SkR8Pn

Good to see V2 up and running, nice work! I should start on my second big jet tear into also. A lot of lessons learnt after the first one! May it rest in peace...

BIG22BIRD

My Feedback: (1)

here is a shot of my ride plate and the water exit.

Vidjaya

Hi.
I bad speak English, but I would like to ask in this topic.

Has built the boat. Weight with battery 2.2 kg, 590 x 180 mm. Time to swim 5 minutes. The speed of the gps 30 km / h. The boat is floating in 50% of the gas, if 100% of the gas, the rotation of the increase, and the speed of the no.

Jet 28-mm-Jet with short steering nozzle
http://www.jet-drive.de/index.php?pa...mart&Itemid=17

Motor Neu-Castle 1410 1Y 3800kv 4 Pole
http://www.amainhobbies.com/product_...m-Shaft-3800kV

Esc Turnigy Marine 180A Brushless Boat ESC
http://hobbyking.com/hobbyking/store..._Boat_ESC.html

Battery Turnigy 5000mAh 2S 40C Lipo Pack
http://hobbyking.com/hobbyking/store...Lipo_Pack.html

Video
http://www.youtube.com/watch?v=53WCB...layer_embedded

Foto
http://forum.rcdesign.ru/f68/thread304846.html

I want to:
Swim of 15 minutes. (It is important)
Speed of 30 - 50 km/h.
Size of 600 mm.
Batteries 2S.

As you think:
Remake this boat? To build a new boat? What Motor to place? If the jet set 19 mm?
Very much I wait for your help.

sundogz

Well, it has been a while since this tread has seen some action, so I'll show a recent project of mine. I purchased a used 24" nonstepped cat hull from a seller on ebay. I had been watching for such a hull for quite some time, since first seeing one for sale on another site a year or so earlier. It had the odor of a burned up speed control along with black discoloration under the canopy. The NQD drives I had would fit perfectly in the sponsons with a bit of work.

sundogz

I prepped the jet drives by removing casting marks from inside, and reshaping the intake ramps. I used Shoe Goo this time (first for me) to install the drives in the hull, and it was faster and easier than epoxy. It took two applications, but the drive bodys are now a part of the hull. I've filled the previous holes in the transom and the former stuffing tube hole, sanded and primered the stern, installed the steering system using some heli parts I had laying around. I fabricated a servo mount where you can remove the servo by just cutting a zip tie, because a screwdriver would be difficult to get in there later on. I dremeled (is that a verb now?) down all those offending epoxy mounds from previous attachments and encounters and (though it doesn't look it in the photos) the deck is relatively smooth now. I've got to drill 4 more holes through the transom to facilitate a long hex screwdriver to more easily remove the motors, and I'll just cover the holes with hockey tape or a decal. And I need to install water pickups on the jets. Waiting on the esc's/motors and the SicRc couplers. Each jet will have it's own motor, cooling, esc and lipo, so will be semi-redundant to the Rx. If something should go wrong, it should make it back on the other jet (that's two 'shoulds', I know). I'm sticking with a single (med size) servo system for now, but am entertaining the idea of removing the steering nozzles completely, and going to Vector steering to see how effective that is. I've not seen a FE Cat hull done with jets low in the sponsons - I've seen 'em in troughs, and in the tunnel and none impressed me very much - other than to get me thinking of how to correctly pull it off. It works well for Ferry Boats, and they have zero turning radius! This boat fit the bill, what with no steps and sponsons just the right size for the NQD drives. I had to cut off the mounting tabs to fit them in

mickieb49

 Nice sundogz,
 It has been a while since i have read any of your projects, looking to be an interesting concept.  Will be interested to see how it goes.

 On another note i have also been busy designing a new jet,  haven't got the full CAD plans finished yet but it is a 30mm impeller (alloy/ ss)  with a trimmable nozzel, it will also have the possibility of putting in a second stage onto it.   Once the plans are finalised i will be building a Injection mould to mass produce them, initial run of approx 200 units.
 Also bought a CNC 4 axis router to build my plugs for the moulds, and i will also go into mass production of 2 types of jet boats,  a Jetsprint and the River Race jetboats, both will be around the 700mm long mark and also have the option of being in Carbon .
 I will obviously be putting some Youtube footage once i get the first one together, please be patient as it may be approx 4 months away before i can let anyone see the finished product.
Cheers All
Mick

dragonfly60

Sounds great Mick, Look forward to seeing the progress!

sundogz

That's nice Mick

*delete M i k e u p delete*

Incorrect typing to find sites.

sundogz

I don't know about Kershaw, but Steve at SicRc is in the process of moving, according to a reply to my inquiry about some couplers I bought from them.

*delete M i k e u p delete*

Thanks!

