Rail Riding - "How To Guide"

Secrets, tips, tools, design considerations, materials, the "science" behind it all, and other topics related to building the cars and semi-trucks.
Post Reply

Have you had success with a "rail rider"?

Yes
90
49%
No
8
4%
Somewhat
12
7%
Haven't tried yet
72
40%
 
Total votes: 182

AlabamaDan
Master Pine Head
Master Pine Head
Posts: 197
Joined: Wed Feb 04, 2009 1:26 pm
Location: Birmingham, Alabama

Re: Rail Riding - "How To Guide"

Post by AlabamaDan » Thu Feb 04, 2010 8:47 am

Ten Thumb Tom wrote:Okay, let me see if I've got this straight :thinking:
Assuming a theortical situation where there are no adjustments necessary for imperfections in wheels, axles, axle holes, etc, the alignment goals for a rail rider would look something like this...

REAR WHEELS
- negative camber
- zero toe

FRONT RAISED WHEEL
Option 1
- zero camber
- slight toe in (to minimize spin-up should the raised wheel come into contact with the center guide).
Option 2
- negative camber (to give it a little extra clearance).
- zero toe

FRONT DOMINANT WHEEL (DFW) -
- slight positive camber (so that the inner edge of the tread rolls against the rail as the outer edge rolls against the track).
- slight toe in (so that the DFW will steer lightly into the center guide).
- the light weight load on the DFW allows the light force of turning into the center guide to push the wheel slightly down the axle enough so that the wheel is not touching the car body.

WHEREAS CAMBER and TOE are defined as:
Image Image
Thank you all for this thread.



User avatar
sporty
Pine Head Legend
Pine Head Legend
Posts: 3355
Joined: Sun Feb 13, 2005 2:00 am
Location: rockfalls, Illinois

Re: Rail Riding - "How To Guide"

Post by sporty » Thu Feb 04, 2010 9:21 am

4 on the ground Rail Runner.


1/16th recess on the right front dom wheel, the wood.. cant toe in, 1 1/4 to 2 degrees, its going to depend on how well those axle wholes are dilled. drill axles wholes first, before doing the recess. this is important !

2- the left wheel, naturally just touching, but still the non dom front wheel, toe out 1/4 degree to 1 degrees, is going to depend on again how well the axles wholes are dilled.

Additionally, the reason the left non dom wheel must be toed out some, if you run it strait, it will want to push the car away from the rail. And to much toe in on the dom right front wheel, will slow the car. Trying to do it this way. To much friction and force is required to keep the car there to the rail.

So that is why the left non dom front wheel needs a slight toe out. Some of this is naturally with a RR, the car goes down the track at a slight angle. So if you run the non dom strait also, it will want to push the car away from the rail.

But to go faster, it's that fine line of tweaking the toe in on the right and the toe out on the left. But usually within 2 hours from the start of build, I can get a pretty fast good running car.


Board set up.

You can at 4 foot. have that car turn 2 to 1/2 inches at 3 1/2 feet.

This seems to be a decent starting point for a board alignment, without a timer and track. It seems to still yield positive results.

Meaning you do not end up going slower than a strait runner !

Sporty



Toman
Apprentice
Apprentice
Posts: 15
Joined: Wed Feb 03, 2010 9:43 am
Location: Brookings, NE

Re: Rail Riding - "How To Guide"

Post by Toman » Mon Feb 08, 2010 7:30 am

Our rules state "The inside wheel-to-wheel width should not be less than 1 3/4 (1.75) inches."

What is the best or easiest way to RR with this rule? The width of the block is already about 1/32 too narrow, which I'm guessing a few coats of paint will get it to within the margin. There is no "4 wheel touching rule." Off hand the only legit way I can think of that would pass a "by the book" inspection would be to build out the raised wheel side with bondo?



doct1010
Pine Head Legend
Pine Head Legend
Posts: 1332
Joined: Wed Dec 21, 2005 6:06 pm

Re: Rail Riding - "How To Guide"

Post by doct1010 » Mon Feb 08, 2010 7:45 am

Ten Thumb Tom wrote: So what would be the advantages or disadvantages of gluing the raised wheel on a rail rider so it doesn't turn?
I believe Joe did some testing with a glued raised wheel. I don't recall specifics.
I do recall being somewhat surprized with results. A search should turn up the posts.



Kenny
Master Pine Head
Master Pine Head
Posts: 288
Joined: Fri Aug 22, 2008 4:19 pm
Location: Houston (Tomball), TX

Re: Rail Riding - "How To Guide"

Post by Kenny » Mon Feb 08, 2010 9:11 am

Toman wrote:Our rules state "The inside wheel-to-wheel width should not be less than 1 3/4 (1.75) inches."

