Quicksilver1

Well, I know Diego boy had good results with a 36-50-2300 in his 26" shockwave, on the 29mm. I've not really broken into BL setups yet, but I would say anything in the 2100-2500 kv range. The 700sc is about 2100kv. I had bought a feigao 12L 2048kv, but I wish I had gone with a 9 or 10L.

I started making this shield, and I'm not particularly happy with it. I need something smaller. This looks ridiculous imo.

DRAGONFIRE81M

im thanking about going and picking up a 29mm sometime this week and put it in big blue . i would just go with a 700sc but i would have to buy a esc for it . i already have a brushless esc that would handle those motors . i came up with around a 1000 kv on the 700 bb but they dont show specs on the 700 sc

Quicksilver1

I forget who told me around 2100kv, but I just checked at OSE and graupners 700 motors range from about 1500-2050 kv. The highest being the 700 9.6v race.
I need to contact steven about this at OSE, he really should state the specs for his own motor.

just looked up the ss1, 1450kv........guess maybe I was misinformed. Perhaps in retrospec I'd recommend a 2000kv motor, the 700sc has more than enough power, you can go hotter. I mean my 700sc doesnt even get warm on 16cell.

DRAGONFIRE81M

well i go with the 2300kv just to have a little more power i plain on running two 11.1v with a mha of 4800 the same set up that im running in the 22" as far as batterys go till i can aford bigger one for this boat.

Quicksilver1

hmm, you'll actually be pushing a little over 25,000rpms under load.

I cant believe I've been calculating my rpms wrong this whole time. so I'm actually running 25,600rpms. Hmm maybe overdrive is in order? [sm=tongue_smile.gif] I've got torque to spare.

edit; theoretically you might go faster than my villain, if your boat weighs less over all and everything is setup right.

DRAGONFIRE81M

thats the thing with the mini jet im running around 40k in the 22" now and no cavatason . i havent got to try it in open water to see how the speed inproved i would hate to see what the minijet v would do on 40k who know i might try it once . i just wish some would list more specs on these drives . its totelly up to us to find the liments of this drives . which can get pretty price .

Quicksilver1

yeah, hey somebody's got to do the R&D.
here's Kehrers specs for the 28mm drive......it's got to be close to the graupners, which means were way over spec [sm=tongue_smile.gif]
Their specs stay the same through the 33mm until the 40mm where they say 10-15k rpms. Being I own both drives, theyve got to be close(28and29mm)
operating RPM : 15.000 - 20.000 rpm
static thrust : 200 - 400 W
13.000 - 16.000 rpm
2,5 - 4 kp
inlet channel dimensions : Length: 130 mm
Width: 38 mm
Height: 45 mm
propshaft diameter : 4 mm
recommended motors : Johnson-700-Neodym Length 66 mm (identical to Graupner 9,6 V BB Turbo Neodym)
Johnson-700-Neodym Length 60 mm (identical to Robbe Power Plus 710/12 and Simprop Power Speed 7/14)
Johnson-800 16 V (identical to Graupner 820 BB Turbo)
Plettenberg

DRAGONFIRE81M

yeah i have read all there info after you posted there link . i didnt even know they where around and i based all my jets on that info but like the minijet its way off . i thank i could really get that drive to move if i could put nedlile bearings on the shaft

headhunter23

Been working on my 22" a bit tonight. Could almost finish it... but a. I do not have coupler (buddy has it) and b. how to wire camera up. Should it have it's own power supply? Or should I use some resistors and change the voltage from 14.8v to 12v (boat will always run on 14.8v). I'm thinking the second option because I don't want to add any more weight to the boat. The camera is fully water proofed, but the transmitter isn't.

Right now I could run the camera through waves and such no problem, but have this feeling that any little drops of water will stick to the lens in a second. Whereas if i further make it more water proof, by making a small case outta plexy, the water should shed off, plus would offer increase protection if for some reason she flips and hits rocks etc. I think I will make the case... have to make one for the transmitter, will have to think on it over night.

In the mean time post your ideas, one way or the other. need some input.

oh as mostly always, more pics!

p.s. had bought the camera system to try it out, and am also getting into aerial photography. Since this is a lesser system than what the airplane would require I decided to make it part of my work boat. It's becoming more and more of a true scout/fishing buddy and should make some kick ***** videos running streams!

headhunter23

The rest from tonight, camera is done, tis drying now.

kahnen

FE Calc has a 700bb 8.4 as 1750kv and an SS1, like you said 1425kv. As I understand it, the 700sc has the same number of winds, timing and magnets as the SS1, so most likely same kv? Does it work that way?

If you want to get FE calc program it can be down loaded here. It doesn't have jet drives but you can probably find out some other info. Might be able to even add in you own info on jets. You can add props so maybe. [sm=50_50.gif]
[link=http://www.rcboataholic.com/fe_calc.htm]FECalc[/link]

DRAGONFIRE81M

thanks kahnen this well really help me out

Quicksilver1

headhunter, you seem to know more about electronics than I, so I guess whatever you think you should do with the power supply. If you think you can supply the camera with the power go for it, I guess you have to make sure it cannot spike over its operating voltage.

headhunter23

Hmmm good point, a capacitor would smooth it out... kinda wished now that I had gone with 11.1v setup would have made things overal simple. But theres no way I'm switching motors again. Had gone through 2 others originally during learning process.

Ivan.

