Derby Talk is a forum for Pinewood Derby, Awana Grand Prix, Kub Kar Rally, Shape N Race Derby, Space Derby, Raingutter Regatta and other similar races where a child and an adult work together to create a race vehicle and a lot of fun and memories
After seeing Laserman's car, and him reporting decent results with it, I'm thinking of trying a new fender concept. The concept is fenders that completely enclose the front wheels. The issue is that it could appear that I'm trying to "hide" something from the judges, or they could be deemed illegal for one reason or another. So I want a way to have them attached to the car, but easily removed for wheel inspection or if I need to eliminate them for one reason or another.
They come ff at the stop section and go flying, never tried the thumb tacks tho.
I tried them in 2010, not thumb tacks, put small pins, made from steel rod. just not a tight enough fit to get them to stay, I tried tape, that would hold for a few runs.
but they also broke too trying to take off and put back on.
Super glue and epoxy was all I had success with.
All you can do is try your idea out and make something and trial and error and see if you can get it to work. I'm sure wheres theres a will theres a way.
I'm kind of thinking of maybe doing an overbody. Have a ladder type car frame, with a balsa body that will include the fenders. The body will have balsa pieces that fit into the ladder slots of the car frame. My biggest concern with this is that parts of the balsa body will be very thin.
I'd like to see how this shapes up! A good CA glue coating can help strengthen balsa. How thin do you imagine the thin sections to be?
DerbyAddicted wrote:I'm kind of thinking of maybe doing an overbody. Have a ladder type car frame, with a balsa body that will include the fenders. The body will have balsa pieces that fit into the ladder slots of the car frame. My biggest concern with this is that parts of the balsa body will be very thin.
Here's something I've considered ... but haven't implemented.
You could attach two small pegs - like dowels - to the side of the body in front of the wheel. Drill holes on the inside of the fender that align with the pegs. Make the holes slightly smaller than the pegs so that there is a little force required to push them on and take them off. If the fender is made of pine, that should be all you need to hold the fender on. If the fender is balsa, then I think the fit would loosen over time and you may need to augment with tape to hold the fender on. You could also experiment with applying CA glue around the holes to strengthen that area and keep the fit tight.
For the peg/dowel material - there are lots of possibilities but I would consider carbon fiber. Carbon fiber rod is available in many diameters, its lightweight, rigid and easy to cut down to size.
LightninBoy wrote:Here's something I've considered ... but haven't implemented.
You could attach two small pegs - like dowels - to the side of the body in front of the wheel. Drill holes on the inside of the fender that align with the pegs. Make the holes slightly smaller than the pegs so that there is a little force required to push them on and take them off. If the fender is made of pine, that should be all you need to hold the fender on. If the fender is balsa, then I think the fit would loosen over time and you may need to augment with tape to hold the fender on. You could also experiment with applying CA glue around the holes to strengthen that area and keep the fit tight.
For the peg/dowel material - there are lots of possibilities but I would consider carbon fiber. Carbon fiber rod is available in many diameters, its lightweight, rigid and easy to cut down to size.
Not a bad idea. The fenders will be balsa, but the pegs could be installed/glued to the fenders and then press fit into holes drilled in the body.
What about little screws that you can run in and out. A touch of elmers and they will be snug time after time.
Finishing nails with the head exposed slightly so you can grab it and pull it out. Make the hole in the fender bigger than the nail. The hole in the car a size that the nails slide in easily with no slop then use elmers to hold them in. They'll come right out with a pull from the needle nose and fit snug again when u need to reinstall. No need to reglue as they don't allow that at weigh in anyways.
