I am concerned about the stress that all the motor mount designs I've seen put on the rear crossbar . I've decided on the motor mount design by KeithB posted here viewtopic.php?f=23&t=57851 . I am considering adding an additional crossbar aft of the crossbar between the hulls that the motor mount arm would bolt to . The crossbar would just rest on the hulls in some fashion without actually being bolted to them to allow for flexing. What are opinions about this. The outboard I have weighs 37 lbs
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2016 Hobie Getaway
1978 Nacra 5.2
1978 Hobie 16 (back in the day)
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Stress on crossbar from motor mounts
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- Rank: Lubber
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Posted: Nov 13, 2016 - 12:59 PM
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Posted: Nov 13, 2016 - 08:12 PM
Edit your post. Click on the button below where you type, that says URL.
That will open up a set of brackets. Copy & paste the full address link inside the brackets, then it will become "live" & all readers can simply click on it.
What Breed of Cat?
I have not heard of people having issues with mounting small engines. I once towed 2 kids on a tube, tied to the rear beam of a Nacra 5.7.
There are several videos of towing a wakeboarder behind a Nacra 5.0
Small engines do not create tons of horsepower, & the Cat hulls create little resistance. The boat moves before much stress is put on a X bar.
If I was worried about 40lbs bending the beam while driving through waves, I'd get a different Cat.
Edited by Edchris177 on Nov 13, 2016 - 08:15 PM.
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Hobie 18 Magnum
Dart 15
Mystere 6.0XL Sold Was a handful solo
Nacra 5.7
Nacra 5.0
Bombardier Invitation (Now officially DEAD)
Various other Dock cluttering WaterCrap
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Posted: Nov 14, 2016 - 11:42 AM
I don't think a second beam system could be setup on most cats. The structure does not exist to mount it on the hulls, and tiller systems move both side to side, and aft as you turn. Avoiding interference with tillers and rudders would be quite a feat. Outboard motors need to be planned and mounted to avoid interfering with steering, and closer to center is better to avoid the motor ending up in the water when you heel. I agree with Ed, the rear crossbeam strength should not be an issue.
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Tom
NACRA 5.7 (1984 Sail 181)
Pennsylvania
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Posted: Nov 17, 2016 - 03:02 PM
Is this the one?
http://cheatabrackets.com/page1.php
If you keep the Bhp around 2/3, stress on the rear-beam shouldn't
be a problem. Anything over it would burry the sterns anyway....
A second beam system seems difficult to me, how does it handle
propulsion/torque, hence rotation without being actually bolted to
the hulls?
I'm thinking about installing a Cheata bracket combined with a
Torqeedo travel 503 on my Tornado.
It has a build-in battery. So no dealing with gasoline and external
batteries. Maybe something for You?
Grtz, A
Edited by catmodding on Nov 17, 2016 - 10:13 PM.
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Tornado (80's Reg White)
Prindle 18-2 (sold)
Dart 16 (hired and hooked)
13 mtr steel cutter (sold)
Etap 22, unsinkable sailing pocket cruiser.
Amsterdam, the Netherlands
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Posted: Nov 17, 2016 - 05:46 PM
Here is the link to the mount design I made for my Hobie Getaway. http://www.hobiecat.com/f…ewtopic.php?f=23&t=57851
Once I mounted the outboard the crossbeam torqued some then settled. Seems stable but I am still a little concerned about how the up and down bouncing of the boat might put excess torque on the beam or on the hull where the beam goes into the hull. Does anyone know how far the beam goes into the hull on the Getaway?
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2016 Hobie Getaway
1978 Nacra 5.2
1978 Hobie 16 (back in the day)
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Posted: Nov 18, 2016 - 01:19 PM
After testing the mount with extra weights it held up fine. The crossbeam appears to extend deep into each hull giving ample support. Nice design.
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2016 Hobie Getaway
1978 Nacra 5.2
1978 Hobie 16 (back in the day)
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