42" Aeromarine Sprint Cat re-build

[millzee]

After a long time building this hull up with twin 1717's, I failed to set it up correctly and burnt out one of the speedo's. I think it had a lot of potential but I simply don't have the time or experience to root around getting it right as a twin so I have decided it'll be rebuilt into a single. My plan of attack is to strip out the hull, fill in the transom holes and start again. I'll leave the servo mount and battery and see how things pan out.
The new set up will be:
Castle 2028 780kv motor
Swordfish 300HV speedo
Octura X457 Prop
Nano Tech 65-130c 8s lipos
Speedmaster inline skeg style rudder assembly
1/4 " flex drive with 3/16" step down

I'm aiming for a boat that'll be fast enough to be fun, maybe a little wow factor and reasonable run times. Any and all advise is more than welcome.

Here's what I'm starting with
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/cleanedup002_zps3f984dcc.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/cleanedup002_zps3f984dcc.jpg.html)
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/cleanedup001_zps89123739.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/cleanedup001_zps89123739.jpg.html)

Here's the goodies, they arrived today, thanks Steve!!
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/catbitz001_zps442e461e.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/catbitz001_zps442e461e.jpg.html)

[millzee]

Here's a few progress pic's, I'm waiting on the k&s tube to come so I can get into the rest of it. Is 10s stretching things a little?? I have 4s and 6s 65-130c 5000mah pack to make up either 10s1p 5000mah or even 102p 10000mah, what do you think???
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/4_zps20d4ea92.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/4_zps20d4ea92.jpg.html)
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/3_zps387a6a38.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/3_zps387a6a38.jpg.html)
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/2_zps388a1405.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/2_zps388a1405.jpg.html)
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/1_zps6ea1ec61.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/1_zps6ea1ec61.jpg.html)
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/5_zps2dffe2e8.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/5_zps2dffe2e8.jpg.html)

[srislash]

Should get her going bid, go 8s to start then move up but 10s2p is a reasonable goal.

[Fluid]

Don't waste time with 8S, that motor is a great 10S motor and pulls props from x457 through x462 easily. Running 8S will require completely different props and will draw more amps than 10S will, so you'll have less run time and will stress the equipment more. A setup which works for 8S will have to be changed considerably going to 10S - prop, strut depth, CG, etc. What speed goals do you have? How much run time would you like?




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[millzee]

I'd like to see 60mph as a good speed and around 5 minutes runtime, what height do you think I should set up the strut for a 10s starting point with the 457 prop?

[photohoward1]

Never getting 60 and 5 minutes run time. More realistic is 60 and 3 minutes. Prop down and slow down to 50 and you could see 5 minutes. Any other thoughts guys?

[millzee]

I'd see a good chance of coming close. Suggested strut depth with the 457 anyone?

[oscarel]

1/4" to 3/8" up would be a guess. 3mins if constant full throttle, maybe 4mins sport. You really won't know till you get it together and run it. Lots of things to factor in.

[RandyatBBY]

I had one that I ran a Lehner 3040 8T on 10S I can not remember the prop, but I raced gas guys in the district. I had a blast, nice size boat handles well. Not in gas boats prop turbulence though, but a good boat for all electric competition.

I usually start with a 3/16 shim under the strut and the boat flat on the table.

[millzee]

Well after a little time I've put it all together, programmed the speedo and she's sitting ready for me to test drive. I had a little self doubt on the cap bank but with a little help I managed to figure it out. There should be plenty of room for me to adjust the COG and I've set it up around 29-30% for it's first test run. I'll run 10s2p and see how the electronics go.

http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/join001_zps558356ef.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/join001_zps558356ef.jpg.html)
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/join002_zpse9521c16.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/join002_zpse9521c16.jpg.html)
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/5_zps8b7e9b56.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/5_zps8b7e9b56.jpg.html)
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/7_zps208e770d.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/7_zps208e770d.jpg.html)
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/1_zps132d7829.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/1_zps132d7829.jpg.html)
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/2_zps3a096e92.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/2_zps3a096e92.jpg.html)

[millzee]

http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/3_zps7ec20459.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/3_zps7ec20459.jpg.html)
http://i1219.photobucket.com/albums/dd439/1millzee/Aeromarine%20Sprint%20Cat%2042/4_zps57cc1362.jpg (http://s1219.photobucket.com/user/1millzee/media/Aeromarine%20Sprint%20Cat%2042/4_zps57cc1362.jpg.html)

[high-tech]

Nice boat, I think you would like an offset rudder bracket, and pitch that prop 3 deg. to the right and you can run straight rudder which means less drag... Ask around and you will find most others chime in on this

[millzee]

3 degrees up or down?, I'm a little unsure what your saying.

