an outfeed support, like a jack stand. These are available, common and cheap. Correct height is set with a setscrew jammed into a vertical tube. But to set height juuust right, to get a square cut one must lift the load with one hand, hold up the outfeed support with one hand and tighten the setscrew with a *third* hand: not easy! And every time the workpiece is a different length the outfeed support height has to be readjusted on a sloping driveway. What's needed is something that works more like a hydraulic jack, so that both hands can stabilize the workpiece and a foot can be used to 'pedal' a hydraulic lift to the correct height. Haven't seen one on the market; have any of you??

PS had a better idea the other day: am going to get a trailer tongue jack, turn it upside down and weld it to a tripod base. That way I'll have a side crank to control height; almost as good as a footpedal.