Wheelnut

My Feedback: (81)

Preacher, Hobbypartz is a great USA supplier. I use them all the time. They also have great batteries. I use the Gens Ace in most of my planes.
The motor you picked looks good to me, I used to run fast electric boats all the time. I usally try to over rate my esc by a good margin. I ordered a 50amp from Hobbycity.
Here is a 60 amp from hobby partz that would work fine. http://www.hobbypartz.com/seaking60aboat.html
This would help save the esc in the even that the motor may get something stuck in it and the amps sky rocet.
I am sure others will offer good advice also for you to choose from.

Wheelnut

My Feedback: (81)

Have you taken it apart and greased it with thich grease like the stuff they sell at offshoreelectrics.com?

sundogz

4 to 6 weeks? Most of my purchases from China only take 2 weeks. The 3900kv motor from Hobbypartz has been used before in this boat with good results. You'll need a 3.17 to 2.3mm coupling (try to find this in the States!). The 60A Seaking esc that Wheelnut picked is a good match as well. If you go with a lesser brand, double the amp rating.

Preacher7

Thanks Wheelnut, I'll keep that part in mind, but for now they are out of stock. I'm mostly stuck on an equivalent to the 4450 motor and cooling jacket or finging it here in the USA.
Sundogz, am I right that I'll use 3S batteries with the 3900KV motor? If so i'm ready to order the HobbyWing 2848 SL 3900kv motor and the SeaKing 60A ESC. I can drill out the coupling no problem. Once I'm clear on 2S or 3S I'll get batteries ordered. Is 35C or 40C adequate or should I go higher?
thanks a lot guys for the input.

UPDATE:
wouldn't you know HobbyPartz is out of the 3900 motor and the 60A ESC.

seehuusen

Welcome to the forum mate

I run the Hobywing 2848 3900KV on 3S, it's fast and fun I used cheap 60A ESCs first, burned out two of them, and now I'm using a good quality 120amp ESC, which I've had NO problems with

Just letting you know, if you want to, you can use the original coupler... 3.17 converts PERFECTLY to 1/8th inch, either you've got a laithe or a press drill?? Perhaps someone you know has one?? Worst case scenario, you can always drill it out by hand, but carefully, so you get it straight
You only need 5 to 10mm drilled out too

Hope that helps
Martin

Preacher7

hey seehuusen thanks for the info. I'm glad to hear from someone that has run this combo. Do I REALLY need 120A ESC? I got the imression a SeaKing 60A would be adequate. Is that motor going to draw that many amps?
I used to be a machinist so doing this kind of stuff is no problem. I'm just not at all familiar with brushless motors and ESC's even though I've been in electronics all of my life.
thanks

seehuusen

to be honest, a good quality 60Amp should be more than enough... I just got peeved off with me burning them out, and when I looked for another one, I got the better quality one, which happened to be a 120amp one... I think these motors spike at like 40-50amps MAX so you should be OK

Preacher7

What do I need here?

sundogz

I have not used this larger 3900kv motor with the NQD's smaller jet drive, but do use it (on 2S) in an ABC jet ski with it's larger drive and it is quite zippy. 40C lipos will be adequate, but you will not regret getting higher 'C' rated lipos if you can afford them. I am currently running [link=http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=11179]this 2900kv[/link] 600W outrunner with no motor cooling on 3S with a 60A esc and am very happy with speed and runtimes. I know that doesn't help you, but you can see the can of worms you've opened up by asking!

Preacher7

Maybe I can fry up some of those worms. Thanks for all the suggestions, I'll order one of these combos and see how long it takes.

Toyotatrucks83

Just ran across this. Was wondering if it is new news in this forum?
http://www.proboatmodels.com/Product...ProdID=PRB3656

sundogz

No, the jet drive for the Duck Decoy recovery 'boat' is quite small. It has a 13mm impeller and is suitable for micro size boats (9" to 16" or thereabouts). You'd need two of these drives to get the power of an NQD or Graupner mini (19mm) drive. Which, by the way would be pretty cool - I don't think a twin micro has been done in this thread.

