Arowana Build...

[electric]

Almost Done

Well, everything is in and hooked up. The only think that is lacking is the collet's I purchased. That has so far proven to be a pain since I have no good tool to measure the diameter of the shaft and it seems to be an odd size. Showing these pictures to prove to a friend that indeed it will all fit. You will also note that I switched to a "thinner" water jacket, the other one was to thick and was hitting the hull. Curious to see how fast this boat will be running 2s. Tomorrow I will probably tub test the roll over on it.

[BHChieftain]

Well, everything is in and hooked up. The only think that is lacking is the collet's I purchased. That has so far proven to be a pain since I have no good tool to measure the diameter of the shaft and it seems to be an odd size. Showing these pictures to prove to a friend that indeed it will all fit. You will also note that I switched to a "thinner" water jacket, the other one was to thick and was hitting the hull. Curious to see how fast this boat will be running 2s. Tomorrow I will probably tub test the roll over on it.

I bet a feigao 380 XL would also work with a bit more room to spare. According to OSE, this motor is supposed to have about the same output as a 540.

Looking forward to seeing 'em run

Chief

[CornelP]

I tried a 380XL, 540S and 540L on the same hull, similar kv, on 2S. The only notable difference is the weight and the fact that the 380 comes in a lot hotter than the others. The 540 will be able to spin a larger prop, but that's abut it... I did settle on the 380 for the reason Chief stated: more room...

[electric]

The boats are ready to test. I had to move the esc to the water chamber side to help with the roll over. Weights were also placed in the flood chamber. The vendor included the weights with the boat so I am pretty sure they were aware. It rolls consistantly in this layout, although the roll over is very sensitive to where the weights are placed. I think this boat will at least need a turn fin, but we will test it this way first.

[electric]

As a wrap up to this thread. I ran the boat last weekend and it worked great. I ran with the stock prop and the speeds were probably low 30's or high 20's. It would spin out in a turn when there was chop in the water, but turned very well when the water was smooth. I know I can prop this thing up and get some pretty ridiculous speeds on just 2s, but for now I am leaving it like this so the four of us can race with equal set ups. Everything runs cool. Oh, it did flip and it did NOT flip back over. That was after numerous sucessfull tub tests. I realized that just the placement of the wiring has an effect on the flip. I did add a bit more weight and it should work fine the the next time out. These are going to be fun boats and surprisingly good speed for 7.2 volts.

[Diesel6401]

As a wrap up to this thread. I ran the boat last weekend and it worked great. I ran with the stock prop and the speeds were probably low 30's or high 20's. It would spin out in a turn when there was chop in the water, but turned very well when the water was smooth. I know I can prop this thing up and get some pretty ridiculous speeds on just 2s, but for now I am leaving it like this so the four of us can race with equal set ups. Everything runs cool. Oh, it did flip and it did NOT flip back over. That was after numerous sucessfull tub tests. I realized that just the placement of the wiring has an effect on the flip. I did add a bit more weight and it should work fine the the next time out. These are going to be fun boats and surprisingly good speed for 7.2 volts.

Just curious with the drive line the way it is on the 22" version and not having a tradtional adjustable strut was their any water intrusion through that area, also do you feel like a starboard side turn fin in neccessary and/or trim tabs neccessary. For less than $100 shipped it could be a fun pond killer...

[electric]

Need some input here. I ran both the boats today with my son and first of all they both ran great with equal speeds and we had a great time with them. They rolled as needed and had nice speed for the small pond. I did have a problem with one of them heating up way more than the other. The one that comes back hot(Motor 155 degrees) is as follows:
Feigao 7L
Swordfish 120
The other one came back cool all around has:

http://www.hobbycity.com/hobbyking/store/uh_viewItem.asp?idProduct=6673

turnigy 120

They both have same batteries, props and driveline.

Here are the esc setting on the Feigao/Swordfish. I am guessing this is what is causing the heat. Could someone suggest a cooler setting?
Current Setting:
Timing is (Auto)
PWM is 8khz
Start Type Standard

[electric]

Here is some data running an x440 prop on this boat. A bigger pond would help, but it did reach 31mph on 2s(7.4 volts). Not bad and everything was running cool. The only issue with this prop is there was too much torque roll. I also ran a 38mm prop(plastic), but the GPS did not work. I did get the amp readings and they appeared to be close in speed.

