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PostPosted: Fri Dec 29, 2017 11:06 pm 
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Joined: Wed Jun 14, 2017 2:55 am
Posts: 2
I could never get my head around drilling more holes in the rear crossbar or in the hulls, so I had a good think about another way to do it.
So about 4m of 38mm x3mm 316 stainless steel tube and some 2mm x 40mm flat bar, this is what I came up with...

Image

2mmx40mm SS flat bar drilled to match existing rudder mount holes. MAKE SURE YOU PUT SCREWS BACK IN WITH LOCTITE!
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Note that this mounting plate is not vertical. I tilted it back so that the motor would drive the rear of the boat up a little under power. I still need to get some caps for the tubes (although these may prove useful for a "boom" tent)
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I bought longer bolts to allow for the plate and nylon washer
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Then I built a deck over the framework - held on with saddle brackets
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Added a rubber V-block for the mast while trailering
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I left 2mm gaps between deck slats to allow straps to go through - useful for tying down extra fuel tanks and coolers. As long as these items are tied down at the back of the deck they shouldn't interfere with the tiller bar.
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Ready to go.
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I have used the boat with this mount prior to adding the deck. Under power it works very well. Under sail, with the motor raised, in flat water it is perfect, but you have to play with your position in the boat a bit when it gets very choppy to stop the mount and rear bar catching the water and spraying the motor (only a little bit). I think the deck should keep the motor drier.


Last edited by Nolipoli on Sat Dec 30, 2017 11:52 am, edited 1 time in total.

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PostPosted: Sat Dec 30, 2017 8:10 am 
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Joined: Mon Oct 26, 2009 10:27 am
Posts: 218
Location: Cheshire, CT USA
Great idea Robert on the new design. I did not need mine to tilt up any further as my honda tilts up plenty to clear the water. Also, I think you were able to shorten your support arm only because of your motor head being much smaller so it doesn't interfere with the tiller.

Keith

_________________
2002 Getaway


"Cheshire Cat"


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PostPosted: Sat Apr 07, 2018 6:48 pm 
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Joined: Wed Jul 19, 2017 8:04 pm
Posts: 3
Flabluka wrote:
Robert-
Very nice job! Couple of thoughts come to mind:
1) Looks like you were able to shorten the distance while still maintaining clearance for the rudder bar, is that true? What is the new distance?
2)Where did you source the 1"x1" (I am guessing on size) bar and complementing bars? 80/20 as well?
3) What technique do you use to raise the motor on the water? Seems like it could be tough to pull pin, raise motor and replace pin on the water
4)Part list and more pictures would be awesome

On a different design....How would a motor mount work if it was just based upon the rear crossbar installed by wanderoo? Seems like it could support the weight no problem but you would have to prevent rotation somehow. That would prevent having to drill the main trampoline support.

Thanks for the new design.
-Dave


CHECK OUT THE LINK TO THE ADDITIONAL PHOTOS OF THE MODIFIED VERSION BELOW.

Dave, sorry for taking so long to reply back to you - not sure if you will check this again or not, but here are your answers:
1) Yes, I was very focused on making the arm as short as possible to minimize stress on the cross bar. I actually developed the new design using SketchUp so I could simulate the distance of the tiller cross bar when the rudders are fully turned (i.e. when the bar is most aft)... this way I could get the lengths perfected. As Keith later points out, this distance is different for every motor since it is the head of the motor that is most likely to bang into the tiller cross bar. You'll want to check it with the motor in the up and down position. I will try to post a link below to JPEGs of the 3-D images (yes, I'm a geek).
2) Yes, I got all the aluminum parts from 80/20 -- it's all stock stuff. I did have to drill the pieces for the supports for the hing. There are flat washers between those pieces and the main 1x1 to keep it from rubbing and let it rotate up and down freely. You can see how I use same pin to secure it to lock it up or down. Note that the retaining latch that goes under main extension bar serves two purposes: retain the pin of course, but it also keeps the arm from rotating higher (yes, higher... in the event you flip the boat! which I've done -- keeps the motor from banging back into the tramp or hanging down in the water).
3) I just use brawn to raise and lower. I'm mid-40's and still able to muscle it up, but my wife and kids can't do it. I thought of a lanyard with a little pulley to give mechanical advantage could work... remember that in my setup, i have just the Torqeedo motor mounted... I keep the battery and tiller on the boat... this means only 20 lbs are on the mount. A gas motor would be harder to lift... I would 1) put in the pully and 2) put another plate below the movable arm part to prevent it from falling down into the water. since there are holes on all sides, you could just bolt this "stop plate" in place.
4) I used all 316 grade stainless steel hardware from Bolt Depot... even the washers... i sail in salt water so it's a must. It was all 5/16 and I used nylon locking washers. I also used 3 Elevator Bolts (not 316 unfortunately) to bolt the wood onto the aluminum L brackets (2 inches each)... I wanted some surface area to compress against the wood (in hind sight - large washers recessed would have been just fine, but it looks nicer it its in the budget). The other odd and expensive part was the 316 grade eye bolt with shoulder (part 18517)... it was $18 but what the heck... 1 and 1/8 long but should have gotten shorter... you can see what I did to solve for this, I have an upside down nylon nut against a washer at the perfect height to allow the retaining nut below to fully tighten, but also prevent the shaft of the eye bolt from going too far down and hitting the existing metal rope retention loop for the mainsail traveler that is riveted to the cross bar (see the detailed photos).

