siberianhusky

A buddy of mine picked up a SV27 used, I have no exp. with this boat at all, first one I've ever seen in the water.
He has a 2300kv motor and a different esc than stock.
The boat seems to run wet and hook and spin out in right turns.
The previous owner drilled two holes in the bottom just forward of the transom about an inch each side of the keel and installed 2 brass tubed as water pickups, they hang down at least a 1/4". I think this is causing his issues, Trim tab or strut adjustments make no difference.
At least 2/3 of the hull is in the water, we moved the batteries and set the cg at 30%, tucked the rudder all the way in. Turn fins are square to the bottom and paralelle to the transom.
It turns beautiful to the left (dual turn fins), as soon as you turn right it pretty much pulls a complete u-turn in about 5 feet.
I have riggers, monos and a 1/16 scale hydro and can usually set up a boat, I've searched all over for a solution to his problem, nobody else seems to talk about this and the only difference is those 2 home hack water pickups from the previous owner.
In right turns it's as if the boat suddenly developes a ton of lift and goes right around.
Props tested from 1438/2 up to grims 40/55 (or 52) 3 blade, as well as a couple de-tongued props of mine. Had at least 5 different props on it!
Runs wet and will not turn smoothly to the right, Swapped in my Spectrum rx and even cut down on the servo travel. Set it so the boat made huge left turns but still hooked to the right!
I think he should pull those tube and fill the holes, I have not read about people needing that much cooling, rudder pickup and 2 others in the bottom of the hull. 2 water outlets, each bottom tube feeds half the cooling plate on the esc I think. And the rudder feeds to motor cooling.
At near 40 mph those things have got to be forcing the bow down, combined with prop lift in the turns I think they are lifting the hull and causing the spin.
How sensitive to trim tab and stinger adjustment is an SV? Some big changes have made no difference in ride attitude. I have never seen this boat get light even in some choppy conditions, Never flips or gets unstable, screams along stuck to the water!
It's is first boat and is in great condition just need to get it running right!
Baffled!

res3567

I don't have the FE version so I will tell you about my nitro;I am on my second one....first one sank......I have never had a problem like that at full tilt boogie with both boats. Both boats did porpoise...and adjusting the trim tabs moderately fixed that with no issues. It don't take much to make a difference. With all things bieng equal (except for the power plants) I would say that those pickups are causing the problem. There is more drag for sure and my SV'sboth liked right turns more than left; the engines revved higher and the boats went faster. I have my pickup mounted from the factory on the transomleft side between the srut and the trim tab. I would do as you suggest and run everything through the rudder, or convert it like mine( I think the 27R has the same setup as well) and see what that does. I have heard that turnig the boat to the left can cause reduced water flow because of the inlet on the rudder is on the right. Aquacraft also did not add theleft turnfin; the theory was racing these boats was done tothe right....like hydrosand my Miss Vegas has arudder mounted pickup as well. But a lot of people do not race these boatsand turn eaqually left and right. That is when theydecded to change the setup....the nitro version first and then the 27R.

The pic below shows my first one...the one that is the boattom of the pond......I had removed my left turn fin to reduce drag but it turned left bad so I reinstalled it. Notice the waterpickup

siberianhusky

No way his boat will porpoise, even with the batts all the way back in the hull and the cg way to far back, never gets light. trim tabs bent way up and stinger set to a positive angle just stays glued down. Nothing at all changes the running attitude!
It's his first boat, he has read too much about stuff overheating and is worried about undoing this modification that was done before he bought the boat.
I commented on it the second I saw the boat. I'm more of a nitro guy but I know those two tubes hanging down like that are the problem. The hull just won't respond to any changes at all. Never seen a rc boat go from - stinger angle to + stinger angle and not change the ride attitude.
There is no way they are not forcing the bow down, they are cut at a 45 angle facing forward and 1/4" below the hull.
With a 2300 kv motor in it that thing should be flying off the water!
I found this pic I took of it, thats flat out running straight and about as light as the hull gets, stinger, cg or tabs don't change it much at all.
2 5600 mah lipos in series, think 40mm prop, HK 2300kv motor 90 amp esc.

res3567

Mine has foam in the bow....has he checked his? Is there some heaver material up front? Lead weights perhaps?

