Darin's ProBoat Miss Elam Race Prep

[Darin Jordan]

Hi Gang,
I've been fortunate enough this season to be asked to join Team Horizon Hobby. I feel honored by this and we'll see what I can do with their products.

So, for my first project, I've decided for this season to race a ProBoat Miss Elam in "LSH" to test the viability of racing this hull. So, it's only fitting that I do a build-up article.

Here is the first installment.

Overall, this boat is nice quality. The hardware if solid, and it's laid-out nicely. My original intent was to leave it nearly stock, but after looking it over, I've decided to stray from that a tad to make it as competitive as possible, and to make it easier to maintain at the races.

Here are some initial pics. Stay tuned for many more...

[Darin Jordan]

Here are a few more initial shots...

As you can see, there is going to be a little bit of work to do to get the sponson ride-pads trued, but overall, it appears that this will be the most extensively worked area. Everything else looks to be fairly simply upgrades.

More to come...

[calcagno45]

Why the fixed strut?? RTR simplicity? or scale-ness?

[Ub Hauled]

Both Calcagno...

Darin, she sure looks nice... I am looking forward to
see the "how-to" you are putting together.
I know that you are thinking about changing out the
strut to the adjustable type, are you planning in changing
square flex as well? Is there room under the cockpit to place
a 4s pack or 2x 2s packs? How do you like the motor mount,
does it have enough support on the base to hold the motor w/o
"bouncing" around or should there be a rear support for the can?
Does the rudder have enough support or do you think it'll have the same
problem as the UL was having with the turn fin?
I apologize for the inquisition in advance...
thanks for this thread.

[Darin Jordan]

are you planning in changing square flex as well?


Yes... the flexshaft will be being replaced with an Octura or Hughey .150 flex. The reason for this is mostly because the stock stub-shaft is only a 3mm shaft and won't accept the props I'm planning on running, so I'll replace the strut/flex assembly with .150 and 3/16" stub...




Is there room under the cockpit to place a 4s pack or 2x 2s packs?


You can fit a 2S pack on either side of the motor. It's a tight squeeze, but they fit. I think the motor position may make it tough to try to fit a 4S pack up in the nose, so I'll be sticking with the saddle position for now. I have other plans for the area up under the cockpit... Stay tuned for that...



How do you like the motor mount, does it have enough support on the base to hold the motor w/o "bouncing" around or should there be a rear support for the can?


Motor mount is rock solid. Other that recoating all the interior wood with epoxy, much like we did on the SV27s... I don't plan on changing a thing here. I did replace the motor mount screws with some new 3mm screws and chased the insert threads with a tap, but we're getting ahead of ourselves here... I'll document that as we get to it... ;)



Does the rudder have enough support or do you think it'll have the same
problem as the UL was having with the turn fin?


It looks like they've added a plywood backer to the entire transom area, which is an update compared to the original ProBoat Miss Bud. Looks like it's rock-solid back there as well.

More to come...

[Darin Jordan]

I would like you all to keep in mind as I progress through this that some of these things I do, I do because I think it makes it easier to work on the boat. All of these updates are NOT necessary to have fun racing this hull. I'll try to tell you when I'm doing something where I think it's more of a "it's just me" thing, and not something you would HAVE to do...

OK, moving forward... After removing all of the gear, I decided that the stock radio tray was just going to be in the way, so I carefully removed it... It's made of thin vacuum formed plastic, so I just cut it out with an Xacto by cutting the walls just below the top lip, then carefully cutting away the top lip. The epoxy used to glue this on is pretty brittle, so you can pop it loose pretty easily with a flat Xacto blade. Just take your time so as to preserve the fiberglass flat underneath it.

I plan on making a subhatch for this area that can be taped down seperately and will fit directly into the remaining fiberglass lip left around the radio box.

This step is NOT neccesarily needed, but it will make working on the boat on raceday a whole lot easier in my opinion, and it's easy to do.

I also plan on moving the ESC forward in the hull to get the weight off the prop. I think I have the perfect place for it... ;)

[Darin Jordan]

Here are some pictures that show the sponsons... Like with most other RTR hulls, the ride-pads are going to need some work. They are currently convex slightly, and are not "flat". This is typical of pretty much any RTR or Production boat, so it's not a big deal. A little attention to detail here will go a LONG way in improving the speed and ride of this boat.

Another thing I found with this hull is that the sponsons actually had dihedral on one side, and anhedral on the other... And NOT in the directions you would want them... The Left sponson actually has about 1-degree or so of anhedral, which means the outside of the ridepad was LOWER than the inside. This sponson should at most be flat, and maybe even have 1-degree or more of dihedral.

The Right sponson was close to flat. It should actually have 1-degree or so of dihedral.

We'll work on fixing that.

Both sponsons were laterally convex along the ride-pad at the back. In other words, the center of the ride-pads were lower than the outside edges. We'll have to square that up as well. Again, this is NOT unusual for a production boat, and easily taken care of with the addition of some harder ride pads...

Once I figure out what the current geometry is, I'll start working on installing some ride-pads, like I did on the other buildup. This one will be a tad different, because of the sponson shape and lack of anti-submarine pads at the front of the sponsons, but it shouldn't be too difficult. I'm even going to do it in a way that preserves the majority of the original paint... hopefully... :thumbup1:

[detox]

Did you mean: dihedral
http://en.wikipedia.org/wiki/Dihedral

What about the AOA of sponsons...using the 1/16" ply measuring method what did Miss Elam measure out of box?




.....................

[Darin Jordan]

Did you mean: dihedral
http://en.wikipedia.org/wiki/Dihedral



OH, probably! ;) I fixed it in the text above... Give me a break... it's EARLY still! ;)




What about the AOA of sponsons...using the 1/16" ply measuring method what did Miss Elam measure out of box?

