grael

sundogz-
Lurking mostly, yes.
I have to change projects now and then to keep life interesting[8D]

waspmike

Ok first post!

SicRC

Hi Mike, it's Steve (SicRC... ondabeach)The main difference between the 2 reversing nozzles is that the Kamewa style is much shorter than the Riva-Calzoni. If you were going to be using the boat in rapids I'd say not to get a reversing bucket at all as it would only get damaged. But since you're going to be using the boat on a park lake then get the Kawema style. Also if you're going to buy the jet unit direct from KMB then the PNP kit to suit is $154.

waspmike

I'm going to buy it from you Just doing my homework, learning more and a bit of research. Does your unit come with a bucket? The more variations in the capability of the boat the more varied the experience?

SicRC

I do have a Kamewa style reversing nozzle in stock so that's cool. I'll set up a twin servo mount for you to operate it, just let me know when you're ready matey

waspmike

Steve, I'll need to direct transfer the money so when I'm ready (about 3 weeks?) I'll send you an email. I did say I'd asked the last question but do I need to upgrade to the better ESC? Also I notice batteries have been removed from your site!

SicRC

No worries Mike, whenever you're ready just email me. The ESC I do is heaps big enough, it's the same one I run in the 540mm boat I do which has a much bigger motor. I do have batteries but I can't post them overseas.

*delete M i k e u p delete*

Mike; 2S4p is 2S and 4 lipos. 2S is 7.4-3S is 11.1-4S is 14.8-5S is 18.5. Steve is where I bought my jet ( modded ) from steve and cooling and coupler and esc and spares. and quality is top notch. Also motor at 4400kv. Tip; to keep things cool; get a 2500kv and run a 3S =27750 rpm. will be super close and will be fast. I found that esc and motor run cooler with a lower kv and higher voltage. Steve is a great guy and honest as the day is long. Remember, have fun!!

waspmike

me again 

SicRC

There's no substitute to volume mike. A 28mm jet unit is pumping twice the amount of water that a 20mm unit is.

mickieb49

Hi guy's, a little more 3D printing done, got one unit nearly together, got a few more tweeks to do then i will be ready for manufacture.
Cheers Mick

damfurst

Looking good there mickieb!! What diameter is this drive going to be?

pa38pilot

Hi, first post here on the forum, long time lurker.

I've installed a KMB 28 into a vintage Dumas Fiberglass Short Stuff 10 -18" deep v from 1985.  The graft went very well, but am needing assistance.  I'm using an old school Futaba receiver with a space age Turnigy 120amp marine ESC, driving a Turnigy XK4042/2000KV Motor -both courtesy of Tollytime here over on Ebay, very helpful dude!

Before I can see how grossly over powered the little boat is with that set-up, I need to do a connector splice for my old school Futaba receiver.  My question is: are the Turnigy ESC wires (black, white, red) the exact polarity as the Futaba black white and red wires?  I would really like to know before I splice on the Futaba Male prong plug and plug it into the expensive new ESC.

I did find that Futaba ESCs do have the same polarity and color on the wires as the older units and actually performed this very splice (installing old male 3 prong) last night after conferring with the RC Car dudes (old Futaba ESC went into my Vintage Kyosho Scorpion last night : )

So I'm currently standing by seeking whether this splice is safe or not.   The new school Turnigy ESC has one of the new school plugs that is not compatible with the old school Futaba receiver.

Thank you for all the wisdom I have gained from reading everyone's posts, I aspire to be as cool as you guys some day.  Will be standing by for direction.

Brian
NATO Aircraft Mechanic
Kandahar, Afghanistan

SicRC

Yes, same polarity. Positive is always red, negative is usually black but sometimes brown and signal is usually white but sometimes orange.Splice away

mickieb49

Thanks mate, these are 30mm Impeller, they will have a Trimmable nozzel, The impellers will either be SS or Alloy, the design also allows you to make them into a 2 stage unit. Should be available within a few months , i will be producing an inital 300 units .
Regards Mick

pa38pilot

Copy that, thank you very much. Might seem like a simple question, just didn't want to smoke any components.

One more question if I may: The power pack I have and plan on using is a six cell 7.2 volt 3300 Tenergy NiMh that I bought two of for the RC Car. Am I good to go to plug this thing into the space age Turnegy 120 amp ESC? I haven't yet picked up any modern Lipo batteries, but am baffled as to whether I can plug this battery in and use it? Iwill post pictures as soon as I'm able to get them on here. Thanks again for the assistance.