siberianhusky

Bit of foam, you can set the cg nicely just by moving the batts a bit forwards like they recommend, batter trays were removed to do this.
One of the worst handling boats I've seen, nothing like any of the video I've seen of them run.
The second last time we were out I only did one run with my boat, spent the rest of the day trying every setting and combination of settings I could think of on Johns.
The only difference between his and everyone elses is those water pick ups on the bottom!
Literally nothing will loosen it up. Even trying stupid settings that should have made it wheelie across the lake did nothing. Batts all the way back, + stinger angle and raised trim tabs! still ran like that! would almost sink the transom on takeoff level out and glue itself to the water as soon as it got to speed. Runs Just like you have the tabs bent way down.
Feel bad I can't help him out any more, Just don't know what else to do, he has to get rid of the under hull water pickups. The boat is bone stock except for motor and esc and those two water pickups!
Tried Octura, TFL and GrimRacer props from 38mm and up, 2 and 3 bladed, stock and modified props. Even one of my 40mm props that has most of the lift taken out of it hoping to keep the transom from lifting at all.
Oh well winter is almost here. Nitro is soooo much easier to deal with in every aspect of boating!
Really hope we can get it running right, he is hooked on boats and thinking of building a new one up over the winter, really don't want this ill handling SV to turn him off! Hard enough to get people to try the hobby!
Thanks!

res3567

Have him remove the pickups on the bottom and add a mount like mine. If he is concerned about overheating, then he could reuse the rudder pickup as well in addition. Just have to have two exit holes....I guess.....

eboat

Does the boat still have the original rudder with water pick up on it ? If so plumb it back up and pull the tubes out of the bottom
ON mine I have the tabs set flat (original ones) with the 2 inside corners bent down a little
Strut is set parallel to bottom of boat
Rudder leaning back (not tucked under) helps lift the back without the extra drag of lifting it with the trim tabs
I still have original motor and esc and I like to use the X440/3 prop or X445

If he has a 2300KV motor I would think he would want to use a smaller prop like a X442 ??

siberianhusky

All original, when he first brought it out we zeroed everything.
We know he can prop up, motor has been coming in 80-90 degrees, Tried a x437/3 a 40/3 and the bigger 3 blade grim prop, 38 up to 42mm 2 bladed.
Only been making one change at a time and literally nothing changes the ride, even taking things to the extreme with cg way to far back and prop angled up and still ran like that.
The boat is actually very fast it just rides all wrong and handles terrible!
Hey Eboat, gettin my P mono together for next season for sure! It's all de nitro'd now. My Wildthing has been finished and has a few runs, gotta get rid of the brushed motor in the hydro still, at least the ni-cads are gone! The only one in the fleet not finished is the mono, thinking about a bigger hydro, I don't know, have to build something the mono will be done in a few weeks or so.
Lets hope the economy picks up a bit, between no snow last winter and how tough it has been to get jobs it has been a bit lean in the boat building dept. Did a ton of quotes but neither me or anybody else got the jobs, I make it a habit to go check to see who gets the jobs I don't get. Most of them didn't get done.
Cheers
I'm pretty sure the issue is the tubes.
He still is using the rudder pick up as well. 3 water pickups on it! 2 outlets, motor and esc are on separate cooling systems. The hull pickups each cool half the esc then Y together and go overboard. Thats the way it was when he bought it, not his own mods.
He got a good deal on it with batteries, charger and some running accesories. I think the previous owner must have frustrated himself with his own mods and sold the boat.

asupervee72

the problem is the tubes but they do not need to be removed, i have the same mod done on mine but one pick up for esc and one for motor, my rudder has no pick up because i had it machined and they couldn't do that part of it. machined for free or 20 bucks for a stock replacement, i went for free. Take a dremel or something similar and just grind the brass tubes down. On mine i have it to where the front of the tube is about flush with the hull and the rear of the tube protrudes no more then an 1/8th inch its actually pretty close to only a 16th of an inch. Are the two locations symmetrical? If they are a pretty close it shouldn't be an issue but a 1/4" is way too much tube in the water and I believe you are correct in your assumption that they are the cause of the spinning. Don't take a whole day waiting around for epoxy to dry though, just grind them down like i suggested and you wont have any problems, mine runs straight as an arrow and turns hard on glass, a little bit of hopping when it is choppy but it still holds the turn. I run 1800 kv on 5s so our set ups are right around the same rpm/speed. My strut is slightly down. Tabs and rudder are neutral and I run my fin either 90 to the transom or as far back as about 45 depending on the intent of the run. You should be able to grind those pickups to reasonable length in no time and be back on the water having fun.