With the stock strut setting, they measure about 2-degrees... I think that's going to have to be increased, but before I decide on the final angle, I want to measure the tunnel angles first to see what kind of lift is happening there... It has a double break, with a steep entry for the first 3" or so, then a shallower section, followed by another break to the flat afterplane portion...

[detox]

I want to measure the tunnel angles first to see what kind of lift is happening there... It has a double break, with a steep entry for the first 3" or so, then a shallower section, followed by another break to the flat afterplane portion...

I have a lot to learn...concerning what works and what does not work.

http://en.wikipedia.org/wiki/Hydroplane





....................

[detox]

Could you show us the turn fin and mount?

[Flying Scotsman]

Darin, congratulations on the Team Horizon position.
That hull has great scale looks, which leads to my question, will you keep the wing for LSH racing.

Douggie

[Darin Jordan]

Alright... I couldn't work on the hull much this weekend, but I did take some time in the evening to take a bunch of measurements and draw up some full-sized sketches of the geometry of this hull for analysis.

After consulting with an expert on the topic, I've decided that I'm NOT going to be adding any ride-pads at this point, but will simply do what is necessary to make the ride-surfaces true, and get the dihedral correct.

This is because the geometry of the hull in as a whole should be really good for racing. The tunnel profile will work well with the ride-pads as they are... The focus will be on truing up the ride surfaces, and then making the modifications necessary to adjust the strut. With these changes, I should be able to tune the hull appropriately.

I've done some of the work already and will post pictures as soon as I have them downloaded from the camera.

[Ub Hauled]

Sweeeet

[Flying Scotsman]

Thanks Snowman, Andy, I presume or? :biggrin:

Douggie

[AndyKunz]

Shoot, Doug, not ME! I'm watching this thread so I can prep MY OWN Elam! I work on radios, not hulls.

Andy

[Jeff Wohlt]

Good thread, Darin. Those are very strong and well built motors but I fugure you may be putting something else in? Love to see how it runs on the UL1 Ammo motor.

[Darin Jordan]

Good thread, Darin. Those are very strong and well built motors but I fugure you may be putting something else in? Love to see how it runs on the UL1 Ammo motor.

I will be running the ProBoat motor and ESC... The extra KV of the UL1 comes at the expense of torque... I think either can be made to compete... I'll stick with ProBoat in this boat for now...

[Darin Jordan]

OK... progress....

Warning... some of this is NOT for the Faint of Heart... Proceed VERY carefully...

In preparation for a more adjustable strut setup, I am modifying the stock stuffing tube to allow for more range of movement, mostly in the UP direction.

I carefully cut away the wooden block that is epoxied between the stuffing tube and the hull. Take your time and be careful as you do this.

Spend some time carefully cleaning away the excess glue and wood.

[Darin Jordan]

Next, I decided to anneal the brass in the area where I wanted it to be a little more bendable...

Using a wet rag to protect the surrounding areas and after removing the teflon liner, I carefully heated the tube to glowing in the area where it would need to bend... As soon as it glowed red, I took away the flame. I heated it to within about 1/2" of the hull exit. This process also burned off the paint from the brass.

If you decide to do this, please use EXTREME care, or you'll warp the bottom of the hull or worse. I'm not sure this step is necessary, but I find it makes adjusting the strut much easier and less likely to kink or snap the brass tubing. Also puts less pressure on the hull where the brass exits.

When it's all finished, I used some 220 wet-dry to clean up the brass tubing then went over it with some scotch-brite... or steel wool to polish it up some...

[Darin Jordan]

I like the area that is supporting the motor and driveline to be RIGID... Flex here can cause binding and snapped flex-shafts.

Using some carbon flat-stock, I cut a few pieces and placed them across the afterplane area of the inner hull in such a way as to support the fiberglass around the stuffing tube.

Once cut, I glued them in place with some thick CA. Don't worry about getting them completely glued down all round the edges... the next step will take care of that...

[Darin Jordan]

To complete the stiffening of the afterplane, I am laying in a layer of 6oz Carbon Fiber cloth.

To do this, I cut a pattern to assure a clean fit.

One problem often associated with laying in fiberglass or carbon is that it's sometimes tough to get clean edges. One solution is to adhere a piece of lightweight glass cloth over the carbon. I used some 1 1/2oz lightweight glass weave (I think it's a hounds-tooth pattern...). Lightly fog the surface of the glass with Super 77 Spray Adhesive, then stick it down to the carbon.

Now, you can cut out your shape without worrying about the edges fraying.

Once you have your carbon cut, lightly fog the back of it (fiberglass side) with Super 77, then stick it down in place.

[Darin Jordan]

Once you have the carbon loosely in place, carefully press it down to make sure it completely conforms to the contours, etc.

Once it's tacked down, you can mix your epoxy and work it into the cloth. Start from the middle and work your way out, liberally applying epoxy and working it in using a cut down piece of a bondo spreader, or other appropriate tool... Acid brushes are useful here as well.

Be careful not to catch the carbon and fray it... Just take your time and make sure you get full saturation.

Then blot of the excess with a clean towel and set asside to completely dry. This would be a good time to make sure the afterplane is still flat... If there is any warp in it, block it up somehow so that when the epoxy dries, the warp is out...

[Darin Jordan]

Here are a few more of the epoxying process...

If you have any leftover epoxy, use it to laminate the wood inside...

Once it's all dry, I'll get to work making a new servo mount (or retrofitting the original... I'll have to look at it), and then I'll move onto trueing the ride-pads... or making the adjustable strut...

[Ub Hauled]

does the boat come with thrust bearings Darin?

