Bracket build
 

Has anyone built there own bracket if so how did it come out? do you have pics? if there is a thread can you send me in it thanks

I've done a few of them . . . after Strick helped me through my first one. FYI - It's about $600 in materials and 40 hours of time (80 hours if it's your first one).


http://www.classicseacraft.com/commu...hlight=Bracket

This is stricks nice yellow one
http://www.casdvm.com/photos/20sf/DSCN7376.JPG

http://www.classicseacraft.com/commu...racket&page=25

http://www.classicseacraft.com/commu...hlight=Bracket

http://www.classicseacraft.com/commu...hlight=Bracket

http://www.wellcraftv20.com/gallery/...653_Medium.jpg

http://www.wellcraftv20.com/gallery/..._013.sized.jpg

http://www.wellcraftv20.com/gallery/...Medium_001.jpg

YO Big shrimp!!

Fun looking at them old posts. Esp the one from 0'4. Sorry I missed your call yesterday...was fighting a striper and the wind at the same time. Lots of fish here now and I've found that it's almost as fun fishing as it is working on boats during the Fall striped bass run!!

strick

A young "whipper snapper" like you would have no problem building a bracket.

strick

My dad is a cabinet maker with his own shop. So i feel when I am ready to tackle a bracket build I would be able to accomplish it with his help no problem. But after reading through some of the thread links I feel that the whole placement and mounting angles some of guys are talking about will completley lose me lol.

yuo guys got my attention i also want to build instead of buy any more help would be great

I have a generic mold that was made for a 23 sea craft
 

I made the mold and I had to cut the part down to fit a 20 sea craft size. It was No problem tho. Take a look.

http://i1230.photobucket.com/albums/...0/P1010106.jpg

http://i1230.photobucket.com/albums/...0/P1010109.jpg

http://i1230.photobucket.com/albums/...0/P1010112.jpg

http://i1230.photobucket.com/albums/...0/P1010114.jpg
This is the full 23 bracket on the 20 transom

http://i1230.photobucket.com/albums/...0/P1010132.jpg
This is the bracket with the full width deck but cut down to fit a 20.
http://i1230.photobucket.com/albums/...0/P1010134.jpg

can anyone give me dimensions on a bracket for a 20. first time building. would like to get some idea. love the stuff i see .and hope mine comes out that good .

It can be your choice. Here is what you want for a base.
 

30inches front to back at the top. You can go a little less on a shorter engine possibly?

Height you should figure about 25 inches at the transom and and about 20 at the far aft end not counting the the Flat reinforced area that the top engine mount bolts go through for lack of a better word.
If you do as I have always done and learned. You want to have a flat straight something projecting from the bottom of the hull. running parallel with the bottom and going aft to where the lower unit cav plate will be. This is where the possible improvement in performance comes from. Clean water near the surface lets prop push boat more efficient. You can sometimes raise an engine or prop height 2 to 3 inches higher near the surface with out grabbing air instead of water. Do as I did. Back ward engineer other brackets and hull bottoms and then come up with your best shot!

Width is mostly for floatation at rest or off plane. This is your choice. I will tell you it is a thin line between a bracket and a stepped hull extension if you go to wide. Then you are throwing in a new equation.

Everything centers around two measurements:

1. Engine shaft length

2. motor clearance when tilted up.

Figure these two things out and the rest comes into place. It is better if you do this in your head and draw it out on paper. 30 inch set back is a bit too much for a 20' foot boat in my mind. The 30 inch set back is for big V 8 motors that go on a 23 foot boat. Another thing....make your flotation chamber as big as possible. Good luck!


strick

I agree with Strick. The 20' hull is a LOT smaller and lighter than the 23, so the CG will shift aft a lot more with a bracket on a 20 than it will on a 23. In other words, the 20 is a lot more sensitive to both setback and engine weight, so it's best to minimize both, AND make the flotation tank as big as possible! I'd bring the bottom of the flotation tub straight back from the transom like the Hermco and Strick brackets. I wouldn't worry about it dragging in the water coming on plane because I think it acts like a big trim tab and provides some extra stern lift (and drag) in that short transient situation. It looks to me like Armstrong put a taper on the bottom of their bracket to avoid the drag, but they're giving up some dynamic lift and a lot of static flotation with it. I think trading a little extra drag during a few seconds climbing on plane for more dynamic lift and static flotation is a move in the right direction!

