JetChopper30 "Hotrod" Build

Christian Z. comissioned me to build a moderately sized mono with smokin' performance. We chose the 30" Jetchopper30 hull as a starting point. A Leopard 4074 2000KV on 4S2P 65C/130C 4000mah Dinogys and the trusty T-180 with Oct M545 for top end and M445 for tamer, longer runtimes. Thanks to MonoJeff for the spiffy windshield :thumbup1:

Attachment 97105

Started out with premium hardware : Speedmaster .21Nitro rudder and 3/16 stinger ; both trimmed down

Attachment 97106 Attachment 97107 Attachment 97108

3/8" servo rod pass-through tube to prevent linkage bind on full articulation of rudder. Big Speedmaster tabs and OSE fins to keep boat in the groove

Attachment 97109

I'm a firm believer in keeping the motor-to-flexshaft alignment 100% perfect so I opted for the longer motor mount which required machining the rear support ring to clear endbell screws. Also allows the larger 55mm-57mm water jacket. Mini-rails also enhance alignment and keep motor anchored as well as providing a base for ESC platform

Attachment 97111 Attachment 97110 Attachment 97112

Added paralled connectors to the ESC battery leads since this will exclusively be a 2P setup

Attachment 97113

Installed 90 degree waterline fittings on the ESC to keep it narrow - hopefully one day this will be a factory upgrade/mod to the T-180

Attachment 97114

The OSE quick-release servo mount had to be modified for the "bump" on the Traxxas servo

Attachment 97115 Attachment 97116

I do the same thing for the servo mount Tony. Only thing I do different is use plastic shim stock on the upper strap. A few dots of glue keeps them put. Looking good. I like that hull and I want to try one eventually.

For quiet, smooth sport running went with 9/32 stuffing tube with teflon stepped down to .250 to enter stinger. Tinned end of flex for longevity. Drivetrain is so smooth it sounds like a turbine.

Attachment 97117

Fabbed some waterline guides to keep interior clean and tight. Battery platforms from 3/32" birch ply on standoff spacers to allow velcro one-wrap to secure batteries and adjust position as batteries get moved to dial in proper CG/running attitude

Attachment 97118 Attachment 97119 Attachment 97120

Strong,clean, tight interior layout is a must for ease of use/maintenence. Takes thought and time but well worth it :smile:

This will be a FAST boat and be a great sport rocket. My personal JetChopper30 is the current NAMBA P-Ltd Mono SAW National Record Holder - and she likes it ROUGH :wink: http://www.youtube.com/watch?v=qkiTfVT1LaE

Attachment 97121

Quote:

---

Originally Posted by Basstronics

I do the same thing for the servo mount Tony. Only thing I do different is use plastic shim stock on the upper strap. A few dots of glue keeps them put. Looking good. I like that hull and I want to try one eventually.

---

Forgot to mention that the hull has a ride pad - can't say/debate the pluses/minuses of this feature but the boat does handle well and is very stable straight ahead

Please address any inquiries to rcboatbuild@hotmail.com - thxs; pm box usually full :cool2:

The Jet Chopper 30 is still a favorite of mine Tony.
That 2000Kv motor is a powerhouse. I've got one in a 36" H & M mono spinning an M447. Doesn't even break a sweat. And quick enough to win a heat now & then.

Tony,

Any words of advice, anything you would have changed since building? I'm 90% sure this is the hull I want to swap components from my son's mono.

Ken

Quote:

---

Originally Posted by Tamelesstgr

Tony,

Any words of advice, anything you would have changed since building? I'm 90% sure this is the hull I want to swap components from my son's mono.

Ken

---

Ken, a good deal of thinking went into the design this hull and it paid off ; the boat, for its size, is a fast running and excellently handling hull. It seems to run (for lack of a better term) "light on its feet" and doesn't need megawatts to get it's boogie on. I'm pretty sure the ride pad adds to this phenomenon. I favor the rear motor setup that Randy taught me years ago. On the tail end I've shortened the Spd. stinger on all the ones I built but probably isn't necessary - the longer the stinger the better it stays wet in the slop.

Appreciate the response on the older thread. With the motor mounted as far back as possible are you in favor of (1) 4s pack secured in the center of the hull, or would you still recommend running (2) 2s packs in series, or (2) 4s packs in parallel?

Quote:

---

Originally Posted by Tamelesstgr

Appreciate the response on the older thread. With the motor mounted as far back as possible are you in favor of (1) 4s pack secured in the center of the hull, or would you still recommend running (2) 2s packs in series, or (2) 4s packs in parallel?

---

If you have a "spec" or "Ltd." setup, you can run a single 4S5000 down the middle in front of a rear set motor (also 2 X 2S 5000.)

With a 4074-type motor a good choice is 4S2P 4000's or even 5000's again in front of motor. Try to keep CG no more than 30% which means trial-layout of all internals before mounting anything.

Another thing I was considering, I recall reading that the hull doesn't require a CF inlay? Are battery trays a must? Can I epoxy straps to the hull and use velcro to secure the packs? Trying to decide if I would be wasting money on doing a CF inlay or CF battery trays. Thanks, Ken

Quote:

---

Originally Posted by Tamelesstgr

Another thing I was considering, I recall reading that the hull doesn't require a CF inlay? Are battery trays a must? Can I epoxy straps to the hull and use velcro to secure the packs? Trying to decide if I would be wasting money on doing a CF inlay or CF battery trays. Thanks, Ken

---

CF inlays aren't required. For the most part (other than el cheapo Asian hulls that the zoom-zoom boys are overpowering for their gofast shots or some select serious SAW builds) CF inlaying is very much a vanity feature, expensive, and a major pain in the caboose.

CF battery trays are convenient but a homemade birch ply tray is more economical (and looks the same once covered in velcro.)

That's all I needed to hear, thanks for the insight Tony, much appreciated.