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Jun 05, 2015, 01:26 PM
RELAX. You'll live longer
785boats's Avatar
Quote:
Originally Posted by JE5TER
I too loved the idea of the twin screw, so I've ordered one. Will post a clip when I hit the water.

Looking at the specs I'm guessing 40mph on stock equipment and 3s LiPo's

It will be my first RC Boat (got a number of car's and multi-rotors) but I know I will want more than 40mph.

So any advice would be great.

So far I've ordered left and right D38mm 1.8"p 3 blade metal prop's to replace the stock D36mm 1.4"p 3 blade plastic props.

As with all things RC I guess replacement motors and compatible ESC's (if necessary) will be a good help for speed. Any suggestions?

Are the Leopard LBP2860/3D 3400KV a good replacement or something better?
I wouldn't be putting those props on the boat at the start. That's a big jump in prop. They might be too big on a pair of unknown motors.
Get the boat set up, aired out & running free, with the stock props first.
Then try them for a short run & check temps & how much they've dragged out of the battery.
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Jun 06, 2015, 02:28 AM
Registered User
Two inches shorter & I expect Leo's to be more efficient than whatever comes in the Flowmaster hull...but this Venom/Atomik/Dragon cat is in the ballpark. I'll be surprised if the Flowmaster cat gets any better than 40 mph on 3 cells per motor & 40mm prop's, with the included electronics.

VENOM SEGAD C1 34 Leopard Motor Max Speed 94 Km/h (3 min 16 sec)
Last edited by lt130th; Jun 06, 2015 at 10:22 AM.
Jun 10, 2015, 02:15 PM
Registered User
In stock at the USA East warehouse for $320. That's what I was expecting. I paid $311 shipped with a buddy code from the Int'l warehouse. But I'm paying with wait time, now...
Jun 10, 2015, 04:00 PM
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JE5TER's Avatar
lt130th - I'm lucky, in Australia with stock in Australia warehouse so it was only a couple of days from order to delivery.

While waiting for the props to turn up I did some more research and worked out that the props are most likely too big as you say Guess I will either have to get some different ones or repower.

If I was to run on stock gear, your saying temps will be an issue? Like over gearing a car I guess.

785boats - who do I see how much they have drawn from the battery?

I found on the HK website Turnigy XK2858-2900KV Brushless Inrunner motors that look good for their price. Any thoughts.

I did get out on stock equipment, with a pair of redback 3S 5000mah 30C batteries, stock props and 0` thrust angle. The GPS logger gave me 62.1Kmh / 38.5mph

Had a young assistant help with the filming of a quick clip of its first run.

C1 Flowmaster Twin Catarmaran (0 min 33 sec)
Jun 11, 2015, 01:42 AM
RELAX. You'll live longer
785boats's Avatar
JE5TER.
But those motors are lower in kv. Why would you want to have lower revs.
If the temps are fine with the props that are on it , keep playing with the balance point & strut angle until the boat is just planing on the rear ride pad. Then try larger props.
But Hey. I just realised that pond in your video is at North Lakes. So you are close by.
Bring your boat along to the Brisbane Entertainment Center on Saturday afternoon after about 12:30 & there will be a few of us there that can help with the set up. We're there every Saturday.
Cheers.
Paul.
Jun 11, 2015, 02:04 AM
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madracer's Avatar
Yes Paul the Kv of those motors are too low.

That's if it's wired to use 3s per screw. In my 6s Apparition twin I used 3500kv motors with 3s per screw.
Jun 11, 2015, 06:27 PM
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JE5TER's Avatar
Thanks Paul if I get some time on Saturday I'll drop by.

