Miss Geico dialed in- strut modification

[Arizonaheat]

Hi,
My son has been racing his Miss Geico (V2) in the p-limited offshore class, and we have it dialed in on stock setup with x642 prop. Batteries are just behind the front end of the motor (non-shaft side). Per the tips on the forum, I ground a wider slot in the strut, allowing a bit of negative angle. I have the strut up pretty high-- with the sponsons on the table the shaft does not touch the table-- close-- probably less than 1/8 above it (in the picture it looks like more, but that is just due to the camera angle).

In race conditions (ie, some race-induced chop in the water), the boat rides perfect, no bounce. In glass water, we get a slow bounce. I have not blueprinted the sponsons, and probably won't bother as the boat is doing great in race conditions.

Been too busy coaching my son through the races to get a video, but will try to get one next time.

Chief

How do you plan to "blueprint" the sponsons?
Is there a dimensional drawing available?

[tlandauer]

How do you plan to "blueprint" the sponsons?
Is there a dimensional drawing available?

So-called "blue printing" the sponsons is just a process to make the bottoms match each other and to make sure that they are flat when placed on a flat surface such as a glass table or granite top counter. See this thread:http://forums.offshoreelectrics.com/...ace-Prep/page2, specifically read from post #43.

[jsturess]

Longest time was bending the stuffing tube correctly and keeping the strut lined up while tightening it.

Do you taking the stuffing out or does you only bend it with hand strenght? heating?
Mine is hard as a stick (stuffing :-) )

[tlandauer]

Do you taking the stuffing out or does you only bend it with hand strenght? heating?
Mine is hard as a stick (stuffing :-) )

If you don't plan to replace the stuffing tube, you need to bend it with your hand strength, heating it on the boat will soften the FG exit point and also the epoxy, that is how people take the factory tube out BTW.
You need to take care not to kink the tube. The only portion you need to bend is where it goes into the strut, basically make it straight so you can point the prop down a bit. The suggestion is to insert the largest drill bit possible to the open end of the tube and gently shape ( bend) it.

[Speedracer128]

@ Alan

What speeds are you hitting on the gps with your setup? Also curious what kv that motor is?

[h8onit]

Just wanted to say thanks to op for the mod. It has helped my bj29 a lot with the traxxas system in it

[AlanD]

@ speed racer - it's a leopard 4082/1600. Haven't GPS'd it yet. Took it out yesterday and got pretty much the same performance out of it.

[BHChieftain]

Well my son ran his boat up on some rocks and ripped up the sponson, so that gave me an excuse to blueprint it! I used West Marine Epoxy Putty. Super strong and sands easily. I'll try to take it out on a test run next weekend before I repaint it.

Chief

[BHChieftain]

Did a test run with the Miss G's repaired and blueprinted sponsons-- wow, what a difference!! The bounce is even further reduced, but the real benefit is that the sharp edges on the back of the rear sponsons keeps the nose down much further than stock (the sponsons are pretty rounded out of the box). I did not change the strut position at all, and the nose is way down. On this run I pulled the batteries back about 1" (which would have caused blowovers previously). I think I can even reduce the negative angle I have on the current strut position a bit.

I think the only thing left causing any bounce at all on glassy water (with this config it is not a problem-- any racing induced chop lets the boat run great) is the rooster tail hitting the center mounted rudder. The next experiment will be to use an offset rudder. For sports running the center mounted rudder works great as it has equal left/right turning, but my son is racing this one in offshore class so offset should work just fine.

I've been doing free s/b of the stock props and also free strut mods on the RTRs I sell at my webiste (see sig), I think I'll add blueprinting as an option since this turned out so well. The marine epoxy putty is a bit expensive but is the perfect consistency and is super strong.

Here's a video of the run:

Chief

[lenny]

Hey.
Look like it came out pretty good,
Is mike legally blind ?
Look, It's a moving green bullseye.
I just started testing the setting on mine today,
And got some pretty good video to I think.
I will see what it looks like and than may be post it if it looks ok.

[angrycat]

hey cheif where did you buy the marine filler? i have my old bj hull awaiting carbon fiber/kevlar inlay and some sponson blueprinting after the seam split

[AlanD]

Chief, she runs pretty flat and smooth. Can you share some close up photos of the edges you're referring to?

[ray schrauwen]

I like that stuff. I wonder if I can get it in Canada??

Well my son ran his boat up on some rocks and ripped up the sponson, so that gave me an excuse to blueprint it! I used West Marine Epoxy Putty. Super strong and sands easily. I'll try to take it out on a test run next weekend before I repaint it.

Chief

[iop65]

i wonder if it would make a difference when you would make the last step 90° angle ?
now it's about 100-110°

the MG v2 iss my first cat ,so i'm not an expert on this matter but in the mono-world we make the point where the water has to "leave" the bottom of the boat razorsharp and 90°

when i was blueprinting mine i was thinking about doing that , but did not
mine has still a very small bounce on flat water

[hydro_pyro]

Same thing with full-scale performance boats. A sharp, 90° square trailing edge is ideal. The water comes off clean with less drag.