swervyn

thanks all, yes i see now how the cooling intake wont properly work inside the jet intake, glad i didnt try to be smart and do it without asking!!
great idea murmuzy re: filing the shaft flat spot all the way to the end..now why didnt i think of that grr, should be able to make do ok with the stock coupling in that case.
still ironing out bugs like these before i get serious lol

swervyn

@ aum-offshore, i am struggling to see the pics of your build as the link is just one page of very small pics? would love to see them in full if possible

cheers

Team Tekin

The ESC in that boat must be the same as the ones in my EDF A-10 Warthog, it has the same startup tones! I wish my boats had that kind of top speed.

skymaster62

1x #4800-2040SL/8595 2040SL 4800kv Brushless Inrunner (WaterCooled) = $22.12
1x #TR-M-35A/7377 Turnigy Marine 35A Brushless Boat ESC = $27.17
1x #HK-GT2/10608 Hobby King GT-2 2.4Ghz 2Ch Tx & Rx = $14.99
1x #BOX-379g/9087 Extra Length Cardboard Box and Packing 379g = $0.00

Been reading this thread for a few days now. Ordered the boat last Saterday and this is what I decided on for power.

skymaster62

Can any one tell me what power set up AUM has in his boat? That thing is sick fast! And it looks like the motor is inexpencive.

murmuzy-tearinto

Hi, i'm having issues getting a water tight seal in my boat. I've currently got the jet drive sealed with hot glue. I've put more and more in the areas I thought were trouble spots (even used wet q-tips to get in the hard to reach areas. I bought a tube of waterproof silicon sealing for indoor/outdoor plastic use and am planning on fixing it tonight.

any pointers or things to watch out for when doing this? / has anyone noticed water coming in from behind the rubber bushing behine the coupler driveshaft area?

thanks,

sundogz

If you're not getting water on top of the boat, and the jet drive is sealed, then it's probably coming in through the stuffing tube (O-ring). To prevent this, apply some sticky marine grease such as Grimreaper to the impeller shaft. I have a syringe I got with some printer ink that I modded to force some into the shaft bore as well. The O-ring is there to keep the grease in, not water out. You will need to re-apply from time to time depending on use.

Edit: Grimracer grease, not Grimreaper!

prontozuk

From aum-offshore post on the 12/03/2009, page 23, post 551 of this forum.

Outrunner Motor Apex 450 Size 3,200 Kv (3mm Shaft) ====== > Very Easy Maintenance
Dragon ESC 40 amp With Cooling Plate


I have his 41 page instruction manual in Thai.

Thanks James

Stein

Here is mine painted green with some stickers on it. Under the green I have blue then Red primer color so when it gets scratched up it will look like its rusted and beat up.
I'm using a Hobbywing seaking 90AMP ESC and a 3900KV Hobbywing motor. I have a TX/RX, 3 cell lipo and and servo on order should be in soon. Cant wait to get it on the water.

While I'm waiting for the parts I built a screen for the bottom and did some cosmetic upgrades on the motor.

TheOtherSide

Looks great! Did you get my private message the other day?

dreadrock

G,day Fellas, Well all the parts have finally arrived, so with some luck i should have this little beasty up and running this weekend (the wait has been driving me nuts).
As this is my first electric I wanted to keep it fairly simple to start with so, For the running gear I went with the leopard LBA2040-4450kv, hobbyking 35amp marine esc and turnigy nano-tech 2650mah 45-90c 2s batteries x2.
I should have quizzed earlier but better late than never, will these packs be ok with the esc? I'm still trying to get a grasp of the whole electric thing as in watt works with watt (haha pun intended). My intention is to run the packs in parallel (longer run times and hopefully a better left /right balance also).
Once it's all together i'll get some happy snaps up for all to see.
Cheers Nigel

sundogz

That all looks fine. Yes those batteries will work fine with that esc. I would try just one battery put in front of the motor across the hull. You may be surprised at the long run time. Did you get a water jacket for the Leopard? You need to cool that motor with a jacket -a coil of tubing won't be sufficient.

