ML Boatworks RSX380 Outrigger! My first FE wood kit build...

[properchopper]

Since we're sharing ideas for tight clearance motor mounts & the like, here's something I've been doing for years (and won me the American Psychiatric Associations "Duh-Aha" Award/Necessity is the Mother of Invention/ Frank Zappa -

But first the backstory : Being a serious "Ltd" Class competitor, several seasons back I experienced the decline in longevity of the later manufactured NAMBA approved "spec" motors which started lasting as long as a burrito outgassing in a windstorm and hence I needed to be able to quickchange kerfuffled motors between heats minus the frustration of looking for that pesky 3mm hex and first engaging , then unscrewing the front mounting hex's 1/331 turns at a time. This is what I came up with (and how I do ALL my motors now) and maybe this could add to your your in/out mount design :

First - get some 3mm capscrews, de-capitate them, red Loctite them into the front endbell to make studs
quickchange stuff002.JPG

Use small box-end to either initially break loose loose or fully tighten
quickchange stuff003.JPG

Make (or find online) a flexible socket drive ( Old hex handle, .150 flexshaft, 7/32 socket)

quickchange flex001.JPG

Go for it

quickchange stuff006.JPG

[sammyha]

Oh wow... Genius!

Who would have thought? Not me on that one...

What's the best angle to mount the motor/ stuffing box?

Sent from my SM-G950U1 using Tapatalk

[properchopper]

Best to have someone answer who has built this before - I haven't. Gradual bends and remember too much straight distance on stuffing tube can often induce harmonics.

[sammyha]

Ok. Thanks for that info, on harmonics

Sent from my SM-G950U1 using Tapatalk

[sammyha]

Someday I won't wonder... what's in this rigger?

Sent from my SM-G950U1 using Tapatalk

[sammyha]

I uploaded a video on my progress building the sponsons. The sponsons to me are the most challenging part of this build.

This is mostly for anyone considering a wood kit but has never built one. I encourage you to try it. It has been daunting, but very satisfying to take this on. Here's the link...

https://youtu.be/K-M0tPlXPfI

Sent from my SM-G950U1 using Tapatalk

[Raydee]

Building wood boats is not for everyone. I prefer to have someone build them for me but lately its been tough so I may end up doing it myself over the winter. It will probably take me the whole winter to build this rigger.

[sammyha]

Building wood boats is not for everyone. I prefer to have someone build them for me but lately its been tough so I may end up doing it myself over the winter. It will probably take me the whole winter to build this rigger.

It certainly is time consuming. I've found it to be rather enjoyable without a time restriction. But definitely make it a winter project. I've been building the sponsons for more than a week now.

This to me is a part of the build that will be good to have done. There's some fun stuff ahead...

Sent from my SM-G950U1 using Tapatalk

[sammyha]

Here's doing whatever it takes again...

The bottom pieces on the back teardrop section are on. Then I epoxied the side pieces up to where the curve started.

After that set, I epoxied it around the bend. The weight will stay on thru the curing of the epoxy.

Not a part of the build to rush...

Sent from my SM-G950U1 using Tapatalk

[sammyha]

The sponson sheeting overlaps, and is put on in a specific order. Each piece overhangs the frame and has to be trimmed.

Here I'm trimming the side sheeting flush to the frames. Next is the rear ride pads. I have one epoxied on and taped.

This is work...

Sent from my SM-G950U1 using Tapatalk

[sammyha]

[Quote] "I already made some changes to the sponsons based on a friend in the knows recommendations. Added dihedral to the outside sponson, which I had at zero (not sure what I was thinking, every other boat I have designed has dihedral on the outside..guess I thought riggers didnt need it!) and changed the AoA on the turn fin side sponson. Upped it a half a degree over the outside sponson. This will help keep the turn fin from sucking down on the inside sponson due to its extra drag." [Quote]

Mike Luszcz


If Mike has features like this in his design, I want them in my build. I'm not changing anything, I want to experience this rigger as he designed it.

I figure the laser cutting to be very accurate. But I noticed the 3/16" square basswood strips varied in size slightly, and if they were tight going in the slots, I simply turned them 90 degrees.

This means they will slightly protrude above the slots, of course.

So as I'm sheeting the sponsons I'm shaving everything down to the laser cut surfaces.

Sounds a bit over the top, but these are small things that make a big difference to me...

Sent from my SM-G950U1 using Tapatalk

[sammyha]

And you can see the dihedral Mike talks about on the left sponson in these shots. The right sponson is flat...

Sent from my SM-G950U1 using Tapatalk

[sammyha]

Again, weighted down and curing overnight. They are coming out very flat. Bottom and side sheeting is finally done. I'm very happy with the sponsons at this point...

Sent from my SM-G950U1 using Tapatalk

[sammyha]

Something I figured out building airplanes...

I don't sand glued assemblies made with multiple materials. As in plywood, basswood strips and epoxy joined together.

