Hospital Hop...how to stop it?

[Shooter]

I think it would be considered a vent. This is what it looks like, more or less.... It can be tuned to achieve the proper amount of bleed-off.

[dreamland s4]

Ride pads work! Thanks to detox!

[InspGadgt]

I was thinking about "the hop"...
Tony's UL did the same thing in the beginning,
looking back I believe it was a combination of factors...
first it was a little lose and started flying and then the first sponsons
would take off and land hard rebounding and throwing the hull to the other side
and so the hop started, violently like described earlier. The reason
it started bouncing side to side like that and get worst, is because the
turn fin would hit the water at an angle and push the hull
up to the other side again and then the vicious cycle would start
over and over again... if you can keep her nose down this dance
probably would not happen.

just my shot at it...

This is where I'm having an issue it seems...when watching my boat on the straights it looks like the turn fin is lifting the right side of the boat out of the water. Then when it hits a rough patch of water it starts the hop.

[InspGadgt]

It's not just depth, but also angle... I haven't run mine yet so I can't give you good answers... I've read to the effect that 1 1/6" of depth with a 3-degree downward angle works... I think that was Tony's setting (Properchopper)...

How are you adjusting angle? I can understand depth s with the strut but the stuffing tube goes all the way through the strut so the prop angle can't be adjusted independently from the stuffing tube...which is just depth.

[NativePaul]

This is where I'm having an issue it seems...when watching my boat on the straights it looks like the turn fin is lifting the right side of the boat out of the water. Then when it hits a rough patch of water it starts the hop.

That means the bend/curve in your turn fin is not parallel to your running attitude, you have to tilt the bottom of your turn fin back a little more, to get it parallel and stop it generating lift in a straight line.

[properchopper]

I did these mods and the UL-1 settled way down. (see vid below)

#1 : Reduced the AoA AND vented the air traps with some diversion strakes

DSC01160.JPG

went to a squared-off turn fin : (picture prior to altering AoA)

DSC00993.JPG

https://www.youtube.com/watch?v=yicE1_TfDDY

[properchopper]

How are you adjusting angle? I can understand depth s with the strut but the stuffing tube goes all the way through the strut so the prop angle can't be adjusted independently from the stuffing tube...which is just depth.

A simple way to allow strut angle adjustment is to [CAREFULLY] shorten stuffing tube so that it only extends roughly3/16" into the strut.Install lead teflon bushings for the propshaft.

[InspGadgt]

That means the bend/curve in your turn fin is not parallel to your running attitude, you have to tilt the bottom of your turn fin back a little more, to get it parallel and stop it generating lift in a straight line.

I've got it turned back as far as it will go...it is still lifting the boat.

However today I did try with a 3/8" air dam...it was rougher out there but my boat was still more stable than last time I ran it.

[InspGadgt]

I did these mods and the UL-1 settled way down. (see vid below)

#1 : Reduced the AoA AND vented the air traps with some diversion strakes

[ATTACH=CONFIG]160194[/ATTACH]

went to a squared-off turn fin : (picture prior to altering AoA)

[ATTACH=CONFIG]160195[/ATTACH]

https://www.youtube.com/watch?v=yicE1_TfDDY

That's what I was thinking on doing with my turn fin...I hadn't thought of a vented air dam. The flat air damn I tried today made it really difficult to get the boat moving so I was thinking about an angled air damn but I like your idea too. How tall did you make your air damn?

[InspGadgt]

Has anyone tried this: https://www.offshoreelectrics.com/pr...d=hug-ul1-foil Any feedback on it?

[InspGadgt]

A simple way to allow strut angle adjustment is to [CAREFULLY] shorten stuffing tube so that it only extends roughly3/16" into the strut.Install lead teflon bushings for the propshaft.

Looking at the strut replacement part listed: https://www.offshoreelectrics.com/pr...od=dh-aqub6950 It looks like the strut should already have a bushing and the stuffing tube should be shorter.

As much as I've enjoyed this little boat and how cool it looks...I'm getting a bit frustrated with not only all I have to go through to get it to keep up with a UL-19 on 4s...but also with the quality control issues I'm running into. First the boat starts to crack along the seam on the inside left sponson. Then I notice the motor does not line up properly with the stuffing tube. Had they made the motor mount adjustable that would have been an easy fix to compensate for any manufacturing misalignments. The rudder has no break away...and my motor strut is not adjustable in angle, only in depth. The motor wires were routed poorly and interfere with battery installation. I had to re-route the wires over the top of the motor and the wire lengths are just barely long enough to work. And the ESC has to be re-programmed every time you plug in the battery...just really poor choice in electronics there. I'd would have rather this boat be offered in an ARR format so I could use my own electronics. Some of the choices made in manufacturing this boat make sense if it were a one off build...but in a mass produced environment where mistakes occur regularly a little bit of added adjustability in the design would have compensated for the inaccuracies. I don't see how they can claim the boat is capable of 65+mph when it starts losing stability around 43mph.


Don't get me wrong...I don't think this is a bad boat...I really like it a lot. I just thing things could have been done better with a little more care and foresight.

[properchopper]

There are auto mechanics schools where the students are given a poorly running engine and their assignment is to find out what's wrong and fix it. They become better mechanics after this learning experience. Sounds like your experience with the UL-1 parallels this (of course only if you choose this way of looking at it ). I know that my personal experiences in boat building follows this closely ; each boat I build teaches me something so the next one comes out even better. The UL-1 is about a decade old and when it was introduced it was one of the best values for a nicely performing rtr. Needless to say the "Igottagofaster" bug bit and the hull was soon pushed past its design limits - but even so it is a decent value (plus remember that to hit a entry level price point the build labor costs are kept down by using nine year old laborers who make cukoo clocks on their morning shifts). To elaborate, one of my bespoke FE30's will set you back double what a fresh rtr UL-1 or Proboat version costs but won't need ANY fiddling for its lifetime - e.g. my personal FE30, the VERY FIRST production model @10 years young) is now current 2018 SCSTA high points holder and the ONLY thing that gets done to it year after year is to grease the flex after every race, put a drop of oil front & rear on the motor bearings, and once a year replace the strut bushings.
Hang in there - it gets better

[InspGadgt]

Thanks...I know it will get better. I've been a bit frustrated is all.

So back to your earlier post where you put the air damn on...the wood under the sponsons...to me it looks like you did this to decrease the angle of the sponsons and to eliminate the step in the sponsons. Is that what you were intending or am I reading it wrong?

[properchopper]

Thanks...I know it will get better. I've been a bit frustrated is all.

So back to your earlier post where you put the air damn on...the wood under the sponsons...to me it looks like you did this to decrease the angle of the sponsons and to eliminate the step in the sponsons. Is that what you were intending or am I reading it wrong?

you did this to decrease the angle of the sponsons ----- yes


to eliminate the step in the sponsons. ----- NO

[Fluid]

One of the initial “problems” with this hull was not a problem with the hull at all. Prior to it’s introduction a highly experienced racer took a pre-production hull and ran it at a SAW event that both Tony and I attended. He ran over 67 mph through the traps and the only mod was screwing on a huge prop. Since then folks have been obsessed with making it go faster than it was designed to go. Tuning secrets like CG and strut adjustment, along with limited run time, were ignored and there were many folks who were disappointed with the boat - through no fault of its own. If the UL-1 is to be run well past it’s design speed then hull mods will likely be necessary.


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