Jetnfast Carbon Fiber Daytona build

[jetnfast]

Hey guys,

I have a build thread on this over at KBB, but thought I would post here. I am mostly finished with this build, just a few loose ends to clean up and install the flex shaft and she should be ready to rock. I got this hull second hand which started life as a twin, but the original owner then epoxied the twin holes and setup areas leaving me with a blank slate for a singe build. I think its turned out half way decent for my first FE build. I tried to use a lot of CF to clean things up and I think the result turned out nicely. Here are the list of parts and pieces I went with to build this boat:


FC3730 1580 Kv Brushless outrunner
.187 Flex shaft coupler 6mm
FC 2 Bolt profile series CF motor mount
Carbon Fiber ESC mount
3/16'' Brass Stuffing Tube 7mm OD w/liner
Aeromarine 3/16'' / .187 Flex Cable
Kintec Strut offset bracket
kintec 3/16'' strut arm
kintec Strut/Rudder w/pickup
Octura M445 prop
Castle Creations 5.5mm bullets
Turnigy/Hobby Wing T180 ESC
Hitec HS-77BB low profile servo
Flysky GT3-C radio

[jetnfast]

Mostly finished....

[jetnfast]

...A few more pics of the drive line setup...I am trying to decide if I want to solder the tip or not. After cutting the flex, all I did was Chamfer the tip. thoughts?

[ozzie-crawl]

thatl looks very tidy. well done.

[jetnfast]

Thanks! Hopefully I will maiden her in the next few days!

[Scott M]

Nice! Looks good. I'm still looking forward to my first build, how hard was it setting up the stuffing tube, motor mount,and flex drive?

[jetnfast]

Nice! Looks good. I'm still looking forward to my first build, how hard was it setting up the stuffing tube, motor mount,and flex drive?

Honestly, not bad at all. I recommend practicing bending some scrap tube before you bend the actual one, in fact make a template while your at it. I used my thumbs wearing gloves and went SLOWLY. In order you want to mount the motor, and rudder/strut hardware then cut the hole in the hull for the stuff tube. After that mock up your stuffing tube and get the angle as minimal as possible between the motor and strut. I used JB weld to mount the motor mount and the stuffing tube. Let it sit overnight and your set. As for cutting the flex, I did that last once everything else was installed.

[jetnfast]

Batteries installed prior to the first run on 4s in series. I wanted to test everything out and make sure it didn't leak. Boat ran fine, but really slow on 4s!! Like 25 mph or so. Seemed to be cavitating when up on plane. Its going to need some tuning!!

[ls1fst98]

beautiful boat!

[ozzie-crawl]

Just a small observation. Were your batteries are look a fair way back. Mine are up near the speedie.
Fairly sure in your other thread you said you were 9.5-10 inches for cog. Make sure that is from rear of sponson and not rear of the hull.
Mine balances around the middle of the second step.
It maybe rite were it is just looks to me like it is not.

[jetnfast]

Just a small observation. Were your batteries are look a fair way back. Mine are up near the speedie.
Fairly sure in your other thread you said you were 9.5-10 inches for cog. Make sure that is from rear of sponson and not rear of the hull.
Mine balances around the middle of the second step.
It maybe rite were it is just looks to me like it is not.

I was wondering that. I wasn't sure on this. I knew it was one or the other (sponson or transom). I saw pics on the net that showed from the transom and others from the sponson. I went with the transom. I might inch them forward a bit...although based on my run of 45 mph on 6s it would seem I would want to inch them/move the CG back to run less wet and reduce friction on the hull to pick up some more speed?

[ozzie-crawl]

Your spinning more rpm than mine with a bigger prop yet less speed. Dont know any thing about those motors maybe it can't spin that size prop.
Do you have like a 440 or 442 to try.
I know it is a out runner and they usually have a lot torque ????

[jetnfast]

Yeah the outrunner is very torquey! I just ran it again, shifted the batts and inch back and ran a 58.4 mph with the gps. I think that is about right for this setup. I need to do some more tuning and get it over 60 mph. I am close though. I am not sure how I picked up 10 mph with a batt shift and maybe some calmer water, but GPS is very accurate. I need to get a vid! I really like its mid acceleration, probably because of the outrunner, plus the outrunner sounds really cool!

I do have some extra props on hand, x442, and an x642, I might continue a few more runs with the m445 to get a good feel for the boat first.

Also, temps and other vitals have been really good. After a 6 minute run each 3s lipo measures about 11.3v per pack, and 105F degrees (85 ambient temo). The ESC measures 110F and Motor is 140F (higher because its an outrunner). These temps are much cooler compared to my Traxxas Spartan.

[Rocstar]

You would be surprised how much speed you gain when the hull is aired out vs. running wet. I had the CG pretty far back on mine, with a little negative on the strut if I remember correctly.

Good job BTW.

[ozzie-crawl]

Mite try that on mine see if I pickup some speed.