Brushless conversion of a Musculus toy boat

[Make-a-Wake]

I'd suggest these

http://www.offshoreelectrics.com/pro...prod=ose-80077

Small turn fins will help too..........if you have room on the transom after the tabs

[iop65]

Its only 22" long

i stand corrected , thought it was around the 26"" mark

in that case : a 3665 with a 180a esc is way overkill

wouldn't a 2860 2700 -2900 Kv with a 60a /90a esc be a better option ? will spin that 37mm prop without any problems on 3s
and he surely would save some weight

[Make-a-Wake]

These smaller "toy" hulls are featherlight and the extra weight helps keep them planted, so overpowering and extra weight are a plus. I had a 2860 in my 27" toy conversion and had to add an 8 ounce sinker to make it stable, then it was slower, so I went with a larger motor too.

[seehuusen]

I'd suggest these

http://www.offshoreelectrics.com/pro...prod=ose-80077

Small turn fins will help too..........if you have room on the transom after the tabs

Thanks! I started looking for some and found that size here in Oz from a local supplier, so I might just get a set. They were $12 pp

i stand corrected , thought it was around the 26"" mark

in that case : a 3665 with a 180a esc is way overkill
wouldn't a 2860 2700 -2900 Kv with a 60a /90a esc be a better option ? will spin that 37mm prop without any problems on 3s
and he surely would save some weight

Thanks, I do see your point, lighter and smaller gear would potentially yield the same sort of results.
I run something very similar to what you suggest, in my jet boat (NQD). I find that the motor gets lukewarm on that boat, and it is smaller and lighter.
Most ESCs I've put into the jet boat with that motor, tends to run a bit on the warm side. With one exception, a 120amp ESC. That and the fact that this ESC was recommended as close to bullet proof, was the reason I went that way.
Weight is obviously not an issue when you have about 1.2 furious electric horsepower in a boat this size haha

For this boat, I wanted something that would run cool, have power to push the boat up around 40mph, and do that, battery pack after battery pack... This is the reason I went a bit larger everything on this boat.
As a result, I can pretty much run anything I want prop-wise, and just worry about trimming the boat and running it.
In its previous state, it did run those types of speeds on 4S. Hopefully trimmed a bit better now, it would run that and a bit more :)

musculus15.jpg musculus16.jpg

I managed to blank out the old holes for the rudder, this was something I'd wanted to do on version 1, because it was on an angle, which led to some funky high-speed behavior, especially when turning left (lifting the back and pushing the front into the water)
I then added a bit of material to straighten the rudder mount a little, as the transom is curved (not that this has any major impact on the handling, though it does put the rudder rearwards a few mm).
Lastly, I drilled the holes on the right angle, and I'm happy with them now.

There should be enough space for the trim tabs, I'd want to put them fairly close to the stinger, right?
If I went and bought some turn fins, could I put them right on the edge of the transom? and what size would be recommendable for a boat this size? smallest I can find is 55mm x 21mm.

Thanks for your input and interest, it's nice being able to draw on other people's experience

Cheers,
Martin

[seehuusen]

Made an order this morning for some 38mm x 32mm Trim tabs.

I'm not 100% happy with the rudder alignment, it is slightly on an angle. I'm considering pulling it off and starting over again, thoughts?
I drilled 4 holes for my hatch screws, it looks OK, but slightly overkill. So I might remove 1 and reconfigure the two front holes to 1 at the very front of the hatch... not sure if it is important enough yet though...
I won't be putting the deck back on the boat until the trim tabs have arrived and I've worked out the best way to set these up... Is closer to the stinger better or further out towards the sides the go?

[seehuusen]

minor update, I pulled my rudder off and re-drilled the holes for the screws.
I can now confidently say it is completely vertical :) The transom is curved as well as the deck being curved, it was extremely tedious to get right, fiberglass is good to clean up mistakes though

I'm expecting the trim tabs to arrive today via the post man, could any of you fine gents let me know what is better, further towards the sides or closer to the stinger?

Thanks in advance,
Martin

[785boats]

I have one of those, but it's called the Dolphin. Same boat though, & it has a little outrunner in it. Haven't even run it yet. But the tabs are installed from the factory towards the outside of the hull. About 1/4" from the outside of the tab to the side of the hull. It's a very narrow transom & I will have to fit some turn fins on it as the boat doesn't have any fitted from the factory. I intend to try the Proboat 1500kv motor in it to see how it performs in our Restricted Mono class. Should be fun.
Where in Queensland are you? Anywhere in Brisbane?

