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View Full Version : My setup notes; suggestions welcome!



sillycon
03-22-2014, 08:51 PM
So today, for the first time since I got the boat, I put some time towards getting it to run decently.

The boat was setup with the CG at ~8.875" from the transom, stock hull, stock motor/ESC/bullets/battery connectors, stock prop (semi-sharpened, not balanced), OSE flex with Moly grease, OSE fins, and speed master tabs. Strut angle is ~1deg negative, and tabs are at ~1.25* (left) and ~1.5* (right). On 5s the boat runs dead straight with the 3s pack on the left side; on 2s the boat has a slight right tendency. The boat was GLUED to the water today; it was the first time I've ever gotten to run it without ANY porpoising or other "undesirable" behavior (aside from flipping it upside down once in a turn which was my fault).

Since I got a micro GPS yesterday, I was finally able to do some speed tests.

On 4s, average top speed was 28.8mph with a 30.4mph peak.
On 5s, average top speed was 34.7mph with a 36.7mph peak.

Given that the boat seems so stable at the moment, I'm thinking the most reasonable/logical change is to set the strut angle to 1deg positive (so, a 2 degree change total) and see where that lands me. I know PB noted they got ~32mph on a stock setup with 4s, but I'm curious to know how far it can really go.

So far as temps go, after 3mins @ 5s the ESC was ~100deg, water jacket was ~120deg, batteries were ~104deg. Wire connectors were the hot spots at 130-135deg (both the EC3 terminals at the batteries, and the connectors from the ESC to the motor). On 4s after 3 minutes the ESC was ~90, water jacket ~105, batteries were ~95. Connectors were still the hot-spot at ~120deg.

I'll probably swap the motor terminals over to 5.5's later this week and see where that gets me as well. I'm not so hot on doing the batteries at the moment as I just converted 4 packs over to EC3 from TRX....

I know proper sharpening and balancing of the prop can be a big winner as well, but my balancer isn't playing nicely and I'm tired of fussing with it. I've got a pre-done x642 on the way to me, and once that gets here I suppose I'll try to find someone to S&B the stock prop for me.

Anyhow, if anyone has additional setup thoughts/comments/suggestions, I'd be happy to hear them! :)

sillycon
03-23-2014, 06:48 PM
I moved the strut/prop angle to +1deg as mentioned, but saw no difference at 5s (peak speed today 36.4mph, with slightly more chop on the water than yesterday).

I also learned that the Moly grease I used is not a good lubricant for the flex. The teflon liner on my new flex caught on fire and went up in smoke ending my day early.

sillycon
03-26-2014, 06:56 PM
Got the liner replaced, and tested it yesterday. Speeds were unchanged from previous days. Temps were also the same. After quickly running out of day light, I went home and replaced the motor/ESC connections with 5.5 bullets.

Ran the boat today after adjusting the strut height; I went from .380" above the keel to .220" above the keel and picked up a some MPH. 5s now peaks at 39.1mph, and 4s is peaking at 30.9mph.

On 5s, however, the temps ROCKETED up (and today is about 25* cooler than it was 4 days ago in my initial post). Batteries came out at 135F! Motor was 132, ESC was around 130, connectors were up around 170F after 4 mins!

After letting everything cool off, I dropped my 4s packs into the boat and went for 3:30min. Temps were back in their normal ranges (motor 104, batteries 98, ESC 94, connectors 130).

Unfortunately, lowering the strut height had the effect of also putting the prop angle back around half a degree negative. That brass tube really is a bear to bend "just right" but I think for now I'm going to just leave it.

I'm quickly getting more eager to swap on the x642 I have on the way to me...