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...

[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?

Douggie