Sprint Cat 29 Build

[midnightsabotage]

I kind of forgot about this build once the cold hit, whoops. I think all I did since my last post was some smoothing and finessing of the hatch and the sponsons a bit. I haven't done any boating this year either!

Gotta get my butt in gear. I'm going to put this hull on the workbench this weekend and see what happens.
Maybe I'll get motivated that way and atleast fill the water exit in the bottom of the tunnel. Then perhaps I can install the pickups and the hull should be ready for paint, if I can come up with a scheme I'll be happy with.

...I did say this wasn't going to be a quick build, lol.

[midnightsabotage]

Success!

Got a little bit of work done over the weekend:
*Plugged the water outlet hole in the bottom of the hull
*Drilled the 2 other holes for the rudder bracket that I had previously neglected
*Filled all sorts of small blemishes here & there
*Dremelled out most of the old carbon fiber & epoxy hull floor reinforcement (the old material was softening and actually peeling up here & there)
*Laid a fresh coat of epoxy and fiberglass reinforcement around the floor of the hull where the stuffing tube passes through after grinding out the old material.
*Sprayed a coat or 2 of primer and re-sanded most of the hull exterior & H. Re-sharpened the sponson edges and such a little bit as well.
*Installed the 2 water cooling outlets, one on each side of the hull.

Still need to figure out the water inlets and lay down new hull reinforcement inside, but things are finally progressing again! Oh, and I need more primer...

There's not much to show of the progress this time, but here's the current state anyhow:
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[midnightsabotage]

Lots more work done...

Laid down a nice new fiberglass floor in the hull, strengthened the motor mount (still don't like not having a rear support with the large motor, may have to work on that), went ahead and primed everything and prepped it for paint.

I then painted the hull a base of white, and laid a really nice blue down on the sponsons. & then cleared the whole hull.
Of course right afterwards I realized I had yet to tackle the water inlets. So I might need to respray the rear ride pads after I put those in. I'd really rather not run any kind of external inlet system.

I had a few issues spraying the hatch next. The first design was wonderful, but the paint lifted and some of the white came up with the tape after I sprayed the blue. So I simplified the design and just shot the whole top blue. Not unhappy with it, but it makes me think I should have just done the entire top of the boat blue now. Instead the white just looks out of place.

But I had the hatch close to done, was just cleaning it and using a tack cloth to ensure there wasn't any last dust settling down on it when I dropped the stupid thing on my garage floor. Damaged the front corner of the hatch & scratched the top of the lid. Very upset. So I filled the missing corner and sanded the nicks out of the paint.

Need to go pick up a new can of blue and then respray the hatch. The white was unaffected, but I'm thinking about just doing the whole hatch blue now. I'd definitely do it if the hull didn't have the white on the front of the tunnel but I really don't want to monkey around with paint on the hull anymore. Thoughts?

Sorry there's no picture yet of the white on the hull, but the front of the tunnel is mostly white. Just use your imagination. It's there under the masking tape!

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[JohnZ]

Thinking about getting one of these.
Does anybody have any motor/battery recommendations for this hull?

[midnightsabotage]

As one option, I mentioned in the first post here that "Fightercat57 also steered me in the right direction with a Leopard 4074 1050kv motor & 80HV esc. I'll be running her on 8s."

I really want to try this setup because it'll run lower amps with the higher voltage. But I haven't got it put together yet, obviously. That guy really knows what he's talking about, so I'm pretty confident in those components performing great in this hull.

Otherwise I usually see 27"-30" catamaran or deep v hulls set up for high power with with a 4074 size motor in the 1800-2200kv range on 4s. I've been out of the rc boat world for a season now, but that's what I recall and have that size Tacon 2200kv in another one of my boats & I'm really happy with it.

Might be able to do a p-spec setup too for class racing, with a 36mm Aquacraft 1800kv or 2030kv on 4s? I don't know if there are other requirements for that or not.

I have a much harder time figuring out all the prop sizes and what's best for each application.
-Jeff

[midnightsabotage]

Puttzing around in the garage a little bit here and there. Haven't made it out to get new paint yet, sop the hatch is still unfinished. Took a few shots of the hull anyway though. Mounted some of the hardware too.

I still don't like how the white stops at the windshield. I may need to re-try the design that I messed up on the first time, then there will be some white on the top of the hatch too. Just need some more white and blue paint.

Definitely digging the color though.
I still need to tackle the dual water inlets too. Need a bunch of brass tubing for that. And some sandpaper & patience.

As for the prop, there's just a grim 42x55 (s&b) there now. No idea how That'll run. I'm guessing I need a larger prop with the low kv motor on 8s?

As always, thanks for looking! Hope someone else out there can get something out of this thread & all my efforts :)
-Jeff








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[midnightsabotage]

Oh! Dropped in a JR DS821 digital high-torque servo too & ran some linkage. Things don't really line up very well through the hull, but after a few carefully placed bends in the pushrod, I think it's working out alright.

Can anyone tell me if these servo specs will be enough for a boat of this size and speed?
Torque:
4.8V: 72.0 oz-in (5.18 kg-cm)
6.0V: 88.0 oz-in (6.34 kg-cm)
Speed:
4.8V: 0.19 sec/60°
6.0V: 0.15 sec/60°

Thanks!
-Jeff

[jamie]

I run 9kg Servos myself but they are readily available where i am. Those specs should be ok thou. Nice build BTW can you tell me what colour blue that is i love it

[midnightsabotage]

It's a Duplicolor spray can, I think in the Perfect Match lineup. Tossed the can, unfortunately. Still need to pick up another one though, so I'll pay attention to the name for you.

Looking online quick, it could be either "Intense Blue Pearl" or "Newport Blue Pearl" or "Medium Quasar" too. Maybe even "Bahama Blue" but that's on the lighter side.

My Napa only had one real nice intense blue, but it's gotta be one of those. The photos here of course look a little different than how it looks in person. And until I polish that clear coat a bit, it won't really *pop* like it should.

There was also a really cool deep blueish teal that I had considered that you should take a look at if you go paint shopping.
-Jeff

[Jersey Crewmax]

Looks great so far. I need to just get started on a project myself.

[tagasagwan]

Hey Jeff,

I would recommend this one bro. I used this on my SM29. The one in my Avatar. It's a 29" deep-V and I used the same rudder that you ordered from hobbyking. Never has a problem with it.

http://www.servodatabase.com/servo/traxxas/2075

[midnightsabotage]

Hey Jeff,

I would recommend this one bro. I used this on my SM29. The one in my Avatar. It's a 29" deep-V and I used the same rudder that you ordered from hobbyking. Never has a problem with it.



http://www.servodatabase.com/servo/traxxas/2075

Yep, I like those servos too, have one in my TenaciousVEE. If you're patient, in the states, they're pretty easy to find brand new for $20 shipped on ebay. I figured I had a decent new servo sitting here anyway, so I dropped in the one I had. Plan on making this hull as waterproof as I can anyhow, so hopefully I won't need the servo to be waterproof.

The rudder still seems awfully long. We'll see how it works though!
-Jeff

Oh! And I bought another can of that paint, but can't remember what it was. I'll be in my garage today, so I'll try to remember and take another look at the name.