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Plate mount bolt-in Duo option

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mopman365
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Plate mount bolt-in Duo option

Postby mopman365 » Thu Aug 10, 2017 1:43 pm

Hi, just thought i'd share back to the group an option for plate mount that seems to work (i haven't been able to break it.. yet).

I've been working on getting a plate mount fitted to a surfboard for strapless kite-foil, foil-surf and normal surf. The idea was to make a foil surfboard with two longboard boxes that could also double as a Duo surfboard (read about it here: http://comparesurfboards.com/reviews/al ... ard-review). But after paying too much for two FCS boxes and being surprised at how heavy these boxes are, I decided to do a test-board first - a cheap board for testing out foil position and that I could ding up in the learning process.

I set a deep SS nut (https://i.ebayimg.com/images/g/nM0AAOSw ... s-l300.jpg) on top of a washer inside a plastic cap, using carbon twisted around the nut and inside the cup like this:
Capture1.JPG
Capture1.JPG (44.62 KiB) Viewed 241 times
This goes into routered holes into the board with a balloon mix. I took the foam out all the way to the deck laminate for added strength. Like this:
Capture2.JPG
I then masked off two strips on the board (two layers of masking tape makes final sanding easier. Then over the caps i put a bi-ax patch and then a UD strip with some balloon mix over all of it. I find the holes using pins (can be pulled out once the epoxy is dry) and let it set for two days. Then just sand back to a smooth level surface:
Capture3.JPG
The end result looks like this:
Capture4.JPG
I think because the plate is quite wide (the Duo fins are placed 6 inches apart), any sideways force creates a push/pull on the plugs, rather than a moment force like you'd get on a centred turtle box. As long as the plate can't squash the carbon strips on the one side, or pull the plugs out on the other side, it will hold. The added bonus with this setup is, two SS plugs (deep nut, washer and cap x 2) weighs less than half of the FCS box.

I'll still do the Duo board some day, but for now the bolt-in cheapy seems to do the job.

Blackrat
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Re: Plate mount bolt-in Duo option

Postby Blackrat » Thu Aug 10, 2017 6:24 pm

Rebel surf board ... You must be in SA ?

BWD
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Re: Plate mount bolt-in Duo option

Postby BWD » Thu Aug 10, 2017 6:32 pm

Cool idea. Have you kited duo surfboards?
I have been curious to try but haven't done it, 90% sessions this year have been flat water and lighter wind learning to foil.
There are some interesting but not widespread designs from "twingle" fin boards 1-3" apart to the duo which looks 5-6" apart.
I bet a configuration could be found that works ok with the standard 90mm spread foil tracks.
maybe with a little cant?

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mopman365
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Posts: 190
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Gear: F-One Bandits, Directional
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Location: S Africa

Re: Plate mount bolt-in Duo option

Postby mopman365 » Fri Aug 11, 2017 5:13 am

BWD wrote:
Thu Aug 10, 2017 6:32 pm
Cool idea. Have you kited duo surfboards?
I have been curious to try but haven't done it, 90% sessions this year have been flat water and lighter wind learning to foil.
There are some interesting but not widespread designs from "twingle" fin boards 1-3" apart to the duo which looks 5-6" apart.
I bet a configuration could be found that works ok with the standard 90mm spread foil tracks.
maybe with a little cant?
Haven't kited or surfed a Duo but keen to try. They apparently work better in bigger waves - something I don't get often. But with the kitesurfing it might get more use. Hmmm.

I was considering just keeping the 90mm plate, but worried that spacing will be too much like a single fin. And I needed to shorten my mast anyway, so decided to rebuild the plate with 90mm and 6inch options. Thinking the wider plate will also make a stronger connection - less force at the plugs. Time will tell.


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