LX210 swim platform

[crazyrings]

Test fit one is in the books. Time to make some mods. And this one is definitely too big. Awesome platform though. Still going to give it some trial runs to get some testing after revising the original step mount.

 

[the MfM]

Yup, this one is substantially bigger than OEM. We had a couple of patterns, and the big one was built first to see what happens. It can easily be scaled down. The other pattern is about 6" shorter than this. It could be made to any size, including OEM if someone wanted to measure it out for me.

You are correct, it will pivot around the ladder mount. However, that is where most of the load is carried. Similar as to when you stand on the ladder. The force is on the pin, then the brackets and bolts into and away from the hull. This design is similar to the ladder in force when standing close to the boat, then a compression force as you move towards the rear. Anyhow, the weight is carried mostly on the pins, with the clocking (or rotation around the pins) being controlled by the side rails as an almost horizontal shear force away from the boat. If the weight is on the sides of the platform, the side rails will be under more vertical forces as well which is actually more concerning to me than the center structure, as my current lengths will create a slightly longer lever.

The center structure is likely to be much stronger than the OEM option. The OEM platform isn't supported near the hull, and is a single vertical plate as you know. It does however have a larger plate against the hull that better distributes the compression force I mentioned. I may ended up with a larger plate that bolts right back into the ladder mount holes if it ends up being a worry after testing. I'd like to know if the hull is reinforced differently on the LX and AR, as my LS is only reinforced at the step mounts. I'd rather keep my plates there then going to the oem style with a backing plate on the thinner section.

All the forces could be calculated for piece of mind if we wanted to turn it into a real deal kit.

As far as what length will drag the water, that's the fun in testing!

My concern would be more for when someone steps on the tail end of the platform. The center brackets would be adding little support. Kind of like if you took a 40’ ladder and leaned it against a roof 20’ high. And tried to walk to the top of the ladder. Once you go past the balance point the ladder will slip. On your swim platform all the weight would be then supported by the outer brackets. The same would be true if the platform is dragging.

Perhaps the outer angle is strong enough but the real unknown is the strength of the fiberglass at the top of the tunnels where the angle is bolted.

FWIW i was a bit surprised at the size of the mounting brackets and hardware when I put my swim platform on. Yamaha definitely wasn’t cutting any corners when they designed it.

 

[crazyrings]

The missing link in your analogy is that the ladder feet are anchored to the ground. The ladder pivots on the anchored feet to get the correct angle to contact the roof. Assuming the roof and walls are sound, and your ladder was structurally capable, you could go to the top. The failure mode would likely be your ladder folding near the roof line, the ladder base cannot escape. You're describing a lever, but we are working with a cantilever if you want to climb past the supporting structure.

Maybe it would help if you think about mounting the platform on the outriggers from the tunnels first. Then you need to support your cantilevered platform right? You'd install a compression brace between the end of the platform and the bottom of the boat. Same as mine, same as Yamaha's. So, actually, if someone is on the end of the my platform, most of the weight will be on the pin, with the brackets being compressed against the hull. The braces in the tunnels will actually be rising against the bottom of the tunnels, as well as being pulled horizontally away from it due to the rotation around the pin.

 

[the MfM]

The braces in the tunnels will actually be rising against the bottom of the tunnels, as well as being pulled horizontally away from it due to the rotation around the pin.

That’s what I’m saying. As the pin rotates due to someone standing or the platform dragging the load is transferred to the tunnel bottom. The strength of the fiberglass in that area would be my concern.

Yamaha could have designed a platform that is strong enough to span the distance from one side to the other. Many boats with swim platforms have only two brackets. But they decided that center bracket with a large fixed bearing surface was needed. Even though that means more holes through the hull below the water line.

I’m only guessing here but I assume when they decided to add a swim platform to the newer models they felt the tunnels weren’t strong enough alone. And that it was cheaper to add the third mounting point then reinforcing the existing hull design

The question in my mind would be does your “pivoting compression brace” add enough support all the time to prevent flexing and potential problems with the fiberglass tunnels?

Perhaps the answer is yes but it seems easy to me to grab a few pieces of flat stock and copy the OEM design.

 

[crazyrings]

You've actually said a lot of things, with a lot of feels and guesses.

