Crackerbox Race Setup for DPI and Maus
Crackerboxes

The Crackerbox Class is one of my favorites, it's also the one I have had the most success in. For the past 4 years I have won the National Championship. Crackerboxes maybe one of the slower classes, but they rely on good boat setup and driving skills just like the faster classes in order to be successful. Some even argue it's one of the most difficult classes to do well in. I hope some of my tips will help make this class just a little more fun for my fellow Crackerbox fanatics!

Bits and Pieces

Motor: Matrix ROAR 95
Radio: Hitec Lynx FM
Speed Control: Hitec HFX
Servo: Hitec HS 225 BB
Prop: Octura  X432
Batteries: Fullers Sanyo 2000's

The Basics

I believe all boats should have good sharp edges on the bottom of the hull. Most vacuum formed boats have rounded edges and need some attention to be competitive. The technique I have used is to build up the edges with "Squadron" putty, (you can get it at your hobby shop) let it dry then block sand the bottom and sides to create a crisp outside edge all the way around. When finished you can carefully wick thin CA onto the new edge to give it strength. (Squadron putty is slightly porous and well soak the thin CA up) This process can be skipped with the Maus hull. The edges on it from the factory are sharp enough.

Stiffen the Hull

Stiffen the bottom up. Both the Maus and DPI have flexible bottoms. These boats have a tendency to bounce, a flexible bottom won't help. To Stiffen up the Maus bottom I glued 2 spruce rails (1/4 x 1/8) 7 inches long from the transom forward About 1 1/2 inches apart (see photo). Do not create a rocker in the bottom by doing this. If anything a slight hook toward the transom is OK. Be careful though, NAMBA allows only 1/18th of an inch deviation from the original design. (See photo below)

To stiffen up the DPI, I cut a small hole in the tray right underneath the servo about the size of the DPI logo molded in (see the photo below) .Then I cut several strips of scrap plastic and glue them together stacked on top of each other. The height of the stack should be just less (about 1/8th inch less) then the distance from the bottom of the boat to the bottom of the servo tray. The width of the strips should be narrow enough to fit through the hole you cut in the servo tray. The length about an inch. The idea here is to tie the bottom of the boat to the servo tray to stiffen that whole area. The fact that the stacks of strips is less than the distance from hull to servo tray will add tension to that area firming it up even more. Once again, do not create rocker in the bottom of the boat and don't use to few strips and create to much hook in the hull. A little is OK but again, NAMBA allows only 1/18th of an inch deviation from the original design.

Adjusting your drive shaft for a smooth
ride

One of the best ways I have found to tune in the ride of my boat is by prop depth. The closer the prop is to the bottom of the hull the flatter the ride, The deeper it is the more the boat will bounce around. Be careful though, If you move the prop up too high the boat won't plane and just bow steer. In my experience 1/8th of an inch from the hull to the tip of the prop  is about right. I tell most people who are building a boat for the first time to just tack the drive shaft in until they are happy with the ride, then glue it in good. (see photo)

Skegs?

I tried many different skegs on the Maus Cbox and found that bigger is better. I ended up with a skeg that looked like a dorsal fin from Jaws. The leading edge of the skeg is 7 1/8 inch from the transom. The depth is 1 1/8 inch and the width is... just see the photo below. It looks crazy but I won nats with it.

For the Maus I have found a slightly larger skeg kept the boat from sliding out in the corners. I actually cut the molded in skeg off and replaced it with an aluminum one the same length but 7/8 inch deep. (See Photo)

Rudders

Just hack it off. I cut mine down so that the length of the rudder  is 2 1/4 long. (I use a DPI rudder on my Maus boat too. Don't tell Sam)

The Guts

In the Maus boat I mount the motor 8 3/4 inches from the back of the motor to the transom. (Stiffen the area under the motor if you can). The speed controller goes in back left corner, the servo goes in the back off set to the right in the middle and the receiver in the back right corner. The center of gravity ready to run is about 6 1/2 inches from the transom. (See the photo below).

The DPI Cbox is setup similar to the Maus. However the factory motor placement is preferred. The center of gravity ready to run is about 6 1/4 inches. (See photo below).

That's It!

Well that's it! I hope this helps. Bang for your buck they're a tough boat to beat. Both the Maus and DPI are great boats. The DPI is a little more stable, but the Maus is a little quicker. All in all it's a pretty even match. Both of these boats run very flat for me even through the corners. If yours is bouncing try these tips. If it works let me know. If you have any other questions drop me a line at dcrowe@drcwebservices.com   .

Finally, I would like to point out I am sponsored by Maus Motorsports, Hitec and Fullers Fast Electrics. I've tried to be very impartial when it comes to these boats and setups.  If I have shown any bias it's because my sponsors have the best stuff! If it wasn't, I wouldn't use it. Thanks for visiting ElectricUnlimiteds Northwest and keep checking back for more boat setups. The next boat to be highlighted will be the 1/16th scale unlimited.

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