SkR8Pn

Nice work sundogz.

sundogz

Well it seems the couplers from SicRc got lost in the mail [] Isn't that the way it goes when you are waiting on something? Steve apologized for the inconvenience and will send replacements out Monday. I got the esc's and motors in, but the [link=http://www.hobbyking.com/hobbyking/store/__28223__HobbyKing_90A_Boat_ESC_4A_SBEC.html]esc's[/link] were just too heavy at 105 grams (I hadn't even thought about that!) Thought I'd try them since they are new to HK and I could use them with other projects as well. I've since ordered some [link=http://www.hobbyking.com/hobbyking/store/__7360__Turnigy_Marine_60A_Brushless_Boat_ESC.html]60A Turnigy's[/link] replacements from the HK USA location that are less than 1/3 the weight and can handle the load fine with the 380A burst current capability [X(] . Now am waiting on the couplers. I may try to find some locally since I use this size coupler (3.17 to 2.3) frequently in my builds.

SicRC

Hi Mikeup, it's Steve from SicRC here buddy. You can get the 4400kv motor direct from HobbyKing, here's a link to it in the US warehouse (http://www.hobbyking.com/hobbyking/s...arehouse_.html)Cheers from Down Under

Lleksam

Hi guys new to posting tend to be a reader, but here goes. please dont shoot me

for some time I have had nothing to do, too cold to go out into man cave, Wife moans if I play with toys in house, But Im a old man all kids have grown up and left home,

I have been collecting bits for a new jet boat. I have ended up with 2 Davette sprints and my old aluminum hull

here is a Picture of jets for the 3 and radio boxes for the DaVettes

The Zenoah engined Jettec unit is going in the Blue DaVette

The MHZ - Proteus electric unit is going in to a Orange DaVette that is still being painted
saw that boat Thursday and its looking good, just needs lacquer

And the graupner with a Leopard 5692 driving it is going to be modified to take a Swashdrive Mk1 Prop and tail cone and go back into Aluminum hull

Steve

scavone128

I have been thinking of a new project for spring, and i wanted to do it on a tight budget, under 100 bucks minus the rx/tx and batt. I was thinking of getting one of the nqd drives off of ebay and putting it into hobbyking's turnigy cobra hull with a 30A watercooled ecs and a turnigy 2040 4500kv motor. do you guys think this combination would be alright? I am a little bit worried that the hull is a little bit too flat and may have some cavitation problems.

sundogz

Steve, you have some nice toys there! [X(]

Scavone, that is a good choice for boat and jet. And that motor is good for 2S - a wise choice in a small boat, IMO. Should work out nicely!

Lleksam

Thanks Sundogz, this unit i cant wait to see move, motor is 910 Kv in Star mode plan on running on 2 x 3 cell in series, it supposed to put out 6300w some where near 8.5hp

sundogz

Yes, that is quite nice. I have a 50mm Gravitix copy of that MHZ unit and I haven't settled on a boat design to drop it into yet. But a Jet Sprint is a stable

Lleksam

My tear into has a slipping prop at moment, need to replace really. it runs on a 3900Kv motor on small 3 cell overlander lipo Just looked into it and I must have stolen the ESC for something else probably Jet ski, ok ok thats 4 boats now to finish

Steve

sundogz

Yeah, it's that motor. It is too fast and powerful. With 3S lipo, 3000kv is about tops with that pump. Anything faster is just more noise (and can slip the impeller). [8D]

SicRC

Hi Lleksam, I agree with sundogz, 3000kv is tops for a stock pump but I run a 4800kv on 3S in my NQD jets and they fly. The secret is to either use a flexible coupler or a flexible shaft like I do. The flex shaft requires a brass tube through to the impeller to support it if you go that way. It's virtually impossible to connect a motor to a solid shaft using a solid coupler and get it to run smoothly, there's always a slight mis-alignment that you can feel as a 'bump' when you turn it over by hand, that's where the vibration and noise comes in, especially with really high kv motors.

Lleksam

could be time to replace Jet unit then with one of the modified ones available here in UK on ebay??? have been looking at your hull for a while too, but just at moment much bigger fish to fry, and only so much money to spend on toys before she castrates me, Cant even hide import stuff the duty catches me out every time, My son bought me one of my DaVette hulls ;-)


Steve

SicRC

I'm hearin' ya brother... she who controls the purse string is the bane of the hard core hobbyist Dunno if you've got a KMB 28mm jet unit in that collection of yours but I've just made a hull that it'll drop straight into, I'll be testing it tomorrow so I'll put up a youtube vid and post a link here. I'm a couple of weeks off having a 540mm version of the Jet Sprint hull kit available that also takes the KMB 28, it's modelled after KMB's 'Splash' hull which is an awesome design... just no good in rocky rapids being made of fibreglass... mine will be 2mm ABS so it'll be tough as nails, also gonna make it available in 2mm polycarbonate for those that want to paint 'em up.

sundogz

LOL, Hi Steve. Thanks for the refund, BTW. Do you have a video of your boat with that 4800/3S setup in it? Something where the boat goes slowly from stop to wide open - with scenery in the background so you can get an idea of the gradual increase in speed. It seems none of the links on your site are operational. I am just hard headed sometimes, but can you explain how eliminating the vibration will allow that size pump to pass (significantly) more water? Or how a flex will eliminate vibration? I don't see either explanation on your site. Or any claims that it will be any faster, longer lasting (or better). It would seem to me that a flex cable running in a bushing would wear out much faster than a solid shaft. When I use the 'contact' link, it sends me to CSSdrive.com - a gallery. None of this makes sense to me, if you could please explain. Thx, Sdg.