Twin Pursuit

[RunningBeer]

Hi, I've just finished my twin pursuit build, it's my 5th boat build. Pics are on my page.It's a beautiful handling sport machine, I'm really stoked with how she runs.
I'd like to say a big thanks to all the people who have shared their knowledge on these pages for us to use and research, and thanks to O.S.E. for hosting.......Cal.

[Peter A]

Twin Pursuit. Interesting. What is the setup? Any vid.?

[RunningBeer]

hi,
The set up is: 2x HET Typhoon 2200Kv 36mm dia 68mm long motors (120amp/2100W). 2x SeaKing 120 amp esc. 3/16" Speedmaster struts and Speedmaster rudder. 2x 5000Mah TP batteries. Futaba radio.
After trying various props and using my eagle tree logger, I am getting a peak of 135 amps at take off and about 80 amps on the plane with 43 mm props. I could only go one size larger in the diameter before they would touch anyway.
I also used a layout with one battery forward and one aft the same distance away from the COG. This has enabled me to try a couple of different size packs without altering the COG. The front battery has room to move forward or back a little for fine adjustments. This hull is very stable with every thing heavy right at the bottom of the vee. It is very hard to upturn this boat as it also has no tendancy to torque over when it leaves the water as the twins counter-act each other.
I had a problem with the boat 'chopping' around the corners at first which I fixed after reading the excellent article on the front of the OSE website about boat set up and rudder effect. I had the rudder too far towards the outside of the hull which meant it had to be too long for left hand turning, but was also too far off the centre line and levering the hull in a sideways manner. I moved the rudder as close to the outside of the prop as I could without getting in the way and shortened the rudder progressively until the problem disappeared....Thanks Glen Cupit for the brilliant article.
I used struts because most people on the site here use 9-10mm height as a starting point for their stinger height. If I transferred that to the distance apart I would need for 44mm props, The exit point would be right at the bottom of the hull. the brass tube comes out right at the bottom and the bottom of the struts is below hull height. I know this means less adjustment, but I still have some prop height to play with, albeit changing the angle too. Copy of IMGP0682.jpgCopy of IMGP0684.jpgCopy of IMGP0685.jpgCopy (2) of IMGP0680.jpgCopy (2) of IMGP0680.jpg
I'm running about 51mph top speed at the moment,although that's taken with a Garmin running watch GPS. I'd like to try another GPS in there to check the accuracy. it's a stable and predictable set up nd lots of fun!
R.E video. I have some footage I would love to put up as well as some footage of my 10s jet boat and twin hydro. Do you have to have a you tube account to do that though?
Cal

[rabosi]

Nicely done.

[Beniki]

That looks brilliant! I notice that like my Pursuit, your hatch is bowed in the middle. How do you find sealing it?

[TheShaughnessy]

You tube makes it simple. Get an account I want to see your jet boat

[RunningBeer]

Hi...Regarding the hatch, it fits well I just had it sitting at an ugly angle for the photo. TheShaunessy.... I'm Working on youtube stuff, almost there.
R.B.

[ray schrauwen]

Thimply fabulous! No really that is a great job. I'd like to see the struts better in another picture please.

[Mad Racer]

Very, Very well done.

Seriously cool. So how does it go??