My boat is a Starcraft 1710 - which is a heavy. I looked at guides but most seem pretty flimsy and the real solid ones were $200 plus. One that I liked used polyurethane bushings, etc but it didn't look like it would mount close enough in to my boat. So I borrowed the concept and built my own.
I used 1 1/2 square steel tubing, about 36 inches long which i just happened to have laying around after - it had been an eve support on the front step. Drilled two holes on a bit of an angle for 7/16 bolts to go through - one above and one below the trailer frame rail. Went to Home Depot and bought a a steel jack plate - (6 inches x 5 inchesx1/4inch- the steel plate that goes on top of the jackpost that supports the main beam of a house) Cost - $8. Cut two 2x6 pieces off the plate with my angle grinder, drilled it for the 7/16 boats and used it for the backing plate. Covered it with rubber so it won't take off the trailer paint - put rubber under the bolt where it crossed the frame rail as well. To get the right angle for the the posts I bought two plastic wedges that are used to hold the kerf open when using a chainsaw to cut trees. ($4 each). Fitted them between the posts and the trailer frame, drilled them and run the bolts through them. They are solid and don't compress and you can get more adjustment by putting washers between the post and wedge. Bought 2 inch gas pipe that fits right over the square steel tubing and actually rolls nicely ($12). I'll take them off and paint everything this winter. Total cost - I had the steel tubing - $35. Sideways they are rock solid, but with the plastic weges they will slide forward if you were to hit them real hard. I'm trying to put some pix on, but don't know if thats working
I used 1 1/2 square steel tubing, about 36 inches long which i just happened to have laying around after - it had been an eve support on the front step. Drilled two holes on a bit of an angle for 7/16 bolts to go through - one above and one below the trailer frame rail. Went to Home Depot and bought a a steel jack plate - (6 inches x 5 inchesx1/4inch- the steel plate that goes on top of the jackpost that supports the main beam of a house) Cost - $8. Cut two 2x6 pieces off the plate with my angle grinder, drilled it for the 7/16 boats and used it for the backing plate. Covered it with rubber so it won't take off the trailer paint - put rubber under the bolt where it crossed the frame rail as well. To get the right angle for the the posts I bought two plastic wedges that are used to hold the kerf open when using a chainsaw to cut trees. ($4 each). Fitted them between the posts and the trailer frame, drilled them and run the bolts through them. They are solid and don't compress and you can get more adjustment by putting washers between the post and wedge. Bought 2 inch gas pipe that fits right over the square steel tubing and actually rolls nicely ($12). I'll take them off and paint everything this winter. Total cost - I had the steel tubing - $35. Sideways they are rock solid, but with the plastic weges they will slide forward if you were to hit them real hard. I'm trying to put some pix on, but don't know if thats working