coopers shocker build #2

[Cooper]

hey guys, i have been messing with fe boat for some time now. in the last three years i really got involved, last year i built a cf daytona, parts from ose, kintec, fightercat and jeff wholt, (thanks to all) i am kinda new to this forum but have been reading almost all the posts and builds, got great knowledge and tips for building. so i decided to put up my build and let you that know what you are doing give me some insight on how im doing. at this point i am working on setting the stuffing tubes so if i have done somethings wrong to that point well ill have to deal with it.
rw boat shocker hull 003.jpgrw boat shocker hull 002.jpg
after asking how to get clean edges on carbon/kevlar i used the idea from daren, backed the ck with light fiberglass with spray adhesive. wow that works great, borrowed wifes craft shears, and edges are are straight as an arrow. the one spot right in middle was where i had low tack tape just to hold up the roll when i put it in and it pulled the weave a little. other that that it came out perfect, and really got it to conform to the inside corners well.

[Cooper]

rw boat shocker hull 009.jpgrw boat shocker hull 016.jpgopps the last attatchments were not ment to be put in yet, im still new to this! oh well they are the pics of me putting in the rudder bracket and stingers. i backed both the rudder and stinger bulkheads with 2mm carbonfiber and also made a plate for the rudder of alluminum , i taped the holes in the alluminum plate for the rudder so i dont have to mess with putting on bolts.

[LarrysDrifter]

Whats the powerplant?

[Cooper]

oh i guess i should include what im trying for, we just run for fun and this summer im up against the neighbor with a etti rigger, so this is more of a go fast boat than racing,
two castle hydra ice 240 speedo's commanding twin fightercat 3740 2000kv outrunners. driveline is going to be 3/16 cables , maby wire drives, have some future questions on that topic, going to be running on 8,s so she will be screaming! as for props im running with cf 40s for testing, but plan to end up with x450's three blades. getting there by many combinations inbetween. i pulled most of the parts from my daytona cat, i am turning that into a single drive system because im getting into prop work and i cant start out doing that with twins. so this build is going to be just balanced and sharp stock props. should be getting into the 80's with luck, yes i know it a long way but i enjoy the building as much as the bragging rights over the river, last year the jet skis were trying to figure what the hell was next to them! this year is going to be whats that in front of us! well untill they go by then its too choppy for speed, usually glass on the river where we are and i can see them comming for about a mile so have time to set them up for ambush!!

[Cooper]

rw boat shocker hull 009.jpgrw boat shocker hull 001.jpg
here i just placed the mounts, i made these with simple angle stock, reason for this was that i am able to lower the motor 5/16 of an inch so more of a straight shot on the drive lines and i can place them farther back in the hull. these mounts will be having the fightercat large water cooled mounts attached to them. i trimmed the bottoms of them also, about a 1/4 inch. i have just put some epoxy in the bottom of the mount for a bed and for filler carbon kevlar will be next.

[Cooper]

rw boat shocker hull 007.jpgrw boat shocker hull 008.jpg

i ran out of the blue/black/yellow cloth so just carbon / kevlar on the mounts, this shows how good of an edge i got with the glass backing

[Cooper]

rw boat shocker hull 011.jpgrw boat shocker hull 010.jpg

placing the cloth onto the mounts

[Cooper]

Have to load more pics to the laptop, I use an iPad almost always now. But I can't load pics from it so I will be posting more later

[Cooper]

rw boat shocker hull 013.jpgrw boat shocker hull 014.jpghull.jpg

got the cf epoxy in the mounts and found the pic of the hull

[Cooper]

rw boat shocker hull 018.jpgtna.jpga.jpg
pic of the motor and mount, my help sleeping on the job! and another of the driveline showing the bend in the stuffing tube.

[keithbradley]

2000kv on 8s?
The only thing that might save your electronics is the fact that your cf props will shred within a minute at that RPM. You are about 3s too high. I'm guessing that's a misprint?

Also, for the speed your shooting for, expect a COG point at around 35% (I noticed you have 25-30 marked out).

Good luck with the build!

[Cooper]

I did pickup up that you're running 447's with 2000kv on 6s? That's about 85mph from my calculations.
That's a quote from Ben when I had this set up in the daytona. And yes I ment to say 6's batteries with that set of motors. 44000 on that set up, doesn't seem bad. And for the 8's I have some 1600kv motors, which I would be running smaller props, turning about 48000rpms, and I did have the 8's set up in my daytona with the 2000kv motors and it didn't sheer anything off! I had an issue with cavitation at first and had to play with the throttle curve. And with those motors and two 4's 6000mh batteries it was just enough weight to make her list, I had too much weight foreword and couldn't get cg back far enough after I had everything installed. That is why im building this shocker for same set up and wider stance. Most of the time I will be running 6's set up but for some speed runs the 8's will be sent out!

[keithbradley]

6s is a little better but still pretty high to be spinning x447s...did he mention what the current draw would be for your 2000kv on 6s? The good news is you will know with the datalogging ESCs. I expect you will be close to the 250-300A range.
I think you should start with the 1600kv motors on 6s to get it set up corretly, then you can move up from there. 1600kv on 6s will surpise you if you run x447s...you might have trouble keeping even that on the water untill you get it setup correctly. Once you get the bugs worked out you can then go for higher speeds. That way you don't have a catastrophic crash the first time out.

If you ran cf props with a 2000kv motor on 8s and didn't shred them, you must have incredible luck. Here is 1900kv on 6s with a cf prop...it didn't last long, and it was one of the three cf props I went through in a matter of minutes:

[srislash]

May I interject here with a tip Cooper,my mounts are 3/4-1" rear of the rear step,I have the 1820 TP motors(4082) and have concerns with my CG being too far forward.I've only run 4s in the Shocker so far but have had a little hooking in the corners.My batteries are crammed against my motors so thats as good as it's gonna get.It will probably get better with 5s and 6s as the weight will have to move up.Just my experience thus far I'm throwing in here.I haven't tested too much yet due to temps and ice.

[Cooper]

That's about where mine are also. When I place the speed controllers, rudders, hatch, all hardware, 3s batteries, and everything else I have the cg at about 25-30%. So I should be in good shape, as in this my batteries are about 1/2" from motors, so with plenty of room to move batteries forward for moving the cg to 25-35% even more for some speed runs I estimate I should be in good shape. I'm using 3s and 4 batts In series for 6-8s and just two 4s batteries for simple testing. I know the running characteristics change with different combinations so I will be starting with 4s. Yes I agree with Keith start small and work up, thanks, as the cf 40 they were on 4s and most of the running with the daytona was using 442s on 6s