Stiletto Race Prep

[Darin Jordan]

OK Gang... I have a Stiletto here so it's time to start racing it, and documenting any mods I decide to make.

Here are a bunch of initial pics. This is a bigger hull than most P-Limited OPC hulls out there... it's a full 30", compared to 27" to 28" for many of the others. As such, it carries a little more weight than those other hulls as well. Empty hull, RTR minus batteries, is 5lbs 5oz, which really isn't too bad, especially for a RTR mass produced hull. Looks VERY sweet!

[Darin Jordan]

Radio box is a little cramped, but the battery area is quite roomy. Two 5000mah 2S hardcase packs will fit end to end in the bottom of the battery area, or a single 5000mah 4S hardcase pack will fit just foward of the ESC. Both setups provide a balance point right at 8 3/4"-9", which is about perfect.

ESC is a new ProBoat 60A unit that is programable for Lipos and other settings, just like their BJ26 45A unit. Contacts are still the 3.5mm for the motor, and Deans for the battery.

Radio Box lid is a clear platic piece that slides in under the steering cables and presses down similiar to tupperware. It is NOT, however, nearly that secure, and I would still suggest that people use some tape on it to keep it in place. It won't keep out ALL of the water, in the event of a flip, but it should prevent the compartment from flooding.

Steering is a Pull-Pull cable system, using an aluminum pull-pull wheel on a ProBoat/Spektrum steering servo. Cable is slightly larger than a 4-40 sized, and should hold up nicely.

[Darin Jordan]

The outboard is really a pretty sweet unit. It's cast halves are machined on the mating surfaces and the fit is clean. It's a very stout unit that should easily handle some decent power. A little heavy for a pure racing outboard, but no too bad for the scaleness of it. I weighed it previously, but now can't remember if it was 1.5lbs... or 1lb 5oz... I'll try to get an exact weight the next time I have it apart.

The outboard uses a standard K&B 3.5 length .150 flex with square-drive ends. Coupler is similiar to the REK or Hyperformance Products units. The example here is stainless. I believe this is how they come, so it's a little heavier, but no nearly as prone to wear, as the others. Also let's them be made smaller in size.

Motor mounts to an aluminum "X" plate, which then mounts to the lower unit. Pretty simple, but effective mounting that works, and should allow upgraded motors without any hassles.

Water cooling comes in through a pickup in the cav plate, and is routed up through the system internally inside the lower unit. Exit is a simple water line, exiting alongside the motor.

Stub Shaft is a standard 3/16" sized, K&B style 3.5 stub shaft. Aftermarket replacement stubshafts should all fit. I've test fit it with a Hyperformance Products stub and it fit fine. The shaft length on the stock piece was designed to be long enough to fit pretty much any prop you might want to run. Centerline to cav-plate clearance is enough to fit at least a 50mm prop. Should be more than enough room there.

Stock prop is a new ProBoat Stainless prop, which comes fairly prepped. More work could certainly be done to it, but it looks like it could be used right out of the box to good effect. It is basically their Miss Elam or stock BJ prop, cast into Stainless. I believe those were basically Prather 215s. They look VERY similiar.

The small grub screws on the side plates near the prop are drain holes for the lower. The two halves are not sealed to each other, so water can get inside the unit. I'll try running it with these screws removed and see if water ends up being forced in, or whether it will get drawn out.

NOTE: There is suppose to be a small water pickup tube in the cav plate. I didn't have it installed when I took these pictures, but I assure you that it's there. I'll try to get some more pics to show that part.

[Darin Jordan]

Bottom is very clean. Sponsons are quite rigid and there is very little flex in the tunnel. Glass work is quite nice for a RTR boat, and the surfaces are quite flat and even reasonably true. This should perform very well right out of the box. I suspect I'll be doing a little bit of block sanding to the ride surfaces to scuff them and make them dead flat, but I honestly don't think much will actually be required. A quite look on my setup board shows that the sponsons are very true just the way it sits. On a glass boat, there is ALWAYS a little room for perfecting the setups.

The sponsons are A-symetrical, but the boat drives very well either direction. Obviously, it's optimized to turn right, but again, it corners VERY well to the left as well. Almost makes me want to run an offshore style course..

Stuble/Recovery blocks are ample and nicely placed. White finish on the entire hull is really quite nice.

Cowl includes a smoked windscreen with a driver in the cockpit; a FUN little styling touch. Cowl is held on with two aluminum thumb screws. Motor tucks in nicely inline with the cowl. Motor cover is also made from fiberglass and has a nice glossy-black finish.

[Darin Jordan]

OK, so... I'm going to run this boat out of the box for the first race, which will be June 26th with NAMBA District 8. After I get that baseline, it's game on.

Some of the very first things I know from experience will need to be done are the following:

1) Upgrade the battery contacts to either 5.5 or 6mm (I use 6mm, just because that's what my batteries already have.)

2) Upgrade the motor contacts to 5.5mm. This upgrade helps the contacts stay cooler and ends the "de-soldering" that happens on these spec boats when you run them at their limits.

3) Block Sand true and scuff the sponson ride surfaces.

4) Prop... Time for a little R&D on Props... I know what works with the BJ26 motor, which was around 1625KV... This one is 1800KV, so we'll see what kind of prop this one likes.


