Vac-U-Cracker 1:10 Scale Crackerbox Kit


Feedback, Tips, & Recommendations From Owners



Matt uses a Uni-Bit to drill extra holes in the liner.  Weight01Matt.jpg (24405 bytes)
Says this bit helps avoid splitting the plastic. Shaves off a bit of weight as well. Weight02Matt.jpg (42136 bytes)

Trim, & Balance

The center of gravity of the boat should be centered on the 2nd raised rib in the floor behind the motor mount as shown. Also balance the boat from the point of the bow to the center of the stern. Then, adjust the CG as needed for your race course and performance you seek. A too-forward CG will cause the bow to dig in, slowing the boat and causing it to "bow steer" in a turn. A CG too far rearward will cause the boat to porpoise while running (bow jumps up and down) and may make the boat more prone to flip in a turn as it bounces against waves. CGPhoto1.jpg (26878 bytes)
Check the CG by suspending the sides of the boat with your fingers at the 2nd full rib as shown. The boat should hang level when supported here. Adjust the battery forward or rearward to balance the boat. Then, check the front-to-rear balance, adjusting the battery left or right to level the boat.  CGPhoto2.jpg (35178 bytes)
The factory stainless steel trim tabs may have a very slight down-angle when installed. If necessary, lift them a bit so they are parallel with the bottom of the boat. Angling them down may slow the boat but improve stability. Angling them up slightly will reduce resistance yet still have an effect in a turn. Use a ruler along the bottom of the boat to check their alignment. 
This is a basic setup. No water-cooling. Battery, receiver, ESC, and servo set up so the model is balanced if you support it from the tip of the bow and the rear center of the hatch opening. Cracker02.jpg (46520 bytes)
Battery is attached with Velcro. Adjust battery left and right to balance the boat. Cracker03.jpg (45304 bytes)
The stern is flat, allowing you to locate your battery and hardware anywhere you wish. You could move the receiver and ESC forward of the battery to move the CG Center of Gravity forward, or modify the battery. Cracker04.jpg (39427 bytes)