Cub Build

[Chief]

I think it is fantastic that you are a stickler for the rules, most honest people are. I think you are going to have at a minimum of two issues...
1st, if you search and ask (which you have) and you and your son build a car following the advice here on the forum, your chances of blowing the other scouts away are Xtremely great. (I am talking car lengths) However, there is a chance that even though you have followed the rules someone will call you a "Cheater" as a lot of us have.

2nd, You need to be VERY careful as this particular hobby is XTREMELY addictive and you could quite possibly get hooked for life in the world of pinewood derby racing and that is ok as we have the NPWDRL.

 

[MacDaddy]

Mestanly- I'm on the fence with the lube. I am leaning toward the idea that if the oil application ends up dry then it is a dry lube. Also I am now gravitating toward cutting my own grooves out. It now seems more simple to drill and cut out the channels to view the axels than cut a part of the block and glue it to the front of the car. I am now trying to decide if I should make the back of the car 5/8 high and 3/8 behind the rear axel to stack the tungsten up behind the rear wheels or keep it at 3/8 high and 5/8 in. in length behind the rear to just make two rows of tungsten rather than stack. Maybe just make more cars.

Chief- I'm guessing this is how the addiction starts?

 

[HurriCrane Racing]

Keep the weight low in the car if possible.

 

[ngyoung]

2 rows of 5 or 6 1/4" cubes behind the rear axle would be best. For a kids car going between 3/8" and 1/2" thick body will keep it from getting too fragile. You don't need to go any thicker for fitting weight. For the league cars there are some that are ultra thin but your scout will have to be pretty careful handling it if he wants to push it past 3/8".

 

[MacDaddy]

I talked to my son at dinner tonight about the two design options and he wants to go with the loswer profile just like you guys are suggesting. Thanks.

 

[txchemist]

The trade off between stacking cubes to move COG way back vs. just two rows one high and a thinner body is that the thinner will be faster, and most likely more stable.

 

[HMH Racing]

We use a combination of 1/4 tungsten cubes and the flat plates.

 

[MacDaddy]

Looks like we should make weight and a decent COM with the tungsten blocks and putty. Has anyone had success with solid fenders/ I noticed dads has a reverse naca scoop on them and I'm not going to attempt to carve that into a small piece of wood.

 

[HurriCrane Racing]

Lightning Boy is lighting everyone up with solid fenders. The Gee fenders are just easier and a lot less work

 

[MacDaddy]

I got one of my fender rejects and dremmeled out a vent. I'm thinking it would be way too much work for this year and with no test track, I might be doing more harm than good. Then again just putting my fenders on it might do more harm than good.

 

[Boydog]

What does a solid fender look like? Solid in the back covering the wheel cavity?

 

[MacDaddy]

Hurricanes car with the single stripe is what I am cutting out and would be solid. The gee fenders have a small slot in the front of the fender and continues to the wheel. At the wheel the slot is much wider which would create a low pressure. I could attempt to make the same thing by cutting out the fender shape and cutting out the naca scoop. I would then have to glue a thin piece of flat balsa on the back to complete it (my car is too narrow to cover the channel).