Body shape help!

[Quicktimederby]

For the most part I have been a plank car style builder. I'm trying to broaden my skills and not having to much luck. What I'm struggling with is getting each side balanced, or mirror the other. Is there a trick or is it really this difficult? I can get them close but just not perfect. Let me hear what you got inside your minds!

 

[Skippy Kicky]

I don't know if this is too elementary, but when I have attempted shapes I have cut out a peice of paper the exact size as my block. I draw the shape I want on one side, fold it in half, then with scissors cut the shape. I can then use the paper as a template. I like this way because I can play with different designs. The wood grain can mess with your perception of balance. Once I think I've got it close I spray a light coat of primer to hide the grain to fix any unbalanced areas.

 

[Downslope]

Great tip Skippy

 

[Chief]

I pretty much do the same as Skippy but instead of cutting the paper, I sand the block with 400 (because of the wood grain) then I just use an embossing tool to trace the design, and make my cut from there.
QUOTE=Skippy Kicky]I don't know if this is too elementary, but when I have attempted shapes I have cut out a peice of paper the exact size as my block. I draw the shape I want on one side, fold it in half, then with scissors cut the shape. I can then use the paper as a template. I like this way because I can play with different designs. The wood grain can mess with your perception of balance. Once I think I've got it close I spray a light coat of primer to hide the grain to fix any unbalanced areas.[/QUOTE]

 

[B-4 Racing]

If you want to use the paper pattern, get some kids rubber school glue (Elmer's) and attach pattern to block. After cutting, paper peals off and remaining glue ball right up and is removed easily by rolling your finger over it.

 

[Quicktimederby]

Great idea's guys. I did graduate elementary school, I think. So I will use all this info. I think Skippy called it, I think that the grain in the wood is playing mind games with me!!!

Thanks for the help keep the ideas coming!!

 

[5js]

I do the same as skippy - it's odd though cus sometime a take a 7" long piece of paper - fold in half - kinda draw the curves I'm looking for - but when I open it - it's not like I really wanted - but hey, paper is cheap (and keeps the loggers employed) - so grab another and try again. Sometimes you just see one that says - I gotta try this. Just remember the things to a fast body style - like keeping flex at bay. I think many try to get real thin (including myself) for aero - but they lose more in flex then they gain in aero. Suppose this is just a hypothesis - but it sounds logical. I remember posts from John that said you don't need to get to 1/4" to be fast....

 

[Guest]

I do the same as skippy - it's odd though cus sometime a take a 7" long piece of paper - fold in half - kinda draw the curves I'm looking for - but when I open it - it's not like I really wanted - but hey, paper is cheap (and keeps the loggers employed) - so grab another and try again. Sometimes you just see one that says - I gotta try this. Just remember the things to a fast body style - like keeping flex at bay. I think many try to get real thin (including myself) for aero - but they lose more in flex then they gain in aero. Suppose this is just a hypothesis - but it sounds logical. I remember posts from John that said you don't need to get to 1/4" to be fast....

I have a couple that are 3/32" thick! /images/boards/smilies/thumb.gif I can't say I noticed any flex and they were competitive. I did it just to try it. It worked, but I would stick with the more conventional way of building. No room to drill axle holes when they are that thin........... axles have to be done in a different way.

 

[5js]

whoa BSB - 3/32" - any reinforcement or just a solid plank? Guess it depends on if you hollow out or not - but regardless at 3/32 i'd be a bit nervous - IMHO.

 

[Guest]

whoa BSB - 3/32" - any reinforcement or just a solid plank? Guess it depends on if you hollow out or not - but regardless at 3/32 i'd be a bit nervous - IMHO.

No re-bar in it at all...........just a plank! There was no need to hollow out. 3/32" is the same thickness as a set of .093 axles.......now that's thin!

 

[5js]

hmm - it's just interesting BSB. I am guessing you were looking for an aero advantage by going that thin - but how much are you gaining and how much risk are you assuming? Interesting thought. I think I'm gonna try a car that tapers up to 7/16" in the rear and power it with lead - just to see home competitive it is against a similairly prep'd 1/4" car powered by tungsten. I'd speculate that it's closer then most would expect - IMHO.

 

[Guest]

Mr. Hankey, Roswell, and Toxic were cars I ran at PWDR and they were all that thin.

 

[Guest]

hmm - it's just interesting BSB. I am guessing you were looking for an aero advantage by going that thin - but how much are you gaining and how much risk are you assuming? Interesting thought. I think I'm gonna try a car that tapers up to 7/16" in the rear and power it with lead - just to see home competitive it is against a similairly prep'd 1/4" car powered by tungsten. I'd speculate that it's closer then most would expect - IMHO.

You don't know unless you try.........They were a lot stronger than they looked! 7/16" is pretty thick........sure you want to go there?

 

[Downslope]

I am still eating the glue like in Elementary school. Why waist it by balling it up.

 

[5js]

........sure you want to go there?

Sure - why not. It's just something to try - make wedge that is 7/16" in the rear and filled with lead just to see how the times compare to a 1/4" car filled with tungsten. Just something different to try /images/boards/smilies/smile.gif

 

[Quicktimederby]

Well just putting a couple coats of clear on my next Eliminator or Unlimited. It is the Eliminator car I ran at the man of the mountain. It was fast but ugly. Now it's pretty and hopefully still fast. It has a similar look to the Goat and Zeeb cars. Sorry guys I am not that original.

 

[Radioactive Racing]

While we're talking body shape... What's the deal with narrowing or notching the DFW side of the car body? I suspect that is to allow the DFW to hit the rail faster and keep the rear wheels off the rail??? I tried that w/ one of my recent builds and the car was dirt slow. Are there any tips or warnings when attempting this process? Any suggestions for how much to narrow? Thx.

 

[Chief]

It is suggested to narrow the DFW side a 1/16". and you are correct,in that the idea is keep the rear wheels off the rail. However, with the car being "dirt Slow" there can be several other possibilities for that. What I am finding out is that tuning is critical..i.e. too much steer or too little steer etc.

While we're talking body shape... What's the deal with narrowing or notching the DFW side of the car body? I suspect that is to allow the DFW to hit the rail faster and keep the rear wheels off the rail??? I tried that w/ one of my recent builds and the car was dirt slow. Are there any tips or warnings when attempting this process? Any suggestions for how much to narrow? Thx.

 

[5js]

I'm not near the expert as others, but you inset the DFW to keep the rears centered on the rail. You want to ensure the rears don't impact the rails.

 

[Quicktimederby]

You are correct on the narrowing the FDW side to keep the rear wheels off the rail. However by adjusting the FDW in or out relative to the body adjust where the rear of the car will track. I posted this somewhere but I will explain it again. In proxy racing you want to make your car as easy to stage as possible,(rear centered) and you want your cars staged the normal way they travel down the track. The best way I have found to get the rear of the car centered in motion is by doing a slow roll down the track and watch where the rear of the car is positioned while in motion. If the dominate side rear wheel is closer to the rail than I need to move the FDW in closer to the body which will move the rear dominate side away from the rail. If the non dominate rear wheel is closer to the rail than I need to move the FDW away from the body. Adjustment can be made by either notching the body or using a spacer. If you don't have a track to do a slow roll on use a yard stick and let the car gravity roll on it to make sure you have the clearance you need.

While we're talking body shape... What's the deal with narrowing or notching the DFW side of the car body? I suspect that is to allow the DFW to hit the rail faster and keep the rear wheels off the rail??? I tried that w/ one of my recent builds and the car was dirt slow. Are there any tips or warnings when attempting this process? Any suggestions for how much to narrow? Thx.