If we were lifting something very heavy, I’d agree. However, the weight of the objects being lifted, the heaviest item is at maximum a 13" 4 jaw chuck that weighs just under 100 pounds. We’re not lifting “really heavy” objects, so our safety factor will be well up there. We’d test load it with 500# which is the limit of the winch without cable doubling, which may be done to reduce speed, which would be ~ 5X without testing to failure or ultimate strength.
Size: The jib you cited has a 80" arm with a 70" usable length or approximately 13’ 4", We only need an arm that goes from center-line of chuck mounting face to the shelf at end of lathe where we store chucks, I’d guess 48" arm would give maximum arm swing range of about 8’ 0". This is a greatly reduced moment arm and would not be swinging out over the blue work table This would extend only about 16" past edge of lathe vs 48".
The cost of the jib you show is ~$1,000 + $250 shipping and that’s without the trolly or the electric hoist, so call it $1,550 total.
We can fabricate, we are a Markerspace, we have more than a few engineers or engineering students that could do a statics moment arm calculation on a 4" I-beam, 150# load at 48". Or at the very least point out we’re doing something very wrong. Using Tim’s suggestion which is conceptually close to what Frank Lima and I discussed, for less $500 plus shipping: Trolly $20, Hoist $30 = $550 total or saving about $1000, but say there’s about 50% error in that SWAG (which would all being the metal cost, other components know cost) and it costs $750, still saving $750 (that’s would also by $500 of steel) enough savings for a new collet chuck and collets,
The advantage of this type of base, IMO, is it is easily moveable if we in the future need to move the machine, it will not interfere with machine. Not against bolting to the floor if we know for certain that’s where it will stay. The engine hoist is smaller dimensional metal than we are looking at and with the same arm length it’s rated at 1,500# or more 15X what we’re lifting.
Anyway, it will be @nicksilva’s (new Chair - well nominated) and the machine shop committee decision which way to go. I’m throwing out suggestions. As is Tim and and yourself. At the next Machine Shop meeting please attend a express your concerns and alternatives. That’s how the Machine Shop committee operates.