[Jeff Wohlt]

Not sure about you all but this is turning me on!!:banana:

Got to give it to you, Darin. Do you have three arms so you can build and shoot pictures???

[Darin Jordan]

does the boat come with thrust bearings Darin?


No... On the stock boat, the thrust is taken at the strut... The coupler and thrust bearing you see in the pics is an Octura coupler and VXB thrust bearing that I added...

[rcboatfan]

lookin' pretty sweet darin:thumbup:

[longballlumber]

Darin,

Why not replace the stuffing tube all together. Seems like a lot of work when replacing would be easier and cleaner without the risk of heat warping the hull.

Ub Hauled, good question about the thrust bearing. I was going to ask the same thing!!!

[Darin Jordan]

Darin,

Why not replace the stuffing tube all together. Seems like a lot of work when replacing would be easier and cleaner without the risk of heat warping the hull.


It wasn't hard to do what I did at all... took all of about 10-minutes, with minimal cutting, grinding, and tearing up the hull... Nothing wrong with the existing tubing, just needed a little tweaking... Do it right, and the hull will be fine... And it turned out VERY clean... Nice shiney brass! (I don't actually have the final pictures posted... but you'll see...)

Just the way I roll... :thumbup1: My intent is to be minimally invasive and to do a minimum amount of work to get the job done right...

[Darin Jordan]

I decided to fab a new servo mount... Nothing special. Just a piece of 3/4" x 3/4" aluminum stock, cut and drilled up to fit...

[Darin Jordan]

Once the mount is made, I marked the location... as far forward as I could get it and inline with the rudder arm, the used 6-minute epoxy to glue it initially in place.

[Darin Jordan]

Once that was dried, I used some light glass cloth and some laminating resin to really secure it in place.

[Darin Jordan]

Alright... after some pondering on the best approach, I decided that, due to the amount of blueprinting needed to get the sponson geometry where I wanted it, that adding ride-pads was the way to go.

I fit some .020" G10 to the existing ride surfaces, and it was obvious that more was going to be needed... So, I used some 1/16" x 3/16" birch strips along the inside edge and aft edge to build it up. I CA'd these in place.

[Darin Jordan]

Once the CA had dried, I carefully sanded in the angle I wanted. I used a strip of tape on the outter edge to keep it from getting sanded down.

For the angles, I have the outside sponson (Left) at near Zero Dihedral, and the inside sponson (right) at 1 1/2 to 2-degrees (estimated... I'll measure actual from the pictures later). I used a block sander and some 180-grit to carefully sand then to shape, making sure to keep the length of the sponson as flat as possible.

Willingness to take your time here and a lot of patience helps a lot... Get it right...


After test fitting the ride-pads and making sure they fit properely, I sanded the leading edge of each at a taper to get it to blend into the front of the sponson with as little filler as possible.

I also trimmed up the ride-pads to that they overhung the aft edge by about 1/16" or so, and they overhang the outter edges by a similiar amount. They are flush with the birch strips on the inside.

[Ub Hauled]

Darin, are you going to fill it under the G10 on the side the strips are holding it?

[Darin Jordan]

After a final check of the angles, I carefully epoxied the ride-pads on. I taped them down from the front to back, using electrical tape (it doesn't stick to the epoxy that runs out)...

Make sure the pads are securely taped in place, then let the epoxy dry.

Next... I'll tackle the turn fin and strut...

I'll post some more pics tomorrow after I remove the tape and clean things up...

[Darin Jordan]

Darin, are you going to fill it under the G10?

By the time I was done sanding the angles in place, there isn't much of a gap under there... The epoxy filled in what there was... I think this is going to work out SWEET... The angles are looking really good thus far... and the G10 will hold nice, sharp edges... and will be a nice clean ride-surface...

[JimClark]

Did you level them out and take care of the dihiedral before the ride pad?

[Darin Jordan]

Did you level them out and take care of the dihiedral before the ride pad?

Yes... I tried to just sand the factory surface, but it was too out of whack, so I added the birch strips, then sanded the angle I wanted. After that, the ride-pads layed perfectly flat onto the surface...

[Ub Hauled]

Why do you want the inner sponson with more angle then the outer?

[JimClark]

Done that before for sure
Where do you get G10? Off stealth bombers/?
Jim


Yes... I tried to just sand the factory surface, but it was too out of whack, so I added the birch strips, then sanded the angle I wanted. After that, the ride-pads layed perfectly flat onto the surface...

[Darin Jordan]

Done that before for sure
Where do you get G10? Off stealth bombers/?
Jim

Nope... McMaster/Carr...

[JimClark]

Cool stuff I may have to get some. How does it sand?

[Jeff Wohlt]

Excellent job. You should see a big increase of speed and handling with those sponsons mods.

Can't wait to see you get it wet.

[detox]

I like that hull color. What color is it...Fluorescent Red or Fluorescent Orange? Have you found a match yet?

[Darin Jordan]

I like that hull color. What color is it...Fluorescent Red or Fluorescent Orange? Have you found a match yet?

I'm not sure... I haven't looked yet... I've been trying to do everything I can to protect the factory paint and not have to repaint anything. The ride-pads, for example, will get left either as they are, or painted white... I'd prefer not to paint them at all... just adds weight and drag to an otherwise very sharp surface... I don't really care what the ride-pads look like... If you can see them, you have bigger problems than looks... ;)

[detox]

White is a good idea...maybe Flat White will break up the surface tension a little?

[Darin Jordan]

Ride pads are finished...

