Stryker F41 Build

[jimi911]

Never done a build Thread before so I thought I would try. With Christmas holidays coming up and should be able to finish this and some other boats if all the bits and pieces arrive. My plan is to make this a bit of an econo-project. My budget is $500 less the batteries, which I already have from my Enerland days. She's big! That's my new Micro Drifter in the one pic.

Hull: 41" RC Boat Works Stryker F41
I got the hull new old stock from a guy down south who did a lot of SAW racing. It got some shelf-wear on it, but seems pretty solid. Its light ... 5.8lbs, Seems most are 6-8lbs. Obviously this was intended to be a gaser so I will need to fill in some holes, which will add some poundage, but I will also be cutting up that cover to make it more tape friendly which will save some. I gave it a kiss with the wet sander to clean it up a bit ... seems like a good hull.
Cost: $150

Power: Leopard 5692 2Y 1090 Kv
Got a great deal on a new one and couldn't pass it up. Never ran a leopard, but it seems decent on paper and with the weight of the hull it should do ok. 8S2P.
Cost: $80

ESC: Castle 110HV Phoenix w/Cap bay
Don't knock it! I got this from Steve Reesor 6 years ago and its still going! I had it in my big Lazer45 Neu 2215 setup while I waited for my Hydra and it did great ... hopefully its ok for this.
Cost: $75

Total so far: $305

[oscarel]

Wow, excellent price for that hull. I have one that's gas and a top gun 2 that's electric. The top gun has twin 1717's in it and is right around 20lbs with 6s2p per motor. I've had it up to 67 so far and it pulls around 300 amp spikes per motor with X452's. I've since gone down to x447's and it's running in the high 50's, haven't checked amp draw.. Instead of trying to glass up the cowl I went with making sure everything was waterproofed real good, so far nothing has fried. Good luck with the build!

[jimi911]

T'was an excellent deal I have been patient getting all the parts for this build and its really paid off. This hull is going to be cheaper than my new N2 Seaducer and LSO!

How did you mount the rudder on your gas one?

I have seen dozens of builds online of the F41 and the rudder is on the right, on the left, way on the right, short, long, etc. The PDF setup guide recommends the left and 5" from the transom, but I think its an older setup guide since it recommends J.G. Racing hardware, which does not exist anymore .

I am going to cut up that cowl pretty good. All the vertical bits make me nervous that it will rip off on a hard roll, stuff or blowover even if I reinforce it.

I think I saw some pics of the twin in the OSE gallary ... that must sound awesome!

[oscarel]

It's on the left. I had it out yesterday in 3-4" chop with a good 10mph wind and I was able to keep it wide open without the slightest hint of blowing over, COG is at 13.25 from the rear. Check with Fluid, he had one with Lehner 3060/10 on 10S2P.

2011-12-17 09.39.06.jpg

[jimi911]

Isn't that rudder on the right side?

What does you gas stryker weigh?

I have seen pics of Fluids stryker. He has the rudder on the other side. I think there's more than a few ways to rig this hull successfully.

[oscarel]

Sorry yes its on the right. I'm right at 14 lbs. It was there when I got it. From what I've read people prefer it on the left because racing clockwise the rudder rod will pull and eliminate any possible flexing.

[jimi911]

Ok so I started hacking up the cowl while I waited for my OSE order.

I love the look of the hull, and hate to change it, but I want to be able to tape this thing so I needed to make some changes. I was going to completely remove the turbine vent, but decided to go with a shorter one. I cut it back 3" and angled so it was even with the back of the boat ... I guess it was the best compromise. I also removed the top scoop ... didn't like it.

Some of the other issue with the cowl are starting to get sorted. The main issue is that its warped and twisted as hell. The back part of the is sucked in causing the vertical bits to leaf up. This also causes the cowl to not fully cover the opening, which is a big problem. I added some cf rails in to stiffen and straighten the rear. I tacked them in with a couple of patches of cf clothe. Much of the warp has been taken out, but now I need to deal with the twist. The rails will also serve as the base to sit the either abs or cured cf deck on. Once I add the deck and do an insert for the open part of the turbine I will cf it all in and fix some of the dings in the front. At the very least the cowl now seals on both sides :)

[jimi911]

Much straighter. Little sanding on the left side and a bit of contouring in the middle should improve the overall fit.

