Avoiding Problems with the UL-1 Hydro

[Fluid]

One thing that needs to be remembered - although I doubt it has any significance with the UL-1 - is that when moving the pushrod to an outer hole on the servo horn you lose steering torque. On large heavy boats or very fast boats this can mean the difference between having enough turning and not having enough, since the rudder can overpower the servo.

I've had this happen on P Sport hydros when using the cheap Futaba 3001 servos with their limited torque value. Substituting an 80-ounce servo returned the hydros to their good steering response. I believe that many steering problems that folks report are due to inadequate servos. Also note that you can increase your servo's steering torque by ~20% when using a 6 volt receiver pack.



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[birdy233]

Quick, question, should I need to re-adjust my strut from box stock factory set up? I ran my UL-1 for the first time today and thought I bought a submarine instead. The front would plow under the water and I could on get it somewhat on plane only if I tossed it, even then it was pathetic as my recovery boat was faster. I'm running a set of Team Orion 3800, 30C race Spec packs, but it seems it's way nose heavy, any thoughts?

[Raydee]

Quick, question, should I need to re-adjust my strut from box stock factory set up? I ran my UL-1 for the first time today and thought I bought a submarine instead. The front would plow under the water and I could on get it somewhat on plane only if I tossed it, even then it was pathetic as my recovery boat was faster. I'm running a set of Team Orion 3800, 30C race Spec packs, but it seems it's way nose heavy, any thoughts?

That is very common with sport hydro's that have the CG up front. Here is a little trick i learned a while back, blip the throttle just enough to raise the front end and let off. Once the nose drops down and starts to pop back up nail the throttle and the hydro will jump up on plain. I might have a youtube vid showing exactly what I mean, let me go look.

[Fluid]

....should I need to re-adjust my strut from box stock factory set up?....front would plow under the water and I could on get it somewhat on plane only if I tossed it, even then it was pathetic as my recovery boat was faster.....

Ray's comments on starting are very good, but I am concerned with your statement that even on plane it was slow. This latter may have to do with the strut setting or something else.
A few questions:

Are you running the stock prop?
Are you running the stock radio?
Are you using the stock pack wiring harness?
Have the LiPos worked well in other boats?
What was the approximate temperature of the LiPos when you started?
How is your strut set up now?

The bottom of the strut on my UL-1 is 7/8" below the hull and angled down about 1-2 degrees at the prop. Set you model on a flat table and measure.



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[birdy233]

Thanks for the quick responses, It was a bit choppy out today, but the boat seemed like it was way heavy up front, the whole front of the boat went under the water. I'm not new to boats, I've owned three or four SV27's several BJ26's, Warehouse Enforcer, BJ 55 to name a few. This is the first hydro I have owned though.

As for the questions, I'm running stock strut setting, measured 7/8" from the bottom of the hull to bottom of the strut angled down about 2 degrees

I am running the upgraded Grim 40X57X3 prop, stock radio, pack wiring harness is stock, Lipo's are brand new (I did run them once on my Traxxas Slash, the packs are fine, temps on the packs, well, I charged them and headed out to the pond, it was about 80 here in Dallas today so I assume close to that temp. So I am stumped, I was thinking about trying the stock prop for the heck of it tomorrow.

One other thing I'm not impressed about on my boat, there is numerous HUGE paint runs all over the sides of the boat and one side near the transom was molded wrong so there is a swoop on the side/bottom of the hull, for $330 I'm not happy. I've seen my 5 y/o nephew paint better. I may need to contact Aquacraft/Grim on these issues.

[Ub Hauled]

Jay, Birdie, Tony (properchopper) had the same problem with his UL, his lipos were a bit on the heavy side and the boat
would not get on plane... we tossed it and then it was slow as hell... I think the stock prop is not the most suitable for a heavier boat.
We ended up changing the prop to an X442 then it would take off (with the little trick Ray mentioned) but still is not unwinding... we ran out of batteries that day, tomorrow we'll test again with a little setup change (strut) and see how it goes... I am sure we'll get it going tomorrow. Maybe the 442 is also not the best choice, but now it doesn't have to be thrown.