Finally, I was really nervous about drilling the cross bar. But I got the nerve and did it, and it worked out great. Really happy with the design and looking forward to season 2 with the setup - it's snowing here in VA on April 7!

Here is the link to more pictures... hopefully this works!?!

https://drive.google.com/open?id=1C82_LY19zZd8tTRL_clWBf6jKCsiDahs

Cheers!


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PostPosted: Sat Apr 07, 2018 7:07 pm 
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Joined: Wed Jul 19, 2017 8:04 pm
Posts: 3
Flabluka wrote:
Robert-
Very nice job! Couple of thoughts come to mind:
1) Looks like you were able to shorten the distance while still maintaining clearance for the rudder bar, is that true? What is the new distance?
2)Where did you source the 1"x1" (I am guessing on size) bar and complementing bars? 80/20 as well?
3) What technique do you use to raise the motor on the water? Seems like it could be tough to pull pin, raise motor and replace pin on the water
4)Part list and more pictures would be awesome

On a different design....How would a motor mount work if it was just based upon the rear crossbar installed by wanderoo? Seems like it could support the weight no problem but you would have to prevent rotation somehow. That would prevent having to drill the main trampoline support.

Thanks for the new design.
-Dave


One other thing I forgot to add: when you look at the photos, you will see I used two of the standard triangular plates from 80/20 that sandwich to the boat. this is a very rigid setup as those two plates are clamped together using two through bolts that go through the main extension shaft and 4 spacer plates (these also are stock parts from 80/20 with two pre-drilled holes). Look at the photos. You bolt all this together first. Then I put this in place using levels and "eyeballing" it get the right angle off the back of the boat so the shaft is not angled too high or low (mine slopes slightly down to the water when in the down mode) and is at a right angle to the rear cross bar... I used a large rafter square to get it right and then marked the bar where to drill. You know, measure 3 times, drill once kind of thing. The fact that the top and bottom plates are one rigid unit I think is another advantage of this setup. I put minimal pressure on the cross bar-- I didn't need to compress these two peices together much as they are already connected with those two other through bolts (I did crank down on those).

Finally: Since i took those photos, I moved all of the spacer plates to BELOW the main extension shaft... this raised the shaft an inch or two upwards as my motor mount was fairly close to the water when down -- especially if the boat is loaded -- the nice part is that you have this to play around with if you need to tweak it when done.

Robert


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PostPosted: Mon Apr 09, 2018 11:56 am 
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Joined: Sat Aug 13, 2016 8:19 am
Posts: 10
Has anybody seen this pipe based motor mount design before, see at position 1.57. Who makes it? How does it attach to the rear?



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PostPosted: Sun Aug 12, 2018 3:43 pm 
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Joined: Mon May 09, 2016 8:29 pm
Posts: 49
Hi Keith, thanks very much for the design idea and all the details and pics. I am in OZ, so a bit harder to get the parts as they all have to be custom coated. Looking forward to getting a motor on the Getaway as It'll sure beat paddling!
I am tempted to put a stainless beam across the back to support the back of the bracket similar to another post. Did you have any thoughts on this?
cheers J


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