Up Next:
- Deck in the rear of the cowl
- Fill in the open bits with either cured cf plate or abs ... re-enforce with cf cloth.
- Clean up the nose.

[jimi911]

New profile.

[jimi911]

Back to it.

The battle with the hatch carries on. I used ABS sheet to fill the the smaller holes and cured CF sheet on the back bit where the pipe hole is. Everything was re-enforced with carbon fiber. I dremeled out the rough spots and filled them on the other side. Needs a heavy sanding now. Still needs some foam in it for flotation and some locks which I will install later.

Hatch began life at 1.1 lbs. Its sits at 1.2 lbs now ... should stay around there.

I started installing all the electrics and hardware. Fun, but it'll be coming out to do some finish work on the floor. CF sans batteries is set at 13.5" from the transom. The batteries will be installed on two rails that will mount to the outside of the wood rails and allow for CG adjustments from 10" to 17" from the transom.

The motor a new Leopard 5692 with jacket ... $80 new (ebay find). Octura 6mm to .250 coupler.

The Mount is a Jim Williams. I wasn't going to get one of these, but splurged ... $60. I had to machined the back clamps a bit to get it to fit nicely around the motor's set screws. I need to make a plate for the esc to rest on above the motor.

The T-Bar is from Top Secret. Most of the hardware you see on this boat is theirs. About 4 years ago I bought a ton of their stuff for next to nothing when they were going out of business ... all on eBay ... this was $8. These things are handy. I have them in 4 boats now. really set the stuffing tube in place well.

[jimi911]

I cut out a large opening for the stuffing tube. I find its easier to bend the tube and set angle of attack just right this way. Once its looking good I will add a cured CF subfloor over the area with a smaller opening. That will be carbon fibered in place, and than flipped over. The raised sub floor gives you a bit of room to put some carbon fiber over the stuffing tube and under the sub floor. Thus its supported all around ... good and strong. Fill the rest with 3M fill and clean it up.

The servo sits on a cured cf plate and is removable. Its set away from the transom so I can get at those screws if need be. Best part about having a big hull is more room to work!

Servo is a blue bird big boy. Tons of torque ... $25 introductory price on that a few years ago ... I think they are $50ish now. Arrow shark tie rod and blue bird CNC horn (had to be machined a bit to fit the tie rod. Top secret servo mount.

2b.jpg3.jpg

[jimi911]

Business end. After much debate I went with this placement for the rudder. Rudder is a twin pick up from Top Secret. Strut is a Speedmaster from OSE. I have not set up strut depth or anything but I installed it with the recommended room for adjustment.

Cameraman crooked ... strut and rudder straight :)

[jimi911]

The bend the stuffing tube is pretty easy on a big cat. Since the motor is mounted fairly far forward its easier to move the tube around to make setup adjustments. I machined the skeg strut a bit to allow the stuffing tube to insert into the front of the strut .250. I will add a bit of shrink tube over it later to smooth it out for water flow.

The motor is also setup so the stuffing tube is exactly the same length as my Lazer45. That means they both use the same length of cable ... which is handy should a blow a cable.

[jimi911]

Lastly ... for now. The plumbing.

I am trying to make this boat a little cleaner and less of a birds nest of rubber tubing. I made up some brass water tubes to carry the water from the transom forward to the motor and esc. They are not in place yet. Once they are I will cover them up with carbon fiber so you will only see the exit bits. Should tidy things up a bit and I suppose improve the flow of water since it will be travelling more directly.

The water will reach the motor and esc through two separate cooling lines. As it leaves it will go through two small reducers to restrict the flow of water, and hopefully create a bit of back pressure so the cooling jacket fills properly.

[jimi911]

PS ... I may be a bit over budget

But not horribly ...