Cant Failure

[Utica-go-fast]

First post guys; lurking a while and appreciate your willingness to share so much experience.

Question relates to canting. We used the block at three degrees for rears. Ran the body down the board following drilling the holes and it ran straight and the wheels moved toward the heads as they should in both directions.

After my son and I polished the axels and got them reinstalled the body pulls and the wheels are not tracking to the heads anymore.

What have we done wrong? I'm wondering if we overpolished the axels. They are spinning well but not moving away from the body anymore.

Thanks in advance for the thoughts.

 

[Vitamin K]

We used the block at three degrees for rears. Ran the body down the board following drilling the holes and it ran straight and the wheels moved toward the heads as they should in both directions.

After my son and I polished the axels and got them reinstalled the body pulls and the wheels are not tracking to the heads anymore.

What have we done wrong? I'm wondering if we overpolished the axels. They are spinning well but not moving away from the body anymore.

Thanks in advance for the thoughts.

Do you have any other axles you can try with your wheels?

Also maybe see if you get the same behavior when your axles and/or wheels are swapped positions?

 

[Mojo Racing]

Honestly, it could be either the axles or the wheels... Truthfully, I would lean toward the wheels before I think of the axles... That is of course, unless you started sanding with 320 grit and hung on for a long time... If you have after market axles from John, your axles need fine grits, not coarse grits.

Now... Opening up a wheel bore or getting it out of whack somehow is much easier than messing up an axle.

My recommendation is to move your wheels around one position clockwise or counter-clockwise to see if the problem shifts / moves.

You can always do the same with your axles (all but the DFW anyhow).

Good luck

 

[bracketracer]

When you roll a car down a tuning board there's a couple of things that it's showing you. One is how much drift you have, but that can be altered if one rear wheel/axle assembly has more drag than the opposite rear wheel/axle. If you were testing originally with unpolished axles, that may be what got you to believe that the car was tracking straight. Probably a better idea to test with polished and lubed parts?

Try as VK said and flip them side for side or possibly just rotate one axle at a time either a quarter or a half a turn and see. If you're running stock BSA nails, they're not really round so they might cause a concern.

Probably overkill for a scout car but something like this is where the LightninBoy test isolates the drill alignment from wheel drag or axle issues so you have a better idea which dog bit you.

 

[BulldogRacing]

did you have the weight on the car during both tests?

 

[Utica-go-fast]

Thanks very much guys.

We took purchased axels and polished them a bit more because they still looked rough.

I will rotate the wheels and also borrow axels from a different car that performed well. I can also put a micrometer on both sets of axels to see how different they may be diameter wise.

Used John's black ice for bores; don't think that would be it.

Bracketracer, yes I did use stock for post drill test and polished for post construction. That could be it.

Bulldog, I did use the weight in both tests, almost 4 oz rear although the COM would have been a little different. It's now about 5/8 from rear axel for new derby magic track. We built your jigs. Thank you!

A couple of days before I can test as you all suggest but will report back. Thanks for the ideas!

 

[Utica-go-fast]

Thanks again for the help guys!

My other set of axles were narrower than those I was having trouble with.

I reversed rear wheels on same axles without migration to the axle heads.

Then used the alternate axles with the same wheels. Still no luck.

Then used alternate axles with alternate wheels and the wheels migrated out beautifully.

So as Mojo Racing suggests, we must have messed up the bores somehow.

I've noticed that the wheels just completed with the just completed axles will spin for much longer than the old ones, but they sort of rumble. They sound a bit like rolling your tongue to sound like a drum. The old ones don't spin as long but they spin much more smoothly, no jitter.

At any rate, problem now solved.

Thanks again for the help! Any additional thoughts appreciated.