Rear wheel allignment help

[B_Regal Racing]

It does not appear to be. When running on a tuning board with a rail, the rear follows well without drifting to either side. I'm thinking the major source of the wiggle was gap related. I don't typically test the car backwards, but when I was running down the list you provided, I was looking closely at everything. The wheels do migrate to the head when running forward. Never had a wiggle such as this that I could not correct with steer and usually 4 or 5 inches over 4' does it. I can induce wiggle when trying to reduce steer to numbers you all run, I'm just not there yet.

(I don't have a test track yet, so high speed tests are performed as a result of racing)

 

[Kinser Racing]

I meant while running in reverse is there steer on the DFW or is it a straight axle. You'll get the push from the steer. Am I making sense?

 

[ngyoung]

I meant while running in reverse is there steer on the DFW or is it a straight axle. You'll get the push from the steer. Am I making sense?

It seems that you would want to check your rear alignment before you start adjusting DFW steer for RR. That will avoid what you are talking about steering the wheel into the body when in reverse. I would expect that the rear wheel opposite the DFW would move in when going in reverse. If you've already set an aggressive steer it is turning into that back wheel when going backwards.

@B_Regal I assume if you used the Revell jig your rear axles are flat and that would also make it very easy for the car to push into that back wheel compared to a canted axle going in reverse.

As for running a new car I don't think that is such a big deal considering how many people do their own upgrades between events anyways.

 

[Guest]

Hey B Regal,

Awesome signature!

LOL. Too funny!

 

[Guest]

I feel that any amount of anything (especially on the outer edge of the rotating disc) will throw off the balance way more than something near the bore.

 

[bracketracer]

Would using the same Pro body tool and a small drill bit for a shim be feasible for the rear hole canter if I made new holes? I do have room to make new holes adjacent to the original ones. I am not worried about my CoM, I can adjust if needed.

I know a local guy that drills his axle holes that way. His sons have fast scout cars.

Dang BR,

You have a very dry wit.

Is this what they mean about a backhanded compliment?

No, seriously, he uses a drill bit under the opposite side of the body to get the cant he needs using a pro body jig. His boys finished second and fourth at the district finals. The car that won was clearly using oil at a graphite race.

You can tell that I wasn't being sarcastic because there was no smiley at the end of the sentence!

 

[Guest]

I did take note of the lack of smiley punctuation by you, but it is hardly the empirical evidence that I have become used to from you.
Who is this and what have you done with BR?

 

[B_Regal Racing]

The rear axles are straight with canted axle holes. Withot going into too much detail, I use to jigs tied together with an aluminum bar. I raise the opposite end being drilled with alumunim rod (.090") to get the 3 degree cant. Tons of room for error, so it is hit or miss if I get it right. You can only tell after the car runs. I know a drill press is inexpensive compared to tracks, timers, weights, "time", etc.; why I do not have one already is beyond me.

<--- "Hammering Axles" - Ain't it the truth?

 

[Pacfanweb]

Would using the same Pro body tool and a small drill bit for a shim be feasible for the rear hole canter if I made new holes? I do have room to make new holes adjacent to the original ones. I am not worried about my CoM, I can adjust if needed.

I know a local guy that drills his axle holes that way. His sons have fast scout cars.

Drilled my son's car with a pro body too. Used a drill bit under the both to get the cant.

Surely not as accurate as a Goatboy tool or the Bullet, but it's probably 95% as accurate if you're careful, which was good enough to win Pack and District this year.

 

[Guest]

Hi B Regal,

I know where you are coming from because I used to think that same thing (and often find myself slipping back to it).

95% is good enough for me.

I am used to model making tolerances where .015 tolerances are good enough.

After hanging out here a bit I realized the machinist's mentality.

Either it is right, or it is wrong. I am sure there is probably a way to do it with that PBJ but it seems bush league to me. The type of thing meant for the scout dad that just wants to win the race and that is enough.

Best of luck racing here.

 

[LightninBoy]

Did a little testing and it appears I had two problems, excessive gap (from reading a credit card sized gap is excessive) and a rear wheel alignment. The rear wheel opposite the DFW wheels does not migrate to the axle head as I expected when the car roles backwards on a tuning board. I tried swapping the rear wheels, but still get the same outcome. <cringe> I drill my axle holes with a revel body jig </cringe>. Getting past the "why do I not have a drill press" questions, I have a moral dilemma (maybe). This car is for the Council race, but I lost districts by .02 seconds over 4 races. I have easily made that time up and then some, but I essentially duplicated the car, drilling the axles correctly (well, at least as good as I can do for now). I also cleaned up a few other minor items that inhibited some performance.

My question is: do I enter the new car (it looks almost identical) with same wheels and axles? At council, there are more Dad tuned cars than scout tuned - you tell when you walk in the door and watch who is handling the entrant cars. Or do I put a 1/2 degree bend (or less) in the misaligned axle hole to correct it, if I even can? My kid hates to lose; so do I. Just looking for opinions.

And yes, there is a drill press in my future...

If there's no rule forbidding a new car I don't understand the moral dilemma. There's nothing in our council rules, at least, indicating that the same car has to be used. So short of a rule forbidding it ... I'd use the new car and not even think twice.