They turned out very well, with one slight issue... The right-side pad slipped under the tape slightly and dried just a tough to the right of where I wanted it... Easy to deal with... I just sanded down the outside edge to get it straight with the hull, then sanded a bevel into the inside edge, which will act as a non-trip while the hull is sliding through the turn. Ideally, I'd have liked it to be flush and square, but I don't anticipate it being an issue.

Once I removed all the tape, I used a block sander and scuffed the surfaces and sanded the edges to get them square and sharp. The pads a very flat now and solid.

At the tops, the epoxy combined with the tape-down method I used blended them in almost perfectly. A light sanding here and it's good to go.

Next I'm going to work on making a new turn-fin bracket.

[Darin Jordan]

Just a few more shots to show the finished results...

[Darin Jordan]

Here are the finished angles...

[Jeff Wohlt]

I was thinking flat black would look good. Nothing slick. Alot of the hydros and drag boats have that on theirs but it is a special coating of something.

[Darin Jordan]

I don't think I'll be painting anything until I find out if it works first... there may be some fine-tuning that needs to be done.... Much easier to do if you don't have to get through the paint first...

If I do paint them, it'll be flat white...

[Ub Hauled]

Why do you want the inner sponson with more angle then the outer?

[Darin Jordan]

Why do you want the inner sponson with more angle then the outer?

Without getting into too much technical detail, which would likely give someone the opportunity to call me out on being totally wrong... it helps the boat track straighter and corner faster... Most of your fast Nitro riggers are done this way as well... and some even use toe-in on the sponsons...

Maybe someone who knows more about what they are talking about could chime in and give more detail... ;)

[Darin Jordan]

I initially set out to just modify the existing turn-fin assembly to give it more rigidity... I added a piece of .060" carbon fiber to the bottom of it and drilled it up. This bracket is PLENTY rigid and would work great...

However, with the stock turn-fin mounting with only a single bolt and way up at the leading end, it flexes some laterally from this point.

I decided to make an extended bracket and will drill up the turn fin for a second mounting hole at the top. This should firm it up.

The stock turn fin should work well. It's very rigid and made of stainless. Just needs to be sharpened some and I think it should be up to the task. I'm not really that fond of curved/bent turn-fins, but I'm going to give this one a shot.

The bracket I made is from some 7075 T6 aluminum angle pieces I had laying around. I got the stuff from Boeing Surplus, and it's INSANELY rigid... especially for being so thin...

I think this new bracket may be overkill for most, but I'm going to do it anyhow! ;)

[Ub Hauled]

Without getting into too much technical detail, which would likely give someone the opportunity to call me out on being totally wrong... it helps the boat track straighter and corner faster... Most of your fast Nitro riggers are done this way as well... and some even use toe-in on the sponsons...

Maybe someone who knows more about what they are talking about could chime in and give more detail... ;)

that's what I thought Darin, but I always thought it was on the outer sponson?!
Hmm, I'll research a bit more on that...

[Jeff Wohlt]

No, inner sponson from all that I've seen. Darin hit the reasoning pretty well.

[Darin Jordan]

I made some more progress...

Got the turn fin assembly ready mounted. I used some JB-weld to affix a piece of .090" carbon fiber to the new turn-fin bracket, then drilled up the sponson to fit. We are in luck guys... the ProBoat Miss Elam has an aluminum backing plate across the ENTIRE width of the sponson transom, so I just had to drill it up and tap it accordingly. I tapped it for 3mm screws so I the wrenches would be consistent.

I decided for now to stick with the stock turn-fin. It's made of stainless and is actually VERY rigid. I sharpened it up a bit more and it's like a kitchen knife now. We'll see how it works before putting time into something else.

For now, I'll also just leave it mounted with the single bolt, but I may add one additional in the future. I may also brace the bracket with a brace to the non-trip, but we'll see if it's needed...

[Darin Jordan]

After mounting the turn-fin, I found that the sponson has a fair amount of "flex" to it. This part was a pain to execute, but I layed in some 5.5oz Carbon Fiber cloth into the sponson the best I could. I cut one piece to go into the turn-fin area, and another to lay down the side, then epoxied the heck out of it. I may put down some more tomorrow, depending on how rigid it feels when I'm done.

No magic tricks here, just a struggle and patience.

[Darin Jordan]

I know it's not very pretty, but this is the bracket I came up with for attaching the adjustable strut. It started out picking up the existing holes, but they just aren't aligned properely in this hull to make the bracket square-up with the transom, so I made new holes and tapped them for 4-40 button head screws. This allows me to rotate the plate around to get the bracket aligned correctly.

I have another piece of angle stock, and if this works, I'll make a new one with fewer holes in it! This will work for now to prove the concept.

I thought about just screwing to the transom, but it doesn't have enough structure to hold the screws, so this was a simpler method that shouldn't have involved making any new holes.

Now I have a fully adjustable strut...

[Darin Jordan]

Just a quick update... no pics this time...

The addition of the carbon fiber cloth in the sponson to add some rigidity to the turn fin area worked PEFECTLY... that area doesn't flex at ALL now. Pain in the butt to do, but well worth it...

[Darin Jordan]

I just got word from another guy in our club concerning the Elams... He and his son both got them, and were out running/testing. One of them flipped, and sunk. Apparently there isn't enough floatation in them.

Interestingly enough, I had just ordered some of the 2-part foam this morning. Look for me to be adding this into the sponsons. The boat needs more forward weight anyhow, and also this will help to make it much more rigid up there...

I'm working on a method to modify the hatch to seal it but still maintain the cool looks. It's going to still need to be taped on the outside, but should be easy to do and look good still.

I'll try to post some pics by tomorrow if I make enough progress. It's almost there. This was going to be the last step, but it sounds like foaming things will be instead...

[Ub Hauled]

Oh man that sucks... I hope they get a replacement from Proboat.
At least they are saving boats in the future....