Rather, I shave them down carefully with an exacto knife. Then a light sanding to finish up.

Ever notice how uneven the joints get from sanding due to the differing hardness of the materials?

Sent from my SM-G950U1 using Tapatalk

[sammyha]

The following is quoted with permission from Mike Luszcz.

It's from his thread on his first rigger design. He said sizing is the main difference in the kits(he has a RSX240 also), and tub width adjustments for each size.

Here's the link...

https://forums.offshoreelectrics.com/...ad.php?t=54937

I'm posting this to consolidate his comments on his rigger designs. So it will take less time to read thru his thread and decide to purchase one of Mike's fine wood kits.

It's for those who are over the top(like me) on riggers, and want to immerse themselves in rigger design...



I've added comments in parenthesis to give some context to his explanations...


(In the beginning of the RSX310 thread, Mike starts sharing some of his design features. )

Yes, the top has a lot of curvature, I wanted this for looks...To combat that, the bottom has the quarter round included, just like my sport hydros...which has been extremely effective in controlling the hulls downforce. Right now, this will be a 31" design, but if it works like I hope, a 38" and probably 44" will follow...we just need to see how this goes!

Sent from my SM-G950U1 using Tapatalk

[sammyha]

(A member questions his use of the 1/4 round on the bottom. )

The 1/4 round is not only there because it works, but it also makes the forward part of the center section be flatter as well, AND gives us FE guys what we always need more of...BATTERY ROOM.


(Here he's responding to a question about attaching the rear skis with double sided tape to make them adjustable.)

I don't want people adjusting something that once the design is proven doesn't need moving! The JAE doesn't have an adjustable ski? Crapshooters are not adjustable are they? These are set at 3.25 degrees AoA, just like the front sponsons, which is where they need to be.


(Back to explaining the quarter round in greater detail.)

Yeah, its definitely not an afterthought. Here is the thing, and why I like it so much. It allows me more design freedom. I can arch the top deck, giving my designs some character, not just dead flat from front to back. When your top deck is longer than your bottom deck, you get lift, so everyone else has to run their tops flat as can be, removing "airplane" wing lift. Because of the quarter round, I can effectively increase the bottom side distance, giving me the ability to add the nice, flowing top deck lines that I want to the hull. This ability to add height on the center section of the hull ALSO gives us FE guys way more battery room, not only in height, but it also allows the bottom of the hull to be at zero further forward, allowing for longer packs. It truly is a win win. A windshield wiper blade glued to the bottom...that's an afterthought. It gains you nothing other than stability. With the quarter round, you gain usable features! I also closely measure top deck, and bottom deck lengths on all my sport hydros, and this rigger. It's a key thing.

Sent from my SM-G950U1 using Tapatalk

[sammyha]

(Here is what I quoted earlier in post #101 about shaving the sheeting and basswood strips to follow the laser cut sponson angles.)

I already made some changes to the sponsons based on a friend in the knows recommendations. Added dihedral to the outside sponson, which I had at zero (not sure what I was thinking, every other boat I have designed has dihedral on the outside..guess I thought riggers didnt need it!) and changed the AoA on the turn fin side sponson. Upped it a half a degree over the outside sponson. This will help keep the turn fin from sucking down on the inside sponson due to its extra drag.

Sent from my SM-G950U1 using Tapatalk

[sammyha]

(Here is where Mike goes in depth, after one member wants to make some changes during his build to Mike's design, and another member asks Mike if he is concerned about too much lift in his design and also questions the sponson ride surface.)

No, I am actually not concerned. I already cross checked the tub curvature against that of the center section GSX310 sport hydro...same overall curve, Then I checked the sponson top deck curvature vs. the GSX310, this rigger has a good deal less curvature. So, overall, based on previous experiences, this one is more tame. You have to use the quarter round on the bottom tho! That is a key feature, allowing me to design in this much curvature into these hulls.

Remember, this quarter round idea started with Don Ferrette trying to go 100 mph with an 1/8th scale FE hydro. He accomplished that. Scale hulls like the 108 hull he used to set that record, have a LOT of top deck curve, so this quarter round proved effective. Now, you might say, yeah, a big battery heavy scale...Well Scott Liddycoat did the exact same thing the following record trials when he set his record (90+ mph...cant remember) with a nitro setup..much lighter hull...same quarter round idea, with some additional testing proving how to adjust its effectiveness!

I also measured the top deck tub length vs. the lower pan tub length, and the numbers work out where the top deck should pull the hull towards the water, not away. The cowling may have some lift effect, but less than any of my sport hydro cowls due to its overall height, and only 2" width. So overall, I am have thought this out very well.

Next, ride pad width is 1-5/8". The GSX310 is a touch more, and the GP310v2 is 2" at the trailing edge, and almost 3" before the air relief. The sponson deck, and center section on the GP310 is also much more radical than the GSX310, or this rigger.

