Since you will need jack for the front of the trailer for parking purposes anyway, why not get a set where the foot is held in with a pin and have an extra set of feet with the wheels attached to them? That probably won't enable you to use the wheels you are thinking about but it would make the jacks dual use and possibly minimize the size of the parts you need to store when not in use.
I do like the idea of an interchangeable foot and wheel. But let me expand, maybe better explain my dilemma.
I did this drawing with an engineers scale, so it is proportionally accurate +/- 6”
If you look on the right, when the Raith is loaded, the tongue extends about 2 feet over the upper deck of the step trailer. That still leaves about 3 1/2 feet for the winch operation.
The problem is not “will it fit.” The problem is the front of the Raith will not clear the back of the step trailer as you pull it up. Before the Raith wheels start to rise on the ramps, the tongue would hit the back of the big trailer. The pink line kind of shows the travel of the nose of the Raith. It will hit the back of the step trailer instead of riding over it.
I put the casket on the trailer yesterday, just strapped down so it wouldn’t slip off when I was moving it. As I had figured, since it is pretty much centered over the two axles, it didn’t really change the tongue weight. I could pick up the tongue off the ground and put it on the hitch, which is about 19 - 20 inches high. It was heavy, but manageable. Remember that I am old and decrepit.
Then I put a couple of full propane tanks under the grill temporarily. I could just barely pick up the tongue at that point, and there would be more weight in the tongue box, etc. I’m guessing it was about 200 pounds. I would not want to do that unless I had to, it’s at my limit. I don’t know if I could do it on one of my bed health days, so I will need some kind of a tongue jack.
Back to the diagram, if I put a tongue jack in the typical location right on the nose, it will actually make the problem of pulling the Raith up on the step trailer worse. More at the end.
The idea I mentioned the other day was putting some light weight wheels at the same track width as the main axles (65”), but something I could retract or remove pretty easily. They would never be used on the road, just for moving the trailer around or loading it. I took my baby carriage apart, and the back wheel assembly is certainly heavy enough for this kind of use.
Obviously, I would split it, and make some kind of a frame, probably out of the aluminum. Think of the mechanism under a folding table.
While it looks wide in the third picture, keep in mind that the gas grill still has to have the two side pieces installed, and, on the sides between the gas grill and the fenders, I’m going to put some kind of step/running board to climb on and off this thing.
If I put those wheels centered under the gas grill (pink shaded area on drawing), so they hit the ramps before the nose hits the back of the step trailer, I think it would work.
I wouldn’t pull the trailer up by the hitch. I would put some kind of winch hook up ring, probably about where the frame tapers in. I already had the idea of making two connection points, and having two chains or cables come to a single connection point, so it doesn’t interfere with tongue, and also acts as a safety, having two connections
Keep in mind that those small wheels would have to be a maximum of about 10 1/2 feet from the back of the trailer so they are still on the lower deck of the step trailer when loaded. I’m thinking of making a strong enough side to side bracket to hold them, and load on the trailer, and also to move it around on the trailer when it’s parked. I’m thinking of making it where they will hinge up towards to the back, with some kind of a locking strut. If it hinges to the back, and it ever broke loose while I was pulling it, it might destroy those wheels, but they would just bounce, not lock down and dislodge the trailer from the hitch.
For flipping those wheels up and down, I thought of making the bracket strong enough that I could put a long handle on it, so I could basically flip it up and down with the long handle. The handle would probably be removable, unless I thought it looked cool to leave it. When I put the wheels down, I would make the centerpoint a little forward, so they would stay in place until I locked the strut.
I also had the thought of putting a couple of 8 inch hard wheels on either side of my receiver tube, inside the frame, so when I pulled the trailer up and it got to the upper deck, the tongue could roll on those wheels instead of sliding on the diamond plate.
I have another, completely different idea, that goes back to a normal tongue jack. If I put a tongue jack up near the nose, with the wheel underneath it, I could use a piece of channel between the two ramps to load the trailer. The tongue jack wheel could ride up the channel, and then on top of the trailer, and the rear wheels would ride up the ramps. I’m pretty sure the aluminum channel ramp would be strong enough, but it would be easy to reinforce if not. But that would also be light enough that it would be easy to move around.
So, other than every detail of this project and the whole concept in general, what am I missing? Or what could I do differently?