Dana W

I modified the bottom on the drag boat and here is the first boat out of the molds . The first test I had the rudder on the right side of the prop and at full throttle the boat was pulling to the right . So I installed the rudder behind the prop , and it wasn't pulling to the right as bad but geee's the steering was very sensitive . Here's a short video of the second test .
http://rcuvideos.com/item/B9LRTG6931HN83QT
I'm going to move the rudder to the left side of the prop and see what happens .

ken0276

My Feedback: (2)

move the rudder blade into the transom side as much as you can and see what's going on, that's the prop walk.

Dana W

I have it set 2 1/2" from the transom so I'll test it tomorrow and see what happens .

ken0276

My Feedback: (2)

Nice looking cat, what's the carb and pipe? I had the same issue on my cats and resolved by this method. good luck.

Paul M

Not a cat. It's a mono with a funky bottom

Dana W

LOL , nice one Paul . It's neither , it's a runner bottom .

Paul M

I never get tired of looking at your work, Dana

Slow Motion

Dana as always your hulls look great. Prop walk is the prop trying to paddle wheel its way across the top of the water in the dirrection of rotation. That causes the transom to go left and the bow to go right. Moving the rudder will " cover up " prop walk by dragging the hull slightly left. The proper solution is to THIN and RAZOR SHARPEN the prop so it cuts cleanly into the water. It will also make the prop much more efficient. Another "fix " is to shim the drive 2 or 3 degrees to the exh. side to counter the thrust. The hull is running VERY WET and I think this is due to the high concentration of glass weight up front in your design. For this hull you may have to move your C of G way back and/or adjust some positive ( up angle ) into your strut setting. That hull should be riding on the last inch or two of its surface. Good luck with further testing.

nvs motorsports

its a flat bottom hydro guys

Dana W

Well you can see by this photo that the boat isn't really riding very wet at all . I did shift the weight back a touch and that made a big difference . I have a Dasboata prop on (275 ) and believe me you can shave with that . I may have to take your advise and do some shimming on the drive but first I'll try the rudder thing .


I have to say though this boat is a kick to drive . Thanks for your ideas .

martno1fan

Hi Dana dont shim the drive remove it and drill the exit hole 1/4" to right of centreline then mount the strut the same that will stop the prop walk .Nice boat mate very unusuall never seen anything like these before this side of the pond YET!!.
Mart

Dana W

OK thanks . A guy in Belgium told me the same thing . It's a sub-surface drive so it's just a matter of shifting the strut to the right . That's why I like this site , lots of feedback . Thanks

Dana W

Well that was the ticket , the rudder needs to be on the left side of the prop . The boat handled perfect . At full throttle and my hands off the wheel it went straight and left & right turns where great and very controlable . Now we'll work on getting more HP in the boat . What's in it now is a stock Zenoah 260 with a 644 carb. & a 275 prop . Nothing fancy . Here's a short video of todays test run .



http://rcuvideos.com/item/F6NDG412GD81504J

ken0276

My Feedback: (2)

glad to hear that you fixed the problem, your boat runs nice in the video, for my first impression, I thought it was a drag cat, nice looking boat again.