Setup for no center rail

[rexhavoc]

Hello to all,

Anyone have setup suggestions for an Awana track with no center rail? Left and right guardrails for each lane only.
Last year we didn't know and we brought our cars with a raised front wheel - doh.

Thanks,

[Darin McGrew]

If I were designing for speed on such a track, I think I'd build a rail rider, inverting some of the details for a normal rail rider.
- dominant front wheel mounted "backwards", with smooth surface to the outside
- rear wheels cambered to stay close to the car body, and spaced narrower than the front wheels
- dominant front wheel toed out, to ride the rail on its side, and cambered to stay away from the car body

[rexhavoc]

Wow, that is interesting Darin.
What's the thinking behind reversing the front wheel? That effectively narrows the front track, and will need some spacers to prevent rubbing the body, no?

Thanks,

[Darin McGrew]

What's the thinking behind reversing the front wheel? That effectively narrows the front track, and will need some spacers to prevent rubbing the body, no?

The idea is that it is better for the edge that is normally inside (i.e., that normally touches the center guide strip) to be outside (i.e., touching the outside guard rails).

I'd cone the car body to keep the point of contact (between the wheel and the car body) close to the axle.

[doct1010]

Darin is on the money on all counts.
Another possibility, if the outside rail is high enough, you can use the axle head to "ride the rail", same basic set-up except camber in opposite direction, leave a tad extra axle lenght, cone body and lube. Whatever you choose to do, turn that dom front around with hub out!

[murphken]

Hey Guys,
I have a post almost like this a little down the list. Here is what Stan said to do:
Right front wheel is dominant.
1. Lift and reverse the left front wheel. Add 1/16" car width to left front. Plan to guide by the left front axle head in a "gutter track". Maybe glue the left front wheel in place. Alternatively (if they balk at reversed wheel), extend the left front axle and glue the wheel close to the car body or just leave that wheel at home or add another round-head guide that extends beyond the wheel ahead of the left front wheel!
2. Toe-in the right front wheel. Indent 1/16" to restore the original wheel separation. Plan to guide by the right front wheel on a center-rail track.
3. Assure alignment that right rear wheel rides 1/16" to right of right front wheel and left reear wheel rides 1/16" to right of left front wheel.
4. Camber per your preference.

There are two approaches here. Our district track is plastic so the edge guide is smooth. Both set-up will probably work!

[murphken]

I explained to my Cub that he should build a different car for our district race and explained the idea to him. He gets it! He is on a mission! Tonight, MaMa went out with the girls so we took a break from school work and did a little work on the car.

He still needs to add the front (of rear axle) weights to the body. We were trying to figure out how aggressive we should be with trying to guide-off the plastic edge. We were figuring weighting for either 3/4 for 1" in front of the rear wheel. Any thoughts?

He had to drill the raised wheel hole after the body was cut because of the need to offset the body with a 1/16" shim. The opposite side has 1/16" removed. We are leaning on gluing the front inside-out raised wheel to the axle. District said it was ok.

I let him use the Black and Decker Mouse for sanding and he got a little carried away. He has the top of the car at a slight angle!

[pwrd by tungsten]

How did it go?

[murphken]

We have the offset car built for center and edge guided track. The car is 1 3/4" wide at the front and rear wheels as per our district rules. We added some wood on the front left and removed some from the front right. It is currently set-up for RR on the center guided track. My son will have the choice if he wants to run it in either of the races (pack (center) and district (edge)).

Currently, the DOM wheel is right and left is raised. If we run on edge guided track at district, we are thinking of making the opposite (left) wheel DOM and steer it towards the left. Consequently, we would raise the right wheel. We kept the COM very conservative @ 1" in front of the rear wheels. We left enough wood around the front axles to to drill two more holes.

For the edge guided track: The $1000 question is: "Do you guide against the edge of the track with a wheel that is rotating or static"? We are thinking that the wheel should be rotating, negative camber and toed-out.

My Cub has a straight runner that that runs very straight and might be a good alternative. We will run them after the pack race, on February 23, and see how they do. If we do run the offset car at district, I will input the results after the race on February 27. We are entering four cars (Cub, Dad, Mom, and Daughter) so we should be able to run this car one way or another. My Cub and I will keep you informed.

[pwrd by tungsten]

Thanks!!!

Best Wishes!

[murphken]

The black car has the offset body and is currently set-up for rail riding @ pack on Tuesday night. After pack, we will bring home and convert to edge runner. Got some work to do on this conversion since district is Saturday.
The orange car was an original straight runner currently being converted to run on edge guided track also. My Cub glued the wood strips in this morning. We have to keep these cars wide at axles (1 3/4") according to the rules. I will let him loose with the Dremel tomorrow night. If the my prayers are answered and my Cub doesn't get too carried-away with the Dremel, hopefully there is a "nub" that inside-out tire hub can rest against.

[murphken]

This is the second try at making an edge rider. Our first attempt failed because we did not move the wheel out far enough > Rear wheel was also riding on the edge because of negative camber on rears. We tried to "dog leg" the car via toe-in/toe-out on the rear canted axles but the car would not cooperate.

The car did not want to align well with just the rear wheels. Several sets of wax paper shims. We had to bend the front DOM axle to get proper toe-out.

This car is going to raise a few eyebrows at the district. The work is a little rough because my Cub was having fun with Dremel. It passes my interpetation of the rules but we will see. The front DOM extension, off the main body, is made of wood with epoxy/graphite coating. I will probably run it in adult. Don't need my Cub interrogated. He is kind of quiet.

LF: 2.5 degrees negative with toe-out, wheel is inside-out
RF: Lifted
Rears: 2.5 degrees negative camber, neutral on toe
COM: 13/16 inch in front of rears
Rear axles: sub micron polished with no bevel on head
Wheels: #15 all around, rears less than 0.001" runout, front slightly more, micromesh bore prep, outside hub step removed.





District is tomorrow. I am testing on board right now. Anything I should change?

[murphken]

The rear end wants to move towards the edge. Hmmm... Looks like it needs more time for work out kinks.... Bummer. We have a couple of straight runners. Next year for the edge runner!

[murphken]

We ran the edge runner in the adult race on the Super Track. The district let me run two cars. The edge runner got smoked by my straight runner. They did not time the race but the straight runner probably pulled two plus car lengths on the edge car. This edge car needs more work. My staight runner had a COM @ approx 3/4".

[murphken]

This is my Cub's Car that he raced on Super Track. Very stable car. Pretty simple and easy to make, especially when your neighbor has a harbor freight vice that can move on both x and y axis for removing wood from bottom.
Our recommendation for running on a track with no center rail is make a straight runner. If the track is Super Track, you might want to bring your front wheels back a bit to keep alignment and wheels intact between races. That stop section is just brutal.