strick i seen yuo used foam in your bracket . first what kind and second is there an advantage over ply other than weight

For a 20 foot seacraft-

Without having made one, but having modeled one in CAD, a 20" shaft inline 4 cylinder 4 stroke gets tight on a 24" transom if you want to tilt it the last few degrees, at least when I modeled a 4 cylinder yamaha tilted up at 70 degrees. At 60-65 degrees tilt, it looks ok.

I think the e-tec powerheads are shorter and you might be able to go to a 22" setback on a 20" shaft motor, maybe.

And I think a 25" shaft motor probably gets the powerhead above the rub rail on the transom on non-master anglers (which have that tall cap).

The pic below is of a 20 foot master angler with a 20" shaft yamaha 4 cylinder 4 stroke (F100)- probably the worst case for clearance, and it still will work at just 24" setback at just a bit less than full tilt up.

Bracket Build
 

Fish,

Here's some more dimensional info for your studies. In the first picture http://i188.photobucket.com/albums/z...tclrncmeas.jpg, you can see that the 25" V-6 E-Tec on my 30" bracket has about 7.5" of horizontal clearance with the filled in transom, to which I have added a rub rail that sticks out about 3/4". I could therefore get by with a min setback of 22.5"; these motors have an adjustable tilt limit switch, so you could go with an even shorter setback if you used that. A V-4 115/130 hp E-Tec would need even less setback, maybe 18-20". When mounted on a bracket, those motors will push a 20' hull to at least 40 mph, and they're about 30 lbs lighter than the V-6, so if you're not a speed demon they'd be an excellent choice for a bracketed 20. The V-6 is overkill unless you run with extremely heavy loads.

Here's a side view of my rig with motor at full tilt on the 30" Hermco bracket. http://i188.photobucket.com/albums/z.../Fltltsdvw.jpg As you can see in this picture, much of the powerhead is actually above the transom, so the horizontal dimension to top of powerhead I quoted above is actually quite conservative. If I had a shorter bracket, the top of transom or rub rail would actually contact the motor about where the decal is on front of cover. I have since raised the motor another inch from when these pictures were taken, so I now have even more clearance than shown. If you'd like more exact dimensions at the current mounting height, let me know and I'll go take some more measurements.
Denny

Bushwacker-

Thanks for the measurements!

I am assuming my pivot point is correct for the Yamaha. It is sitting under 2 tarps waiting for snow...

I plan on on recreating the cap contour atop the transom, so that's what is shown in the model I have. Now I have to find the Yamaha manual and make sure I didn't goof the pivot point. I was lazy and pivoted it about the top of the bracket edge, but it is probably 1 to 1.5" above and forward of that point. With the 20" shaft, I will need the motor low on the bracket, I think. If I could only find a 25" Yamaha F100, it you be easier.

I do have a CAD model of the 130 from the internet. It seems to be the real deal. Maybe I can drop it in and compare. But no E-Tec for me. My F100 was $1000, and that's my kind of budget. Unless I find a 115 Etec for $1000 :)

What about a mercury 6 cyl 150 HP Opti I went over and could not believe how high
 

and big the engine cowing is. Between that and the rake in the sea craft transom? I do not see how to cut the bracket down very much. If he wants to be able to tilt the lower unit out of the water.

I'm doing a similar thing and have the same interest in clearance. I have a pdf of the yamaha rigging clearances for all their outboards, that has every clearance stat you could want. Let me know if you want it.

T

I used corecell. The no rot thing with the foam is the biggest advantage I guess. Corecell has good compression strength but not as good as plywood. The set back on the yellow bracket is 22.5" and if I remember right I built it I could be able to put a Suzuki 140 on it and be able to tilt it up all the way once the Yamaha dies.

strick