Last year my son won districts with your help...big thanks! We moved and the new district rules require using the slots and all wheels must be flat, but we can move the slot if it is "bad." Does anyone know what angle we can drill rears using the old silver bullet and still have flat wheels. I have a bandsaw, so we can connect the dots. Also, any help on angles for the DFW would be appreciated since we can't bend the axels but only have to have 3 wheels touching.
Damn Rules
- Thread starter Al321
- Start date
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Vitamin K
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I can't find the post (I think it may have been eaten by the upgrade), but TXChemist had a brilliant method for adjusting DFW drift without using bent axles. It went something like this:
- Build a car. Drill your rears with your 1.5(?) degree cant. Drill the front DFW straight (or with 1.5 degrees of positive camber?)
- Cut the car into two pieces so that the front end is separate from the rear end.
- Apply a slow-setting epoxy (e.g. Loctite Marine epoxy) to the cut ends of the car and use a few strong rubber bands to hold the halves together while the epoxy is still wet.
- Run the car down a tuning board to get an idea of how it is drifting.
- Insert incremental slim paper shims into the cut line of the car, behind the DFW, in order to slowly add toe-in to the DFW wheel. Test on the board each time.
- When your drift gets to where you want it, take the car off the board and let the epoxy cure and harden. The rubber bands will hold it in place at the shimmed level of drift.
- Sand out the join area so it is smooth and seamless (so as not to give a judge something to squawk about, even though you are following the rules).
- Build a car. Drill your rears with your 1.5(?) degree cant. Drill the front DFW straight (or with 1.5 degrees of positive camber?)
- Cut the car into two pieces so that the front end is separate from the rear end.
- Apply a slow-setting epoxy (e.g. Loctite Marine epoxy) to the cut ends of the car and use a few strong rubber bands to hold the halves together while the epoxy is still wet.
- Run the car down a tuning board to get an idea of how it is drifting.
- Insert incremental slim paper shims into the cut line of the car, behind the DFW, in order to slowly add toe-in to the DFW wheel. Test on the board each time.
- When your drift gets to where you want it, take the car off the board and let the epoxy cure and harden. The rubber bands will hold it in place at the shimmed level of drift.
- Sand out the join area so it is smooth and seamless (so as not to give a judge something to squawk about, even though you are following the rules).
LOL wow.
Pro Body Jig Tool to align 4 wheels on the ground $43
http://www.scoutstuff.org/pro-body-jig-tool-new.html#.WIubEVUrJhE
Pro Rail Rider tool $13
http://www.derbymonkeygarage.com/product-p/2025.htm
If this is a physics lesson for the kids I don't understand why the rules aren't: use the BSA wheels, axles, be under 5 oz and watch this
Pro Body Jig Tool to align 4 wheels on the ground $43
http://www.scoutstuff.org/pro-body-jig-tool-new.html#.WIubEVUrJhE
Pro Rail Rider tool $13
http://www.derbymonkeygarage.com/product-p/2025.htm
If this is a physics lesson for the kids I don't understand why the rules aren't: use the BSA wheels, axles, be under 5 oz and watch this
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Thanks! Like this idea. Made me think of something. Might try a test car on a tuning board with a horizontal reverse cant slot on DFW where we can move the axel for steer. One we get the angle, we can drill it in the race car. Won't be prefect, but with good DDFH prep on axels and wheels, might do the trick. Thoughts?
Not to be a Debby Downer, but those tools are cheap and although they may be slightly better than nothing, I think they are a bit of a rip-off. You'd do better if you used Pro Tools like a Goat Boy Axle Bender for the DFW, and the Silver Bullet, or much much better, the Silver Bullet Pro to drill axle holes....
Better to buy the best tool first, instead of filling your toolbox with many paperweights.....
Perhaps in your Derby, those tools may be good enough, and if that's the case, great!
The video is Awesome by the Way, Mark really understands the physics and explains it in such a relatable way, and I like that. However, he does get a few point wrong IMHO....
1. Graphite isn't always graphite. Some is better for burnishing, some is better for racing. I'd recommend Hob-e-Lube for those on a budget, and for those like me who want the fastest racing graphite available, use DD4H Graphite Blend....
1b. Oil, Mark didn't even mention oil! Oil is cleaner, faster, and more consistent for a much greater number of heats. But, the downside is Oil requires an education, You do need some knowledge to understand how to apply Oil correctly.
2. Grooved axles make an important difference, and are, I believe, faster. Why? Axles and Wheels will always have small flaws even after polishing. Many wheels have a void or high spot on one side of the bore, that means on every rotation the amount of plastic touching metal is changing. When you have a grooved axle, less wheel bore comes into contact with the axle, therefore fewer flaws are rubbing in the wheel axle system, giving a better consistent running surface. That reduces friction and equals: SPEED!
Yes Civil War, I'll agree. Measurements are everything in racing. It's why Ray Evernham's 24 cars kicked everyone's butts when I was growing up. For Scouting, I think they do the job. I'm sure for the league they'd fall short.
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