Darin's Top Speed 2 FE Conversion...

[calcagno45]

Looks great! Nice action pics too!! Digital SLR?

Ok. I have pretty much the same, Hitec 325, thats I was intending on using. I guess I'll change that option out.

I have a 28" MRP Tunnel hull that I'm building for scale looks. I'm painting up and stickering an Aquacraft EP1 to look like a Merc 300 o/b. (maybe 2.5 instead) to use on there. I am using the SV27 motor/controller in it. I know the EP1 might not have the same performance as the REK o/b but I'm going for scale looks, (that first impression of D@mn!).

[Stinger9D9]

I was just using the servo that came with the Hitec FM radio...an HS-322. I didn't expect much of it.

After reading back a couple of pages of this thread, I'm going with Darin's advice of a Hitec HS-645MG. It'll be a direct replacement, and since it's equivalent to what the nitro guys use, it'll do the trick just fine.

[calcagno45]

What servo were you running? as far as torque?

Looks good tho!

[Stinger9D9]

Thanks Darin,

So back when I ran it the first time out (with the motor much lower...maybe too low) it probably ran so poorly because of a combination of a bad motor and flat cells (first time out after winter).

Here are some pics of today's run:




Also, here's a video of today's run:

http://www.youtube.com/watch?v=0delTLbB5VU

You can see it hook in the corner when it comes in close. It hooked a bit worse farther in the distance. It's also running really wet, but with the windy conditions, that was probably a good thing.

I also found that the servo is too weak (wouldn't readily pull out of turns at times), but that's an easy fix.

So next time out, I'll drop the motor down to 1/8" above the board, and angle the motor up about oh...say 2 degrees?

[Darin Jordan]

Guys... Just like any other hull-type running a surface drive setup... the boat is going to attempt to run down the centerline of the prop... Therefore, the deeper you run it, the "looser" the back of the boat will get...

In other words, when you lower the drive DOWN, you raise the hull up out of the water more... Conversely, when you raise UP the drive, you lower the hull in the water...

Your TS-2 should run really well with the drive about 1/8" or so above the setup board, with a slight angled up shaft angle. This is assuming a 42mm or so prop...

It'll be a little loose, but then, this is a tunnel... it's not suppose to run tight, but rather on the very backs of the sponsons...

Don't try to get all of the nose up using the lower unit angle... It should air out well at speed... Too much shaft angle will cause it to bounce at speed....

Expect about 38mph or so from a well tuned setup that can actually be raced through the turns.... Like I said, it'll be loose... you'll have to drive it... but that's about what you'll get...

[Stinger9D9]

Ok, well here are the changes:

- moved the motor up until the prop shaft was 1/4" above the bottom of the boat
- changed the motor...I'm pretty sure the used SV motor I picked up a while ago on the Swap Shop forum was bad (after the puff of smoke that came out of it)
- changed to a detongued X642 prop
- re-peaked the packs (they are still a bit flat from sitting around all winter)
- increased water pickup diameter and tygon tubing all around

Now the results:

It ran a TON better, MUCH cooler, just a bit too slow, and way too wet. Although the CofG is exactly 9 1/2" from the stern, it runs like it's nose heavy. I haven't trimmed the motor up at all yet.

Also, it hooked pretty bad in the turns despite the fact that it has recovery pads.

In all though, it was a successful (though unexciting) trip to the pond, and, like I always say, I'd rather be bored than frustrated.

[Stinger9D9]

Wow, so that's 3/8" above the bottom of the sponsons? I never would have thought to try it that high.

There's no denying that it's running well in that video though.

I installed my threaded inserts too low. I'll have to add another set of 4 just above them to get the lower unit any higher. It is doable though.

[TRUNKMUNKY]

It was mother's day and after taking mom out to dinner she spied the boats already loaded in the back of the truck and asked to go with me to run them.I was like,you really want to go run boats?Instant camera man,and she was really curious as to the tech part of the whole thing,so I let her run the camera and explained the basics of rc boating as I went along,being a retired scientist from Corning,she quickly grasped the concept and was having as much fun as I was.Amazing woman for sure.I can see why dad married her.I raised up the motor quarter inch above recomended height and had much better handling as a result,ran cooler too.http://www.youtube.com/watch?v=3S7kvSJLiJU

[Stinger9D9]

anybody know where to get the mount? looks perfect for my next build

Check way back on post #48 of this thread.

[smm_cbf]

anybody know where to get the mount? looks perfect for my next build

[Stinger9D9]

Ok, I raised the motor up to get the bottom of the prop shaft 1/8" above the bottom of the sponsons, and also trimmed it to exactly neutral.

It's better, notceably faster (still pretty slow though), but it still runs REALLY wet. I still don't think the motor is hitting full rpm.

I think I read somewhere that the SV motor likes to be a bit higher out of the water than the recommended 1/8" above the sponsons. I'll need to slot out the dubro mount a bit to get the lower unit higher up.

The motor ran really hot again. I think a better water jacket is in order as well.

[smm_cbf]

im sure it can get on to plan with cells. you might just have to find the right balance point, i might do a bby tunnel on 12 cells, but thats built for cells, so....

[Stinger9D9]

Yeah, I think the motor was too low in the water, the prop was in too deep, and could not wind out. It started to get going, but looked like the motor just could not get the rpm needed to push the boat up on plane properly.

Has anyone had any success at all running one of these on nimh's? Or will I have to put it back on the shelf until the budget allows for a pair of those?

[TRUNKMUNKY]

Maybe I can help.,you must have the lower unit set at the proper height,this will mean using the ts2 manual.Just use the biggest side of the stand it came with to set your boat on,then you can set the motor and lower unit height,..just make sure you use the wide side of the boat stand.

[Stinger9D9]

I finally finished the orange TS2 I bought off the swap shop forum a couple of months back. (It was a bit of a challenge considering the state I received it in, but that's a different story for a different thread).

First off, here's the setup:

SV27 motor on a REK lower tilted up a bit to (try) and lift the nose, 70A ETTI ESC, Octura X440 2 blade and...12 IB 3600's

What a dismal failure.

It's WAY too heavy with nimh cells. The prop cavitated like crazy. The nose actually plowed down into the water at least once, and the water pickup was basically non functional because of the cavitation. I tried to lower the outboard a bit, then tried a graupner 40mm CF prop, neither made much difference.

So basically, it was slow (like 10-12mph), WAY too hot and tried to end it all by heading for Davy Jone's locker a couple of times. Let's just say, I ended that trip to the pond shortly after it started.

Ok, I know now that this setup is not even worth considering nimh's, Lipo's are a must.

My question is about prop selection, outboard depth and angle, what prop would be better? I think my overly aggressive upward angle contributed to the cavitation too, do you agree?