New to the forum and the World of Footy’s. A quick thanks to all that post here for the wealth of information available to someone like me with no RC experience, extremely limited sailing experience(sailing our Sailfish for endless hours as a kid).
As a very experienced wood worker (some would say master woodworker, but that is just because they don’t yet know that the more you know, the more you realize you don’t know), I have spent a great deal of time in life building jigs to accomplish different tasks. So, the question: Is there a standard model boat building jig that is commonly used to insure proper alignment of hull, fin, rudder and mast when dealing with scratch built chine hulled Footy’s ?
I currently mount my hull in a stand (jig) that has the boat sitting on its intended water line. I then use a combination of levels, plumb lines , bubble levels and crossed sticks to eyeball where I am. It works fairly well to a certain level of accuracy. But,very time consuming. I am contemplating building an adjustable jig for this purpose (to accomodate different builds), but thought that there is no need to reinvent the wheel if a picture or plans are available of the original wheel.
Thanks in advance. And, thanks to all here for hours of entertainment.
Thanks Rusty. Clean,simple and effective. Right up my alley.
But, I had a thought! To anyone reading, that should sound a warning signal off ( not generally a good thing)! I have a supply of laser pointers. Is it possible that this may provide a path to enlightenment? I shall go away and get my fingers dirty.
Wilbur - My alignment jig is a section of “C” channel aluminum, 4" on the vertical part. Since I use keel trunks and removable keels my jig is specialized for keeping all hull assemblies in line along the centerline.
The beam is set up for M Class length boats, but smaller hulls can be aligned on it as well (I have a smaller version for Footies that is 16" long). When on the jig the maximum depth of the hull is only about 1/2" above the top of the beam. The bow and stern are held in place along the centerline by fixtures that capture them to keep them from moving. Think of these fixtures as end-caps for the hull. The fixtures don’t have to match the section shapes of the bow and the stern perfectly, but they should wedge both ends of the boat, along the vertical axis, snugly into place without distorting the hull in any way.
Now, as end-caps these fixtures are mounted on either end of the hull and are perpendicular to the centerline of the hull. Since we want the centerline of the hull to align with the long edge of the jig, these fixtures need flanges attached to hold them against the beam. The flanges will be clamped to the beam to hold the hull suspended above, so they need to extend far enough below the fixtures to engage the 4" vertical surface of the “C” part of the beam. The flanges I make for my fixtures are mounted on one side of the centerline on the back side, so that the fixture’s centerline is a vertical extension of the edge of the jig beam. The bow and stern fixtures are opposite hand from each other so the flanges for each must be on the correct side of the centerline for each.
I also have a fixture to keep the keel trunk aligned and in the vertical plane. This piece mimics the root of the keel that the trunk can slide over. The fixture is made up from two pieces of equal thickness, one is cut short to land on top of the beam (and to keep the trunk square) and the other is long to act as the flange to be clamped to the 4" flat side of the beam. I have a similar split fixture with a rod the same diameter as my rudder shaft, located on center, that is used to mount the rudder tube and ensure that it is in the same vertical plane with the keel trunk.
Now, the part of all this alignment that is a bit tricky is to get the hull set up so that the waterline of the hull is parallel to the top edge of the beam and the right height above the beam so that the keel trunk (which I cast long) extends into the hull the correct amount to match the keel root. To get this right can take a while, but once everything is in place, glue up goes very quickly. And all the worry about eyeballing straightness is over.
I also use the jig to mark the centerline location for the rudder tube hole and the slot for the keel trunk. The bow and stern fixtures can be clamped in different places to lower the middle of the boat or the stern of the boat down onto the top edge of the beam so that a pencil line can be drawn along the edge of the beam in the right locations for each.
Thanks Niel. Had to read a couple of times, but I get it (I can be a bit thick at times!). I have a piece of aluminum channel that will fit the bill. So, this weekend won’t be near as boring as I was thinking it might be. I greatly appreciate the detailed information.
Dear Neil
I’m intrigued by your alignment jig description but am not sure I really understand exactly how it all works yet alone how to make one !
Once the details of the ‘T rig” become public knowledge, would you please release a sketch / drawing / diagram of your alignment jig ?
Many thanks, in advance.
Phil