My First entry to PWD

[notfastenough]

Here is my entry to the world of PWD. My son won the pack and county races placed 16th of 40 in the district. It runs 2.2843 average on best track (32ft I think). The district winners averaged 2.2612 so i have to figure out how to get there any input would be appreciated. I run rail with three wheels touching no cant on back 1.5 on front for steering. Derby doc can really paint mine is montecoated (I am no where near talented enough to paint). What is the advantage to people running three wheels on same side of car?

[roosclan]

May 3, 2009 17:55:20 GMT -6 notfastenough said:

Here is my entry to the world of PWD. My son won the pack and county races placed 16th of 40 in the district. It runs 2.2843 average on best track (32ft I think). The district winners averaged 2.2612 so i have to figure out how to get there any input would be appreciated. I run rail with three wheels touching no cant on back 1.5 on front for steering. Derby doc can really paint mine is montecoated (I am no where near talented enough to paint). What is the advantage to people running three wheels on same side of car?

Nice looking Detonator there! Without knowing more about the car, it will be somewhat difficult to know how to help you improve it

• what is your Center of Mass? You want it about an inch or a little less in front of the rear axle.
  
• what kind of alignment did you do on the wheels? Just because you didn't can't the rear axles doesn't mean they don't need to be aligned.
  
• what tools did you use to work on your car? Do you have any DerbyWorx tools?
  
• what kind of axle prep and wheel prep did you do?
  
• what type of lube are you allowed to use?
  

As for the painting, if you can push a spray can nozzle, then you can get nice paint jobs. Maybe not like DerbyDoc's, but they can turn out decent, especially if you use his stencils.

My 7y.o. son did this with a spray can of black paint, DerbyDoc's stencils, and then some color shifting paint (which can also be found in spray cans):

[khouse]

Make sure your car weighs 5 oz. First thing I would do is move all your weight as far back as you can. Bunch them all up. Cant your rear axles. That would be a start. Good luck.

[derbydominator]

Congratulations on your pack and county wins! Very impressive!!!

Car looks awesome! Tory (DerbyDoc) does some great work for sure!!!!!

The advantage of the three wheels on one side is for the two rear wheels to share wind resistance. Sorta like drafting in Nascar I guess. Did you notch in at the FDW for the rail rider? Also, any certain reason you did not cant the rear wheels? One of the reasons for the rail rider technique is to get the rear wheels off the guide rail. You need to cant the rear wheels and notch in the front to best apply that technique. How did you cant the front? Most are going with what is referred to as positive camber on the FDW where the wheel is riding on the outer edge of the wheel which allows the wheel to ride on the guide rail so to speak as opposed to rubbing along the top. The rear wheels would have negative camber where you are riding on the inner edge of the wheel.

Darryl

[notfastenough]

I do have the front wheel set in slightly from the back, in fact i have it cant the wrong way (negative) now that i know that it might help some. I used bullet lube and as far as wheel prep i didn't do any thing they are derby works 1 gram wheels. I used nickel plated axels slightly polished I might could get away with a 1.5 cant on back axels but we suppose to have 3 wheels flat. He didn't notice the front cant so probably wouldn't notice the same on back. The cog is about 3/4 in front of the rear axel.

Darryl the car in your avatar is very nice.

roosclan your son might be the next picasso

[notfastenough]

Forgot to ask is the extended wheel base a big speed enhancement?

[notfastenough]

Darryl just realized I ordered a car from you the "BLUE MOON" hook it up right....for my next year car. www.derbydominator.com/

[the woodbutcher]

I will tell you that if this is your first entry the others are in for trouble!
You have put together a good running car. The thing is you need to be able to repeat it. Keep careful notes of your build, and make several while your at it.
Keeping the wheels flat doesn't mean they can't be aligned properly. I've spent way too much time thinking of ways to do it without bending the axles. It can be done but bending them is a lot easier. Truth is, if you prepare your car body carefully, it won't take much to tune it in.
These guys are right, the main principle to RR is to keep all but one wheel off the rail. And the one remaining wheel (from the "driver's perspective") is turned to the right so as to steer the car into the rail. It is also leaned over so the inner tread is slightly raised. When the edge of the wheel touches the rail it is less likely to bind and so on.
All these "secrets" to building a car are great to know, but unless you can execute them properly they do you no good.

So, build some more. Take lots of notes. Spend time talking about the physics of the car with your kid. You never know, you may have a Nobel prize winner all thanks to the pine wood derby!