the pic shows one of my early attempts at a water pick up, this one was too long, if yours looks anything like the one in the picture or longer then that you need to grind it down until the rear of the tube penetrates the water just enough. All you need is about 3/32 to get a nice bead of water coming out of the outlet. One cooling line for the esc is adequate, 2 just makes for extra plumbing mess inside the hull

siberianhusky

That is exactly what John has on the bottom of his, both sides and at least that deep.
Thanks for the info, I'll print that out and pass it along to him.
We might get out one more time this year, starting to get ice on the puddles in the morning! He'll be happy if he can get this straightned out.
Thanks for the info and pic!
Exactly what I was hoping for.

John MacLean

Just came across this thread this evening. Been reviewing a number of supervee threads on the OSE website and here and as challenging as it has been to get this hull behaving properly there is no way I would ever be discouraged enough to walk away from the hobby. Not to worry about that, Mark. I'm just too much of a boat guy, period. Love my full sizeCruisers Inc Vee-sport, mymini-vee and the supervee 27. I don't give up easily and intend to see this thing running properly. Looking forward to the day when we'll each drop our boats in the water and race them around the course.

Also looking forward todoing some cosmetic stuffduring the off season. . . a new paint job for the sv and perhaps trying my hand at a build. . . . at least a hull for the time being.. . . while saving my pennies for the electrics and hardware neccessaryfor a spring launch.The season here is just way too short.

eboat

Where are you guys running ?? On the Trent just up from the university or at Little lake (I have ran my stuff a couple of times just in the corner by the fountain)

res3567

Pics and maybe a vid might help the electric gurusherebetter serve you John.

siberianhusky

We've been running out a lock 23 near trent U and once at the north end of the causway at chemong lake, great place if the wind is right.
I've got a bit of video of Johns boat, I'll try to figure out how to post some so you can see it running.
Glad your not getting discouraged! With some help we'll get it running right.

http://www.youtube.com/watch?v=-y3PBR2t54Y

Don't know how to do the embedded thing.
This is a clip of the best we got it running that day.

dicko

When I had my SV I filed the slots in the holes of the trim tabs to raise them up about 1mm above the transom. Then I ran them almost flat & used the battery placement to shift the COG to trim the boat out for different conditions. I also filed the hole in the rudder forward to make a small divet in the leading edge of the rudder to improve water pickup & cooling dramatically over the stock rudder pickup configuration.

siberianhusky

Thanks Dicko. trim tabs are about a mm above the bottom, been down, neutral, up, SAme for the stinger, CG has been all over the place, Only trying one change at a time of course. We're hoping to get out again this weekend, I have a new nitro boat I want to finish getting set up, and hopefully get Johns SV figured out, He is filing down the under hull water pickups. That will probably fix things. Then it will be a basically stock SV aside from the serious motor upgrade.
LOL big hit to my ego, can't get his boat running right, I've been at this for over 20 years! Being kicked by my first experiences with an electric mono!

John MacLean

Lost my home internet connection since Monday so I haven't been able to participate in this thread. Using a work connection on my lunch break right now but hoping to get things straightened away with Bell Canada by this evening.

Looking forward to getting the sv back on the water on Saturday. Weather network is forecasting a half decent day for this neck of the woods. Will have a much lower profile on the through-hull pick-ups.

John MacLean

Finally got my internet issues resolved. After a 90 minute conversation with tech support and the business office, Ma Bell realized her error and restored the connection this afternoon with a 10.00 credit to our account for the inconvenience caused.

Spent the evening reducing the profile of those under-hull water pick-ups. Using the rudder pick up to cool the motor and only one of the two under-hull pick-ups to cool the ESC. The starboard side one has been sealed up.

Also did some extensive testing re: COG and found that the batteries need to be way forward to achieve the recommended 30% range.

