Quicksilver

finally a real update. Motor is in. stuffing tube complete, drive setup, including homemade flex coupler, and painted. I know the boat obviously isnt going to win beauty contests and I feel I rushed it, but if I didnt do it right now, it might not ever get done this summer. The hull is green, but it's so light you cannot hardly see it on camera.

DRAGONFIRE81M

looks pretty good man . so you went with a flex shaft thats pretty cool . cant wait to see some test runs

Quicksilver

thx, yeah I had to, the jet is angled up a bit so it was really my only choice. It does make switching out motors between boats. Now for setting up the steering, I absolutely hate mounting servos, it gives me a headache over how complicated it is to install something so simple.

DRAGONFIRE81M

same here it tock me a month to come up with the most semple mount .

joccee

quicksilver - wich drive do you like better, the KMB or the graupner?? and why?
I'm planning a new build...more scale looking then any of my other

posted this question in the scale boats forum but i think you can relate more to what I'm looking for so I'll post here to

I'm planning a new build with dual jets in but I'm having problems finding a radio that can control all the thing I want.
I want to be able to steer the jets individualy so thats 2 channels for steering.
Then I want to be able to reverse them individualy, thats another 2 channels for reversing.
And last but not least I want to be able to control the speed too:P....
is it possible to set a radio up so that i can use the forward on a throttlestick to rev up the motor and then when I pull it all the way back A servo kicks in and put the jetunit in reverse??

Hope you understand what I'm trying to ask...I added a picture to help me explain:P

if this isn't possible is there some radio out there that has the same features as the "Ace Rc Nautical Commander"??

DRAGONFIRE81M

here you go jocce i had a little on this on to but i could get it on here with it ill go back and repost it in here . or you could get a 6ch radio and put the to buckets on the two switchs on the top corners on the radio


you could also do that with just a servo and a swich and a revering esc of coures brushed . you tie the servo in to the esc and also have the switch on the servo arm to change the plaraty going to the motor . this will make it go back in to forward and the bucket will drop

joccee

yeah I thought about doing something like that but I dont think its possible with brushless...and I think it'll be hard cuz when you have it in forward the puchrod that goes to the reversebucket will stop the servo...wow that was hard to explain in another language:P...hope you understand anyway

DRAGONFIRE81M

i got your language just fine . if you ever messed with a nitro car when you trottle and brake is on one servo so you put a spring so it will move and not efact that. yeah they wont work with brushless only brushed . no wait a min you could do that with a brushless just change the two wires around like a brushed so it will work with a brusless setup . man i got one on qiuck

joccee

...nice...to bad I want to run brushless...otherwise it would have worked:P...is there any way to like program a radio to do the same thing when you push the stick up and down...so that you have neutral in the middle and full throttle at the top AND the bottom??

DRAGONFIRE81M

if you read in that post again it will work with bl too . on the radio i have no experiance on that . or even a clue if you cant i would go with the two switchs on top to contral the buckits .

joccee

nope...unless there's a mechanical speedcontrol for brushless i dont see how that will work on a brushless setup

DRAGONFIRE81M

you didnt read my comment on that with a switch on a electronce esc . " you could also do that with just a servo and a swich and a revering esc of coures brushed . you tie the servo in to the esc and also have the switch on the servo arm to change the plaraty going to the motor . this will make it go back in to forward and the bucket will drop " when you wont to change the rotasion of a brushless motor you just swap two wires right just like you would with a brushed motor . so if you key in reverse on a reverable esc the motor will turn reverse well just swap the wires then it goes in to reverse and you have forward again

joccee

oh sorry...didnt see that. hmm now a got a lot to think about:P...but atleast I have some ideas now

Quicksilver

well, being I have just about no experience with 4-channel radios...

As for jet units, I prefer the graupner, but if I was in Europe, I might like the kmb just as much. Here in the states it cost quite a bit to get a kmb drive over, so there's one bias. My real problem with the kmb drive was the plastic quality. It was brittle on the unit I got, and had one of the vanes behind the impeller break on the 3rd run or so. I never even really knew what broke it. My graupner drive on the other hand hasnt broke at all and is a decade old now, with probably something like 40hrs on it. Besides that, the kmb does have an actual bearing and overall looks more refined. I havent used a reversing bucket on any drive, but I think the kmb unit looks better there too. They do use essentially the same impeller, size, pitch etc..

Things like, which is faster? dont know since the kmb broke so quickly. So really this is up to you, since this will be scale you probably wont be doing as many stupid things that I do with my boats, so perhaps the kmb wins out, but I would weigh the adv/dis. Hope this helps a bit.

joccee

thanks
well the boat will probably be a 1:36(100cm) of the Wally 118 so it would be nice with some good speed:P. Or maybe the swedish policeboat that kmb has. wich would be pretty cool since I went for a ride in the real version
I think the graupner unit is the more expensive for me (yeah...I live in europe^^) and the kmb is, just as you say, a nicer looking unit.
this was really good info cuz I got the feeling that the kmb unit was better quality

fragglez

http://www.youtube.com/watch?v=Qh8XRCs8N-Q
http://www.youtube.com/watch?v=Bs0gOgkUI4U

took me lil jet sprint out this afternoon for a test run now everythings fixed did not seem as fast dunno if that is because of the water conditions.

