Good Morning LJ.
The assembled mechanism moves up and down fine, it's just my thinking that needed some adjustment.
I have an adjust-by-hand toplink, nothing fancy. So, as you lift the 3pt the hitch ball moves through an arc. Not a problem, just different, and actually useful for the trailer hitch in the picture. Being able to rotate the ball through the arc helps to seat it in this trailer hitch, once you have the basic position right.
Worth doing ? Definitely in my case. (My tractor is 5x more flexible in tight quarters than my tow vehicle).
Learning curve for hitching up ? Yep, just a little one. I think most people with a little practice would find this easy to use.
I wouldn't try this maneuver for the first time if you where in an extreme hurry/panic to move something (ex. out of control grass fire heading for the valued travel trailer). But, given a bit of time (or in my case, at least 2 cups of coffee ) I think most people would find this easy to use.
Hi Ken - I understand your concern. It doesn't show in the pictures, but my heavy duty shield on the PTO would prevent the toplink from dropping too far, IF I happened to drop the 3pt hitch control lever accidentally. The toplink might get a little beat up, if I didn't notice right away, but in my case there is no significant safety issues for my application.
GENERAL DISCLAIMER - my application is for shunting on my property - I would NOT suggest that someone build this and haul their trailer down a public roadway with it. Safe or not, I have no idea if this contravenes any local (public roadway) transport regulations.
Build components:
Off the shelf bolt on receiver - rated for higher load (at highway speeds) than my trailers.
Eye bolts, to weld on - forged, each one can carry much more load than the tongue weight I have.
Welding: - not a novice level weld, just because of the safety aspect.
To re-state - in my application, the only safety risk would be from shoddy welding of the eye-bolt eyes, onto the receiver.
(My buddy that welded it for me came up building tube frame race cars. I would bet my life on anything he welds, as I know he has actually done that (bet his life), countless times).
To wrap up, the only other engineering consideration is that the 3pt has to have the lift capacity for the tongue weight you are dealing with. Huge safety margin, in my case.
But, yes, if you are not comfortable with these type of modifications, it is not a project I'd recommend.
Rgds, D.