Industry Figure | Berkeley | Wild Dagger
Wild Dagger Questions and Answers
I get some good (and some lame) questions via email. Here are some of the good ones and my answers.
Locking the Differentials
BrutalBrody asks: "Can you explain to me in detail how you locked the differential?"
Berkeley answers: Yes and no. I'll explain how the differential works and why you should consider locking it. Plus, I'll tell you how I did it. Keep in mind, however, that I used materials at-hand and there are lots of ways to accomplish the same thing.
Take a look at the Wild Dagger assembly instructions. The first step, Step 1, is to assemble the "Differential gear" and that's what were talking about.
It's called a differential because it allows the two opposing wheels to spin independent of one another, or not depending on one another, or differentially. Pick up the car and spin the wheels... they aren't connected to each other, so you can spin them any which way. If you turn on the motor and both tires have traction, the car will move. But if you lift one tire off the ground, all the power will go to that no-traction wheel and the other tire (the one with traction) will get no power. The car can't move.
Locking the differential prevents wheel spin when one wheel loses traction. To lock the diff, you need to prevent the three "small bevel gears" (MA11) from spinning on the "Large bevel gear" (MA10). You need to turn the entire assembly in Step 1 into one piece.
A few methods have been used so far. Filling the assembly with Elmer's (white) glue failed as did filling it with bits of paper-clip wire. Stuffing rubber bands into the rear differential has worked for me. Some speculate that hot glue, which is both tough and flexible, should work even better (just don't plug the little hole in the center). I also locked the front differential. With both front and rear diffs locked the traction is incredible. You'll trade steering for traction in the front, though. I have since unlocked the front to regain the better steering.
Painting Tips
Dan Jones asks: "I just bought a Wild Dagger, and I'm looking to do a nice job on the body. I am impressed by your paint job [I love this guy!]. Your truck looks great (so does Mark's). I am wondering if you did the paint yourself, or had someone do it. If you did do it yourself, do you have any tips for me?"
Berkeley responds: Make sure you buy paint designed for use with polycarbonate (lexan). The car comes with a clear polycarbonate body and is ready to be painted on the inside. You can do the best job with spray paint, but some colors (for example: the pink I used for my lovely dots) don't come in a spray.
Remember that you're painting the inside of the body when you mask. Use the expensive blue masking tape designed specifically for painting; it comes off easily. I masked the windows first (silver), then the window trim (black... I didn't use the included trim stickers), then the dots (pink). I first sprayed yellow, then brushed pink, then sprayed black, and finally sprayed silver. Use many light coats.
Follow Tamiya's instructions for preparing the body for paint. Just before spraying, some people warm the spray can in warm/hot water (don't make the can hot, or it will explode and kill you) and they heat the inside of the polycarbonate car body with a hair dryer. This is supposed to make the paint stick better and it probably works well. I didn't heat the body and my paint is coming off in places.
Remove the nearly-invisible protective plastic film after painting, but before applying the stickers.
Bearing/Shock Upgrade
Dan with a follow-up: "I am also thinking of upgrading the bearings and shocks before I assemble the truck. What do you think?"
Berkeley replys: I think you ought to do what I did. The Wild Dagger, in Tamiya's effort to reduce the cost of the kit, includes all plastic bearings. These will eventually wear out and will need to be replaced. Why not do it now? To replace the bearings, you'll need to completely disassemble the kit. It can be done, but what a pain! The Wild Dagger is turning out to be a much tougher and longer-lasting car then I would have guessed. Do yourself a favor and buy the good Teflon sealed chromed steel ball bearings now.
Only one of our eight Wild Daggers has upgraded shocks. The stock shocks make the car a little bouncy, but it's not that bad. Shocks can easily be upgraded later, so save your money for now.