New to site - and need some serious help!!!
 

Hi, hope that you can help a boat building virgin with his first project.

Basically, I am trying to convert a twin electric motor (prop) boat with twin jet drives. The boat is used for carp fishing, to accurately deliver the loose feed and rig at distance.

What I am having problems with is deciding which jet drive/motor/battery combination would be right for me.

I've attached some pictures of the boat for your information.....

Questions I have are as follows:-

1. The boat weighs around 2kg in it's current state, ie: with motors but no batteries - it carries a max of 1kg of bait in the central hopper, so we'll call it 3.5kg fully laden weight.
Will the Graupner mini jet drive (x2) be suitable, ie: have enough thrust? The speed of the boat is not that important.....

2. Which motors should I be running? Speed 500 or 600?

3. Do the motors require cooling, as the hull will be completely sealed.

4. What voltage is best? The boat will be used for 10-15 mins at a time, and I would like it to last at least a couple of trips out.

5. With regard to steering, is this required, or can the speed of the motors be independently adjusted to turn the boat?

6. Would be nice to have the reversing option.....

7. The boat will require the following functions:-

Forward/Reverse
Steering
Hopper open/close
Lights on/off

8. Any help on wiring it up would be gratefully appreciated!

Appreciate your time to respond..........

Best regards
James

RE: New to site - and need some serious help!!!
 

The mini jet drive will be suitable, you are not looking for speed or performance. You cab set it up using two 500's, as many high capacity batteries as you can hold, two speed controls, a steering servo and a radio setup. Basically wire up all the batteries paralell and follow thw speed control and radio instructions. The speed controls, you will need a y-connector to plug both into one channel of the radio.

RE: New to site - and need some serious help!!!
 

what's the size of the boat? the mini jets might be ok and most importantly low cost

RE: New to site - and need some serious help!!!
 

get ready for some reading :)


I concur, mini jets. For once, here's a great application for a jet. You know with the power you're going to get with twin mini jets, you can actually fish with the thing. I got my first jet boat, which was underpowered to pull my inflatable boat (8' 6") with a 5hp outboard and me in it. Were talking 300lbs and it pulled the boat at like 3mph. Jets are great for pulling since there's very little slippage.

Some questions

That's a weird profile on that, what's she look like underneath?

How long is the boat? and if you could how wide? and perhaps a pic of transom?

now your questions

1. yes, it will have ridiculous power, in fact again with my first boat, she took water on once and short circuited, causing the boat to run full throttle with no control, she hit a full size boat (42ft) went under the bottom(2ft) and popped out the other side like a rocket.. After this happened I actually put diving planes on it, sealed and made it into a sub. No, I'm not kidding, blew peoples minds I'll tell ya what. Anyways, yeah

2. I would run two 6 cell high capacity packs in parallel. Since you want a long run time and don't care about speed, I would stay in a safe voltage range to avoid over heating.

3. Since you want to run a long time I would use water cooling. Doing this on the mini-jet can be tough due to clearance, but you seem handy so I think I can show you how, if you stick around the site. I would also suggest, since you'll be running at low speeds, that you use the water-jets to "pump" the water, it's very easy to do, normal pickups wont work in your case. Like I said though, it's easy and works very well.

4. speed 500's for efficiency.

5. I would use steering, you're suggesting vector steering which really isn't very good and is normally only used on toy boats. It's not tough at all to hook up and it comes with the drive, you might be able get away with one servo, but they only cost $15, so 7 in UK money. I think you should get a esc out of the traxxas villain, which can run two 540 size motors, and run high amps(good if you're pulling a lot of weight).

6. Reverse, well yeah it's good, but you'll need a three channel radio, which aren't as cheap as a two channel. The extra channel is needed to actuate another servo to drop the reversing bucket. I would only use it if you really need it. If you already have a decent two channel hobby grade radio, I'd try it without first. Jet boat maneuver very well, and with three jet boats under my belt I've never used reverse.

7. Lights huh? you gonna be using this at night? I would run the lights on a completely different circuit, with another battery pack. Some headlamps from walmart would work great. I've got one that has a spot light, red LED, or triple white LEDs, which run on 3 AAA's and last forever. A couple of those would be all you need. ($15 a piece). Ok after reading hopper closed/open. I guess you can use reverse, as you'll need a 3 channel anyway. So I'd up that to a 4 channel radio. Gonna be pricy, a bit over a $100. So you may need a total of between 3-5 servos for everything.

8. I can help you wire this puppy once you start.

I hope you stick around, I like weird project and this is a weird one, but seems doable.

~QS

p.s. I'll try to get you some helpful links for equipment and ideas.

RE: New to site - and need some serious help!!!
 

Some links first two are my builds and then some other links. Getting tired, try more tommorow

jet villain
http://www.rcuniverse.com/forum/m_45...tm.htm#4549478

billing jet boat
http://www.rcuniverse.com/forum/m_52..._1/key_/tm.htm

mini jet thread
http://www.rcuniverse.com/forum/m_3141961/tm.htm

graupner speed 500
http://www.hobby-lobby.com/speed500.htm

traxxas villain esc XL-10M
http://www.horizonhobby.com/Products...ProdID=TRA3017

Spektrum 4-channel radio apperently is one of the few 4 channel radios that's legal for surface use...as I heard. Sorry no link, they look expensive, maybe weigh your options, might want to opt for 3-channel and ditch reverse.