Darin, I was hoping for a few pics, I need my "fix" man!
;)

I don't think I ever asked you but, did you run the Elam prior to the mods?

[Darin Jordan]

Darin, I was hoping for a few pics, I need my "fix" man!
;)

I don't think I ever asked you but, did you run the Elam prior to the mods?

Pix will come shortly. I just needed time to make some progress...

I did NOT run this boat first, but I did run my previous one a bit. There are just some things on Hydros that you just KNOW need to be a certain way... And I'm not really changing anything in the general geometry of this boat, just "blueprinting" what was already designed into it.

With the interesting conversation about the sponson angles on the other buildup thread, it will be interesting to see how this works, because it has a very different set of angles... In theory, it should be able to handle some decent speeds with stability and low fly-off risk, but we'll see... The two cannards up front are the variable I haven't measured out yet... But if they give too much lift, the quick application of a "Gurney" flap or other lift-killing device wouldn't be hard to add...

[JimClark]

Darin I am going to fiberlay today to see if they have it and I knoe Tap Plastics has it for sure in quarts. don't buy too much it has a short shelf life

Jim


I just got word from another guy in our club concerning the Elams... He and his son both got them, and were out running/testing. One of them flipped, and sunk. Apparently there isn't enough floatation in them.

Interestingly enough, I had just ordered some of the 2-part foam this morning. Look for me to be adding this into the sponsons. The boat needs more forward weight anyhow, and also this will help to make it much more rigid up there...

I'm working on a method to modify the hatch to seal it but still maintain the cool looks. It's going to still need to be taped on the outside, but should be easy to do and look good still.

I'll try to post some pics by tomorrow if I make enough progress. It's almost there. This was going to be the last step, but it sounds like foaming things will be instead...

[Ub Hauled]

I am assuming you guys are using the NON expanding stuff... specially since there is no room for the excess to come out... right?!

[Doby]

I use the low expansion foam in all my boats. As long as you do small sections over a few days,,no problems!

[Darin Jordan]

I use the low expansion foam in all my boats. As long as you do small sections over a few days,,no problems!


I bought the 2lbs density stuff, and will pour it in SMALL amounts into the sponsons with the transom up in the air... Just do a little at a time and see where it goes... Should be fine if done with care.

[Ub Hauled]

why is it that people don't like the non expandable stuff?
do they soak? smell? not hard enough?

[Darin Jordan]

why is it that people don't like the non expandable stuff?
do they soak? smell? not hard enough?

I don't even know what it is... If it doesn't expand, I'm not sure I see the point... it has to be poured into the area, then the hope is that it will fill UP the area by expanding into the gaps, etc...

[Ub Hauled]

it is like a foamy liquid, it just does not expand... lemme see if I can find a link.

[Darin Jordan]

With the strut now mounted, I'm getting closer. It's time to turn the attention to keeping things DRY! That's a challenge on this hull, but I think I have a solution.

First, I made a new subhatch to cover the radio box area. This won't seal anything, but it gives an extra layer of protection none-the-less.

I used the factory hatch and some extra tape to make a pattern, then cut-out a G10 hatch cover.

[Darin Jordan]

To solve the problem of how to seal the hatch itself, I made some modifications that I think worked out great.

First, I sealed the factory antenna hole by taping over the outside of it with electrical tape, then glassing and epoxying it on the inside.

I sealed up the exhaust cone hole using a piece of fitted G10 sheet, glassed and epoxied into place from the inside.

[Darin Jordan]

The area under the stack has a pair of "gutters" to shed water away from the hatch area. These don't allow good taping, so I dammed them up and filled with Epoxy, then got them truely even with the deck using filler, with a thin layer of epoxy over the top to seal it...

While I was waiting for the epoxy to dry, I also installed an new 4-40 steering rod and rubber boot....

[Darin Jordan]

OK, this is the cool idea I had...

To solve the issue of HOW to seal around the stack, my solution was to make the stack MOVABLE...

SOOOOO... I got an aircraft aileron hinge, and mouted the back of the stack to the transom with the hinge.

I marked the stack so that I could trim it to JUST touch the cowling, then sanded it down to fit.

I used one of the magnets for the factory hatch and embedded it into the front original stack mounting hole. I used a 3/8" wood hole bit to drill down. There is a piece of foam or wood or ??? under the deck in the back, so if you are VERY careful, you can slowly drill it down to a depth where the magnet side of the latch is JUST below the deck.

ON the stack, I modified the front mounting hole to accept the other halve of the magnetic latch, and epoxied it into place.

[Darin Jordan]

I used epoxy and a piece of electrical tape to glue it in place.

Using some of the left over epoxy, I also glued a brass tube into the factory water line hole...

[Darin Jordan]

With everything all dry, I now have a hinged exhaust stack that can be moved out of the way for taping, and securely stays down afterward... Pretty slick in my opinion and very functional, while maintaining the look...

[detox]

Sorry Darin, but I have to say this. THIS IS REDICULOUS! Sounds to me like Pro Boat really screwed this hull up. They need to redesign a new more simple hull.

[Darin Jordan]

With the hatch now sealable, all that's left is to do the finishing assembly and install the electronics...

It's all ready to go. After my 2-part foam arrives, I will put that into the sponsons. In the meantime, I just have to dial in the radio and then get her wet. I'll let you all know how it does!

Also, I didn't show it in any pics, but I trimmed out the forward two magnetic mounts.... You'll need every bit of extra space to fit Lipos in there...

I have been able to fit a pair of Elite 30C 4500 2S1P packs in there. Any longer and they won't fit. One might be able to make them slightly thicker, but it's a TIGHT squeeze, and there is NO adjustment with the way the boat is setup. You could make them go backwards if you trimmed out the bulkhead, but you'd never want to do that. Any balance issues will have to be resolved with lead in the nose somewhere...