Now its back to the lake for one last kick at the can before freeze over.

siberianhusky

http://www.youtube.com/watch?v=901jDMpS_RU
Amazed at the difference, It was rough when I shot this video, the earlier ones aren't as clear or close up (idiot driving the camera forgot about zoom!).
Not going to steal Johns thunder I'll let him talk!
Sorry I didn't get better video when the water was smoother, That was a great day,
Got my 25" Wildthing nitro running right, needed some prop work to let it get on the pipe.
What an amazing day to the end of the season. November 13 and right on the water we were taking the coats off!
Cheers all!

John MacLean

yep. . . even though the video isn't the truest reflection of the best part of the day, it really is amazing the difference some careful listening and implementation of good advice can make. Trimmed the profile on the water pick-ups on the bottom of the hull . . . set my tabs and stinger to neutral as per Darin Jordan's recommendations in one of his threads re: tuning the supervee and the boat ran beautfully on the 4/38 2 blade TFL prop I purhased from Kintec. Motor and ESC temps never went above 85*. I think the best part of the day was finally getting a chance to see my sv27 and Siberianhusky'swild thing flying around the course together. Managed to grab some great action shots of Mark's boat and would have loved to havea third person to run the video camera.

The wind had picked up by the time I had both packs recharged about 90 minutes later. . . but we decided to try the 4/37 TFL 3 blade from Kintec. Didn't need to coax the boat out of the hole because there was little or no cavitation. She jumped up on plane and spent about a third of the time cresting the chop that the wind had whipped up. Don't know what the final speed was because there was no gps but there was a marked increase again. It was like the boat suddenly woke up. Very impressive even though the rougher water meant at least one complete barrel roll and a flip. Probably could have used a little more trim tabs in the rougher water. Batteries were as far forward as they could have been and I tried to stay on the throttle to avoid overworking the ESC which made the ride seem a little scary at times . . . as witnessed in the barrel roll and flip at the end. At the end of the day, though,I was satisfied to see the sv27 begin to perform as described by so many of her fans. . . providing lots of fun. The plan is to secure two other sets of packs and a decent charge over the winter so that she will be ready for a great season next year.

Love the hobby and appreciate the many helpful tips from experienced hobbyists. Looking forwar to meeting some other FE friendshere and in person beside a pond or lake next season.

res3567

You got any more vids of your stuff as well?

John MacLean

Wish we did, thought we had. Mark's boat was running very well and I wanted to make sure he had something to evaluate everything afterwards. His camera was new to me. Thought I captured some decent footage but I may have screwed up on the focus . . . Next time out I'll have a camera that I am familar with. The one I used to grab the stills he has posted in the nitro forum is pretty limited.

res3567

OK did some running myself....training a young man new to the fast nitro hobby...got a vid if him running his Dueceon the M-V-D thread in the general forum....running a 42mm prop on my SV andshe scooting in the water....when the engine wantsto act right.....stronglyconsidering an electric version sometime next year.

John MacLean

I don't have any experiencewith nitro other than watching Siberianhusky run his. I prefer the convenience of electric and as near as I can tell I'm not sacrificing anything in performance by staying with that format. And as an industrial maintenance electrician I have a natural inclination towards the FEaspect of the hobby

siberianhusky

I'll post more on youtube. The ones I shot are not very good, I have a clip John shot of mine on the first run that is good. I'm ok with a still camera, I don't have a real video camera, we were using the video mode on my digital camera. I was having a hard time keeping Johns boat in the frame and should have zoomed it in more. You can see his is moving right along but not really close enough to get a good idea what it's doing! I can try my hand at some editing and try to piece together the parts where he came close enough to see what's going on. There is one nice high speed close in pass but thats only about 5 seconds of the segment I shot the, rest is pretty bad!
If the plowing is good this winter I may see if I can pick one up, spending my allowance on the boats has top priority though.
Could probably buy it under the business and claim I use it to document restoration work! Claim it on taxes that way, let the government pay for it!
My business used to be my sponsor for kart racing! LOL another write off! Wonder if I can do that with RC boats if I stick my logo on the boats!
My book keeper/tax person gets a kick out of some of the things I try to claim!
I claim my guitars and stuff, "working musician", I get receipts from the bars when I play, as long as I can prove it is part of my work I can do it!
Cheers,
I'll head out for coffee today and take the laptop, use Starbucks high speed wireless for the uploads!
Yes I'm a cheap bugger! Why pay for something I can use for free while having a coffee!
Cheers all and great help! Thanks a lot!
Sibe.