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. :thumbup1:

[ozzie-crawl]

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

[jetnfast]

Yeah, this boat is awesome. I am very happy my build turned out great! I cant complain, but of course I want to keep tuning!!

[ozzie-crawl]

I was not thinking to well when I said about your cog. Mine runs great at 30% but have only run it half a dozen times and each time water has been fairly rough to the point I rolled it by it being side on to the waves.
Love this hull tho and thinking of a 6s one

[jetnfast]

6s is awesome, I recommend it if your motor and ESC can support it. After 4 runs It is very stable at WOT, way more so than my traxxas Spartan. I have mostly run on calm water, but even with a little chop its fine.

[ozzie-crawl]

I will keep this one 4s but know I have finished my twin cat I am building a 6s for more speed.
The 4s one has a bit of weight with the neu 1515 and 4s 2p but will handle a fair amount of choppy water.

[jetnfast]

Finally got some video up....

http://www.youtube.com/watch?v=59qSDwX74QI&feature=youtu.be

[ozzie-crawl]

Looking good. Any reason tho for the left hand turning ?

[larryrose11]

Hello, a battery question for ya.
On the 6S setup, is that 6s per side, running in parallel?
Or another way, 2 separate 6S packs?

[jetnfast]

Looking good. Any reason tho for the left hand turning ?

Never thought about it! Maybe because I am a lefty?? I was taking the turns slow since I think that is the highest likely hood of a blow over.



Hello, a battery question for ya.
On the 6S setup, is that 6s per side, running in parallel?
Or another way, 2 separate 6S packs?

Correct, 2 x 3s 5000 mah packs in series (corrected!) for 5000 mah 6s total. They fit perfectly in the hull space.

[jetnfast]

Sweet decals from Monojeff arrived today. They look sick!!

[ozzie-crawl]

Try turning right. The way our props spin on single motor setup they turn much better anti clock wise.
Hard to beat that look with carbonfibre and silver decals. Wish mine was CF looks awsome.

[jetnfast]

yup, it definitely turns better to the right overall. Although, at that slow a speed in my vid it still turns on a dime!!

[monojeff]

Nice work on the decals.
Sure does set the boat off and you realize it is going to be going at least mph faster now with the new upgrade!!

[larryrose11]

Correct, 2 x 3s 500 mah packs in parallel for 5000 mah 6s total. They fit perfectly in the hull space.

Most people on here recommend 10000 mAh for a similar setup. Do your batteries come in hot? What is your run-time? Do you use the LVC, and what is it set to?

[jetnfast]

Most people on here recommend 10000 mAh for a similar setup. Do your batteries come in hot? What is your run-time? Do you use the LVC, and what is it set to?

I am very happy with the 2x 5000 mah 3s in series, I am sorry if I confused you there when I said parallel in my previous post, I meant series! So basically, I have 5000 mah in total. I am averaging a 6 minute run and voltage around 11.3v per pack (3.7v per cell), so there is a good deal of capacity left and voltage per cell. I would say my max run time with a 3.4v cutoff would be around 7-9 min. The ESC is cool to the touch with caps around 105F. Motor is an outrunner so it runs much hotter, nearing 140F. My inrruner on my traxxas Spartan average 110F after a 5 min run, so the outrunner is harder to cool. These measurements were with an ambient around 80F or so and lake water around 70F (its not that deep of a lake).

[larryrose11]

Wow, thats cool. Im will have the maden voyage of my cat in a few weeks. Hearing about the 5000, 6S total is good news, as I had a cell go bad on one of my 3S packs. I will deff try that first!!
My build thread is not up to date, but Im trying
http://forums.offshoreelectrics.com/showthread.php?41038-Cheetah-6S-My-first-cat!
Thanks!!