[Darin Jordan]

They need to redesign a new more simple hull.

Ummm... Unless I'm missing something... I think that's what I just got done doing...

You have to remember... this boat was NOT built for the racing crowd... It works fine for market it was intended...

Now it will work fine for us racers as well... :thumbup1:

[JimClark]

When and where?

Jim


With the hatch now sealable, all that's left is to do the finishing assembly and install the electronics...

It's all ready to go. After my 2-part foam arrives, I will put that into the sponsons. In the meantime, I just have to dial in the radio and then get her wet. I'll let you all know how it does!

[Darin Jordan]

Jim,

I'm not going to the practice race tomorrow, as I have to work at work, then come home and work on finishing up the bathroom remodel I'm doing...

Probably won't be until the 28th...

[AndyKunz]

Darin,

I think my competition hull will include just the sponson and strut mods. The rest is your preference for keeping the insides dry. I'll concentrate on keeping the wet side down ;)

Andy

[Darin Jordan]

Darin,

I think my competition hull will include just the sponson and strut mods. The rest is your preference for keeping the insides dry. I'll concentrate on keeping the wet side down ;)

Andy


Just make sure you add FLOTATION! We had a guy in our club loose one of these last weekend with the stock setup... Hatch blew open, whole deal sunk right to the bottom...

Oh, and by the way... Mine will stay dry, AND stay right-side-down... :tt2:

[Darin Jordan]

Quick Update...

I used 2lb density 2-part expanding foam in the sponsons and down the non-trips last night... Worked out well... I did 2-pours of 20cc volume (10cc part A / 10cc part B) into each sponson, then a 20cc pour down each non-trip... waiting about 15-minutes between pours for it to harden and fully expand... Seems to have worked out very well... the sponsons are solid now, and the additional foam in the non-trip area helps make that more rigid as well. I think this will help reinforce the seams as well as add much needed floatation...

I have the boat completely ready to race, and will be racing it tomorrow (Saturday, March 28th) if the weather holds up. It's suppose to be COLD, RAINY, and "GUSTY", so we'll see how that goes...

I have an EagleTree V3 onboard, with two temp probes (battery and motor) and an RPM sensor. If I can run it, we'll see what kind of data comes back. When time permits, I'm going to also see if I can get the airspeed sensor hooked up (maybe up in the scoop) and we'll see if I can get real speeds as well...

Fully ready to race, with two 4500mah Elite 30C 2S1P packs and the EagleTree onboard, the weight is 5lbs 4.1oz...

Hopefully we can run tomorrow and I can report back some useful data...

[JimClark]

Darin how many heats of LSH would you usually run? I am not going to miss it if I get there around Noon am I?

Jim

[paulwilliams]

how many heats of LSH

Forgive my ignorance, but what is "LSH"?

Paul

[JimClark]

Limited sport or spec Hydro

[paulwilliams]

Limited sport or spec Hydro

Ok, a controlled formula then - restricted motor etc.?

Paul

[Flying Scotsman]

Darin, very interesting mods...how many hours?

I trust that all goes well on the maiden voyage.

Douggie

[Ub Hauled]

Ok, a controlled formula then - restricted motor etc.?

Paul



Restricted motor and ESC... supposedly... Clubs run their own versions.
NAMBA stated Nixx batteries and a 700 brushed motor only and a minimum of 24" long and real hydro resemblance.

[paulwilliams]

Restricted motor and ESC... supposedly... Clubs run their own versions.
NAMBA stated Nixx batteries and a 700 brushed motor only and a minimum of 24" long and real hydro resemblance.

SWAMBC, the club I race with here in the UK, had a similar class which we updated for this year to a restricted brushless (Mega 22/30/2), 4S 5000 lipos and 2Kg weight limit - everything else is open.

We ditched the Speed 700 BB, as 5 minute heat racing meant you got maybe 2 meetings from a motor before it burned up. 3-4 motors for a season's racing was getting a bit expensive, compared to brushless.

Paul

[Darin Jordan]

We ditched the Speed 700 BB, as 5 minute heat racing meant you got maybe 2 meetings from a motor before it burned up. 3-4 motors for a season's racing was getting a bit expensive, compared to brushless.

Paul

We were working on "ditching" the 700s as well, but don't have anything official in place yet, so what our clubs around the country are doing is making up their own sets of spec rules... all seem to be basically based on the SV27, BJ26, or UL1 motor packages and 4S1P Power systems... Hull just has to be fit the existing LSH rules and be 24" or longer.

Maybe something more official will be in place by next season... Things move a little slowly in that department in NAMBA...

[Darin Jordan]

Darin how many heats of LSH would you usually run? I am not going to miss it if I get there around Noon am I?

Jim

Our races usually last until around 4:00-4:30pm... we have up to 9-classes running if everyone shows up... There should be at least 3-heats...

[paulwilliams]

Hull just has to be fit the existing LSH rules and be 24" or longer.

I was very keen to get a minimum hull length as part of the updated rules for 2009, but instead we settled on a minimum weight limit. There's always someone who's convinced a tiny boat with monster power will be unbeatable. Uncontrollable? Yes. Not unbeatable :olleyes:

We chose the Mega as these are relatively cheap in the UK, but are well made and should last a long time.

Paul

[Darin Jordan]

We chose the Mega as these are relatively cheap in the UK, but are well made and should last a long time.

Paul

The reason most are picking one of the RTR motor offerings is just for that reason... We wanted a place where people could race their RTR boats off the shelf and be somewhat competitive... We'll see how that works out this season, as many out there have UL1s, and a few of us have Elams...