I need a small diameter prop with good pitch...

[electric]

Just curious with the drive line the way it is on the 22" version and not having a tradtional adjustable strut was their any water intrusion through that area, also do you feel like a starboard side turn fin in neccessary and/or trim tabs neccessary. For less than $100 shipped it could be a fun pond killer...

Actually,yes there was water leaking around the strut. They NEVER even glued it. I epoxied it in and that is solved. Works great just how it is. I will eventually add a turn fin, but it really handles turns very well right now. No need for trim tabs. It really is turning out to be a fun boat.

[electric]

Thought I would add a few more thoughts for those that decide to build/buy one of these boats. After some running time I want to point out a few more things. The stinger/strut really needs more support than just a tube glued to the transom. I ended up putting in an SV stinger I had and that helped quite a bit. Also, the drive shaft the boat comes with is prone to breaking where the flex wire is soldered to the shaft. You might as well look for a 3/16" shaft solution for the boat. Never did put a turn fin on it, maybe this summer. We really ran them pretty hard last year and they were great fun for the kids.

[slappy]

Thanks for documenting your build/s. I have just received two hulls (for the same reasons you bought yours) and Im starting the build this weekend.

I have a spare set of SuperVee 27r running gear buts its looking like everything is too big! Hopefully I can get a good motor and ESC combo for under $100 that will make my first boat go well, planning a jet drive for my second :)

I want a normal servo so Ill try your setup!

[electric]

The first pics (blue boat) show the Arowana set up with the SV27 hardware. I had a strut and the stuffing tube all together. I just enlarged the whole a bit, and then slid the whole SV27 assembly in place. It fit pretty much perfectly.

The second pics (red boat) are of the standard shaft. I purchased a collet that would work(will get you the measurements later), and then removed the bearing up on the shaft on the collet side. I then inserted a teflon liner to fill the space and kept the bearing on the drive dog side in place. Keeps the water out and still provides the support that is needed for the shaft.

Will get you the measurements for the collet as soon as I get the battery for my calipers.

Notice how beat up the prop is from racing with my 6 year old...

[electric]

I believe this is the collet you will need for shaft that comes with the boat:
http://www.etti.com.hk/product_info....products_id=39 5mm/3.2mm

By the way. If I was doing it all over again, I would also give serious consideration to a drive line set up that allows for 1/8" props. Much better selection to fit this size boat, but if like me, you already have an sv27 drive line sitting aroud then it will do.

[slappy]

Well after completing my first arowana build, I think Im going to retire it before its even seen the pond. The bath tub tests have not gone well. I'm pretty sure its going to sink.

Pulled out the stock drive line and put in a complete SV27r setup, sealed it all up. It wont take on water while the right way up but if I put it on its lid it fills up pretty quick.

Its so heavily weighted to the the flood chamber side that it lists really badly when not moving. Even with all the supplied lead weights, a 5000 mah 2 cell lipo, the ESC all against the flood chamber wall it doesn't self right either. In fact its more likely to self wrong if it loses drive in the middle of the pond.

I cant see how its going to have any decent performance when 70% of the weight is on one side and the boat is barely buoyant in the water.

Frustrating because its taken over a month to get the parts and find the time to put it together..

[electric]

Sorry to hear it did not go well for you. I am running mine as you described and all is fine. Hmmm. I will tell you that most all flood chamber boats sit sideways in the water at a pretty sharp angle. I used the two rows of weights it came with and one more row and that worked for my boats. I am also set up the same with a turnigy 5000mah, 120amp esc etc.

The bouyancy and weight are not an issue once the boat is underway. It will fly. I ran the one I have that has the SV27 hardware set up through a bunch of battery packs a few weeks ago. Hmmm. the big issue is your leakage problem.

My buddy had two of these also, and he did have an issue with one of his having a leak along the flood chamber wall. He ended up running some epoxy along the seam to get that taken care of.

With the time you have in it, just try and fix the leak and give it a try. I think if you do, you will be surprised how well they run. OR (I think you had two right?) finish the second one and make sure it does not leak and try it first to convince yourself whether you want to put the effort in to fix the flood chamber or not.

If you have had it, and I would understand that, you might try another hull so you can move the motor and esc to it only. I think I did see one that might be a good fit a few days ago, although I have not tried it myself. I will find the link.