Edit point: had remembered I picked up a few extra 450mah single cell lipo's... instead of trusting voltage of 14.8 down to 12v, going to install this small pack somewhere on boat. Weighs 30g so not worried about that much weight! Also decided on video camera case. Am going to run it as is and see how it goes.

Ivan

DRAGONFIRE81M

QUICKSILVER what did you use to out the abs drive together ca, superglue ect went and picked one up on lunch brake.

Quicksilver1

just CA glue, just make sure you get the whole seam, or it will leak. Afterwards, for good measure you could coat it in epoxy.

The trick with installing the drive is, put the two halves of the duct together. Figure out where it will be secured.

Mark out the hole for the transom...check and recheck the measurements a million times. Then cut the transom hole, insert the black piece that connects directly to the white duct. So the screw holes are on the outside of the boat.

Then make sure everything lines up, is level and then glue the duct to the bottom of the boat. Insert that black piece again through the hole and glue that in place, cut the hole in the bottom of the boat and your basically all set. I prefer to cut the hole in the bottom after I glue the duct down, then I know I wont cut the hole too big.

edit; I forgot to add, I would use fiberglass to secure the duct to the hull, you could tack it down with CA first

DRAGONFIRE81M

man its not like i havent done it before just a little diffrent i figered out i would have to put the black ring in after i cut the hole out . plus in going to atach it to some alum sence theres two hole already in the hull

oh yeah thanks for the help

Quicksilver1

oh that's true forgot about all the holes already there.......sorry, I thought the minijets came fully assembled. I'm not quite sure why Graupner cant produce a one piece duct. Must be a tooling issue. Does this unit look more appropriate.......pictures man!

DRAGONFIRE81M

i got the last mini-jet out tonight and i have the drive put together just need to smooth out the inlet with epoxy and im going to cut the hull in two to make it easyer to get the wood transom out so i can install the alum . man what a diffrents in size . it would be nice to have a full mold of the intake instaid of two pices

MKMotorsport

Well, engineerjoe and I finally received our "knock off" Jet Sprints, and am doing all I can to type straight still laughing from our initial running episode

Initial impression: not bad for 36 bucks. The throttle is non- porportional which makes it pretty difficult to drive (on/off only). The steering servo, I mean swervo, has a good .5-.75 second delay adding to the excitement of the on/off throttle action

We managed to find some open water in a pretty swift flowing stream, the stock batteries at 9.6V could barely propel against the current. I had one of my park flyer 3D planes in the back of the truck with a slew of 3S 11.1 V li-pos, and all of the sudden 2+2 clicked Knowing we were going to change all the guts out anyway, we decided to go for it.

engineerjoe managed to push his luck powering up an inlet that was too shallow, and subsequently inhaled some gravel which stalled the impeller and broke the coupler right at the mold seam about 1/2 way through run #2. We managed to rip the living daylights out of mine on 3S lipo until the motor shaft welded itself to the motor bushings at about run #5. We were rewarded with an overwhelming smoke cloud from the boat and subsequent stall which made for a mad dash out into the creek to save the hull & drive. Upon removing the hatch a nice cloud of smoke and burnt motor reek greeted us. Laughing like fools, we quit for the day We did get some cool pics and some video of it running on 3S before the motor smoked, hopefully we can share that soon.

I just finished ripping out the pathetic joke of electronics, which passes for a radio system. I cannot understand what could possibly be in the monsterous brick of a receiver/esc unit that requires it be 4"x4"x3" ! hehehe.... That alone should save some significant weight. The servo is a redicilous 6 wire spring loaded contraption the likes which I've never had the disfortune of laying my eyes on before

Anyway we're having fun! Mine is going to get a Novak XXL RX, 4300KV inrunner, Hobbico cs-35 high speed/high torque mini servo. ESC still yet to be determined. Haven't decided on 3S or 2S li-po for sure yet. More pics/docuumentation to come!!

Quicksilver1

the new one is a bit bigger size to see them together. I'm willing to sell my aluminum plate for shipping cost. It's still good

headhunter23

Motorsport! I was laughing my ass off reading your post, wished it was caught on video. Absolutely hilarious. I want to see how fast yours goes on your 4300k!

Ivan

MKMotorsport

Headhunter,

We'll post some pics of the 3S action on the stock motor within the next week or so (engineerjoe has the pics and his CD writer was acting up, he's out on vacation for the next week). We'll definetly update the speed report once the 4300 is installed, who knows, it may be way too much rpm for that little drive, engineerjoe is going to build his up with a inrunner in the 2000-3000kv range (probably more sensible ) What is everyone doing for couplers on these things?? Seems the stock one is super fragile.

Thanks,
MKM

DRAGONFIRE81M

im with head hunter i was lol the hole time reading it to . im just going to make one from some alum rod . man that kinda scares me im running a 3s 2400 mah on the stock motor with a 12v esc will see how long before it blows havent had time to go run it . getting pretty close to xmas and things are getting crazy .

quicksilver i wont to see if i can put my matel skills to some use first . pluse i have a pretty large holes to fill . but if it doesnt work out ill keep your alfeare in mind . thanks
[/quote]

MKMotorsport

Dragonfire,

I think we'll look into making a few spares out of alu or brass bar stock, that sounds like a good idea for eliminating that point of failure. I think what killed the motor is that we were running the li-pos (between 1500-2100mah), back to back to back, as fast as we could switch them out, with -0- cooling time between runs The motor progressivley smelled worse and got slower with each run The other stock electronics held up just fine. I think had we let the motor cool between runs it would have lasted much longer, but then again we were on a mission of destruction at the time

MKM