RE: New to site - and need some serious help!!!
 

While the 'Spektrum' radios are nice, I sort of doubt that they would be needed, besides costing 2 or 3 times as much as other 4 channel systems. 'Run of the mill' 4 channel radio ought'a work just fine.
- 'Doc

RE: New to site - and need some serious help!!!
 

I just thought it was a legality issue since most 4-channel radio are made for planes, which ones can be used?

RE: New to site - and need some serious help!!!
 

Guys,

Many thanks for your help - very informative, all be it a little daunting......

What i'm taking out from the above is:-

1. Use 2 x Graupner Mini-Jets, steering only
2. Use 2 x SPEED 500-Eco motors,
QUESTION - Is the rpm enough?
QUESTION - Does the motors require any cooling?
3. Use 2 x Speed controllers
QUESTION - Any makes/models that i should be looking at - reliable/cheap!
4. Use Y-shaped connector for speed controller
QUESTION - Any ideas where to get this from?
5. Batteries
QUESTION - As the motors are 12v, what Ah should I be looking at ?
6. Mount a torch for the lights !

Getting a little excited now.... will keep you all posted on my progress, once again thanks for the advice !

Best regards
James

RE: New to site - and need some serious help!!!
 

As requested, images of the boat bottom..... (not sure of the technical term !):)

Regards
James

RE: New to site - and need some serious help!!!
 

James,
Just for the @#$$ of it, try here;

http://www.modelboatmayhem.co.uk/Forum_1.htm

Not that you aren't welcome, you are. It's just that we know less about 'where' to get things in the UK than the guys on 'Mayhem's site. They are a bit closer to you than we are (about 4500 miles give or take a few).
Differential motor steering tends to be a bit more expensive than just using a rudder. That's because each motor has to be controlled separately to do the turning. It will also require at least two control channels unless you can do some 'mixing' either by a feature in the transmitter programing or by means of a separate 'mixer'.
If I'm not mistaken, 40 Mhz is the 'surface' band in the UK. No idea how 'strict' the enforcement is 'over there', but it just saves lots of time and trouble if you are using the correct band.
I'm really interested in how this turns out for you so I hope you keep us posted.
- 'Doc

RE: New to site - and need some serious help!!!
 

Cheers for that.

Not a problem buying stuff in the US, great exchange rate currently and I work for a US Company in the UK!

Thanks for the link, have now registered & posted....

Keep in touch
James

RE: New to site - and need some serious help!!!
 

james, steering on mini jets are quiet good using the steering noozles. might even turn on a dime. 500 or 540 size motors are fine for your application and rpm i think are enough for the purpose. waatercooling will depend on how you run it. i have run a mini-jet with 6v once and seems ok for a scale boat. so you might try to use your 12v and then wire the motors in series so you can have 6v each motor.
my next project (current actually) is a 1 meter long semi-scale patrol boat with 2 mini jets, which i really am excited to have a test run.
goodluck on your project.
ernest

RE: New to site - and need some serious help!!!
 

ernest,

thanks for that.... do you know much about what speed controllers i should use ?

Regards
james

RE: New to site - and need some serious help!!!
 

Like I said you can use one Traxxas XL-10 speed control to power both motors.

ernest- what boat are you building? have a link, would by chance be a PBR?

RE: New to site - and need some serious help!!!
 

james, i dont know much about speed controller, but as QS suggested, xl-10. if it can handle 2-motors then its should be fine, and i assume it can handle 2 motors running 7.2v each, which is even better.
QS, its not PBR, it's a scratchbuilt offshore patrol boat, semi scale since i only made the plans myself.

RE: New to site - and need some serious help!!!
 

yeah the XL-10 is meant for the villain 7.2, which runs two 540, 19turn (I think 19t) motors. So it will definitely handle twin speed 500's. It's also decently priced, around $90.

ernest- I was thinking, depending on the dimensions of your patrol boat hull, you might want to run twin 28mm graupner drives, the 28mm drives are good for boats up to 30", the mini jets I would assume are rated for boats maybe 20" long. I would think you might want more power. Maybe the mini-jets are ok, but something to think about. The only problem with the 28's is you'd need twin 700 motors, which will mean lots of battery weight, but she'll move real nice.

RE: New to site - and need some serious help!!!
 

Hi tg7383.

I’m curious about this carp fishing bit. Just how does it work? You carry out bait and a hook out to a certain distance, then release the bait and hook? The fishing line is ties to the shore (or reel) the whole time?

I know it may seem a dumb question to you, but I never heard of it before.

Thanks.

-J

RE: New to site - and need some serious help!!!
 

Basically, you have a hook and line on a quick release attached to a boat, the other end on your rod and reel. The boat has a bait hopper and dispenses it for chum, when you get a hit, you snatch the line, the quick release opens and you reel her in. If that quick release doesn't open, your bait boat becomes a submarine :D

RE: New to site - and need some serious help!!!
 

I did some Googling about carps. Their are many species. All the way from pets to ones bigger than the guy sitting on it!

http://en.wikipedia.org/wiki/Carp

http://www.carp.com/ (Check out the photo in fishing in Spain link.)

Sure looks like fun!

Thanks!

-J