[srislash]

I think he is saying to the side to compensate for propwalk Danny.

[high-tech]

3 degrees to the right and yes that is compensation for propwalk, to do this either bend the strut brackets that attach to the transom or fabricate a shim that fits between the strut bracket and the boat.

[millzee]

I am absolutely stoked right now, I just maiden her in windy conditions and it handled awesome. I took it a bit easy for the first two minutes but after checking the temps I let rip. I was able to pin the throttle with the wind behind me and it's the first boat I've driven that's made my lake very small quickly. WOW, great speeds and perfect cog off the table, it's about time I got one right first up, lol. When heading into the wind it lifted a tad but never looked like flipping, I was able to see the driveshaft leading down to the prop and it was running nicely on the last inch or so of the sponsons most the time but prop only a bit too. I was by myself but will have a camera man/boy with me next run. I LOVe this boat finally after two years!!

[oscarel]

:-) congrats!

[srislash]

Atta boy Danny. Can't wait to see a vid.

[millzee]

I through it out again this evening on calmer water and she seemed to bounce around a bit, what suggestions to smooth it out on glassy water? I managed to get my son to hold my phone to get some footage, I ran for around 6 minutes and temps where getting up there a bit but still safe. Here's a bit of the footage my young fella got, it's a bit shaky and on sun down but you'll get the idea of how it's running and hopefully you can share your knowledge.

http://youtu.be/5vBTQ24Zv_I

[srislash]

I am going to say to put the strut up some. Based on the hop and the heat buildup. Put it up, let it cavitate on takeoff, and gradually bring bring it down till you are happy with takeoff.

[millzee]

Cheers mate, I'll try it tomorrow afternoon with the strut raised a bit more.

[high-tech]

I would try adjusting the strut down a little and see if it helps

[dasboata]

You don't need the skeged strut with that boat ! I would cut it off and sand it nice ! PS I got dizzy watching that vid LOL run the boat in counter clockwis circles for best handling

[millzee]

I was a bit unsure on the skeg but I wanted the inline set up so it was on there, I'll take your advice and get rid of it, thanks Chris.

[Simonj]

Hey Guys, I couldnt find a place for an introduction thread on here so i thought i would introduce myself on here as i have just purchased this boat. I hope you dont mind Danny. Im Simon 25yrs old born and bred in New Zealand, been living and working in Northern Western Australia for about the last 16 months. I have been into RCs for about 4 years now and Brushless electric is where its at as far as im concerned. about eight 1/8 and 1/10 scale bashers crawlers and racers. I have a HPI Baja with 30.5 full mod rooster tail motor, a Losi with a LEHNER 3080 and MGM 25063 which is on its way back to the Czech republic now for repairs, mean time its fitted with 31.5 full mod rooster tail motor. I enjoy working on my RCs more than anything.
Like i said i purchased this boat of Danny(my first decent boat) and a good mate of mine bought his 41" mono so once they both get here we are really looking forward to taking them out and seeing how they go.
This seems like a great Forum and im looking forward to learning alot from a bunch of knowledgeable guys.
Cheers
Regards
Simon

[RandyatBBY]

Try bigger smoother ovals, sounds low on power but that could be just the speed you are scuffing off by not being smooth.

[Simonj]

What are you referring to mate?

[RandyatBBY]

What are you referring to mate?

Video, I am just trying to help. A boat really does not get to full speed until it airs out.

[RandyatBBY]

It is just like drifting is not the fastest way around the track but it sure looks like fun.

[Simonj]

Oh thanks mate! When it gets here ill take it to a nice big lake and lift the strut a little bit like suggested and see how that goes. If its still not fast enough then I guess I'll buy a water jacket for the 3080 and throw that in and run it on 14s! That will wake it up! I'm very new to RC boating so some of the terminology escapes me!
Thanks for your help mate!
Simon
P.S Milzee I hope you don't mind me taking this thread over since I bought it? Or would people on here prefer I started a new thread of my own?