There will be a very small upforce on the tunnel, especially since they are near veritical from the pin center line. There is almost no lever to act as a force multiplier. As I said before, it'll have a shear force to stop the rotation. Never mind the fact that in the water the stern will just sink instead of presenting a rigid structure.

There is no "pivoting compression brace." It's a platform. Hooked to the ladder mount. With a pin. Yes it gets compression against the boat. It's had a whole lot of crazy forces with people and a 2ft lever (ladder) for the last 18 years.

The point is to make it easier for others to install. Exsisting mounts. Existing reinforcements in the hull at the mounts. My boat is thin where the oem plate goes. I can't speak for yours. I could add backing plates sure, but the ladder mounts already have wood reinforcements glassed in.

Not sure why you think it's so different. You have the same thing, with the exception of two bolts on the top of the plate that try to pull through the hull when you stand on the end of the platform. Yes, the tunnel braces are helping the bolts not let the platet pull away from your boat at the top and rotate around the bottom edge of it.

I've never taken anything away from the Yamaha design. And I didn't set out to duplicate it. If I was going to mass produce it for every new boat going out the door, I'd probably do it their way too. Way cheaper in a production environment. Some plates, some fixtures, stick em together, pop in 4 holes. Simple. I could build the automated cell, CNC or gang head, and robots to do it. It's what I do. But that's not what I'm doing with this. Mine will be stronger, cheaper than buying oem if it was available, easier to mount, and completely customizable for size, shape, color, and engraving.

Now then, I need to go back to bouncing on the end of mine so much that the front of the trailer comes off the ground. I'm cheating a bit right now with a strap to the tow hook since I don't have the tunnel mounts on.

 

[M@__]

Good on you. Check the thread I made about mine, also using king sb.

A few points.

I believe the OEM brackets that go under the tunnels have a step up. I didn’t do that my water level with no load is about an inch above water. With one person on the platform only I have the platform right at the water level.

I think the material is very slick. The logo will help a lot.

It does drag getting up on plane.

On the center support, consider adding two simple bolts at the top into the hull. Without that, your two outer supports are actually holding up the middle support. The hull is about a half inch to an inch thick. Any support from that plus a massive washer would be a lot better than nothing. I actually think it would hold up fine with the center removed. What you want is stiffness though, which you get with more attachment points. That’s made even more important as you make it larger.

Looks cool. Keep taking pictures.

Matt

 

[heloskick]

Hey crazyrings

You've actually said a lot of things, with a lot of feels and guesses.

There will be a very small upforce on the tunnel, especially since they are near veritical from the pin center line. There is almost no lever to act as a force multiplier. As I said before, it'll have a shear force to stop the rotation. Never mind the fact that in the water the stern will just sink instead of presenting a rigid structure.

There is no "pivoting compression brace." It's a platform. Hooked to the ladder mount. With a pin. Yes it gets compression against the boat. It's had a whole lot of crazy forces with people and a 2ft lever (ladder) for the last 18 years.

The point is to make it easier for others to install. Exsisting mounts. Existing reinforcements in the hull at the mounts. My boat is thin where the oem plate goes. I can't speak for yours. I could add backing plates sure, but the ladder mounts already have wood reinforcements glassed in.

Not sure why you think it's so different. You have the same thing, with the exception of two bolts on the top of the plate that try to pull through the hull when you stand on the end of the platform. Yes, the tunnel braces are helping the bolts not let the platet pull away from your boat at the top and rotate around the bottom edge of it.

I've never taken anything away from the Yamaha design. And I didn't set out to duplicate it. If I was going to mass produce it for every new boat going out the door, I'd probably do it their way too. Way cheaper in a production environment. Some plates, some fixtures, stick em together, pop in 4 holes. Simple. I could build the automated cell, CNC or gang head, and robots to do it. It's what I do. But that's not what I'm doing with this. Mine will be stronger, cheaper than buying oem if it was available, easier to mount, and completely customizable for size, shape, color, and engraving.

Now then, I need to go back to bouncing on the end of mine so much that the front of the trailer comes off the ground. I'm cheating a bit right now with a strap to the tow hook since I don't have the tunnel mounts on.

View attachment 83103

I wonder to check in with you and see how your swim platform is working out? Did you end up making any adjustments?