dreadrock

Howdy All, Thanks Sundogz. Yes there is a cooling jacket. Got it together ruffenough for a test run, i got about 10mins total (5min each pack) before the low voltage cut of kicks in. I'm having trouble getting the esc set up correctly i think, first i couldn't get it to program at all (AM) unit so i pinched the reciever for another boat (FM) then i could get it to work but i cant seem to get it to change from default settings or at least i dont think so. From what i can gather is the pack should be going down to around 5.6v but the mutimeters (two differant) are saying 7.3-8.4v. When i try to recharge/discharge/balance or anything i'm just getting an overvoltage message from the charger (Hobbyking eco 6-10) so basically i'm just really confused and frustrated now??? The Gas boats are looking good at the moment....lmao
Anywho heres a couple of progress shots to date still have more to but here we are for the moment
Cheers Nigel

sundogz

Lookin' good. Yeah, it sounds like you're not programming the esc correctly. It takes patience or somebody who's done it before or a program card to get it done. You'll figure it out, it just takes time. Sounds like there's quite a bit of charge left in the lipo's when the LVD kicks in. You should be getting 10 minutes run time (or thereabouts) from those 2650's.

Stein

How does everyone seal the cover on their boat. Do you use foam on the bottom of the cover? Or is there a better way to seal it up.

I have foam on the cover and use screws where the black post were so I can tighten it down so it wont leak. I still had a small leak when I put it in water in the sink. I since have glued the gaps in the foam where there joined and will try it soon to see if it leaks.

Please post of your ideas and pics of how you keep the water out.

Thanks

Stein

Well I got the rest of my stuff today. Two 2200 3 cell Blue lipo, Flysky 3ch RX/TX 2.4ghz and servo to go along with my 3900 motor and 90amp ESC.
Now I just need to put it all together.

Team Tekin

That boat should fly with that 3900kV on 3S!

Stein

Thanks I hope it rocks

skymaster62

Sundogz, you seem to be the goto guy in this thread. I have read the entire thread and have a question. If I am running 2200 mah 40-70C 2Swith a 35a Turnigy water cooled ESC. With the given formula A=Ah x C
at 40 C I would be at 88a, and at 70C I would be at 156a. Depening on who you believe Turnigy max burst amps 150ish or Seaking max burst amps 70, am I heading for a melt down or is the water cooling making it workable.

SpeedDaemon

No no!You don't want it to 'rock' from side to side, you want it to go smoothly!

(Ho ho ho!)

dreadrock

G'day Guys, I've busy with work of late but it's all going well, i think i've got the esc working better for me now, still seems to drop off quicker than expected (voltage wise) at any rate (goes into limp mode) at about 6.4 volt (2s) about the 8-10min mark (seems about right tho (Sundogz) still learning this electric world)). Not sure if this is normal or not as in where it should be??
As for feed back on the leopard LBA2040-4450kv on 2s,
Goes well but i'd like more, thinking more along the lines of the 3900kv on 3s as these seem to have the bit more of the kick ass factor!!
I'm coming from a gas background, this build started out as a recovery boat for my gas boats and kind of got side tracked rather (as we do)!!!!
Stein, i stuck some foam to the lid as such and works quite well for keeping the water out, not 100% but i also have a small drain hole near the top of the hull for letting water out which seems to be working well for me. There is a rather cool set up with a flat lid/deck and foam under the drivers/lid etc back in the thread somewhere (way too many pages to know where exactly) that i personally like, that is what i'll be doing at some stage.
Looking forward to seeing your's up and running]
Cheers Nigel

similar

Sky,

Although accurate in your calculations, you're slightly misguided in their application. A=AhxC gives what your battery CAN supply, not what it will.

Short answer - you can never have too much battery... (aside from weight)

dreadrock

Nothing to do with the NQD other than it's a jet/ near on indestructible and the ultra cool factor http://www.jettec.co.nz/
Cheers Nigel

similar

Haha - awesome - my home river.

Stein

True so true