2 problems
the motor gets very hot very quick, checked it after 10 minutes and smoke or steam seemed to be coming from it.

its only a little brushless motor

Keda KB20-40-12L Brushless Inrunner

Shaft Size: Φ2.3mm×10mm (Custom 2.0mm)
Motor Dimensions: Φ20mm×40mm
Weight: 60g
KV: 4800
Idle current: 1.6
Resistance: 0.0371
Max amps: 20

I bought a too higher performance speed controller I think, 70 amp but its made for 4 cell lipo and up, with a voltage cut off of around 12 volts, I've only got a 3 cell 11.1v that produces 12.2v on the old amp meter volt meter thingy ive got, so its not using all the battery juice.

anyone got motor tips what i should do?

Also put 16 cell in my nqd high wind and tried that, bit heavy off the mark good fun put will probably go back to 12 cell

joccee

try adding watercooling to the motor. if that doesnt work I think you have to either swith to a 7.4v pack and probably loose some speed or swith to a 380 sized motor.
I think 4800kv on 11.1v is a bit too much for the jetdrive.

the esc cutoff is for 4 cells (14.4v) so if you use it with a 3cell(11.1v) lipo you'll have to change the cutoff setting.

edit: missed the part "4 cells AND UP"
then you should change your motor to one with like 2500kv and change your lipos to 4S
, or change esc to a one that has cutoff for 3S

DRAGONFIRE81M

joccee is right on the money 4800kv on 11.1 is way to match rpm . 39k is the liment any way any more then that and its just wasted enargy the top speed for this drive is about 20-25 mph . put some cooling on it but i dont thank that will help end the end the motor is going to pop . the esc has nothing to go with is when it has mor amp the what the motor is rated for its when its the other way around . anyway its a good rule of thum to go dubble the rated amp draw . what mah lipo are you useing and are you running one or two packs . why im asking is it looks a little slow conpared to my 2580kv and 3500kv nockoffs .

headhunter23

I would change to lower rpm motor(3200-3400) if you expect to run 11.1v even less on 14.8v. Also if you do change motors, get one that pumps out 30amps and she'll pretty much be maxed on 11.1v.

Took jet villain out... still hadn't made top, really should because having the nose up along shore puts some water in the back. Anyways threw gps in it, 29km/hr. She needs some more volts to wake up. Also interesting crappy side note, since redoing and straightening the back end, it now chine walks. I think before when it didn't the back end was off which meant compensating for the angle by changing the jet angle. Which makes sense because I had to actually do that for her to ride straight before redo. She's running 14.8v, oh and when esc blew due to water, it took the lipo with it, found that out today when I went out with doby.[:@]

Other than that, still fun.

Woodmandan2

Heres the type of radio you need. Nice n' Cheap too http://cgi.ebay.com/JR-SPORT-SX600-6...QQcmdZViewItem

Woodmandan2

fragglez

Cheers Guys!!

The battery im running is a LM Loong max 1300mah 3S1P 15C Lipo Battery

I am wondering what brushless motor to get to replace the one I have got, I still have not got the total understanding of the different types (what model are the ones in your Knockoff jet sprints)

I'll probably only be getting a Keda Motor as they are cheap!! Im having trouble understanding Brushless numbers related to the motors, Though brief research in the past mentioned the types (S, L, XL) and that L and XL are best hence i got a Keda KB20-40-12L


I found a bigger can keda motor

Keda Brushless Inrunner KB28-47-11S
http://www.giantcod.co.uk/product_in...580cc3ab64dd31

Shaft Size: Φ3.17mm×12mm
Motor Dimensions: Φ27.6mm×47mm
Weight: 135g
KV: 3600
Idle current: 1.9
Resistance: 0.0179
Max amps: 38

But it is a (S) ?

Would this be any good?

Sorry for lots of questions

DRAGONFIRE81M

thats a good motor to go with has all the right spec only thing i see is youll need to make a capler for the 1/8" motor shaft to go down to the 2.3 mm pump shaft . the s,l and xl stand for the middle # whitch in this case is 47mm in L the 28 mains the diamater of the can whitch is the same size as the 380size that came out of the nockoff .

just to give some idea on motors im running a 28-35-2850 in my white nockoff and a 28-35-3500 in my red nockoff

Kustom Jet

Joccee,

I have a 6 channel radio brand new that I have programmed to do excatly what you want. Neutral stick in the middle ramping to full throtte at forward and reverse. The open and closing of the bucket is on side flaps and the steering is indivual on the stick as well. I have also set it up to work on the brushless motors running 45AMP ESC with dual 14.4 Volt ( 2 7.2 packs) per motor. No heat issue. I also have the KMB jets. I am getting into the high 30's. Take a look at the pics i posted earlier.

headhunter23

Fragglez your going to need a second pack same size and run in parallel in order to supply that motor. Your lipo currently handles 19.5amps constant.

Ivan.

joccee

woodmanda2 - cant use 72mhz as it is a channel not t¨reserved for rc here in sweden:/

Kustom Jet - your boat is setup with the exact same stuf that I was planing to use in mine^^ high 30s sound really good
How big is your boat?

I think I'll skip the part with individual steering and throttle. I'll just have the steerin and throotle like you usualy do on a stick radio and on the other stick i'll put the 2 reversebuckets and a bowthruster. both cheaper and easier that way:P
I'm also think of building an older version of a Bertram instead of the Wally.