Overniter in SC: Flipped 5-27-17

Designs for inboard or outboard power

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Adrock1
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Re: Overniter in SC

Post by Adrock1 »

Okay guys. Got another rather important decision to make soon and have a question.

Frames are coming along nicely. I'll be buying plywood and starting on the transom before long. That means I'm going to have to have some sort of vision for how I intend to power the boat and of course how I will construct the motor well.

I've been using this glen-l link as a reference as I think through this:
http://www.glen-l.com/designs/outboard/ ... html#chart

Anyway the motor isn't in the budget yet. That will come down the road. So I'm going to have decide now what the dimensions of the motor well will be and what the transom cut out will be. I'll have to build this in such a way that it will accommodate whatever motor I decide to go with in the future.

My intent is to go with a 20" shaft of up to but not necessarily 100hp. Most likely a used 2 stroke in order to manage the weight but not necessarily. When I get the money together I will likely take my time searching and jump on a good deal when I find one. That means I could end with about anything in the 60-100 HP range, new or used. The only thing I'm settled on is 20" just because of availability.

So can anyone offer some guidance on how big to make the motor well so that it will accommodate any motor I might select? The Glen-l page indicates 33" wide by 25" deep with a 6" clamping area. Will that be big enough to accommodate anything I might get or do I need to go bigger?

hoodman
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Re: Overniter in SC

Post by hoodman »

My motorwell will be 36" wide. This necessitated adding an additional (smaller) batten between the two main ones that the motorwell sides will tie into. I wanted a generous amount of width as I've seen some other guys occasionally have trouble getting steering etc to work in a tight area.

Tohatsu provides a very convenient document showing the required dimensions for their outboards: http://tohatsu.com/outboards/90tldi_dims.html

The owners manuals from other manufacturers may provide similar information.
Matt

Building a Geronimo......!
viewtopic.php?f=2&t=25139

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specialk
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Re: Overniter in SC

Post by specialk »

Just found your build... I am just a couple of hours down I-26 from you ... and I agree with Matt I would make your motor well 36" that way if you go with a larger motor... you will still have plenty of room for a left hand turn... please do not ask how I know this...Nice clean shop...!
Kelly...1st Boat...Flats Flyer
2nd Boat.....?

Adrock1
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Re: Overniter in SC

Post by Adrock1 »

Thanks for the feedback guys. So I guess a little on the big side is no harm. Adding the extra batten for the motorwell sides is no problem thats easy enough. I'm assuming a depth of 25" is plenty or should I go a little big there too? Id rather not if I dont have too as that eats up space in the cockpit.

By the way Hoodman any chance I could see a pic of your transom and how its framed? The geronimo is similar in size to the overniter. I'm struggling to understand the transom framing. What I see in my plans doesn't appear to match what I showed in that link from Glen-L. I'm kind of unsure how to proceed with it.
Last edited by Adrock1 on Thu Mar 10, 2016 5:08 pm, edited 1 time in total.

Adrock1
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Re: Overniter in SC

Post by Adrock1 »

Specialk you must be in Columbia. Ever get up towards Greenville?

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mrintense
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Re: Overniter in SC

Post by mrintense »

My boat, the Vera Cruise is a bigger version of the Geronimo / Sea Knight hull. Here are some pics of my transom. There are lots more available via links on my blog. Hope this helps.
Transom Motorwell Plan.jpg
IMG_20140215_164134.jpg
IMG_20140209_122754.jpg
Carl

Crafting a classically styled Vera Cruise

Clipper Boating

Adrock1
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Re: Overniter in SC

Post by Adrock1 »

Thanks Carl. That looks pretty much like the construction outlined in the link I posted earlier and is exactly the way I would like to do my transom. The plans for my overniter look somewhat different though. Have a look:

Image

As you can see the plans call for a 3/4 plywood panel for the transom. To that you apply a frame member and side frame members exactly like you have and like the construction shown in the motorwell link from Glen L. The difference is on my plans it shows an additional frame member running across the full width of the transom.