Area = Pi x Radius squared
Radius of 13=6.5; Pi=3.14
3.14x (6.5x6.5) 42.25=132.67sqmm

Radius of 19=9.5
3.14x (9.5x9.5)=283.4 sqmm

Toyotatrucks83

Thanks for the info sundogz. I'd be willing to try a twin drive jet boat. But I think a hobby grade hull would be a better choice. Any suggestions? I really like the size of the nqd tear into. I'm currently building one. I think a slower speed twin drive jet boat in the 20" would be a cool too.

sundogz

The [link=http://www.hobbyking.com/hobbyking/store/__11984__Turnigy_Taipan_Fiberglass_V_Hull_385mm_Hu ll_Only_.html]Turnigy Taipan[/link] and the [link=http://www.hobbyking.com/hobbyking/store/__11983__Turnigy_Cobra_Fiberglass_V_Hull_385mm_Hul l_Only_.html]Turnigy Cobra[/link] both are fiberglass and have 90 degree transoms, so would be good candidates for twin 'Duck' drives or an NQD/Graupner mini drive.

Wheelnut

My Feedback: (81)

I'm going to ask a question I should have asked a long time ago.
Is most everyone here using the stock jet drive?
I used to have a mini graupner jet drive but I don't know what I did with it. I'm going to do a search tonight. But I think I sold it a long time ago. [&:]

Toyotatrucks83

I'm using the stock nqd jet drive.

Wheelnut

My Feedback: (81)

Cool! No problems yet? How many runs?

Is anyone else experiencing long load times on RCU?

seehuusen

Interesting... Going on that, the area of two of those duck drives is still less than that of the NQD jet

I'm also running the original drive, but I've seen a NQD Tear Into 4S setup, using the larger groupner jet drive, which they purchased from a UK hobby shop (should pop up if you google it )
I've run my jet boat for a while now, maybe 40 battery charges through it... I've run it on the beach, in salt water/ sand and in the creeks with mud and crud... NO PROBLEMS (and I don't run a grate or anything like that either!!!)

I've got a complete spare boat, so if it ever died on me, I've got another boat

Cheers
Martin

PS. Time out errors and slow loading times seems to be the go for me too

Preacher7

YES! Often it is very slow.

Preacher7

Hey guys can I permanently glue in the removable ramp that is attached to the original intake grate?  It seem there is no reason not to but there may be a reason I havn't come up against yet.  Secondly when the ramp is in place there is a gap between it and the end of the housing (which was addressed several pages back with two drawings).  It can't leak but the gap seems like it could disrupt the water flow.  If it is moved fully to the rear of the housing the rear edge on top would have to be trimmed a little.  Any thoughts?

Preacher7

Sundogz you have mentioned several times super glueing the pump assy into the hull. What if it has to be replaced. How will you remove it? I like the idea but I'm worried that I could never remove it in the future. Will the super glue remover attack the hull material? If not then that might work.

Joshsubmec

My Feedback: (2)

Yeah..

seehuusen

I used silicone to glue my drive in, plenty of it, and it's 99.9999% water proof

sundogz

I have recently had problems with the email link to this forum not taking me here - I have to manually get on and locate this thread. They must be experiencing problems of some kind. On gluing the jet to the hull, if it doesn't leak (around the jet body) I don't remove it - there is no need to. But if it leaks, I'll remove the jet body and reinstall it and the intake ramp permanently, eliminating any potential leaks. I used to use superglue, but it outgasses and leaves a white discoloration, so I now use a 2 part epoxy made for plastic. I then install the stator housing to the transom with silicone. I have never 'worn out' a jet drive bore, but if it was to happen, I can re-line it in the hull easily enough with a drill bit and 1/8" brass tubing (if the hull was still in decent shape by then). And let's face it - it's just a $45 boat. If something went bad wrong, I'd just buy another boat.

Preacher, the intake ramp is installed fully to the rear - the bottom two screws of the stator housing pull it into place. What needs to be trimmed? Pics?

swervyn

i used longer screws to hold the thingymajig to the transom and they protruded into the hull, the water pressure when running forced the water to run up the thread into the inside of the boat, issue 2.3 million & 1....