SicRC

Better safe than sorry... I'm sure the pilots whose planes you work on appreciate your having that ideal Yes you can use NiMH and even NiCad batteries with that ESC. But you should turn the battery protection feature off if you're not using LiPos. The reason is that NiMH and NiCad batteries' voltage will start to taper off while they still have a fair amount of charge in them and if the battery protection feature is on, the ESC will reduce power or cut off altogether (depending on the setting) so you will get shorter run times. If you do get some LiPos later on make sure you turn the battery protection feature back on or you will damage them by over-discharging them. LiPo batteries maintain a fairly constant voltage until they are almost depleted and then the voltage drops off dramatically, that's why the battery protection feature is there.Keep an eye on the temperature of your NiMH battery, they're not designed to deliver as much current as LiPos and the ESC and motor may require more amps then the battery is happy to deliver.

pa38pilot

Thank you for the details on the ESC, the information you're providing is really helping ease my concern on proper proceedures. Iwill have more questions, but I'm due to upload some images, so here we go. Flying in the face of what I see you guys doing here, I'm bucking the system and daring the Cavitation Gods and profiled my KMB28 to the profile of the hull. If it cavitates, I'll hack the bottom off the hull and restore the 90 degree intake profile as it appears everyone else is doing -Ihad to try, ok? Iwanted to at least attempt running the original hull profile before committing to the radical 90 degree flat cut. Ishould know -for myself- if it works soon. Ok, here are some images:
http://www.rcuniverse.com/gallery/ga...berID%3D581388
http://www.rcuniverse.com/gallery/ga...berID%3D581388
http://www.rcuniverse.com/gallery/ga...berID%3D581388
http://www.rcuniverse.com/gallery/ga...berID%3D581388
http://www.rcuniverse.com/gallery/ga...berID%3D581388
http://www.rcuniverse.com/gallery/ga...berID%3D581388

SicRC

I like it No idea how well it'll work but I look forward to hearing the results. Just make sure you round the transition from hull bottom into the tunnel at the front especially. Sharp edges leading into the intake will cause problems. At the sides you can just have a slight rounding but at the front for the width of the intake make that transition as smooth as possible.

*delete M i k e u p delete*

My hat is off to you on how you have setup the pictures to view, best I've seen.

pa38pilot

Wow, cool, Ikind of got the pictures up here! I'll be happy when I can post them correctly, but that I've been able to finally share my work with all you guys makes me proud. I live on Kandahar Air Field and I've found getting back in to RC has helped me keep a higher morale. Whether its just looking forward to a box of RCjunk arriving by mail, or looking forword to some down time at work so I can tinker, the RC program is currently ROCKING! Thank you guys for all the inspiration. I have a couple vintage Kyosho cars I blast around the hangar too, a Super Alta, from 1985, and the Scorpion that I'm proud to say, Ifinally finished rebuiling today, and just finished running it for the first time. BIG fun! The Boat program is why I'm here though, so I'll keep it strictly Jet Boat from here on out. Yes, smooth transition from hull to forward tunnel... very smooth and generously tapered. Hoping to back to wiring the boat tomorrow.

Cheers from Kandahar!

Brian

damfurst

Good pictures pa38. Looking forward to seeing video of it running. Keep up the good work.

*delete M i k e u p delete*

pa38; if you put up more pictures, don't change a thing and leave them like you did before. I consider that as a CLASS ACT!

pa38pilot

Here's what I was installing last night for the fifth time... lol. Screws go all the way into the Hisol Epoxy on the other side. Faired the KMB nozzle assembly so its just flush with the bottom and zero sharp edges. Have boat in back pack right now... on bicycle at midnight on the way to work... down Sniper Alley : ) Will be tinkering at work today.

pa38pilot

Significant progress on the wiring this morning.  ESC to battery bullet connectors soldered and shrink wrapped and ESC to receiver plug cut off and old school three prong soldered and shrink wrapped on.  I'm planning on splitting the 6-cell NiMi battery and wire extentions with bullet connectors so as to be able to place 3 batteries on one side and 3 on the other.  Where in the tight quarters of the tiny hull this will occur is to be determined by float/balance test in the communal bathroom sink here : )

Question about ESC programing.  I'll need to set the ESC for running Nimi and not LiPo.  In order to do this, I'll be making the connection to my receiver, then with radio on, do some monkey business with the throttle stick?  Yes, I'm running an 1980s controller.  I do have the specific instructions and I'll be reading them again soon, but thought I'd toss that out there since I've never seen this kind of hocus pokus done before.

I notice that this ESC doesn't have a separate on/off switch.  Does this mean as soon as I connect the main battery, the BEC automatically turns on the ESC?

About to start setting up the single S28 servo to do the cha cha with the nozzle.

Sun still on the other side of the planet.  Dust blows outside, all is well.