To build a motor well I am assuming I omit that frame member and replace it with the large clamping board of 3/4 ply like you have and like shown in the motor well link from Glen L. Is that Correct?

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mrintense
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Re: Overniter in SC

Post by mrintense »

Well, I would say that the plans are pretty specific about using a frame there. That's the first time I've seen it shown this way. There are a couple of things to consider here. First off, when these boats were designed, motors were considerably lighter. Secondly, This may simply be the approach the designer took with this transom. Before dropping the frame, you really should write Gayle and Glen L and get some additional input. Like most builders here, I am not a marine engineer, so I would be hesitant to suggest replacing the board with a plywood motorboard. On my boat I actually went thicker than the original design (two laminations) in anticipation of a heavier motor.

Bottom line, the transom will take the brunt of the stress from the motor's operation so you want to get that structure right.
Carl

Crafting a classically styled Vera Cruise

Clipper Boating

hoodman
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Re: Overniter in SC

Post by hoodman »

I haven't seen a design like that either. Do the full size patterns show it that way too? I would dig up a picture of my transom but it's pretty similar to Carl's. I am thinking of adding another 3/8 lamination to my motor board after the flip. There's a Glen-l document somewhere that shows recommended transom thickness for given horsepower ranges and I'm a little shy at the moment.
Matt

Building a Geronimo......!
viewtopic.php?f=2&t=25139

Adrock1
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Re: Overniter in SC

Post by Adrock1 »

The full size patterns only show the outline. No detail of co struction.

To be clear I would of course keep the frame around the perimeter of the transom as shown and just modify the clamping board making it co sistent with what Glen L shows in the link I provided as opposed to what's shown on the plan.

Another option would be to build the transom exactly as drawn on the plans and modify the motor well design to fit accordingly.

Maybe I should just reach out to Gail and see what they recommend.

Adrock1
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Re: Overniter in SC

Post by Adrock1 »

So I went to send Gayle a PM and noticed that all the PMs I have been sending are sitting in my outbox. It looks like none of them have actually been sent to the recipient. Anyone know how to fix that?
Last edited by Adrock1 on Fri Mar 11, 2016 11:13 am, edited 1 time in total.

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Gayle Brantuk
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Re: Overniter in SC

Post by Gayle Brantuk »

Yes, if you are doing the motorwell, omit the bottom shelf support and build the motorwell as shown on our site. I did get your email and PM by the way.

Adrock1
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Re: Overniter in SC

Post by Adrock1 »

Gayle Brantuk wrote:Yes, if you are doing the motorwell, omit the bottom shelf support and build the motorwell as shown on our site. I did get your email and PM by the way.

I guess my PMs were going through. Thanks so much for prompt response. So just to be clear I omit the horizontal frame member going across the middle of the transom and replace that with a plywood clamping board.

One final questions, the motor well details provided online suggest a minimum transom thickness of 1 5/8". If I use 3/4" plywood and 3/4" lumber to frame the transom I will only get to a total of 1 1/2" thickness. Do I need to shoot for greater total thickness? If so should I just increase the thickness of the transom framing and clamping board or should I increase the thickness of the entire transom with an additional layer of plywood? 3/8" perhaps.

Again thanks to all of you for the help.

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Gayle Brantuk
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Re: Overniter in SC

Post by Gayle Brantuk »

Personally, I wouldn't go below or even at the minimum thickness for the transom. It sounds like you are considering up to 100hp, so I'd rather err on the side of safety and go more than 1-5/8".

Adrock1
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Re: Overniter in SC

Post by Adrock1 »

Gayle Brantuk wrote:Personally, I wouldn't go below or even at the minimum thickness for the transom. It sounds like you are considering up to 100hp, so I'd rather err on the side of safety and go more than 1-5/8".
Absolutely. I don't know what size motor I'll go with. My intent is to build it to handle the max though. Anything less will be just fine then.

That said, I agree. I'll need to shoot for a thicker transom. Its still not clear to me if it's best to stick with 3/4 for the plywood and just increase the thickness of the framing or if I should increase the thickness of the plywood as well. Or both for that matter. What would you recommend?

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