sundogz

Ha! No, I had some problems with that boat. But was impressed by how far it could heel over in turns without losing prime. Sounds like you have your vacuum table working nicely.

asupervee72

Traditional hulls aside grael has the best running rc jet boat i've seen to date. The video he just posted sounded like he was wot the entire time through corners and everything and i didn't hear the boat loose prime at all. Jumped, sucked in air and when it landed the pump just primed right up. Most other videos i've seen, and my own jet boat (before it had a 4 inch hole in the side) you gotta let off the throttle if you suck in any air before it will prime again.

Sundogz. Yours looked fast in a straight line, but you do suck in air while keeled over in a hard turn no? Pretty sure grael would blast by you in tight corners.

sundogz

Asupervee, watch the video through, and you'll see it (usually) takes hard turns heeled well over without aeration - that's what I liked about it. But the Naceilles ramped intake caused other problems - aeration on waves and such. It really needed trim tabs, but I've since retired it and used the jet drive on another project. Yes, Graels boat looks fast and is very fast to reprime. A good design worth persuing!

nwnitro

Hey guys..... here's the link to my Davette with KMB jet and NEU1518y BL....... Dana has his powered with gas, think he is still running the KMB jet..... it is a little on the small side. (maybe ok for stock motors). My 1518y is a little to much for the KMB. If the HobbyKing jet is any good I hope to put one in DaVette drag hull w/ modded zen........

I plan to put on a RC sprint boat race this summer...... will post more when I have it all together....???

here's the link, Jerry Dunlap was driving...........
http://www.youtube.com/watch?v=dRSWGYgZz-w

dragonfly60

NW Nitro,
Where did you get the DaVette Jetboat hull from, Looks great!

nwnitro

Dana DaVette..... Dana here on RCU manf. these and other great hulls... I carry them in my store..
http://nwnitro*********.com;)

dont slow down

Where can I get a jet drive setup? Everywhere I look they are out of stock! I would like to start my rescue boat project soon and would like to use a jet drive.

nwnitro

I am out of the 40mm KMB jet drive but still have a few of the 28mm..... check on ebay also......

dont slow down

Which size would you recommend for a 30" hull? Doesn't have to go fast, just get on a plane.

nwnitro

Here is the KMB link for there 28mm jet, they have a video on there site of a 'sprint boat' with twin 28mm pumps that really scoots.......
single 28mm would work on 30" hull, motor and batteries would determine performance......

http://www.jet-drive.de/index.php?op...id=4&Itemid=17

dont slow down

Man those are sweet jet drives, but $100 is a little more than I wanted to spend on a drive setup for this build.

evilb

Hey guys, I've been reading ths thread for several days(obviously) and I love all the great info. This is my first post. I've been into jet boats for years and own a full size boat. I'm excited about hotrodding an NQD (on its way) and I too am having trouble finding sources for drives. I'm aware of the KMB drives but I think the graupner 29mm is what I'm looking for with my build plans. Is it now the consencus that they are no longer produced? Any other leads? Also, many of you who use the graupner 29mm drive have a black outlet venturi and steering nozzle. The ones listed on hobby lobby and cornwell are red and look different. Can someone tell me the difference and how it was aquired? Thanks.

sundogz

All this is moot as Graupner drives are non-existent and no word of availability. Same goes for Swashdrive, MHZ and the new HobbyKing drive. I know someone dissed the KMB drives earlier in this post, but they look like they are solid and well thought out (and available!). And if you want a large drive, I can vouch for the PowerJet 40mm drive sold by KMB. The are a brute of a drive - very well made. But too large for smaller projects - more suitable for 28-40" boats. The 13mm mini ABC copy (proboat decoy duck) is available as a replacement and you can buy the 19mm NQD some places for the price of the drive itself ($45). That's about it, unless someone is holding out!

Grael: Here's your opportunity! There is a scarcity of small drives right now. Someone could make a killing manufacturing smaller drives right now. I'll be your first customer!

evilb

If I were to go with the KMB drive is there any reason to choose the long or short steering version over the other? The only thing I can think of is the short one would be less prone to dammage from strikes although it may be less responsive (that dosent really seem to be a problem with these boats however).

sundogz

I prefer the shortest available. It looks better, and has less tenancy to hang up on anything.

evilb

Thanks sundogz. I may have missed them but I only remember seeing one video of your bat boat. Did you post more? I was looking forward to seeing a rooster tail from that monster..

scavone128

i just recently got a second hand shockwave 26 brushless hull and i want to remove the inner part of the hull, the one where the servo would be mounted, but im not sure how to without breaking the hull

sundogz

Long story short, the trim-able nozzle was more a bother than a convenience. It wouldn't tilt high enough for the roostertail effect without jumping clean out of the water in the process! And it was hard on speedo's doing that (but cool looking). So I installed trim tabs which tamed the porpoising and mean to remove the trim nozzle and reduce the stator housing diameter for more pressure (speed) but have shelved it for now. Some day...

grael

I still have to get my own drives in order first

I have a few decent stator-outlet moulds, but I've been busy most of this last year flying planes.

Ideally, I'd like to do hard silicon rubber moulds for water glass mix sand cores, and then assemble the sand cores into each mould, be it an outlet stator, or inlet. I still have my pump I cast in aluminium that I used way way back with the weed eater motors, and I'd love to be able to do a proper smaller size in aluminium, especially as just a two piece main jet unit. Normal sand casting alone won't cut it for my type of outlet stator, as I need hard sand cores for the water channels, same for the intake, as I don't want to have to piece it together.

Thanks guys for the positive feedback on the Tyrap boat, and yes, in that video I posted, it was at WOT all the way, except for on one stretch, where I slowed it down a bit prior to making a burst vectored turn.

Having the vacuum table now, moulding's so much easier and faster, but I need even more heaters if I'm going to do a larger boat. The PETg material is great in 0.5mm and 0.75mm, but past that, it's more succeptable to cracking as it's more likely to shatter than bend, i.e. I was trying to flex a piece of 2mm once, and it broke off.

I still think the smaller sizes are the way to go for any competetive racing, as it cuts down your required investment in BESCs, motor, LiPo, charger etc, allowing more people to be able to afford to compete.

oscarel

How much are the DaVette Jetboat hulls?

nwnitro

new hull in my store $275.....
shipping actual cost plus $15 for packaging........

sundogz

You're preaching to the choir here!

sundogz

Hey, check [link=http://wavejet.com/]this[/link] out. Ring a bell?

grael

Now all the flabby people can surf with a simple flick of the wrist.

Not!

I doubt the 20 pounds thrust lasts for more than 5 minutes..

RandyatBBY

Well guys I have been back at ti with my little drag Runner Bottom. I thought I would share. we are building these hulls Now in Fiber glass and Carbon fiber.




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