New KOS C1 w/ 50C 11.1V 5000mAh 3S LiPo

[fleckster48]

Hello All,

I'm new to the forum and just getting back into RC boats after a rather long absence. I use to run Nitro Boats mostly home built and a few kits. Anyway, I have purchased a KOS w/twin brushless motors and 2 50C 11.1V 5000mAh 3S LiPo pacs. Just wondering if I'm asking for trouble? It appears the boat can handle it but would I be better off with 20 or 35c. I guess I don't want to fry anything the first time out. Your thoughts would be appreciated.

Fleckster

[forescott]

Any of those batteries will work just fine. Anything over 30c may not increase speed or performance on the ekos. They wont hurt it, but usually higher c-rated batteries are reserved for high amp setups. The ekos in stock form is set up relatively conservative for 3s.

[fleckster48]

Hello Scott,

Thanks very much for your reply. I hope to be putting the boat in the water this weekend. I want to get the feel of the boat before thinking about any changes unless she requires some changes to her trim and or playing with battery placement. I'm thinking mid-ship for the batteries on the first run....also checking the temp of everything after 5 minutes or so.

John

[wht73]

My ekos w/ 2 3400kv leo's and x442 oct props and 45/90c 3s pacs does 60.2mph (GPS). Mtrs were 110* esc's on top of caps was 135 to 140*. Run times get eaten up with those props....but its FAST!
Everybody that watches it is amazed.
My next mod is to change the stingers to good ones.

Good luck with your boat.

[fleckster48]

Hey thanks. I have 4 runs on my boat so far and haven't had any mechanical problems. I did have a problem when I first hooked evreything up.....the starboard engine would run slightly so I backed the throttle trim back two clicks and now they seem fine. One thing I have observed is that it appears as though the boats cavatating. I will accelerate and the engines rev up but the boat takes a while to get moving fast. You can hear her dig in and then she moves pretty good. The drives are set at zero and I was thinking about droping them a degree at a time and making a full run at each setting. The other was going up to the optional size props. Lastly, batteries, ESC's and the port engine run right around 90 degrees. The starboard engine is around 111 degrees F and I noted that toward the end of the run she wants to turn into the port engine. I've lubricated everything and checked alignment and everything turns free. I plan to check the timing of both engines to see if they are the same. Any other thoughts would be appreciated.

[lenny]

If cavitating on take off try moving the stinger up one degree at a time,
To make the boat transom ride deeper in the water and lift the bow to get more air under it.
Just watch out for high speed blow overs if to much lift.

[fleckster48]

Right now their at 0. When you punch on takeoff it just about jumps out of the water but once the bow comes down thats when she seems t loose her bite and the motors spool up....so I will move them down a degree at a time.

[forescott]

Which props are you using?

[fleckster48]

Hi Scott,

I'm running the stock plastic props. I ran the boat again over the weekend and it seems that it runs best at about 3/4 throttle. If I go anything past that it seems like it actually slows down a little. It seems to be sucking air. I still need to drop the drives a degree or so but I would like to try the larger aluminum props that are available.

[forescott]

When I bought my ekos it came with 2-sets of plastic props. 32mm and 36mm. Did yours too?

[fleckster48]

I looked at the numbers on the props and they are the same. I thought one set looked slightly larger but I would think they would have different numbers. Also my motor timing was out of wack. 3.35 p and 26.25s. I set them both to 0.

[fleckster48]

All,

I posted a note a few weeks about my new KOS twin running 5000MAh 3S 50C Venom batteries and some start up problems. Tonight was the first night she really flew. It turns out that my ESC's we not programmed the same. After picking up a HOBBYWING Program Card. I corrected that. So, shes set up with reverse, auto cell selection, 3v low cut off and 0 for timing. The way it was set, the port motor was at 3.25 and the starboard was at 26.25. The starboard motor drew the most current out of the battery.

Now at between 1/4 and 1/2 power she comes up on plane.....mash the throttle and shes at the other end of the pond in a few seconds. We had some fog rolling in tonight and I didn't was to loose site of her. I really ran her pretty hard and at the end, the temps were as follows: ESC's 90 F, Batteries 115 F, Port Motor 98 F and Starboard...still running hotter at 115 F. The props are the standard resin 36mm. I have checked and lubed the drives several times and everything is free on both engines but the starboard engine always runs hotter. The drives are set at 0 degrees.

As of now I am happy with the boat and will run her until something breaks as she seems pretty well suited to the pond I'm running in. I guess the only thing I might try is the 34 mm props to see what that does to performance. Any questions, shoot me a note

[tryinotocrash]

You used the hobbywing to program the stock esc's? Got a link to the card you used? Have you done anymore prop testing? Thanks.

[fleckster48]

Hello,

I bought my card off of ebay...but OSE sells the same one under ESC accessories. As far as props go, I'm running the stock 36s with the 3s and the 32s with the 4s. It really flys with the 4s. I'd like to buy the cnc machined ones but that would set me back close to 200 bucks for 4 props and for sport running she does fine.

[tryinotocrash]

Now I love OSE but they are cheaper on this sight. $34.00 if you are interested..http://www.rchobbyexplosion.com/Electric_Segad_C1_Parts_s/585.htm We have to save where we can right. :-) That is enough to get another battery :-)

[fleckster48]

Hey thanks, those are much better prices for all of the Venom parts :)