question with adjustments on the strut

[tlandauer]

HI, I didn't want to ask this old question, but as much as I have read/learned from other posts I still have this confusion: as i understand in order to minimize the wah-wahs, the strut has to be on the high side. Well, as I raise the strut, it goes in an arc, so when I have the desired position unfortunately the prop shaft has a positive angle, doesn't the positive shaft angle raise the bow and will promote bounce more? Is there a way to raise the strut without having the prop shaft going positive? I am afraid to use force to bent the stuffing tube.

[HYDROJERRY]

First off is your MG stock , if not what are you runing in it,, mine has the stock motor and a Turnigy 120 esc and i run 4s2p with a M445 prop and my strut is level with the ride pads and no wawaw,, and i have the kintec offset rudder..

[tlandauer]

I have a 4082 2200kv leopard /seaking 180a ESc and a s/b x642, Kintec offset. GPS'ed @ 53.3mph. ( 4s2p config.) The strange thing is that if I go WOT, the boat is actually smooth w/o wawaw, but that is a very narrow threshold and I feel any moment there will be a flip because it is running dry, from the low 40's to 50's the boat has wawaw. I think a M445 might be the answer but I don't have it at the moment.

[highflyerbill]

This hull in my opinion has a real problem with porpoiseing . I've tried and tried and by raising the strut 1/4 in and moving the batterys foward has helped a lot ,it will still porpose but not as bad . It's now a matter of making small movements with the packs to see if I can dial it in better . By the way I also trued up the sponsons , it din't help the wawaw but it does corner much better .

[tlandauer]

The problem partly lies on the fact that every boat is different: all depends the "curve" of the stuffing tube. Mine is very pronounced----it is curved up so the prop is pointing to the sky ( positive trim). Now according to the manual you need to raise the strut to eliminate the porpoising---wrong! in my case I would have made the prop even more positive and thus driving the bow of the boat out of water.
After my last post here I went the other way until my strut was below the last ride pad. ( Between 1/8 to 1/16") The boat is rinding much better. Try lower no more than 1/16 to 1/8 of an inch at a time, I also use a sharp file tip to mark lines on the strut, so I see different lines, marker's tip is not sharp enough. One member suggested bending the tube---I haven't tried.
Until you adjusted the strut right I find the effects of adjusting battery position to be minimal.
BYW, I went back to the stock in-line rudder for my latest adjustment, now I will go back to Kintec off -set next time since Kintec does provide better turning.
It is my opinion that the majority of the boats have a "neutral stuffing tube" , meaning that if you adjust the strut level with the ride pad, the prop is more or less at a "neutral" setting, therefore most of the post here point to that adjustment. That is why for the longest time I didn't think of lowering the strut BELOW the riding pad.

[highflyerbill]

I would try bending the stuffing tube . If you Can get the next size larger tube slip it over the 1/4 in brass tube and it will make it a bit easyer to bend it slightly . that way you hopefully you will not deform the 1/4 tube .

[tlandauer]

Yes, this is really a good idea, although I still need to see why with the stock rudder I can get rid of all the porpoising but the hull chine walks, like a cobra snake out in the lake, where as the Kintec off-set rudder allows the boat to track like its on rails, but with porpoise. As I said in my previous post I have not tried this setting of the strut with Kintec yet. I want to stay within all the known facts before attempting anything new. My speed is still really good and even with the lowered strut the boat is not running wet. Keep me posted of your further adjustment. I find it interesting that you don't think truing the sponsons helped because I was just toying with the idea to do the same, but I am lazy by nature and now I won't do it.

[joker rc]

mine with almost the same setup ,gr 42x55 prop 4074 2200kv ,only bounced at a set speed as you say bettween 40 50 ,after that it would level out .any rudder input would see it run smooth , so to day i adjusted the strut , negative few degrees ,keeping the stuffing tube level with rid pads and it was spot on the money , run dead flat riding high up on the ride pads , it was blowing 20not head wind and the water was little choppy even flat out into the wind it was stable , .video up to soon

[tlandauer]

That's great! I think I will have to bent the tube a bit as I mentioned earlier mine has a positive angle. I got my attention fixed on my Pursuit for the last month and only today did I get the problem solved thanks to all the people here, now i will refocus on the MG in the coming weeks hopefully, your info. is very valuable to me as i always wanted to know what effects with a little negative strut would bring.