Paul.

[seehuusen]

Hi Paul,

Thanks for the directions on the trim tabs. That's how I will install them then :)

I'm on the Sunshine Coast, I normally run my boat in the pelican waters canals, you can always find something flat to run on
Mine doesn't like too choppy waters, despite the hull shape.
I am actually planning on a trip down to Tripple S boat club's waters in the beginning of April, do you run your boat there by any chance?

Cheers,
Martin

[785boats]

Yep.
That's my main scale/fun club. We are there every Saturday afternoon running fast boats too. Scale & sail & submarines etc are in the morning.

But this Saturday coming our Race club meets at Lakeside Raceway at Petrie. So most of us will be there instead of Boondall.

[seehuusen]

I was thinking about coming down 11th or 12th, so that might coincide perfectly :)
I do wonder, I don't have the safety power cut-off lanyard on the outside of my hull, well I don't have any on the inside either LOL What are the rules surrounding that?
What time do you run in the afternoon?

Back into the build again, I've installed my trim tabs as I read the suggestion above, we'll see how that runs on the lake.
Apologies for the terrible photos
musculus17.jpg

Additionally, I trimmed the stinger up to as much positive angle I could give it (moved prop up, should lift the nose out a bit better)
I'll control the ride via the trim tabs and stinger angle, although I do think I could need even more of an angle upward, so I might take some metal out of the stinger mount, where the adjustable screw goes.

Additionally, I found a crack along the deck and the hull, after my sneaky maiden voyage (without camera).
So I did this
musculus18.jpg

Now, I'm aware it's not super pretty right now, but a bit of sanding will see that blended in nicely

I should have the boat on 4S tomorrow, but that is weather depending.
Additionally, the 4S batteries both report a cell with high voltage... Might be because they've been stored for a long period of time and getting old...
Someone told me to flog it and then re-charge it, that this might get them back on track... I'll try that and take my charger to the lake.

Cheers
Martin

[Make-a-Wake]

Trim tab placement is very good, deck of boat may have a touch of cancer or some condition..............LOL

How did the boat run in your sneaky maiden???

As for the voltage issue, discharge your batts then balance charge them. In some cases if they are way off..............I have actually charged the one cell that was low with charging pins into the balance plug. You can also discharge one cell this way

[seehuusen]

Thanks for the tip on the LIPO mate, I'll give that a shot, fingers crossed they're not dead...

The maiden was good, in the sense I managed to run to 3S batteries through it.
The rudder is MUCH better now, in fact I could increase the 55% limitations I had on there to 65% and will increase more on net runt. No more crazy weird turns, clean in both directions.
The stinger was a bit on the negative side, and I didn't realize before I was cleaning up and taking it all apart for a re-grease... This has been addressed now though.

So all in all, it's still fun, it still runs wet, but hopefully the changes will sort that out for the next run

[Make-a-Wake]

Put your cog at 28-30% from transom..............

[seehuusen]

The missus was out, so I snug off for another test run. I'm glad I did actually, it ran extremely wet with the new trim tabs, after adjusting them up as well, I got it running OK, but still drawing more amps going by the heat of the battery.
It's very stable now with the tabs though, I think it's an improvement, but just need to adjust the boat to be out of the water more...
I need to take some material of the rudder post, I need a bit more adjustment from the trim tab under the rudder, and the screw is hitting the bottom post for the rudder...

Also, batteries were shocking... I'm not sure if leaving them was such a good idea... 2 of the 2200mah 3S were great, the rest (1x 2200mah 3S, 1x 2650mah 3S & 2 x 2650mah 4S) were all really crap. I'm hoping giving them a run and deflating them a bit today, followed by another balance charge will make them come good... Actually, I'm thinking I might get 2 x 3000mah 2S batteries and run 4P2S (? is that what it's called?), run them in series anyway, for 4S power but with a battery on either side of the hull...

Cheers,
Martin

[Make-a-Wake]

Ok..................so hopefully you are checking your cog.............all you are talking about is your tabs and screws and stuff. If the cog is way off it doesn't matter. What is your cog from transom? That will help you.