DRAGONFIRE81M

just het me i mite make my own jet drive and insted of a nossil ill use a rudder . i never pained on running rapids with these boats

headhunter23

Then why get a jet drive unless your using them in a shallow pond like I have out back that destroys hammer prop after hammer prop? In which case it would still be better to use the nozzles to turn, because u can still wreck the rudder as I did too... all this exciting stuff of wrecking... besides it seems the nozzles are better than the rudder anyways in terms of simplicity.

Yes quicksilver they do look familiar... I won't use as much luminum as u did.

DRAGONFIRE81M

The only reason i got in to jet drives is i had a trashed mini-v hull and i checked everywhere to see what has been done and what hasnt . so thats how i started my first jet drive project . pluse i like to be diffrent my have someing thays the same as a nother.

DRAGONFIRE81M

that bit size was 5/64 but you could go two sizes larger and use the brass as the pinto hold the flap on

Quicksilver1

I dont know about using a rudder instead of the steering nozzle. Not sure why you think that would be better. The steering nozzle is a rudder. Anything other than a steering nozzle just is not going to work as well. I'd be willing to place some obscene bet on that. It would have to be directly behind the bowl(nozzle) and still would only deflect some water and not most, like a steering nozzle would. anyway, you can try, just saying imo I wouldnt bother.
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On the subject of reverse buckets; I dont use em and dont see a need to, considering how much goes into making it function. Running a cooling line off the mounts sounds fine, I'd use 1.8" brass tube. One way to get decent reverse and I've done this before, it to simply use a reversing esc. If the jet unit is fully submerged at rest, reversing the impeller's rotation will give a considerable amount of thrust. Those reverse flaps dont work that great anyway and if I really want reverse I'd just do what I said and you only need a reversing esc, instead of a 3 channel radio, an extra servo, and the reversing bucket.

If all you have is a forward only esc, you still could do this if you have a mechanical speed control and servo laying around. Simply remove the plates that give you forward movement on the mechanical speed control, splice the servo wires into your esc wires and splice in battery and motor wires, so they go to both speed controls. So if you push forward on the throttle the esc will provide power the mechanical speed control will advance as well, but do nothing since the forward contact plates have been removed, Then if you pull back on the stick into reverse, the esc will do nothing and mechanical speed control will cause the motor to reverse rotation.
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Simple right If either of you guys want to do either of these things let me know, I'll draw up some wiring diagrams. it will work and both mods are much cheaper than a new radio, just to have reverse.

SV27dayton

I agree on the rudder thing. If you want to use a rudder go with the surface drive. All things being equal they are typically faster. The jets accell at manuverability and shallow water operation. You will loose both if you lock the jet and use a rudder.

DRAGONFIRE81M

Big blue has reversing esc and i have used it to slow the forward movent

DRAGONFIRE81M

OK its time to do some re working on the mini-v im going to put in a bl setup i wont to see how hot headhunters run with the 1/18 motor .mite go with it or a 380L and im going to try my hardest to make an ajustable trim nossil.i have how i wont it now just to get it in metal.

DRAGONFIRE81M

this is on a seadoo spx but this is what i wont to make for the mini jet drive

headhunter23

Hey dragon, can't get to mine till thursday., was hoping I had time but have exam the same day. Was thinking though, instead of repositioning the jet I might beable to adjust the nozzle up or down by loosining the screws on it and pulling the nozzle out either at the top or bottom. Should make it easier to test and if need be pull jet if it requires repositioning. Been looking for jet drive boat hull pictures, pretty slim on the net.

Any of you guys have luck in jet drive hull pics?

Ivan.

DRAGONFIRE81M

I only see one problemin siming the nossel youll lose your seal at the transom . you would have to adjust and reseal everytime .

DRAGONFIRE81M

just thoght of #2 reson you throw off your pilot bearing in the nossel

headhunter23

Ah crap your right... forgot about the brass rod in there.

LJH01

I have a Graupner Sprint Jet with the small drive in it, I have tried a couple motors and I have to say the an Align 430L (KV3550) was way too much on 3S. I know it is a fairly short motor but it got hot as heck VERY quickly. I ended up getting a Fiegao (SP?) 380 long can in somewhere around a 2600KV and there is no diffrence in the apparent speed and the motor and and controller are MUCH cooler.


Cheers,
Jim

DRAGONFIRE81M

ljho1 i would love to see some pic and vid of your sprint jet . if you have any . im sure others would to .

headhunter23

I had done a bath test on 7.2v versus 11.1 on the 3200 rpm/v 25amp brushless on the microjet. The 11.1v had a lot more speed... would say 1/3 to 1/4 faster. Alot more torque too, motor didn't heat up but only ran for a few seconds.