 

[heloskick]

Sorry for the delay in posting up my progress. I started the project last year by getting mtrl but just completed installing the unit this spring. Thanks to @smthng (I don’t know how to tag him) for providing the basic dimensions for me to get started.


Attached are some pictures with basic measurements I used with notes and a key. I cut the mtrl up into appropriate lengths. I then transferred all the holes from the swim platform into the angle plate supports. I bolted the supports to the swim platform and then carefully drilled up thru the hull. I drilled my own holes into the hull to where it may it convenient for me to access with a long drill bit.

Mounted cutting board and angle plate for support, applied 3m adhesive and bolted tight. 2 outside brackets are done. The center piece was a little more involved. Top plate, transferred holes thru swim platform and mounted. The bottom bracket mounted to the hull I machined the curvature/shape of the hull into the aluminum plate for a nice form fit. The last piece was the long 20” brace between the two (I started with 20”x 4”x .250” plate and custom fit). I taped the hull bracket to the boat and used a cardboard cutout to shape the center bracket prior to cutting the original mtrl. Transferred that shape to the aluminum brace, doubled check fit and welded tight. Drilled holes thru the hull, mounted cutting board and large washers, bolted tight. Project complete. I used 3/8” cutting boards for support against the fiberglass. It provides some give and can be heated with a heat gun to form fit or mold to the boat shape. Pictures attached. After mounting the blue swim platform I had to redo the seats to match the color scheme. Out with the tan, in with the blue. YAMATUF was resurrected.


FYI – Yamaha informed me I bought the last swim platform available for the LS/LX series boat.



View attachment 42561View attachment 42561 View attachment 42566

Do you have the dimensions for the original swim platform? I am looking building one. Do you still have your on your boat?

Thanks!

 

[heloskick]

Well I was going to use the measurement and info in this thread to build my own. But one showed up including the brackets, ladder and hardware. It’s a little rough... I think the previous owner might of used it as a battering ram. But it should clean up fine with a little work and some new gelcoat.View attachment 70107View attachment 70110View attachment 70109

Were you able to install the platform to the back of you boat? Do you by chance have the dimensions?

Thanks!

 

[the MfM]

Were you able to install the platform to the back of you boat? Do you by chance have the dimensions?

Thanks!

I did...best mod I’ve done to the boat.

The boats at my camp, I’ll get some measurements this weekend.

 

[heloskick]

Ok that would be great. Do you think its around 6 ft x 2 ft?

 

[the MfM]

Ok that would be great. Do you think its around 6 ft x 2 ft?

Side to side it goes from stern eye to stern eye but tapers slightly.

As far as depth at the center of the platform it’s more like 18”. You might need a 2’ piece of whatever you’re cutting it out of because of the curve.

 

[heloskick]

LX210 owners,

I see the two outside brkts are right angle brkts bolted directly under the boat's swim platform and extended to the external swim platform. This should be easy to duplicate just need overall length, hole locations from end with thickness of mtrl a bonus. The center post is the one of concern. I would need a cardboard (something similar)cut out or trace the brkt on a sheet. (angle and length is important here) measure the width and length of each top and bottom plate for bolting ladder on. If a JB'er has one I would be glad to explain what I need and how to obtain it, just send me an email. I will then draw up a print and post. Cardboard and a sharpie works wonders for providing a blueprint! WE could do the same for the platform itself.

Thanks for the pictures Bruce,

Did you custom make your swim plat form brackets or did you find them online? The two out side ones dont look that hard its the middle one that looks like a pain. Any info would be great.

Thanks!

 

[heloskick]

Do you by chance have the dimensions of the 3 brackets? Especially the middle one?

Thanks

Sorry for the delay in posting up my progress. I started the project last year by getting mtrl but just completed installing the unit this spring. Thanks to @smthng (I don’t know how to tag him) for providing the basic dimensions for me to get started.


Attached are some pictures with basic measurements I used with notes and a key. I cut the mtrl up into appropriate lengths. I then transferred all the holes from the swim platform into the angle plate supports. I bolted the supports to the swim platform and then carefully drilled up thru the hull. I drilled my own holes into the hull to where it may it convenient for me to access with a long drill bit.