The stock 3300kv motors and ESC's can only run 3s. The Turnigy XK2858-2900KV can run up to 5s so I was thinking lower Kv more torque = bigger prop and with 4s higher RPM's (3s 11.1v x 3300kv = 36,630rpm Vs 4s 14.8v x 2900kv = 42,920rpm) or am I looking at this wrong?
Jun 12, 2015, 12:56 AM
RELAX. You'll live longer
785boats's Avatar
Yes. Slightly from the wrong direction.
With a lower kv you can run slightly bigger props. But mainly if you stay at the same voltage.
If you want to change to 4s then you would really come down in kv a lot more. Say between 2200kv & 2400kv in a twin cat. 43000revs is not required for a sport cat. You would definitely need to up the size of the ESC,s. The amps being pulled would probably destroy the motors. They might be able to handle a higher voltage but not the amps.They are only rated to 43A, & you would be pulling more than that with those larger props at those revs, I'd say.
But if you bring it along we can have a play with settings & props & see what we can get out of the stock set up.
Last edited by 785boats; Jun 15, 2015 at 09:49 AM.
Jun 12, 2015, 02:49 AM
Registered User
785boats is on the right track, JE5TER. You have to find the right balance of kv, prop & input voltage, and make sure you have ESC's that can handle the amp draw. In a hull like this, you'd be sufficiently covered by a pair of 120amp ESC's behind a couple 2200kv motors on 4s per prop. The electronics in a twin aren't taxed as much due to the shared load. Thanks for posting the video, by the way. I found out today, the shipped price from the US warehouse is the same as I paid for the order from the Int'l warehouse. I cancelled my backorder & ordered from the US warehouse. Should have mine in a couple weeks, now.
Jun 14, 2015, 01:01 PM
RELAX. You'll live longer
785boats's Avatar
Well JE5TER brought the cat along to Boondall on Saturday & we had a bit of a play around with things.
The first time I've ever seen this: the motors were stone cold after about 5 laps even with a fair bit of stopping & starting as he tried to get used to our small pond without hitting the rocks. The ESCs were only tepid. The hottest part was the wiring because it had a Deans plug to XT60 plug adaptor between the battery & ESC. But we will get that fixed up.
And it only used about 20% of the packs.
So we decided to try the larger props. Definitely more speed & the motors were still cool. As in not even warm. Again after about 5 or so laps of on & off running.
Packs were down to 60% after that run.

I noticed that the two struts were not at the same angle so we adjusted that & took it for another run.
Jeremy was kind enough to let me have a go at driving a couple of laps at full noise to see what she could really do. I liked the feel of it. Very sensitive in the steering but dialing down the rates on the Tx will fix that.
Unfortunately the packs were down to about 25% by then & I had no adaptors that would fit the packs to charge them up & none of my packs had the same connectors to fit. So that was it .
But a good little test session that proved those larger props were ok on those motors.
I'd like to know what brand they actually are.
Jun 14, 2015, 10:00 PM
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JE5TER's Avatar
Thanks for the help on Saturday Paul. Great to meet meet you and to learn a few more things.

Looking forward to a bit more practice and getting used to the tighter turns. Was real happy I could run the props without issues. Does have me wondering how big it will spin on the stock gear.

Will need to organise a few more batteries and switch to the bullet connectors over the deans/XT60 adapter. And have a closer look next time at the way the isolation lead is mounted to hull. Really like that idea.

Was happy with the speed increase of the props. GPS logger showed 71.5kph / 44mph as the top speed after the strut angle was sorted, on the 1838 props and 60% batteries.
Jun 15, 2015, 09:46 AM
RELAX. You'll live longer
785boats's Avatar
It was good to meet you too. We'll have you racing with us up at Lakeside in no time.
I was thinking though after that last run that the struts may have a tad too much negative angle in them with the extra lift from those 1.8 pitch props. You saw how I used the straight edge along the ride pads over the struts right? Well, increase the gap at the drive dogs by another 1.0mm for your next run. This will raise the nose a bit & increase the speed.
See you next time you come to Boondall.
Jun 15, 2015, 01:23 PM
Registered User
Mine will be here tomorrow. I've got a nice set of 45mm 3-brade brass props that dasboata did for my Shocker. Those are probably too much for the stock electronics in this hull, but I'm tempted based on your feedback. I'll head to the lake later this week for some testing, GPS results and maybe video. Sure would like to know the origin of the included inrunners.
Jun 16, 2015, 06:45 PM
timritchieblue's Avatar
I'm interested in hearing some reveiws of this boat.
Jun 19, 2015, 01:32 AM
Registered User
Quote:
Originally Posted by lt130th
Mine will be here tomorrow. I've got a nice set of 45mm 3-brade brass props that dasboata did for my Shocker. Those are probably too much for the stock electronics in this hull, but I'm tempted based on your feedback. I'll head to the lake later this week for some testing, GPS results and maybe video. Sure would like to know the origin of the included inrunners.
45/3 mm too much : you think? :-)




i don't know the origin of the included inrunners but i can tell you the destination of those inrunners with a 45/3 prop!

sorry for the sarcasme , but really?


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