Rich's MHZ Shockwave m version build aka Fountain

[Rich]

Ok I raised the strut to about center of the tube and had the cg at about 29% ish. I had some chop today but it handled it very will at about 75% throttle 67.29 amps, 40.9 mph. Not to bad, I'll have to see what she does on glass. I still had that prop torque problem so I brought her in and gave the left trim tab some down and that seemed to help it go smooth. No vid yet I will get one soon. THANKS GUYS!!

[Rich]

Update: I ran her in calmer water and she still has the hop. I noticed the water hits the hull about 2/3rds from the transom. I still think its front heavy and will add just a bit of weight to the rear and see what happens then.

[Rich]

I took the trim tabs off and it loosened the hull up a lot! It hopped like mad, so I gave the strut some negative pitch and it helped. I will move the cg forward and give it another go.

[Rich]

Ok guys I am just about fed up with this hull. I have no idea what I can do. I moved my 3300 4s forward and moved the strut all over the place and she still wants to take off at speed. I am running her in some chop too. Once I let go of the throttle a bit the front begins to slap the water. I have on an X637. I even tried to use the 5000 4s to see if it was a weight problem and it still does it. I am completely lost....

[jcald2000]

The 6 series props have a good amount of lift, try a 440 low lift prop.

[Rich]

Thanks, jclad2000 I was thinking about that I have an x440 and I think a m440 Ill give those a try and see what happens

[Jesse J]

Hold on rich, don't give up yet! Sorry you are getting frustrated... I know how it feels.
I will take mine out today and get the specs for you. Hopefully there will be something in my formula that will work for you.

[Jesse J]

Rich, I just ran mine yesterday and she is running sweet!
I have a castle sidewinder motor 4600 KV (less than 200grams - 2/3 the weight of your motor)
batteries 2S2P, saddle packs (each are 2200mah 2S nanotechs)
m440 prop and the CG is 1/4" behind the front step.
the strut is mounted so the center of the drive line is 1/2" up from deepest keel and 2deg negative angle (it is a Venom P1 strut)
leading edge of prop is 2.5" back
rudder is offset 1" to starboard, 3" back, 2" deep and 3/4" wide
trim tabs 1.5" long, flush with bottom; starboard is flat, port is down a millimeter.
turn fins are the small carbon fiber ones lifted about 1/4" above the base of the keel.
the rear of the motor is positioned 2" in front of the front step, esc is along port side, port battery is an inch from the transom, the starboard one is 4" forward.
I have a Traxxas micro servo mounted on the drive line an inch from the transom
the whole thing sitting in the water is 1200 grams weight.

Hope this helps. I can post a picture of the inside and of the hardware if that would help.
good luck and stay with it, these are so sweet to watch cruise along in 2-4" chop!

[Rich]

Thanks Jesse for the info! What speeds are you getting with that setup? My boat weighs in at about 1650 grams....wonder if that has something to do with it. So you have the strut 1/2" up from the first step? Is that what you meant by keel?

[Jesse J]

Thanks Jesse for the info! What speeds are you getting with that setup? My boat weighs in at about 1650 grams....wonder if that has something to do with it. So you have the strut 1/2" up from the first step? Is that what you meant by keel?

speeds are probably upper 30s-low 40s - no gps
yes I am thinking weight is your trouble maker
the keel is the lowest line of the hull. If you took a tape measure from the bottom of the transom up to the center of the drive line it would be 1/2"

[Rich]

That would put my at about the center of the flooded stuffing tube....I think Ill give it a try with some negative. Correct me if I am wrong, but wouldn't it be better to have more weight with higher speeds? I mean my MM ran great with heavy lipos, and the speed increased too. I have had the shockwave at 49.3 and its fine at about 46 mph. I will give your suggestions a try after I get my rx fixed.

[Rich]

Jesse, does your Shockwave lean to the left at speed? Mine does.

[Jesse J]

Mine only leans when not balanced out well. It would want to lean starboard (clockwise looking at the transom) due to torque roll, so I weight the port until it is balanced out when underway.
Sounds like you need to shift or add weight to the starboard?
That is assuming you have a true hull and it's not your trim tabs causing you problems...

[Rich]

I should say that I have my rudder trim to the left to keep it straight. I also have shims on the right side of the strut looking from the back. If your rudder center mounted? I was thinking going to a smaller motor, a 2860 or a 3650 what do you think and what kv?

[cugino]

Hi Rich,

i have ShockWave too and it handles very well witth good speed result (about 80-100kmh, dependind on prop used). There is my setup in the table: http://olaf.webz.cz/shockwave.htm