[birdy233]

Jay, Birdie, Tony (properchopper) had the same problem with his UL, his lipos were a bit on the heavy side and the boat
would not get on plane... we tossed it and then it was slow as hell... I think the stock prop is not the most suitable for a heavier boat.
We ended up changing the prop to an X442 then it would take off (with the little trick Ray mentioned) but still is not unwinding... we ran out of batteries that day, tomorrow we'll test again with a little setup change (strut) and see how it goes... I am sure we'll get it going tomorrow. Maybe the 442 is also not the best choice, but now it doesn't have to be thrown.

Well I call BS, or Aquacraft needs to explain and send a refund check to me for the $230 I laid out for my Lipos. The stock battery they recommend weighs 6.2 oz, the optional upgrade battery printed in their manual weighs 9.2 oz, my pack which I just bought specific for this boat weigh in at 8.6 oz per pack. My pack weight should not be the issue, seems like a strut issue or cg issue, if it's a pack weight issue, someone has some explaining to do!

[Ub Hauled]

Birdie,
try extrapolating the positive strut to 4 degrees and nailing the gun... maybe you'll get enough momentum to get outta the hole, if she gets a bit too lose, at least you can take a degree off to try to make up for it... I was talking to Tony about something else as well, maybe if push comes to shove you can use a different motor mount and take that bar away from the middle so you can push your packs back a bit.
I wonder what B. Buaas faced on his maiden voyage...

[egneg]

I ran my boat for the first time yesterday stock except for the prop which was a M445 (mentioned by Brian B in another thread). It did take a couple of trigger pulls to hook up but once it did it was fast (GPS'd at 44.2 mph). I had 2 x 2s1p polyrc 4250's at 7.4 oz each. The upgrade 40x57/3 I believe is a lifter prop and when I tried a V940/3 also a lifter prop it turned into a submarine.

[properchopper]

I ran my boat for the first time yesterday stock except for the prop which was a M445 (mentioned by Brian B in another thread). It did take a couple of trigger pulls to hook up but once it did it was fast (GPS'd at 44.2 mph). I had 2 x 2s1p polyrc 4250's at 7.4 oz each. The upgrade 40x57/3 I believe is a lifter prop and when I tried a V940/3 also a lifter prop it turned into a submarine.

I had the submarine experience with the 40X50/3 also, [ with some fairly heavy Elite 2S 4800's]. Switching to a Bar cut X442 got 'er going pretty good. I've re-adjusted the strut & just got some smaller & lighter Elite 35C 5000's inside now & will try the M445 today. How were your temps ?

Tony

[Raydee]

Tony let us know how the 35c Elite's work in that hull. We are planning to use them in our UL-1's this season.

[properchopper]

Elite 35C 5000 2S

Tony let us know how the 35c Elite's work in that hull. We are planning to use them in our UL-1's this season.

Ray, as soon as I laid eyes on them last week in Jan's hydro, I had to jump on them. They're smaller & lighter than the leftover Elite 25C 4800's I used last week.
I'll post some results tonight.

Tony

[LuckyDuc]

Lipos

You might also consider Xcite Packs. I've used these in my EDF jets and they hold voltage better than Thunder Power Extreme packs, and are pretty reasonable price wise.
Their 4100mAh packs weigh 203g and their 4800mAh packs weigh 270g.

http://www.xcitebattery.com/newfrontpage74V.htm

[egneg]

I had the submarine experience with the 40X50/3 also, [ with some fairly heavy Elite 2S 4800's]. Switching to a Bar cut X442 got 'er going pretty good. I've re-adjusted the strut & just got some smaller & lighter Elite 35C 5000's inside now & will try the M445 today. How were your temps ?

Tony

I forgot my temp gun so I don't have accurate readings but the motor and esc were only warm and the lipo's a bit warmer but not hot to the touch after 2 or three minutes.

[Raydee]

Ray, as soon as I laid eyes on them last week in Jan's hydro, I had to jump on them. They're smaller & lighter than the leftover Elite 25C 4800's I used last week.
I'll post some results tonight.

Tony

Yeah I plan to try them in my Whiplash Hydro this season too. I was running 4s2p3200mah cells and they were Ok but I am going to try two of the Elite 2s5000mah packs in series and see how they handle in that hull. That way I can use the same cells in multiple boats and cut some of my pack costs down a bit.