I'll start there, after the first outting, and we'll see what else might need to be done to get this boat competitive with the front-runners.

[Doby]

Nice, I like the way the cooling on the lower unit in integrated into the housing.

[johnf]

Darin,

Did you notice if the fitment of the plastic tupperware style cover on the Miss Geico cat has the same seal, or lack of? As in, hatch tape will still be necessary to seal it from water?

Thanks,
John

[Darin Jordan]

Darin,

Did you notice if the fitment of the plastic tupperware style cover on the Miss Geico cat has the same seal, or lack of? As in, hatch tape will still be necessary to seal it from water?

Thanks,
John

NONE of these tops will completely seal the compartments from water. It would take a real tupperware lid to make that happen. However, on the Geico, it was much easier to create a lip on the hatch opening to provide more of a "snap" fit, compared to the tunnel. The top deck of the tunnel has the battery box built into it, and trying to provide a "snap on" type lip would have prevented it from releasing from the mold.

I would recommend a little bit of tape on both. The first Geico I tested lost the inner cover during a serious flip, when the outter hatch ripped off and the water sucked the inner hatch off. It sinks, by the way! A little bit of tape on there would have prevented that.

On the tunnel, I would run a tape along the sides. That should keep out most of the water. Everything in there is water-resistant, however, so a little water isn't going to hurt anything.

[johnf]

Thanks for the info Darin! I know I've been pestering you a lot lately about that cat, but I'm just pumped up about it! I planned on using some hatch tape anyway, but I may just seal the whole cover with tape.

BTW, are you trying to hint that you sent a Miss Geico to the bottom??? LOL

ALSO, to keep things on topic here, that Stiletto looks nice. The outboard is sweet looking!

[Darin Jordan]

BTW, are you trying to hint that you sent a Miss Geico to the bottom??? LOL

I'll continue the sidebar to answer your question...

ALMOST! Not me, but my neighbor... He took me over to his Dad's place on Lake Sammamish, and I was testing there. I wanted him to drive it as he had NEVER driven an RC boat or even a car really, and I wanted to see how it would be have for a complete novice. Worked GREAT. VERY forgiving and he was having a blast.

I had him do some high-speed fly-by's and during the last one, the boat hit a bad wave, and did a roll in the air, landing on the top HARD. Ripped off the hatch. By the time I got to it, it was just the tips of the boat out of the water.

I recommended that they add WAY more floatation, which they have!

OK, back on topic...

[Steven Vaccaro]

Thanks for the detailed pictures and info!

[Darin Jordan]

Thanks for the detailed pictures and info!

No problem... I hope to have some more detailed pics of the inner workings of the lower unit shortly. I have some now, but they are of the prototypes, which are machined and an earlier design, so there are bosses and structure inside that aren't in the new ones. Plus the Production versions are cast, not machined. I'm trying not to show anything that isn't just what you get when you open the box.

The yellow zip-ties on the example boat above, however, are mine... the ones you'll get will be white...

[johnf]

I'll continue the sidebar to answer your question...

ALMOST! Not me, but my neighbor... He took me over to his Dad's place on Lake Sammamish, and I was testing there. I wanted him to drive it as he had NEVER driven an RC boat or even a car really, and I wanted to see how it would be have for a complete novice. Worked GREAT. VERY forgiving and he was having a blast.

I had him do some high-speed fly-by's and during the last one, the boat hit a bad wave, and did a roll in the air, landing on the top HARD. Ripped off the hatch. By the time I got to it, it was just the tips of the boat out of the water.

I recommended that they add WAY more floatation, which they have!

OK, back on topic...

hah, funny stuff! Glad to hear it was recovered.

[Rumdog]

Man, You guys really did a great job with these 2 new rigs! They both look great and appear to work really well too! Damn, I want both! I love that Proboat beat Aquacraft in building the first true FE tunnel. I have to say, I didn't see it coming. Curious, did the same guy come up with the idea for these 2 new boats, or was it more of a collective decision? Way to get me back into RTR's guy's! Darin, what size is the stock Stiletto prop?

[Darin Jordan]

Man, You guys really did a great job with these 2 new rigs! They both look great and appear to work really well too! Damn, I want both! I love that Proboat beat Aquacraft in building the first true FE tunnel. I have to say, I didn't see it coming. Curious, did the same guy come up with the idea for these 2 new boats, or was it more of a collective decision? Way to get me back into RTR's guy's! Darin, what size is the stock Stiletto prop?

The short version of the story goes like this... ProBoat contacted me and said they had a boat they wanted me to evaluate. A very odd looking OPC arrived. I evaluated it and essentially told them that it needed to be a total redo. I asked if they would like ME to do a design and build them a plug. A year or so later, we have the Stiletto.

On the cat... Kind of the same deal... I got a note, saying another hull was on the way. After a review, the top looked good but the size and scale and geometry were all wrong for RC (water doesn't scale... you can't... CAN'T... just scale down a real boat... doesn't work)... I asked it they wanted me to draw something up. I drew up a set of full-scale drawings of the bottom and told them to adapt their deck to the lower hull I had drawn up. The Geico is the result.

So... the seeds for both of these project were started at ProBoat. I only got involved after they had already received initial prototypes that didn't really do the trick. I still have them at home, as a matter of fact...