UL-1's Sponson AOA (4 degrees)

[detox]

OK I decided to try the composit door shims. I measured for slight toe in (1/16" total)...then tacked them in place using 3M spray adhesive. If I am not happy I can allways remove them. I will test this evening.

[properchopper]

Ran today; the splaying outward of the batteries substantially reduced the chine dancing; probably @ 80 %. I also closely observed the hull under acceleration and noticed a pronounced lifting of the left sponson in rough water or wake crossing when the prop unloads and loads again, which will induce the dance for sure. I'll experiment with props to see what helps [ I usually run with a hub-cut X442 ; easy out of the hole & close to 50 mph]. Left the prop box home today so couldn't test any others. Wil run tomorrow with a SV 27 motor 'cause I need to borrow the UL-1 motor for my VS-1 which threw a magnet when I did a dumb thing today-don't ask

[detox]

OK here's my results. After sponson mod the UL-1 was only a little more stable. I will replace the door shims (2 1/2 - 3 degrees BTW) and try less angle (1 - 2 degrees) using the bass wood.

[detox]

The door shims removed fairly easily, I pryed up edge then peeled them off using a good bit of effort. The 3M spray tack residue was remove using acetone and paper towels. Once I receive my bass wood I will cut then try them.

[properchopper]

Here's what I found today, after yesterday's run with the "splayed battery" location which substantially reduced chine dance : I propped up to a M445 to compensate for the lower KV -SV27 motor [ I had to borrow the UL-1 motor for my VS-1]. With the bigger prop the chine dance returned big time, confirming my suspicion that prop torque can set up the conditions for the "dance". Frankly, I'm pretty much done with trying to dial in this boat. A youngster was there with a 1/12 Proboat hydro with an upgraded motor and it ran & cornered on RAILS. Detox, I wish you luck. For myself, I'm geting my hydro fix with my H&M 31" shovel which is running mid-sixties with LOTS more prop to go. When a LSH Spec race comes up, I'll build a PT SS 20, period.

[detox]

Have you tried the Grimracer L40 x 57/3 prop? It's 3 blades should chine walk less.

[properchopper]

That was my exact thinking. Cavitation city. It worked with the UL-1 motor a little better.

[detox]

OK I will try it again. I have a feeling it will work better this time. I placed shims on outward edges of sponsons and stopping at trailing edge (no overhang). This lowered ride height slightly...AOA is 2degrees now. Since my favorite Grimracer L40 x 57/3 prop is damaged I will have to use my second favorite for the next test...Octura m440. My Octura m440 is slightly faster than my GR L38 x 55.

[detox]

Boat did verywell this morning...sponson mod DOES work. Strut was also lowered deeper into water 1 1/4". Using the NUE 1515 1y power combo this boat hauls ace.


...

[Brushless55]

Sounds like this cool mod is working..

[detox]

Yea... UL-1 is handling wakes lots better.

Now I will have to adjust rudder a little more "fore" to settle down the stern hop in corners. Stock UL-1 came with too much "aft" or positive angle according to picture attached. I will have to file adjustment hole larger to achieve the required "fore"or "zero" angle.

[detox]

Been working on my new 2 degree ride pads. I cut these from a block of basswood. Hopefully after sanding and shaping they will look more streamlined...trailing edge will be much thinner than in picture. I may also cut some 3 degree pieces. I am not certin how I want to attach them.

[detox]

I ended up gluing ride pads on using Z POXY finishing epoxy. After epoxy set up I sanded pads down flat using a piece of flat 9" x 2" MDF board and sandpaper. I glued the 100grit paper on MDF board using 3M contacted spray adhesive. Next I will finish the ride pads using the Z POXY finishing resin then paint flat White..

[Brushless55]

Looks good man, keeps us posted on how she runs..

[longballlumber]

Nice work on the sponson mod!!!