[paulwilliams]

The reason most are picking one of the RTR motor offerings is just for that reason... We wanted a place where people could race their RTR boats off the shelf and be somewhat competitive... We'll see how that works out this season, as many out there have UL1s, and a few of us have Elams...

The Speed 700 BB in the UK has given us some of the best and closest racing for something like 14 years or so. High capacity cells (and, I suspect, a lowering of quality standards) have basically killed the 700BB as a viable FE racing motor, especially for 5 minute racing - it just gets way too hot, then burns up. The 22/30/2, in contrast, is barely warm - not surprising, given the difference in efficiency between the two motors.

We're expecting the new restricted class in 2009 (we call it Formula 4) to be a lot of fun, especially as the boats are faster, even with an extra 2 minutes run time (7 minutes required). Not sure my nerves are capable of dealing with 7 minute heats :w00t:

Paul

[AndyKunz]

It's an official NAMBA class which limits both motor and cells, as well as the standard hull size limits. You can download the rules from the NAMBA website.

I think Darin's club has a little more liberal rules than the national set.

Andy

[Darin Jordan]

I think Darin's club has a little more liberal rules than the national set.

Andy

Not really... we follow NAMBA LSH rules, except for the motor and cells... It's not just our club... I don't know of any clubs still running LSH as a 700 class...

[AndyKunz]

That's exactly what I meant.

90% of the National rules are the motor and cells. The other parts are P Sport hull and 1 mile heat.

Give me a holler when you get back.

Andy

[JimClark]

Man Darins boat was so fast today that this is all I could get for a picture:thumbup::banana::rockon2:

http://jimclark.smugmug.com/photos/500870493_EmgyS-M-0.jpg

[calcagno45]

I think we know better than that!!

[Ub Hauled]

More pics!!! More pics!!!

[Darin Jordan]

Very Funny Jim...

I didn't make it to the race because as I was driving up there, my 2003 Tahoe died on I405... Had to have it towed home...

Symptoms pointed to either a fuel filter, fuel pump, or TPS, so I replaced the fuel filter, which I found upon inspection was very obviously clogged, and it's been fine since then, so hopefully that's all it was.. didn't have time to drive up there after I got it fixed or I would have...

Guess the testing will have to wait for another day... bummer, but it is what it is...

[eboat]

Darin have you had this in the water yet ??

[Darin Jordan]

I've made a couple of small updates, based on data gathered from the two previous races.

First... At the last race, I decided after three heats of the sponson tips trying to see if the sun was still there, to strap on about 8oz of lead to the front wing. Boat instantly settled down and was able to be driven HARD around the entire course... handled great... SO, I've added about 6oz of lead into the front of the hull. I did this by VERY carefully drilling two 1/4" holes through the side of the sponson and ALL the way through the wing (it's hollow... just had to drill through the 2-part foam I had put in there) to the other sponson. I then slid two sticks of 1/4" fishing lead across the front of the boat, through the wing. Each stick weighs right at 3oz. The holes through the sponson didn't turn out that clean, due to the brittleness of the glass on these, but I've filled them in with epoxy and will clean them up tomorrow and hopefully be able to cleanly touch up the paint there.

For those of you who are "weight-a-phobes", don't be concerned... a light boat doesn't do you any good if you can't keep it on the water, and we have plenty of power with these motors. I'd rather be heavier and be able to run all out than light and have to feather the throttle the whole race...

The problem with these pickle forks is that you simply can't get the CG right with batteries. You can't get them far enough forward with most designs. Since the Elam is 6oz lighter or so than the UL1 in stock trim anyhow, I don't feel like I'll be giving up much, if anything. I actually feel like this will gain me speed, because I'll be able to get back to some real props, now that the nose will stay down when I need it to.


Second... I've made a new turn fin. Just about 1/4" longer, and a longer chord length to give it more area. It's made from .060" 7075 T6, and has two slight bends in it to hook it at the bottom, one 1/2" up and the second 1" up... Not quite as hooked as the stock one. Sharpened and drilled up. Should provide a bit more control in the corners when the water gets "racey".

I'll test all this on Sunday and let you know how it works out.

[Jesse J]

Great idea: the weight in the wing! I have since thrown two dead nicad packs in the sponsons and it ends up just about 6 lbs! I may try your trick - weight way up front. I really do love this hull, looks are top for me.

Have you noticed any reluctance to turn in this hull? I may just not have enough servo throw, or maybe its the turn fin. I am curious to see how this new fin works.

[saleens7]

i just read through this whole thread and i have to say im impressed.....looks like it took a lot of work to get the hull to be race worthy.....goes to show just how well built a race hull would need to be....

[Darin Jordan]

i just read through this whole thread and i have to say im impressed.....looks like it took a lot of work to get the hull to be race worthy.....goes to show just how well built a race hull would need to be....

Please keep in mind what I said at the beginning... a LOT of this work is just because I have a certain way I like things to be. The most important thing I did was to blueprint and add the ridepads... Second would be the adjustable strut modification. Everything else was just for ease of maintenance and to keep things dry... I guess also to make it survive under race conditions in case it gets hit or flips...

Hopefully some of these ideas will make it into future offerings... I may have some pull with that! ;)

[Darin Jordan]

Have you noticed any reluctance to turn in this hull? I may just not have enough servo throw, or maybe its the turn fin. I am curious to see how this new fin works.


Mine turns fine, but the stock turn-fin doesn't have enough area, and is a tad too shallow... at least on mine it is (keep in mind, I made a new bracket and the ride pads added a touch of sponson depth...)... A longer chord and a tad deeper will certainly help. I was having trouble holding lane one at speed... this should certainly help.

