Darin's Phil Thomas Stealth Build

[Darin Jordan]

I'm thrashing, trying to get a fleet of boats prepped for the Nats... Figured I'd do another build thread for one of them.

Phil Thomas Stealth for P-Ltd Sport and P-Sport Hydro.

I made the transom NAMBA legal by adding a piece of 1/4" hard balsa down each side non-trip, sanded them flush with the sides and the bottom, and then epoxied a piece of 1.5oz fiberglass cloth over the area. Turned out pretty nice. Just need to do some filler to get it smooth again.

In the meantime, I have the motor mount installed. I believe it's an Etti brand? I got it here as OSE quite a while ago. I had to machine the center hole and the screw hole slots to allow the plate the fit the range of motors I want to have the option of running, as some of them use larger screws (3mm vs 2.5mm). I tacked the side plates down with CA, then laminated them in place with some 5.5oz carbon fiber and epoxy.

The Speedmaster Sport 20 strut was mounted on the center line.

Stuffing tube and rudder will be next...

[ron1950]

hey darin .... is that 1/4 in running down the angle? what is the rule that u have to do that for anyway? (too lazy to look it up here)

[longballlumber]

Just curious, did you sand off the "numbs" on the bottom of the boat? Making the entire after plane flat?

Later,
Mike

[phil t]

The transom bottom should be at least 65%of the ride pad width for FE NAMBA racing. I have done about the same to my boat, soon will have the mold redone too.

While on this subject what have you guys had for a good balance point and the best prop for the UL1 setup Stealth boats. I tried mine out with a m440 but it seemed to want more prop for speed.
PHIL T

[ron1950]

phill two guys i know run the m445 on your boats with spec set ups

[phil t]

phill two guys i know run the m445 on your boats with spec set ups

Thanks, I only had a m440 so it wasnt real fast and motor esc barely got warm.

Darin, get it done I want to see you guys boat s run.. You dont have to have the long strut mount, I started recomending the shorter 21 hydro strut, I feel the boat runs better with the prop closer to the transom.

[detox]

I hear a M445 with a little cup added to the tips works good (UL-1 motor esc). Keep the weight light.

[Jesse J]

Down here in the heat, I can't go bigger than a Prather 215 or detounged 442... Motor consistently approaches 150 after a full race.

[Darin Jordan]

I started recomending the shorter 21 hydro strut, I feel the boat runs better with the prop closer to the transom.

-
That's interesting, Phil, because I just happened to have the Sport 20 strut here, which is shorter than the Sport 21 struts I use on my P-Ltd Hydro (rigger)...

I have the strut and rudder mounted now, and should be done with the steering servo tomorrow.

To mount the servo, I fabbed a mount from aluminum. The area where I wanted to mount the servo has a gap between the inner liner and the hull bottom, so I drilled a series of holes in the inner liner and injected some epoxy mixed with milled-fiber into this area. Once dried, it should be nice and solid. The servo mount will bolt to the bottom of the tub.

Hopefully, Turn Fin bracket will happen tomorrow... I'd like to get this running before the 3rd of June so I can get some testing done at our club race. If all works out, I'll take measurements for the setup, pull it down, and try to get it painted before the Nats... Still a bit to do!

[Jesse J]

Darin, where are you putting your cog?

[Darin Jordan]

Darin, where are you putting your cog?

Initially... per Phil's instructions... 15.5 to 16" from the transom.

[Darin Jordan]

You dont have to have the long strut mount, I started recomending the shorter 21 hydro strut, I feel the boat runs better with the prop closer to the transom.

You know, Phil... Looking at the photos... I see now what you are saying. I may have to relocate the strut in the strut mount forward to shorten up the driveline a bit. I'll have to relocate the rudder closer to the transom too, I suspect, if it's in the prop wash. I'll take a look at it tonight.

[Darin Jordan]

Tonight I finished up mounting the steering servo. Pretty straight forward. Added a 3/16" aluminum water pickup tube to the transom, and used a 3/16" aluminum rivet epoxied on the right side of the deck as an antenna tube holder. Opened up a small section of the inner liner liner to accomodate routing for the antenna wires.

Turned my attention to the turn fin. Phil does a NICE job of making this area pretty solid, but I decided that I wanted to just make sure that the turn-fin mounting area was completely solid, so I shaped a piece of 1/4" heavy ply to fit inside, and epoxied it in place. I pulled it into place using a small wood-screw through the sponson transom.

Once this was in place, I laminated a layer of 5.5oz Carbon Fiber over the area. Had to stop for the night to let the epoxy dry. Will fab a turn fin mount for it tomorrow and hopefully get it all fitted. Once this is done, I should be set to start the painting. All of the running gear will be in place.

[ray schrauwen]

You have a motor pretty far back there Darin.

Mine is built but waiting for paint. It runs great too but, I mounted everything as far foeward as possible to get the CG correct Without adding weight.

I can't see you not adding weight by the looks of your motor position but, maybe you have something sneaky in store?

In order for me to avoid adding any weight, I bought the most recent Nano-techs at HK.

I will be using the 6700MaH 2S2P packs in series. it seems to be the perfect weight up front with no lead needed but, I have not water tested it, just bench COG setup.

I did test the cells in my Whip 21 with UL-1 motor and they are excellent, perfect weight balance.

[Darin Jordan]

Ray,

Where are you setting your CG?? How far forward of the transom? Instructions suggest 15.5-16" forward of the transom.

With the motor where it is, I can get the CG where I think I want it with a single 4S1P 5000 setting way up in the front. But this boat will be doubling as a P-Sport boat, so 4S2P 5000 (10,000 total) will be used as well, so I needed the flexibility.

Nothing sneaky in mind yet... Just trying to get it together... We'll see how it works.