First foray into RC boats: FeiLun FT012

[Coelacanth]

Here's the inexpensive but nice aluminum generic rudder assembly I bought to upgrade the larger, clunkier plastic one. I had to do some mods to get rid of some slop, drilling the hole slightly bigger and cutting up a Dremel tool shaft to make a hinge pin to fit like a glove. I found that the aluminum rudder came down with a slight forward angle instead of being perfectly vertical, so I enlarged the bottom mounting hole into an oval so I could adjust the angle. You can see the 2 halves of the rudder assembly are no longer perfectly horizontal, but have a slight angle.

After test-mounting the rudder, I found that it was partially obstructing the mounting hole for the right side trim tab, so I had to grind down the bottom right corner, filed it smooth, and then the rudder and right trim tab both installed nicely.

I relocated the water cooling tube entrance into the hull to the right rear corner. The original location was where I needed to install the top rudder assembly screw, I epoxied on a piece of plastic on the inside of the stern to help brace the rudder, and drilled 2 new holes in the stern for the mounting screws. I bought some green & blue 5mm hose for cheap on eBay...and decided that I liked the contrasting green hose/blue rudder best.

I noticed after slipping the hose into the new hole that it would affect the steering behavior if it was twisted too much one way or the other as it entered the hole...so I carefully rotated it to a position where the rudder was perfectly neutral, and used some DAP Kwik Seal Plus to secure it in this position from the inside.

[sbednara]

great build thread! you will have to post some videos of this boat running up the lake! im excited to see what it can do.

[Coelacanth]

I had to shim the front of the motor mount bracket a tad to get the front dogbone coupler to line up perfectly with the rear prop shaft coupler. One of the well-documented issues with this boat model is that the dogbone doesn't line up perfectly between the couplers, which generates unnecessary heat & friction. This is probably why they used a dogbone, but fixing the alignment will only help. What worked for me is a pair of 1.5 mm aluminum spacers between the front 2 motor mounting posts and motor mount holes.

I have an annoyance to fix, though..."Made In China" reared it's ugly head; the two rear motor mounting posts/standoffs were cracked. The mere act of unscrewing the motor was enough to crack the plastic posts. Either the plastic was cheap, or it had aged to the point it was brittle...this might've sat on a storage shelf for some time before shipping my way.

[Coelacanth]

Here are the cracked motor mounting posts...this ended up being an annoying obstacle, but here's how I repaired it.

I was very lucky to find that 7/32" aluminum tubing was a perfect diameter to fit over the plastic mounting posts nice and snug. However, the outside diameter was now just a tad too big for the tubing to fit inside the bottom motor mount recessed holes. I used a Dremel tool, careful work with an X-Acto knife and filing/sandpaper to open up the holes just enough so the aluminum tube could push inside to the same depth as the mounting posts did (I used a smaller 5/32" tube to confirm the depth).

I then cut my 7/32" tubing into a couple of pieces and did a bunch of filing to add slots so the tubing would slip down over the 3 mounting post "webs". I didn't just want thin rings to fit over top as there's only about 1/8" of mounting post above the webs and the cracks were extending down well below the webs...so I made these repair tubes to fit almost all the way down onto the posts & webs. Once the fit was filed perfectly, and the aluminum repair tube bits were the exact same height as the posts, I applied some JB Weld slow-setting "Cold Weld" epoxy, pressed on the repair tubes and applied more JB Weld for good measure. I think it'll hold up much better now...hopefully it's a permanent repair!

[Blink916]

Hello guys. I need some help here. I recently purchased a feilun ft012 and I'm having some issues with it out of the box. It appears to be going top speed in reverse but slow in foward position. What can I do to fix this. Thanks in advance.

[Coelacanth]

Hello guys. I need some help here. I recently purchased a feilun ft012 and I'm having some issues with it out of the box. It appears to be going top speed in reverse but slow in foward position. What can I do to fix this. Thanks in advance.

With brushless motor systems, simply changing 2 wires in the motor-to-ESC connections should reverse motor direction...instead of connecting them all red-red, blue-blue, black-black...switch two wires and see if that corrects the problem.

Your comment reviving this topic should motivate me to finish this build...I was working on resolving some waterproofing issues when my Pontiac Torrent got totalled early in the summer, and my eventual purchase of a new car, working on that car and such meant I had to put my RC projects on the back burner. My FT012 has a leak in the top cover, where the front tab on the cover slots into the hole in the hull when installing the cover. It slots into a kind of box that's supposed to be sealed, but clearly had a crack...that's the last thing I was working on when I shelved it. I hope to finish it come spring and take it for a splash.

[Coelacanth]

I thought I'd update with some pics of the finished paint job after clearcoating and a lot of careful wet-sanding, buffing and polishing. The maiden voyage should happen this summer...I'm still working on resolving a water leakage issue where the top cover inserts into a slotted box at the front of the upper deck, though. I'm interested to see how she runs with the modest upgrades and improvements.

[THEYTOOKMYTHUMB]

Looks awesome! Reminds me of The Jetsons.

[Coelacanth]

Looks awesome! Reminds me of The Jetsons.

Thanks, TTMThumb...now if only it could make the Jetsons' funky flying saucer sound, too!

[SJFE]

You're doing an excellent job for your first boat. If I may offer a few bits of advice from my 25 years of experience with electric boats. Offshore electrics is a great place to deal with. I am friends with the owner now for more than a decade. In general when it comes to boats keeping perspective on the limits of whatever you're working with is key to saving money and frustration. This is a small hull and probably is performing at close to it's potential with the factory power system and prop. Another thing I'll offer is if you move to a bigger hull eventually painting the running surface is not optimal. Some less expensive hulls will need leveling or "blueprinting" as it's called. Larger ABS hulls such as these are subject to torque deformation when high end power systems are installed. It creates tuning issues you can not correct. Another observation is the deeper your rudder the more throw you will need to dial out of it. Also make sure it is at a 90 degree angle to the stern. Hope I offered some insight. Feel free to pick my brain anytime. Have fun!

[Coelacanth]

Thanks for joining the forum and for your advice, SJFE! The main reason I painted the hull was because I wanted to get rid of the raised logos and markings embossed on the bottom of the hull. I figured sanding those off and repainting could only help the hydrodynamics. With all the modding I did, everything will need to be adjusted to tune it properly, especially the front/rear weight distribution with the changed componentry inside and out. I hope to finally test it this summer...last summer, it rained practically the entire summer and I had no opportunity to get out to a local pond on a good weather day. I think the rudder is pretty close to 90 degrees, but I'll make sure it's positioned that way before the first drive.