Also, I'm running a stronger Hitec HS-225MG servo, so that may help as well...

[Darin Jordan]

Epoxied over the two holes in the sponson last night, and sanded it smooth today. Just going to tape over it for now. Still need to find the appropriate touch-up paint for this kind of thing.

We'll see how she does tomorrow... CG is now right about the center of the turn fin, which is a LOT closer to ideal... Should translate to better race performance.

[rcboatfan]

looks great!!1

[Jesse J]

Darin, did you coat your stickers with a clear coat? they look really good!

[Darin Jordan]

No... they are factory that way... They are starting to peel off where I've been taping the hatch, however, but otherwise, it really does look great.

The weight REALLY helped... boat was really a lot easier to drive... Turn fin helped as well, but I still think it needs to be deeper. I have another one that I started to make that is 3/8" deeper or so. I'll be putting that one on next.

I ended up adding another 2-oz of lead taped up under the center of the front wing... this seemed to really be a good final tweak.. boat was really good in the straight... flat out. I think once the turn fin is hooked up a little better in the corners, it'll be exceptionally competitive... it really goes well.

I think that there should be some great pics forthcoming... Jim Clark was there with his amazing eye and camera equipment...

Oh... and after flipping on the second lap of the first heat, I won the next two, then had a runoff for second overall for the day, and won that too. Boat is becoming VERY raceable....

[JimClark]

Here is one teaser
http://jimclark.smugmug.com/photos/545190424_HGVyD-L.jpg

the rest can be seen here

http://jimclark.smugmug.com/gallery/8321718_esjPP/1/545190424_HGVyD

[saleens7]

I'm still impressed by that camera work of yours.....great pictures of the race :thumbup1:

every one of them are desktop background worthy.....

not to mention the detail work of some of those boats too....

[Jesse J]

Darin, what speeds are you getting? I ran mine yesterday, totally unmodified hull but with my two dead nicads in the sponsons (UL1 motor/X640 prop) and she clocked in at 44mph. Dam stable too, with 6lbs she will be reluctant to flip. I still need deeper turn fin as well; I couldn't talk you into makin an extra could I?

[longballlumber]

Darin,

Sorry if I missed it but, are you running 1P or 2P? What is your weight ready to run (w/batteries)?

Thanks
Mike

[Flying Scotsman]

Here is one teaser
http://jimclark.smugmug.com/photos/545190424_HGVyD-L.jpg

the rest can be seen here

http://jimclark.smugmug.com/gallery/8321718_esjPP/1/545190424_HGVyD

Jim, as usual stunning photography. Darin, not too shabby on the boat also.

Douggie

[Darin Jordan]

Darin,

Sorry if I missed it but, are you running 1P or 2P? What is your weight ready to run (w/batteries)?

Thanks
Mike

I'm running 4S1P Elite 4500 cells, 2S on each side of the motor... can't fit anymore than that, and those are stuffed in...

Not sure the final weight now... was right at 5.5lbs or so... I'll weigh it again... don't really care, to tell you the truth, because the heavier I've made it, the faster it goes... :biggrin:

[longballlumber]

Thanks for the reply Darin,

I am looking for a basline for weight on the P powered "spec" hydro hulls. Even though I have room, I am limited to 1P. So, I don't have the option of the added battery weight in the front of the boat.

[Darin Jordan]

Thanks for the reply Darin,

I am looking for a basline for weight on the P powered "spec" hydro hulls. Even though I have room, I am limited to 1P. So, I don't have the option of the added battery weight in the front of the boat.

Nothing wrong with 1P... Anything under 6lbs will be fine... I'm pretty sure mine is approaching that... I'll get an accurate weight hopefully tonight when I get home from work...

Like I said... each time I've added weight... it's gone faster around the course... Can't use the power if you are trying to keep the nose down all the time by having to back off the throttle...

[DCam]

Darin, I have an older Bud version of this hull I think? Dan Proulx gave it to me. He'd ran it as a P-sport some years ago and it ran well. He got it as a bare hull and set it up as FE. It has some side-to-side structrual weakness in it that developed over time I need to fix. Probably just a carbon rod will do. I'm gonna check with this hull on sponsons etc. per your thread. Thanks for all the info. I may give that Bud a go with LSH for some experimentation.

[bdmridgeback]

I had a good idea, I think! At least it worked. I am a south Florida Distributor for Dyna Beads, ceramic beads used to balance tires on motorcycles and cars.

I poured 3 oz of beads into each of the sponsons with the boat standing on its nose. I then injected a small amount of epoxy down into the sponson on top of them to seal them in. It worked great and boat handles awesome. I wanted something that I could get as far forward as possible and this was it! And being Ceramic, they are heavy for the amount of media used.

I am running a Ammo 2300, Castle 120 speed control and a pair of 2S ThunderPower 5000mAh 45C batts. Just working on the prop dial in now.

Some very good info in this thread.

[mp3ranger]

Hello Darin

I am building a miss elam. I got the hull with no Strut on the boat. So I going to use a strut off a ul-1. I cut out the brass tube out of the hull and going to replace it. I like know what is a good strut height to start with. Also replacing the motor mount with a adjustable 540 XL water cooled one. Do you think moveing the motor forward (1/4") in the hull would make the boat handle bad?

[Jokerswild]

Yea I know this is an old stickied thread, long time reader... first time poster.

I run a lot of on road and off road track rigs and have a couple planes..... as for boats I've driven but never built. I too like above poster have a nitro bud that's been a wall hanger for a while and wanted to go to electric in it......... my shaft is a straight one with no strut.what's the go to and level of difficulty on getting a flex shaft set up in this rig? I have building skills on many levels just never done or set up anything in a boat.