Project Apparition!

[NOZ69R]

This is the single motor model. I've changed the motor and ESC to a Turnigy 180 and a Castle Neu 2650. I run twin 3s packs in parallel. I also sometimes do the same with two 4s packs and a smaller prop.

I'm just running for fun and don't mind the extra weight of running in parallel. If you're running for speed, series is the way to go. Much lighter configuration. With the twin motor model, I don't know if there's enough speed to warrant battery placement in the nose forward of the motors. That moves the COG pretty far forward.

Hope this helps.

Thanks Fightercat57,

It is the single and I too will be only running for fun & have a couple of 3s 3000's from my planes that I can use until I recoup my play money. I guessed that running the batts down each side gives you better control over CoG.

Also when measuring CoG do you start from the transom or the bow?

Cheers

[FighterCat57]

Thanks Fightercat57,

It is the single and I too will be only running for fun & have a couple of 3s 3000's from my planes that I can use until I recoup my play money. I guessed that running the batts down each side gives you better control over CoG.

Also when measuring CoG do you start from the transom or the bow?

Cheers

Twin 3s should give you some good run time with the stock setup.

Measure forward from the sponson transom (where the stingers mount to the hull)

HTH

[NOZ69R]

Twin 3s should give you some good run time with the stock setup.

Measure forward from the sponson transom (where the stingers mount to the hull)

HTH

Again thanks,

Can't wait to get her in the water.

Cheers

[NOZ69R]

I'm stuck

Trying to set up the CoG and with the batts (3000 3S's) right at the very back and measuring from where the strut mounts to the hull the CoG is at 11".

Any idea's.

Cheers

[FighterCat57]

I'm stuck

Trying to set up the CoG and with the batts (3000 3S's) right at the very back and measuring from where the strut mounts to the hull the CoG is at 11".

Any idea's.

Cheers

How about a photo of the inside of the hull and a photo of the measuring tape in place? Maybe something we can spot.

[NOZ69R]

Here's a photo of where I'm am at the moment. Also note that 1 battery is out of the boat as i'm charging it.

Cheers

[FighterCat57]

Here's a photo of where I'm am at the moment. Also note that 1 battery is out of the boat as i'm charging it.

Cheers

Have a look at page 15 of this link: http://www.venom-group.com/mmVENOMGR...S%20Manual.pdf

There's an item called CG range. I want to make sure this is what we are measuring.

[NOZ69R]

Thanks FighterCat57,

Just read the link, my starting point was NO where near it, that was why I was getting 11".

All good now.

Cheers

[FighterCat57]

Cool. Let us know how it goes!

[NOZ69R]

Just come back from her first outing..set CoG at 210mm (8" 1/4') and ran nice but maybe a little wet.

On 3S it seemed slow... motor and ESC cool to touch so. Cant wait till my new batteries turn up so I can run 4S.

Very happy and looks so cool in the water.

Cheers

[FighterCat57]

Just an update on my Apparition build, Jeff W is making an 078 "Step Up" shaft for this bad boy.
The water leak was due to the nylon washer being too large and too loose. The prop dog needs to be snug against the teflon washer on these 4mm hex cable setups.

PSA- If there is cable slack, like on normal cable/shafts, they will leak grease into the hull.

[FighterCat57]

Ran a great run today, 7 minutes and a top speed of 44.7 on 3s2p 10k 25c with an x440 Sharpened & Balanced prop. Plenty of battery left, had to pull in due to a steering servo failure.

It ran so cool and soooo smooth! Temps all about 100 after the run.

The x445 is too much prop and usually ends up putting the ESC in low voltage mode within a few seconds, so would like to try an x442 next and see how it goes.

It goes like a bat out of hell on 4s, but that's asking way too much of this cheap drive system. I know it wouldn't last long that way.... So sticking with 3s2p and not going for any speed records. =)

[FighterCat57]

Some updated photos of the cat;

The epoxy patch of the right sponson nose has held up well! That was quite a hit. (read up in the thread for photos of the carnage)

[FighterCat57]

Wow, I'm a bit confused on this one!

