CF 3.5 Rigger Project

[Hammerhead]

Battleships are made of steel

The thing you have to be careful with is the interferance in the radio signal. Make sure your antenna goes through the radio box lid, and I would use acrylic or abs to make the lid out of. The carbon has conductive properties that seem to screw things up with the signal.

as far as bouyancy, if one sponson is enough to keep it floating then you will be alright. ( general rule of thumb) losing both sponsons in a crash is very rare.

If you have to stick with composites, even for the radio lid, I would check out some other stuff besides carbon. Use an ohm meter.

Hammer

 

[Mark Sholund]

MikeP,

How far out did you mount the sponsons from the tub?

I have a nice 21 Rigger all Carbon it runs 75 MPH to 80 MPH

You have done a nice job, keep up the project.If you need

help with props drop me some mail.

Mark Sholund

[email protected]

 

[MikeP]

Hi Mark,

The sponson width can be set 12"-15". I am thinking about 13" to start out with, thats total inside width. Looking forward to moving them around just to see how it affects handling. The x440 prop seems to be a good prop for the mac .21 at this alt.(4200'). What props have you used on yours?

I would really like to see your rigger, if you have some pictures you could post that would be cool.

-Mike

 

[Mark Sholund]

MikeP,

The best Props are 1445,1450 Cut down to 45MM,H-6,H-7

Cut down to 45MM. X props are not really any good on my

Hydros. My 21 Carbon is getting cleared presently.I do not

have a digital camera but I will try to get a picture to you.

Got To Go,

Mark Sholund

[email protected]

 

[MikeP]

Got some more work done. The turn fin is made from 10 layers of cloth alternating weave on each layer. Spray glued mylar to a piece of foam for a mold. Pressed, rolled squeezed it in the vacume bag. Came out .092" really stiff has no flex at all.

 

[MikeP]

Got the cowling finished, still need a good idea on the rear latch.

 

[MikeP]

First trip outside.

 

[TomMoorehouse]

I love it mike.... totally cool!

do your sponson tubes go all the way through the sponson?.... cause i'd hate to see ya hit a bouy and have the tube break out the side.

I usually cut my cowls so you dont have to remove them to start the boat.... then just hold it on with radio box tape....

other than that... ive seen these little white plastic latches... it think that they are made by goldberg??? one side you screw into the boat then is swings on to a screw in the cowl.... make sense.... maybe i can get a pic

 

[ggillman]

Mike,

I am hard to impress, But that rigger of yours just blew me away,

Outstanding Workmanship!!!!!

Gene ;D

 

[MikeP]

Thanks for all the nice compliments and support from everyone.

It's finally done.

I have a few more pictures of the finishing touches.

The rear latches are 2 posts that have screws in the ends, there is a piece of piano wire going through the hull that catches the heads of the screws. Snaps on and doesn't come off untill you slide the buttons on the side forward.

Mike

 

[MikeP]

The pipe mount is made with piano wire finished with gun blue, brass tube glued into the foam bulkhead and polished dubro brass wheel collar to secure it.

 

[MikeP]

More pics

 

[MikeP]

Air intakes and water outlet

 

[MikeP]

Rear sponsons attached with body molding tape. I plan to make a 23 deg. vee bottom to test and wanted to be able to remove the rear sponsons.

 

[MikeP]

;D

S#%t still need a boat stand

 

[TimD]

Mike,

That is truly a work of art! Great detailed pic's too!

I suppose a CF boat stand is the next item right?

Tim.

 

[Twin_k90]

Mike,

Thats looks awesome

one thing tho, watch that pipe bracket, one nudge in racing and the pipe could go, i like the look of the speedmaster pipe mounts, never used one but they look the goods.

Dale

 

[TomMoorehouse]

holy cow Mike! thats all i can say holy cow!

 

[MikeP]

Got the boat in the water Thursday and Sunday. I am very happy with the hull, very well behaved great corner speed even crossing wakes. I can only compare it to my friends MAC/SG. I was running a prather 215 55% 2deg pos. strut angle. I was not quite as fast but close. (est speed 60). Going to try and make a 1445 work next.

Problems that came up, the servo mounting screws stripping out the cf. Had to use nut and bolt. The tape on the sponson tubes could be a better seems to move in and out a little. Sponson setting was off a bit.

There are a few things I could use some advise on.

Taping the sponson tubes.

The sponson width is 14" at the inside edges I think this is a little wide. But have no reason to change it. Hmmm..

The back end tends to kick up higher than the front on big wakes (from gas vee hulls). Would be nice if it jumped level.

-Mike

 

[Hammerhead]

Hey Mike!

Glad your happy with it.

Don't you think a 215 is a little small? Most of the guys here who run prathers are running 225s.

In my small boats, I use double sided tape to hold my servos in.

No screws at all. I made little walls about half the height of the servos and taped them in. I have been running my wave slave like this for about 3 years, and have never had to change the tape.

With my big Hammer, I use the same double sided tape to tape in my servo mount assembly. The assembly is made of aluminum. A little heavy for your boat, I think.

As far as taping the sponsons with electrical tape, there is a trick to it.

1: Wrap the tape around the inner pipe until it is as wide as the outer pipe.

2: Cut it.

3: then tape across the outer pipe and the taped part of the inner pipe.

Another thing you could try, is to use the clear radio box tape on the

inner pipe on both sides of the hull. This alone will keep the pipe from sliding back and forth. Then uses steps 1,2,and 3 for the sponson sides.

I measured the time trial .21 rigger that my friend is lending to me.

The turnfin side is 5 1/2 inches between the hull and sponson, and the other side is 6 inches. The hull is 31/2 inches wide so the total width of the sponson reach, inner edge to inner edge is 15 inches.

I think 14 inches is fine for a small course. If you have long straights, you might want to make them a little shorter.

I think that the porposing will stop if you lift your strut just a bit.

Or, changing your screw might do it.

Is the CG 30 % from the transom? I think it will trim out nice between 28 and 38 %. Check it out.

Good luck

Hammer