My Trailer Motor Mount and Mast Crutch

[bm1981]

Like a few others I didn't trust my outboard hanging off my transom while I trailered, nor did I like the idea of it it sliding around in the boat. I ended up throwing it in the back of my SUV, that lasted 1 trip the smell of 2 stroke was just too much for the admiral to take.

I went to the drawing board and came up with this setup. I used all PT lumber since it will be outside all the time.

I took at 10 foot 2X12 plank and cut it into 4 pieces only 3 are used.

I roughly measured the length of OB shaft plus the jack bracket with 2" extra added in for strength. In my case it was 28" I wanted to be sure that the prop was just about even with the bottom of the trailer tongue and didn't hang lower for worry of damage.

I took off the jack and used the starboard side mounting bracket as a template leaving at least 2" of wood below the bottom hole. I drilled the 4 holes and used longer grade 8 bolts (5-6" from what I remember). I reassembled the jack with the board added in. I wasn't happy that it wiggled up high so I added in 2 shorter boars to help stabilize it.

Be sure to measure the depth of your OB mounting clamps and cut the middle board shorter than that measurement. In my case 17". For looks I cut the third board at 13"

Now line up the 2 shorter board with the longer board and mark the location of the bolts on the shorter boards. Only the top 2 bolts will be marked. You will need to notch the boards so they straddle the bolts. Your goal is to get both boards to to sit flush on the top 4X4 aluminum piece of the trailer.

I loosened up the top 2 jack bolts and screwed the middle and longest board together, then the shortest to middle. The I tool some long screws and went thru all 3 boards. I tightened up the jack bolts and this thing was super solid.

I added in a ratchet strap to go around the OB to prevent it from rising up off the base. I figured the less it moves the safer.

Sorry it's sideways you get the idea



Now that the motor was secure I turned my attention to the mast. I added in 2X4 that I cut to 53". I can't remember why I chose that length but it gets the mast off the deck. I cut 2 feet of garden hose split it down the middle and looped that over the 2x4 to act as bumper to protect the mast. I used another ratchet strap, attaching the ratchet by the tail end to the wood with screws and trimmed the male end so that it looped over the top of the mast and was secured on the other side. When I put the mast on down I use the cunningham cleat ( on the mast) as a stopper on the boat side of the 2x4. I have just enough room to open the hatch of my truck and clear the mast.

Now to the stern:




I assembled this "t" out of some 1X4 and added a "V" on top to hold the mast in place Approx cut to 24 and 20. I used some brackets I had lying around to make the V and covered it with garden hose to protect the mast. I just eyeballed the height and wasn't concerned about keeping the mast level I just wanted to keep it off the deck and as low as possible to keep a low profile while trailering.

I drilled a hole in the T and ran a rope thru it. I take that rope thru the transom drain, around the plank and tie up a few knots and its super secure.

The blue things are ladder bumpers that I had under the workbench.





You'll get the idea here, I just laid the mast down for the pic I didn't want to de-rig the whole boat. I'll add that picture when I'm ready to trailer it down. Oh and the green bottle... thats for the buoyancy project. More on that to come.

Please let me know your thoughts of if you end up building this yourself. For me this started out as a weeknight project to make a mast crutch and ended up with this creation. I didn't have plans, I had some lumber and a saw and ended up with this. Totally not my super anal over analyze everything style but I had the wind with me that day and ran with it.

[GreenLake]

Very nice. Thanks for the pictures. I'm in the electric camp, so mine can go into the truck, but this seems a good solution.

A comment on the inverted T mast crutch. In my experience, anchoring the rear mast crutch in the rudder gudgeons instead of an inverse T, would be a workable alternative design. That kind of setup would require some sort of a hold-down, in addition to using a second set of pintles (transom mount, so their brackets fit a flat surface).

[Alan]

My mast crutch is a flat board, notched at the top to fit the mast, with a second set of pintles. The board swivels a bit around the vertical axis of the pintles when it's mounted by itself, but the mast straightens it out when it's laid into the notch.

I keep the board from bouncing out with a cotter pin that passes through a drilled hole in the lower pintle below the gudgeon. The mast is secured by a cargo strap.

It's worked fine so far, with maybe 2500 to 2800 miles of towing. The longest trip was from California to Wyoming, just about 1000 miles each way, with long stretches of 75-mph speed limits in Nevada and Idaho.

[bm1981]

I was going to go the pintle route as many here have, but for the price of a set of pintles, I did the whole project. I used what I had laying around then if it didn't work I have a backup plan.

[GreenLake]

@bm1981: Pintles are surprisingly expensive. Found that out again when I put a set on my new rudder. Being able to use the materials at hand is always nice.

What I like about the pintle setup is that it provides positive fixation both fore and aft as well as sideways. I got my setup from the P.O. and all I have done with it is to re-build it when the wood gave out after many seasons.

@Alan: Nice solution, with the cotter pin.

Like the P.O, I initially relied on the little part for the rudder hold down plus gravity (mostly short hauls) then, with experience, backed that up with bungee cords.

[Peterw11]

I'm building a pintle mounted one right now. I bought a pair from D&R and they come pre drilled, with cotter clips (the reusable thingies) installed.

I'm using a piece of leftover 5 1/2" wide x 1" thick mahogany from my outside deck project. With the clevises slightly rebent, the pintles fit well.

With the board on edge and the pintles installed, it does pivot on it's own, so I'm fashioning a flat brace that mounts perpendicular to the upright piece, to prevent that from happening. The brace also has a flat component that rests on the transom decking to take the mast weight off the gudgeons while on the road.

I'm finishing the top with a 3" bow roller to hold the mast when trailering, and also to make it easier to slide it back and forth while lining up the tabernacle pins. I'm also making the vertical section slightly higher than the cuddy, so that the mast tilts slightly downward to the tabernacle, making it easier to manipulate when rigging the boat single handed.

I think I've doped out all the major parts of the design. The only real problem is that the wood I'm using is pretty heavy and the whole crutch will weigh 15 to 20 lbs when done. I plan to jig out a series of long holes down the center of the vertical piece to lighten it up a bit without giving up any strength.

I'll try to post pics when it's done.

[GreenLake]

Mine's a simple 3-4ft length of 1x6 in pine. Epoxy sealed and varnished with cross-linked water reducible PU. Mast rest in a curved V slot that's an approximate fit to the profile. The weight is negligible, mostly from the pintles, I suspect, and has held for years of local trailering and winter storage.

I've not found pivoting an issue, since the mast will force it in the parallel position.

I could see how a roller would help when repositioning the mast for raising single handed.