Now, The JAE 21 is a 1-1/4" sponson width on the ride surface. Yes, that is slightly less than mine..what 3/8"? But, due to that narrow width and lack of non trip, you have to run the CoG way back, or in rough water, the boat tanks. (See a Gas JAE with the original sponsons..disaster) With my more traditional non trip style sponson, you can run your CoG more like a sport hydro, and keep the bow down where it needs to be, and have the advantage of non trips in rough water, which to me..is a huge goal in this project. The huge amount of space in the tub to shift the battery forward or back, gives us a LOT of adjustability.

Next, we have the inside sponson edge upper air trap rails. These, which you have seen me use on tunnels, and sport hydros just the same, have been incorporated into my design of this rigger. This helps air flow come across the sponson deck in a turn, forcing the air to stay on the deck, in turn holding down the inside sponson, instead of letting it come up, being loose, or potentially blowing off in the turn.

Finally, I will discuss the sponson shear outside edge and the front leading edge. You will notice, I have used a double sponson sheer, creating a 1/4" thick shear....same as all my GSX series hulls. You may have noticed this same rounded outside edge on another few hulls, mainly, full size unlimited hydros. Why do I use these? Simple, the rounded edge, just like the rounded nosing block on my sport hydros, helps stop snap blow offs. These slow down the air flow as it enters the sponsons front, or outside edge, effectively keeping the hull stable. Why? The air hits this edge, slows down, and if the boat does get out of shape due to a wave, or wind, it slows down how fast the airflow change from top deck down force, the underside up force. This effectively gives you more time to react, letting off the throttle, settling the hull back down. If you take a look at some other boats out there, and how they blow off vs. a great Video Jesse J did a few years back of the GP335 (the round, blunt nosing block demonstration), you will see how much slower my designs are to "take flight", giving you a time advantage to settle the boat down.

So, as you can see, a LOT goes into these designs. Function is a must, but I have to have some form...or I quit! haha. Simple history tells us, yes...there is a lot of curvature going on, you are right..but the other things I do to the hull counteract that, which is why it is imperative once the design is done, and tested, and works, not to remove things like the quarter round. It is there so all these ideas work in harmony.

I don't usually discuss these ideas publicly, but I figured it was time to share why I do what I do!

But at the end of the day, it may not work. If it doesn't, I already have a backup idea ready, and can design those changes in less than a day. Will I need them..I really don't think so, but if so, they will be done, and I will test it again, and again until I am happy with the results!

I Hope this clarified everything? If not, let me know, and I will do better to answer.

Sent from my SM-G950U1 using Tapatalk

[sammyha]

Enjoy some great insight into the fertile mind of one of our members!

And maybe get a better understanding of the design and engineering it takes for these riggers to go so crazy fast and yet handle so well.

After I absorbed all this as best I could, I was convinced beyond a doubt I wanted to buy this rigger...

Sent from my SM-G950U1 using Tapatalk

[sammyha]

Another huge step in the build completed!

Those who have built a wooden boat will understand this video...

https://youtu.be/ZQNfyLnNlUU
Sent from my SM-G950U1 using Tapatalk

[sammyha]

Making the removable motor mount I sketched earlier in post #88. Had to make some changes(go figure). I'll just roll some pictures...

Setting the angle with a digital pitch gauge zeroed off the counter...

Sent from my SM-G950U1 using Tapatalk

[sammyha]

Here's one of the changes. The stuffing tube mount is larger than I figured...

Sent from my SM-G950U1 using Tapatalk

[sammyha]

All the pieces mocked up...

Sent from my SM-G950U1 using Tapatalk

[sammyha]

Epoxied together and the blind nuts are in...

Sent from my SM-G950U1 using Tapatalk

[sammyha]

Milled 3/16" wide slots that are .150 deep. The spruce stringers are .200 thick, so the carbon fiber mounts are only raised .050 off the bottom. The tops of the holes in the carbon fiber mount are just below top of the spruce stringers. Should really hold the mounts when filled with epoxy and regain the strength lost from milling the slots...

Sent from my SM-G950U1 using Tapatalk

[sammyha]

Here's another change from my original sketch. Had to split the front end block to fit around the sponson boom support.

With this design I will have access to the screws from the top for easy motor removal. The stringers will come out with carbon fiber mount and the motor.

Of course the stuffing tube mount will stay in the boat...


Sent from my SM-G950U1 using Tapatalk

[bhorowitz]

Very nice.

[boatsrnew2me]

just curious ,why the barb on the stuffing tube mount?

[sammyha]

Very nice.

Thank you

Sent from my SM-G950U1 using Tapatalk

[sammyha]

just curious ,why the barb on the stuffing tube mount?

For oiling the flex shaft. I'm not a fan of it but liked the mount

Sent from my SM-G950U1 using Tapatalk