Aeromarine Sprintcat 40

[bustitup]

Any updates here

[DISAR]

No updates at all. I've been very busy with work and I am overseas now for quite a long time so no possible to touch the boat.

[DISAR]

Total rebuilt, and runs very stable now. The large extended Speedmaster strut made the difference! Propeller is further back (abt 3.9" from transom) and it makes the boat much more stable, Thank you knpc for your advise!
I Cut the rails and fit platforms in the sponsons (on top of foam) (also knpc's advise) and fit the lipos in there, also moved the motor further forward to 12.6" from transom in order to leave more space for additional lipos and flexible cog adjustment. Added also carbon-aramid fibre on the tunnel and platforms, I like the look. Tested with ESCs MGM 25035 and Hydra HV240, a good ESC over 200amps is necessary to run this boat. Total RTR weight is 11lbs which might be too much but I'm very happy with the boat, Thank you, Jay and Kevin!

[knpc]

Nice that everything worked out and you got her dialed in. I had mine out this morning in windy conditions and it was still runnng fast and stable. If you get a chance post some pics of the inside layout and hardware. I'd like to see your setup.

Kevin

[D&D]

I ran this boat for years (nitro) and built several. Push the back of the boat down on a flat surface with the strut loose. While holding the boat (as above) push the strut down flat and tighten. This is the correct setup for the strut, however; CG will vary with each different Sprint Cat hull and that is probably causing the hull to fly up and then they are famous for nose dives. Good Luck

[DISAR]

Oh yes I had a couple of nasty nose dives before with the small strut, but with the new extended large strut no dives any more. I have the strut 10mm above, have not tried with even yet.
Added some transparent plexiglass for watching the gps without removing the hatch and modified also the aft part for taping down more easily.
Some photos

[D&D]

DISAR, I like that extended strut, if I could figure out how to post a picture I would show you a picture of my 60 Spint Cat in my album on this site. Then you would be able to see the extended strut that I worked out and how much weight I had up front in the boat with an .67 OPS, an 16oz fuel tank, etc., etc..... Seeing your build sure makes me want to build another Sprint Cat - electric this time.

[DISAR]

D&D, I saw your pics in your album and you have very nice boats. With what colors did you paint them? An electirc conversion is easy.

[D&D]

DISAR, The red color of my cat boats (these are actually four different boats) came as ordered from Areomarine, the black and white were many sanded and polished coats of Krylon (sp?) rattle can. Even running 60% nitro I never had a problem with the Krylon.

What I like about your new "big strut" is the setback it gives the boat which makes the boat handle as though it is longer. I am looking forward to learn how your boat is running, have you captured mph yet?

This is a test to see if I finally figured out how to post a picture:

user2811_pic940_1250963632_thumb.jpg

user2811_pic940_1250963632_thumb.jpg

[D&D]

Well I guess that is one way to post a picture, but how do you guys get them to open up? Do you take them from youjr posted album on this site?

[DISAR]

In the "Quick reply" box you click "Go Advanced", then further down you click "Manage Attachments" new window opens click browse and select the photos that you want from your PC, then wait and when they are attached you close that window and post reply.

The colors are very shiny, did you use varnish-lacquer-clear coat?

[DISAR]

Ok today tested some propellers 646 detongued, 225, 648, 235, 447/3. My best one was the 235 for good handling and speed of 44mph. I run the boat in sea water where conditions are different from ponds and speeds are less I believe, I have not compared speeds between fresh and sea water since there is not any pond here! The 646 d/t was also very good and 40 mph. I didn't like the 648 which made the boat quite unstable for me. 447/3 also good but with similar amps as the 235 but less speed. I am not into racing chasing speed I just want a reliable and nice handling fast boat. For the exact amps I don't know, only comparing, because the MGM black box sometimes gives me !@#$%!.
The boat is very nice.

[D&D]

DISAR, That's what I did to post the pictures and the pictures are OK, but I see all of the other pictures that open up into a nice sized picture for viewing when you click on them (OK, it might just be my "old age" desires). As to the shinny paint on the boats, that is just a lot of elbow grease, 1200 grit sand paper, polish, and wax. Also please note all the work on the inside of the boats, all sanded out and recoated with a red tinted resin. Yep, I was certifyably nuts! But I just loved it when the other boaters came to look at my boats and just walked away shaking their heads.

[D&D]

DISAR, I'm really surprised that the Octura 447-3 didn't work for you. As I thought about building a boat like yours that would have been my first selection. But, of course, I don't know nothing about the electronics and how props affect them. My 60 nitro ran a cut down 455-3 and three bladed props always ran the best on the 40/60 hull.

[DISAR]

The 447/3 was good also but I think the 235 better. From the props that I tested I will run the 646 d/t for general purpose and when need more speed the 235. Next thing is to measure the exact amps before going any higher. Very important in electrics in order to blow your ESC (expensive) or motor- also expensive. With the above props. everything was cool.

You can either have my setup or this
http://forums.offshoreelectrics.com/...ight=sprintcat

Neu 1521 1.5D, 4s2p, hydra 240 which may be better and a bit cheaper