speed-king

is any body familiar with this drive system? is it good? what is the mounting area (? x ?) is the prop that comes with it a surface prop or does it get settup below the surface? can i run it using two 6 cell batteries from my electric buggy?
thanks

RaceCraftRC

I have one I don't know two much about it I belive the prop is semi sumeraged, this is a much older system , I haven't had the boat lond but I run it this weekend with 2 packs from a truggy in series and a cheap o speed controller its not a rocket fast but its still fun ( bushnell rader guning 22mph) sorry have no idea the prop size.

Stokes

Hiya SpeedKing - AE is right - it's a surface drive. I've used it before, and it's pretty solid, though the teflon tube is much wider than the flex shaft running in it. This means that water gets sucked up into the hull. This is not a good thing, i'm sure you'll agree.

I found that using a 4 mm i.d. - 5mm o.d. brass tube insert (just 10mm long) in the flex (on the motor side), with plenty of grease should help avoiding water getting sucked in with the flex cable. You can run it on 2x 6cell packs in series, but since you're running 14.4v, you should really consider can cooling and brush-cooling too (especially if your motor is rated for 9.6 volts or less. I would go for the 9.6v motor, and over-volt it to 14.4v with brush and can cooling. Many theories on the subject - but a wealth of info in these forums - particularly the discussion on your other thread (first RC build)...

To AE. just a few tips to improve things a little bit. May i suggest you try using a different prop to the one you're using? try and get your hands on a couple of Graupner K series props with different diameters. The leap in performance you'll see should be significant. I've tried the props you're using on similar setups...and really the K series are what you want to be running. Also - my advice to Speed-king holds for you too - can cooling and brush cooling are a must if you're running 12 cells (on any motor rated for 9.6v or less..
With 12 cells and a K43 mm prop you should get that thing moving (i would guesstimate around 30mph+)

speed-king

when setting the system up in a tunnel like AE's boat for example, should the propshaft be set level with the bottom of the sponsons? or does it need to be higher than that?
thanks

Stokes

On single drive setups yes, i think that is the rule, although perhaps someone else can confirm. On my dual-drive iceberg though, they're about 1/4'' above that. what have you decided so far (about your project i mean)?

speed-king

ive decided that im going to go with a 24'' tunnel hull (similar to AE's boat) for better handling and stability, instead of a mono. im goin to use the Graupner hydrospeed flex drive with the 700 motor. jeti 600 navi esc on 2 six cell batery packs. is water cooling going to be necisary with this set-up? what is the best prop for this settup? should i juts use the prop that it comes with? if i set the prop shaft at the lowest part of the hull like you said to do with a single drive, and i decide later that it needs to be a bit higher or lower can i adjust it easily with the flex drive(height wise)?
thanks

SV27dayton

I don't have much setup experience but I'm building a cat that has a drive with some adjustability lik yours. I'm planning on mounging so that I cna put the entire prop hub above the sponson line all the way to putting the entire prop hub below the sponson line. From there I'll dial it in using the GPS and evaluating how she turns. You are adjustable too with that system so the important thing is making sure you have the stroke to put it where you need to.