X/F-Hydro All Carbon Time Trial Rigger

[RaceMechaniX]

I reached the limits of what the trusty Eagle 67SG with 90 power was going to take so it was time to build a little stouter 2-lap specific rigger. Pics from Mario taken at a Cinci TT a couple years ago.




The entire boat was drafted in Solidworks including all the small details of VAC 91, fuel tank, linkages, etc.


I model all the servos, mounts and pushrods so I know where the holes for the Woods seals need to go.



Several parts including all the servo trays and engine mounts were 3D printed from carbon reinforced nylon.

 

[RaceMechaniX]

I bought 2x4' sheet of carbon sandwich material for the sides and bulkheads and a 2x4' sheet of 1/32" for the top and bottom skins. I created 2D DXF files for all the major parts and had acrylic templates laser cut. The acrylic templates were double sided taped to the carbon material and rough cut out.


Using a router table with a flush trim bit I cut all the parts to final size. Next up the sides were bonded to the bulkheads using a very accurate straightedge.



The bottom skin was lined up and masked so I know where to scuff where the bulkheads meet the skin.



Next I bond in a tubular piece of carbon for the nose and add two additional pieces to stiffen up the front. I joke, but I think this could drive through a piling and only have scuff marks on the nose.

 

[RaceMechaniX]

Although it may be overkill I liked the idea of an engine girdle to help strengthen the engine compartment. I copied the traditional design and masked the area around the girdle where I did not want to scuff the carbon for bonding.


With the girdle in, the blue head was test fitted to make sure a starting belt can get in and out. Notice the motor mounts. These are similar to CMDi's with rubber grommets going through the tub sidewalls, but the spacers and mount are one piece and dead on the money. This makes them very stiff and light.



Before the top skin is bonded on, two lid liners (shelfs) were bonded in so the radio box and bait box lids would be flush with the top.


Next the top deck was bonded on.


Prior to the top skin going on the radio hardware was installed. A pair of ProModeler mini servos for throttle and mixture plus a standard servo for steering. Later on I trimmed all the servo leads short to make the radio box tidy. I call that the "Terry Keely treatment"

 

[RaceMechaniX]

Here is the radio box after tidying up.


Onto the transom hardware. I am using a mix of stuff. The rudder is a Grim Reaper gas rudder which is my favorite for 67-101 size riggers as it ties in the transom to the side of the tub. The strut brackets are standard Speedmaster with some additional holes to take some weight out. The strut is from Lenny Blake of Rum Racing Products.



What the business end looks like when complete.


A single JAE style ski on the bottom. It did not come out as nice as I hoped, but its removable in case we need to make changes.



A Pat Gill Fuel Doctor was tucked up near the bulkhead and took a fair amount of massaging to tuck it under the 91 VAC carb.

 

[RaceMechaniX]

Fuel lines are big and short.

Walt made a tank that should hold enough juice for a couple needle setting laps and then a couple full boogie laps. There is foam packed in on all sides of the tank for cushioning.

1/32" carbon lids cover the fuel tank, radio box and bait box. All were routered out using acrylic templates like the other parts. Fitment was line on line.


Several pipes were fitted to check position on where to put the rear mount. Only pipe I am missing is the Bouchie 91/101. What do you say TJ Hammons?

 

[RaceMechaniX]

67 Muffled.

Mac 13cc.


The sponsons were made from 1" Divinycell foam cores with the same sidewall sandwich material as the tub. Admittedly, these are too heavy when the skins are applied, but for a first rip around the balloons they will work. The ridepads are 3D printed and removable for fine tuning.


Threaded aluminum inserts are bonded into the turnfin sponson for the turnfin.


The turnfin was designed, laser cut, bent and sharpened. The first one maybe a little too big so I will scale and make different versions.

 

[RaceMechaniX]

Here is the almost finished product:

 

[RaceMechaniX]

Always good to have back up motor options so the different mounts were printed to shoehorn a 91 M-Line in.

 

[RaceMechaniX]

For the initial runs I will start with a broke in 91HR/VAC where I know the settings to get the hull dialed in without worrying about the motor. Valdosta will be the maiden runs.

 

[Wasted wages]

Man, that is just badass.... looks like one for the record books!!
Good luck with it !!

 

[longballlumber]

Cool Stuff Tyler!

 

[RonVanWagnen]

Very nice, you are a true craftsman.

 

[Glenn Quarles]

Yep that is officially awesome!!! Can’t wait to see it run!!

GQ

 

[ALLAN YUEN]

How much of weights overall Full load ?

 

[RaceMechaniX]

How much of weights overall Full load ?

Allan, keeping the weight and other specs under wraps.

 

[Wasted wages]

I like your "funny car" in the background....
Electric ?

 

[RaceMechaniX]

I like your "funny car" in the background....
Electric ?View attachment 313165

It's a gas powered, chain drive funny car. A true weedwacker or chainsaw motor. It was given to me by a boating friend for restoration. It's on the "to do" list after I get finished with the boat builds.

 

[Terry Keeley]

Very cool build Ty, I like your idea of having the templates drawn up and laser cut, man I wish I had your command of Solidworks!

Just curious what that plate you're using for the sides is made up of, two layers of 6oz cloth/side? Also, what's that bonding resin your using, it looks white?

Again, amazing work!

 

[Kent Fowler]

Allan, keeping the weight and other specs under wraps.

Holy cow very nice build !!! at this point weight doesn't matter.

Kent

 

[RaceMechaniX]

I can say it is several pounds lighter than my heat racing F-Hydro and that's a competitive weight for a single 101 boat.