Hydro balance

[domwilson]

To me, it looks just a tad too long. But I wouldn't worry about that until you get the bobbing problem resolved. You can PM the above guys. I'm sure they would be more than willing to give you some advise. Darin Jordan has written several very informative posts on this forum on how to prep a hydro.

[sporthydrofan]

ok im going to serch for that

[Jeepers]

ok so ill try to raise the stut. keep the same angle the bobbing seemed to go away at higher speeds.. just had enough light left to run it with the 150a esc. is the long rudder good or bad? i figured its is good for stability it turns very well, I dont even have the turn fin on it and it still turns well. my COG is about 2" back from the sponson right now. What should i do to move it forward..? the 5s 5amp lipo is already shoved all the way in the nose. should i fill the sponsons with foam? then stick a metal rod in the foam once it is dry? any ideas?

try this first go to a smaller prop, x437 y536 and raise the strut as close to the hull as possible since your running high rpm, take that bag of sand out of the hull and leave the battery in the nose, DONT worry about the CG yet. Lets worry about the hopping first, after the hopping is gone then we will worry about CG.I think that you have so much rpm at the prop that its plowing the nose instead of skimming across the top of the water, the extra weight in the nose is not helping, pickle forks don't have as much lift as a vintage shovel. (The hydro that ran just under 70mph with the cg forward of the sponson transom was a shovel two totally different hulls.)

[Jeepers]

another big thing that would help is to lower your RPM do you have any 2s or 4s packs?

[sporthydrofan]

ok i put on a 440 prop, ill take the strut and move it all the way up with a 0 degree.. all i have is 5s right now. ill try it first thing in the morning and get back to you with results..


I do have a y537/3 should i use that? umm forget it i have to do some grinding to it... it wont fit perfectly the 3rd blade is in the way.

i looked at what i have it is x640 prop not a x440

[Hydromaniac]

Just under 70mph on 4S .. what motor and prop did you use?
did you use 2 batteries?
Im only using a single 5S 5amp battery, should i use 2 to weigh it down more?

my COG is about 50% of the length of the boat... i didnt want to move it to far foward because i was worried it will nose dive since it hops so much... i did put a zip lock sandwitch bag full of sand under the cowl seems like 1.5 lbs and the hopping was reduced a great deal. im thinking of buying some automotive rim lead weights and sticking them in the hull to weigh it down a bit. just testing now the min amount of weight that it will take to eliminate the hopping at higher speeds.

I would really love to achieve that 65-70 mph mark. Im not racing the boat or anything but id like it to do laps at my pond and smoke all the other guys that have those stock UL-1 RTR's without blowing over...

right now it wont go WOP because it hops and almost blows over right around 40

The motor was a Hacker 7XL, prop was an X447 Detounged, cupped and slight tip roll.
It was a hull I had built 2 summers ago, Very light Eagle Electric semi scale Hydro. I wish I still had that boat with the new lipos that are out now.

[ozzie-crawl]

if the picture you have taken of the strut is were you set it to thats positive angle not negative.

[sporthydrofan]

if the picture you have taken of the strut is were you set it to thats positive angle not negative.

according to this photo you are telling me to go positive angle 1 degree..
I think positive angle would give me bow rise and a higher rooseter tail.

if it doesnt work i will adjust the strut up at like 1/2" with zero angle and then try 1 degree positive / negative ill post results its raining here so gimmie a few

[ozzie-crawl]

no what i am saying is the picture you posted on the last page of your strut has posative angle, there saying to run negative which has the prop pointing down not up

[sporthydrofan]

Sorry, I didnt read the entire thread. You did give some relative details. Get rid of the transom hopping first. If the hull comes up on plane with few issues then focus on that problem. A 1" deep strut and a 445 prop should be fine to begin with. Angle the strut down to reduce the lift. That means the prop nut up and the strut nose piece down in case that doesnt make sense. Once the hopping is gone get busy with your COB. And it could end up forward or aft of the turn fin.

John

im confused now does this mean positive angle or negative... i had the strut at 0 angle that is a picture of the adjustment "prop nut up" a degree...

[ozzie-crawl]

sorry my bad,re read it and yes he is talking about pulling the transom down so positive angle, i was thinking keeping the front down, sorry about they confusion

[m4a1usr]

im confused now does this mean positive angle or negative... i had the strut at 0 angle that is a picture of the adjustment "prop nut up" a degree...

Using the diagram that Oz put up it would be positive angle. My description was poor. Either way, the transom needs to be stable. I still dont know what to make of the comment about the whole hull coming out of the water. Unless its porposing.

If your hull is the Proboat 1/12th scale nitro version here are some basic facts about the stock setup. Its designed for a submerged prop, has 4 ride pads (sponsons and aft), the strut is set to 1 inch below the tunnel and it has a slight negative angle (prop nut pointing up), the rudder extends 2" below the bottom of the strut.

I'm dying to see the inside of your setup. if it is the nitro hull, getting that 580 motor in would be a chore. The inside is very narrow. The radio box is probably gone. Thats good. I used an Aveox motor with a FDM tranny in my Miss Bud conversion. Too bad the computer I had at the time has since died. I lost all my pictures of the conversion.


John

[sporthydrofan]

ok been testing luckily i have a pond in my back yard... strut down 1" 1 degree positive angle.. hops bad and 80% of hull out of water at 30mph and hopping.... strut down 1" negative angle still hops a lil better... raised the strut to 1/2" from bottom of hull negative angle still hops a little bit more than with strut at 1" negative angle...1/2" strut at positive angle and it bunny hops almost at low speeds like 25 mph.. it is defiantly bow hop not stern and the sponsons hop evenly... gonna drop the strut to 1" lowest it will go and lots of negative angle.. if that doesn't work gonna add weight to the front with sand.. perhaps 1lb.. ill brb

[sporthydrofan]

Using the diagram that Oz put up it would be positive angle. My description was poor. Either way, the transom needs to be stable. I still dont know what to make of the comment about the whole hull coming out of the water. Unless its porposing.

If your hull is the Proboat 1/12th scale nitro version here are some basic facts about the stock setup. Its designed for a submerged prop, has 4 ride pads (sponsons and aft), the strut is set to 1 inch below the tunnel and it has a slight negative angle (prop nut pointing up), the rudder extends 2" below the bottom of the strut.

I'm dying to see the inside of your setup. if it is the nitro hull, getting that 580 motor in would be a chore. The inside is very narrow. The radio box is probably gone. Thats good. I used an Aveox motor with a FDM tranny in my Miss Bud conversion. Too bad the computer I had at the time has since died. I lost all my pictures of the conversion.


John

it is not a conversion it is a 32" hull... the srtinger in there is wide enough to fit a 45mm motor and a bulky cooling sleeve with about 1/2" on either side very clean setup ill take some pics when i get this all worked out.

[sporthydrofan]

holy sh$t i put 1.5lb sand under the cowl up front cog was 3 inches from sponson... still hops! then i took out the bag and taped it to the front spoiler brought the cog to about 1" behind sponsons STILL HOPS!! i gave it 60% and its got the whole hull out of the water about 80% and bow hopping... i have the strut at 1" and all the negative it will go i just cant keep that bow down... im going to try more sand and a bunch of positive angle