How do you get them to roll straight when swapping to brass axles

gtaman Saturday, 7/8/2017

I have swapped to brass axle tubes a few times and I honestly can't get the car to roll straight when done. 

I basically put the tube in the stock slot, and use a plier to crimp the axle into the tube so they don't fall out, however when done the car rolls to one side.

I am not a pro racer and don't pretend to be, but I would like for the car to roll straight when I put a lot of work in.  

Any tips appreciated.

I put a lot of work into this guy but alas after cutting up 3 fte cars and a well worn thunder roller it does not roll straight.  Starting to make me want to give up on customizing for racing with brass tubing.




Discussion

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Mopar_Mafia 7/11/17

gtaman - I assume that maybe the problem you are having is run-out tolerance on the outer edge of the wheel? Or is it more like a crab walk between front and rear?

Nice rig btw

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gtaman 7/11/17

I think in crimping the brass to keep the axle in slightly bent the axle

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VoxxerRacing 7/12/17

"  I basically put the tube in the stock slot  "   Problem # 1    How do you know that the " slot " is level and parallel to the chassis.   More important - how do you know that the back " slot " is parallel to the front " slot " ?????

Problem # 2  UNLESS the rule state, that the racer must be " as " in package - GET RID of the center wheels !!    

With 6 wheels - you now have 24 axis points that you have to worry about, Plus, two extra wheels and the friction they cause.  With 2 axles and 4 wheels, you now only have 16 axis points to worry about.   Up, down, left and right, for each wheel.  

Problem # 3   Thunder Roller has most of its weight in the front of the car...Again check rules, IF allowed or not stated, run the car backwards.   The weight that is now in the back, gives you more momentum. 

Problem # 4    Small front wheels !!  With all the weight up, the racer, will be pushing.  Second, again, with the weight up front - if wheels are NOT level and parallel, your problems front the start, will multiply !!!

Voxxer Racing    

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gtaman 7/12/17

"  I basically put the tube in the stock slot  "   Problem # 1    How do you know that the " slot " is level and parallel to the chassis.   More important - how do you know that the back " slot " is parallel to the front " slot " ?????  

What else do you have to go from?


I definitely get that Thunder Roller is not the best laid out vehicle to race for weight distribution

  • Your looking at it from in the race car. Think " outside " the box. Alignment tool. Just like a real car. — VoxxerRacing
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redlinederby 7/14/17
Site manager

Sadly enough, most of the alignment jig posts are now missing photos (FU, PhotoBucket)...but using an alignment jig of some sort will certainly help. It should at least make the axles parallel with each other...but...not necessarily parallel with the chassis, which is another trick entirely.

You can make a jig out of various things. All you need is just 2 grooves that are parallel. Some guys have used pencils/dowels in a box. Some have just routed out grooves in a board. And, of course, those with resources have made their own from plastic or 3D printed them.

No matter what you do, it's better to have something than nothing. It might not make you crow straight, but straighter than eyeballing it.

  • Two thumbs way up, I keep runnin into uses for a 3d printer — gtaman
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redlinederby 7/14/17
Site manager

On the tube crimping thing...when I tube my axles, I grind a little hole in the middle of the tube, making a little "window". I put the JB/glue in that hole and then slide in the car axles (then put the whole thing in the alignment jig). This usually holds them pretty well and does't require you to crimp anything.

And again, there was a photo of this but it's gone. I'm going to work on re-doing some of the how-to topics with photos.

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LeagueofSpeed 7/14/17
Event coordinator

My jig is straws glued together and graph paper which gives me a grid, and I also just place the chassis right on the graph paper and line-up the outside/inside of the wheels with the graph paper grid....works pretty decent.

  • Now thats a tip I am going to try! Thanks! — gtaman
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gtaman 7/14/17

I have one of these, just need to use it better!


http://redlinederby.bigcartel.com/product/raab-wheel-axle-jig

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gtaman 7/14/17

A quick google search brought up the old imges i believe

https://www.google.com/search?q=pinewood+alignment+jig&rlz=1CDGOYI_enUS659US659&hl=en-US&prmd=sivn&s...

  • Awesome...might have to do a grab session before their cache is refreshed — redlinederby
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redlinederby 7/15/17
Site manager

Here is the pencil jig one guy made. Probably works pretty well, as long as everything is square.

http://img.redlinederby.com/mmd/a1fd2af5.jpg

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LeagueofSpeed 7/16/17
Event coordinator

Here is my jig GTA, the straws can be moved to accommodate different wheel bases or like I said, sometimes I just use the graph paper grid. The toothpicks are a great way to get the inner wheel spacing/variance the same.

https://www.redlinederby.com/media/img/5b82070a.jpg

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