She's getting up to 46mph on an x440 prop, but sucking two full 3s 30c 5000mah packs to the LVC in less than 4 minutes!

The temps are a bit confusing too. The motor comes in at about ambient temp, 80-90 and the ESC around 110-120 and the batteries about 120. I don't have an amp meter big enough to monitor the amp draw on this setup but just want to get a head check, does that seem right?

The drive spins freely (it's a wire drive) and there aren't any heat issues. It just sucks them down fast.

[suckmywake]

Here is some data from running my HOTR cat with different motors and props. My set up started with an ARTR HOTR cat. Twist was removed from hull. The sponsons still have some angle. I added a layer of 6oz fg cloth to bottom as far forward is I could reach. I added another layer around motor mount. The front was foamed. The strut was drilled out for SV type bushing and I am running .78 piano wire drive. The strut is set at gap of 1/8” above sponsons. The COG is 8.5” from sponson end. I run 6s1p on 2 Turnigy 3s 5000mah 35c/45c batt. All run were with same batts. The esc is 200a Himodel type w/bec. (ESC setting 0deg timing and PWM 8k on all runs)

Motors
Feigao 13xl 1339kv
ARC 36-55-2 1400kv (This looks to have wye windings)
Neu 1515 1.5y 1500kv
ARC 36-75-1 1680kv (This looks to have wye windings)


...................................( .... @ speed indicated ....... )
.........Motor......MPH ... RPM ... Amp ... Volts ... Watts ... Peak Amps

X440
... ARC 1680kv... 55 ... 35046 ... 74 ... 23.46 ... 1737 ... 139

X440/3
... ARC 1400kv ... 51 ... 28409... 55 ... 23.80 ... 1318 ... 106
... Neu 1500kv ... 53 ... 31250 ... 65 ... 23.29 ... 1521 ... 128
... ARC 1680kv ... 59 ... 34722 ... 74 ... 23.66 ... 1754 ... 153

X442
Feigao 1339kv... 52 ... 28089 ... 58 ... 22.68 ... 1325 ... 109
...ARC 1400kv ... 52 ... 28190 ... 55 ... 23.81 ... 1326 ... 110
...NEU 1500kv ... 59 ... 30737 ... 80 ... 22.98 ... 1844 ... 137
...ARC 1680kv.... 64 ... 33783 ... 85 ... 22.77 ... 1945 ... 166

Temps after running 1000mah

Feigao 1339kv..... Motor 106 F.......ESC 102 F
... ARC 1400kv .... Motor 87 F.........ESC 99 F
... NEU 1500kv .... Motor 117 F ......ESC 125 F
... ARC 1680kv .... Motor 114 F...... ESC 121 F

Temps after running 2000mah

ARC 1400kv .... Motor 125 F ..... ESC 120 F
ARC 1680kv .... Motor 125 F ..... ESC 160+ F (HOT)


Notes on temp.
Feigao motor temp. continued to rise up to 140 deg. F just sitting. I take this as stator temp is way higher than the can temp. I never trust can temp on 2 pole motors. I always do 10 second finger test on end bell of all motors.

Neu motor was run with silicone SV type cooler. Not the most idea cooler. This is all I could fit with motor mounts.

The thing I found most interesting was the feigoa peak amps was lower than all other 4 pole motors. I always thought a 2 pole had a higher peak amp load than a 4 pole.

Another thing I find very interesting is that for any given speed and prop/motor combo the watts were about the same. So for the boat to do 52mph is around 1300 watts. If the speed goes up to 60mph the watts goes up to around 1800 watts. If the speed moves up to 64mph the watts go up to 1950 watts. This does make sense because a watt is basically Horse Power. 746 watts = 1 HP

So if your boat is in mid 40’s mph I would think your watts is around 1100 to 1200 watts. If you divide your watts by your voltage you will come out with you amps.
Watts=Volt * Amps or Watts/Volts=Amps
1150/11.1(3s) = 103 Amps

So I would guess your amps draw is around 100amps at 45mph with spike peaks close to doubling this.