Ivan.

dirtysouth31

been testing now for a couple of days and made a few vids.(thanks to diegoboy)pay no attention that the last vid is over 4 minutes long,diego was making a movie..the first vid to the last is testing to see if it will work..come to the relization that the jet is too small and ive maxed it out for speed..will now order a bigger jet that can handle the brushless..snapped 2 couplers already..

http://www.diegoboy.com/media/jet-rigger01.wmv
http://www.diegoboy.com/media/jet-rigger02.wmv
http://www.diegoboy.com/media/jet-rigger03.wmv
http://www.diegoboy.com/media/jet-rigger04.wmv

we have one more vid thats not ready yet
not bad for something thats not designed for a jet drive

headhunter23

Just curious about a couple things, how heavy is your boat? And what size is the jet? Was taking a look at kehrer jet drives to see what would give ya more speed(28mm and 33mm max speed at 40km), which would be the 40mm drive(30-50km). Not sure if there's much of a difference for the granuper's, would assume they're close. Oh, no way to ramp up the volts into the bad boy?

I like how there's no porposing, and very cool idea. Now ya can run and not worry bout breaking the prop!

Oh quicksilver, you ever do any gps tests on your boat?

Very cool.

dirtysouth31

dont know about weight but its real,real light.the problem is the smaller jet is at its limit as far as power it can handle.i ordered the bigger jet so the brushless can really open up..

DRAGONFIRE81M

what kv is the bl system you put in and are you still useing the stock ujoint on that mini jet . there is a stronger ujoint hat some guy found for the mini-v its all metal . ill see if i can find it . i dont know anything about ringer boats but is it running wet in the rear . it seems like the rear needs to come out of the water alot more . you only need about 1/4 -1/2 of water to feed the jet.

DRAGONFIRE81M

ujoint page 23 post 556 on proboat mini-v tread

DRAGONFIRE81M

by the way i ordered a eflite Six-Series Brushless 2700 Kv Motor (28mm)

Key Features

Perfect match for 3D and aerobatic models weighing 28–35 oz (790–990 g) using a gearbox
Ideal for scale park flyers weighing 25–40 oz (710–1140 g) using a gearbox
Ideal direct drive motor in models 18–28 oz (510–800 g)
Ideal for models requiring up to 400 watts of power
Perfect upgrade for brushed 400 and 480 motors with same diameter and mounting hole pattern
High-torque, 6-pole slotted rotor design
Includes connectors, prop adapter and mounting hardware
High-quality construction with ball bearings and hardened steel 3.2mm shaft


Overview

Six-Series Brushless 6-pole motors are high torque motors suitable for either direct drive or geared or geared applications. They feature the same diameter and mounting hole pattern as brushed 400 and 480 motors so they make excellent upgrades for these classes of models. Six-Series motors are ideal for direct drive applications such as hotliners and other LMR products 18- to 28-ounces. They are also ideal for 3D and aerobatic models weighing 28- to 35-ounces, and for scale park flyers weighing 25- to 40-ounces, when using a gearbox. This is a perfect match for aerobatic and 3D models like the E-Flite Brio 10 (EFL2275) when using a gearbox, and pylon racers and hotliners when used direct drive.


Specs

Type: 6-Pole Inrunner
Size: 400 / 480 Upgrade
Bearings or Bushings: Ball Bearings
Recommended Prop Range: 5 x 4 to 6 x 5.5 direct drive or 10 x 6 to 12 x 6 with 2:1 to 3:1 gearbox
Voltage: 7.2 - 12
RPM/Volt (Kv): 2700
Resistance (Ri): .03 ohms
Idle Current (Io): 2.05A @ 10V
Continuous Current: 34A
Maximum Burst Current: 42A (15 sec)
Cells: 6-10 Ni-MH/Ni-Cd or 2-3S Li-Po
Speed Control: 35A - 45A Brushless
Weight: 80g (2.9 oz)
Overall Diameter: 28mm (1.10 in)
Shaft Diameter: 3.17mm (1/8 in)
Overall Length: 36mm (1.40 in)

and

DRAGONFIRE81M

oh ya thats for the mini jet v

headhunter23

Good choice on motor.... it still seems that your boat could go faster, from your videos it would seem my 12.5" jet drive boat can go faster than yours providing the it stops the porpoising using the graupner mini jet. The rear of yours seems to be way to low in the water, I would have figured your boat to be similar weight seeing that yours is balsa. It's strange it's slow. What's the motor that you were running when it operated the best?

Ivan.

headhunter23

Hey quicksilver, question about your villian before ya ripped her apart. When you had the aluminum skid plate on, and the drive on the plate. Would the grills of the jet have been flat with the plate? Or would they have been on an angle?

Still trying to determine if I should adjust jet or leave it.

Ivan.