Mounted cutting board and angle plate for support, applied 3m adhesive and bolted tight. 2 outside brackets are done. The center piece was a little more involved. Top plate, transferred holes thru swim platform and mounted. The bottom bracket mounted to the hull I machined the curvature/shape of the hull into the aluminum plate for a nice form fit. The last piece was the long 20” brace between the two (I started with 20”x 4”x .250” plate and custom fit). I taped the hull bracket to the boat and used a cardboard cutout to shape the center bracket prior to cutting the original mtrl. Transferred that shape to the aluminum brace, doubled check fit and welded tight. Drilled holes thru the hull, mounted cutting board and large washers, bolted tight. Project complete. I used 3/8” cutting boards for support against the fiberglass. It provides some give and can be heated with a heat gun to form fit or mold to the boat shape. Pictures attached. After mounting the blue swim platform I had to redo the seats to match the color scheme. Out with the tan, in with the blue. YAMATUF was resurrected.


FYI – Yamaha informed me I bought the last swim platform available for the LS/LX series boat.



View attachment 42561View attachment 42561 View attachment 42566

 

[heloskick]

Side to side it goes from stern eye to stern eye but tapers slightly.

As far as depth at the center of the platform it’s more like 18”. You might need a 2’ piece of whatever you’re cutting it out of because of the curve.

Do you by chance have the dimensions and angles of the 3 brackets? Especially the middle one?

Thanks

 

[the MfM]

I measured the platform...

55” wide tapering to approximately 50” wide at the center of the radius on the corners

17.5” deep in the center

18.5” deep on either side

 

[the MfM]

Do you by chance have the dimensions and angles of the 3 brackets? Especially the middle one?

Thanks

I don’t have any bracket measurements. But earlier in this thread @Yamatuf posted a pic with measurements. Pretty easy to fabricate if you can weld aluminum.

https://jetboaters.net/threads/lx210-swim-platform.4448/page-2#post-181213

I wouldn’t worry about the machined curve in the transom bracket. Just use flat stock and bed it in thickened epoxy.

The outer brackets are just 2” angle. There might have been spacers originally on to of the outer brackets to raise the swim deck slightly above the water line. The salvage pieces I bought didn’t include them. So I used 1/2” strips of plastic o ntop of the 2” angles to get everything to line up.

 

[heloskick]

I don’t have any bracket measurements. But earlier in this thread @Yamatuf posted a pic with measurements. Pretty easy to fabricate if you can weld aluminum.

https://jetboaters.net/threads/lx210-swim-platform.4448/page-2#post-181213

I wouldn’t worry about the machined curve in the transom bracket. Just use flat stock and bed it in thickened epoxy.

The outer brackets are just 2” angle. There might have been spacers originally on to of the outer brackets to raise the swim deck slightly above the water line. The salvage pieces I bought didn’t include them. So I used 1/2” strips of plastic o ntop of the 2” angles to get everything to line up.

Thanks for the info. I saw the pictures you were talking about earlier on in the thread. I mainly need to know how long to make the bracket form the transom to the swim platform. I have a buddy who is a master welder and he said he could make them no problem. Problem is I don’t know what dimensions to send him at the moment.

 

[the MfM]

Thanks for the info. I saw the pictures you were talking about earlier on in the thread. I mainly need to know how long to make the bracket form the transom to the swim platform. I have a buddy who is a master welder and he said he could make them no problem. Problem is I don’t know what dimensions to send him at the moment.

I won’t be able to get you measurements till I take the boat out of the water.

But I don’t think any measurements I give you will be accurate enough. The OEM platform varies in thickness and has molded in mounting points.

If I was building new brackets I’d mount the outer ones to the boat, which are just pieces of angle. Then lay a board or the actual platform across them and make a template out of some luan ply.

 

[heloskick]

I won’t be able to get you measurements till I take the boat out of the water.

But I don’t think any measurements I give you will be accurate enough. The OEM platform varies in thickness and has molded in mounting points.

If I was building new brackets I’d mount the outer ones to the boat, which are just pieces of angle. Then lay a board or the actual platform across them and make a template out of some luan ply.

Ok so you are saying to put the 2 side brackets on left and right then set the swim platform on it. Once it’s laying on the brackets make a template out of ply wood for the center bracket. That’s a good idea. Thanks