What is the best or easiest way to RR with this rule? The width of the block is already about 1/32 too narrow, which I'm guessing a few coats of paint will get it to within the margin. There is no "4 wheel touching rule." Off hand the only legit way I can think of that would pass a "by the book" inspection would be to build out the raised wheel side with bondo?
No need to build up the block, the finish will take care of that 1/32 in deficit.

Also, remember that you will have a gap between wheel and body of at least 1/32 in on each side. If you apply neg camber to rears the distance between the wheel edge grows even more in the rear.

In short, I wouldn't worry about it.



doct1010
Pine Head Legend
Pine Head Legend
Posts: 1332
Joined: Wed Dec 21, 2005 6:06 pm

Re: Rail Riding - "How To Guide"

Post by doct1010 » Mon Feb 08, 2010 10:03 am

Toman wrote:Our rules state "The inside wheel-to-wheel width should not be less than 1 3/4 (1.75) inches."

What is the best or easiest way to RR with this rule? The width of the block is already about 1/32 too narrow, which I'm guessing a few coats of paint will get it to within the margin. There is no "4 wheel touching rule." Off hand the only legit way I can think of that would pass a "by the book" inspection would be to build out the raised wheel side with bondo?
What is the concern? Narrowing the front end? As stated above wheel gap should offer ample clearance for a three wheel RR.



Toman
Apprentice
Apprentice
Posts: 15
Joined: Wed Feb 03, 2010 9:43 am
Location: Brookings, NE

Re: Rail Riding - "How To Guide"

Post by Toman » Mon Feb 08, 2010 3:21 pm

Sorry about not being clear. I've read on several posts about narrowing the width of the block on the dfw area 1/16" so the rear wheels stay off the rail. Are you saying a good option is to leave larger gaps in the rear axles? From what I have seen, I think a normal gap is around 1/32". should I go with 3/32" on the rear gaps? Then I assume cant the rear axles with camber to keep the wheels near the axle heads. If I recall, some say to align the rear axles straight and some say give them camber?

This is our first car and I don't have an axle press or the rail rider tools yet. Will this be too much to do with just common bench vice and ballparking it? I think someplace mentioned pushing the axle very lightly and if you feel it bend, you've gone too far. (i"ll use practice axles first!!)



User avatar
Stan Pope
Pine Head Legend
Pine Head Legend
Posts: 6888
Joined: Sat Jul 05, 2003 7:01 pm
Location: Morton, Illinois
Contact:

Re: Rail Riding - "How To Guide"

Post by Stan Pope » Mon Feb 08, 2010 4:06 pm

Toman wrote:This is our first car and I don't have an axle press or the rail rider tools yet. Will this be too much to do with just common bench vice and ballparking it? I think someplace mentioned pushing the axle very lightly and if you feel it bend, you've gone too far. (i"ll use practice axles first!!)
In a pinch, I've successfully grabbed the point end of a nail in pliars (crosswise), laid the exposed nail head and shaft on a board, and pressed down on the jaws of the pliars with the heel of my other hand while holding the handle vertical. It takes a few tries to get the hang of "just about right." But it works.


Stan
"If it's not for the boys, it's for the birds!"

User avatar
ah8tk
Master Pine Head
Master Pine Head
Posts: 323
Joined: Fri Dec 14, 2007 5:23 pm
Location: Minneapolis, MN - north

Re: Rail Riding - "How To Guide"

Post by ah8tk » Mon Feb 08, 2010 7:35 pm

Toman wrote:Our rules state "The inside wheel-to-wheel width should not be less than 1 3/4 (1.75) inches."
The wheel to wheel width on a PWD block (1 3/4" width) with wheels attached with 1/32” clearance is 1 29/32” (between 7/8” and 15/16”). If you remove 1/16” or so you make the block 1 11/16”, and the wheel to wheel width is 1 27/32” (see drawing below). Well over the 1 3/4" stated in your rules.

Image
Last edited by ah8tk on Mon Mar 08, 2010 1:19 pm, edited 1 time in total.



brentsherman
Apprentice
Apprentice
Posts: 4
Joined: Mon Feb 22, 2010 12:24 pm
Location: Huntsville, AL

Re: Rail Riding - "How To Guide"

Post by brentsherman » Mon Feb 22, 2010 2:24 pm

I have helped my son build his first rail riding car. Seems like we have the correct amount of turn, about 2 - 3 inches over 4 - 5 feet. We have the front dominant side of the car sanded in about 1/16 of an inch. One problem we are having is the rear wheel on the dominant side does not move out to the axle head, it really does not move much either way. Our rules state "Axles may not be angled in the car body slots/holes so as to prevent the wheel from running flat on the track surface." Question is, are we better off keeping a front dominant wheel not knowing what the rear wheel will do or should we scrap rail riding? Is there another method to get the rear wheel to move towards the axle head?
Thanks,
Brent



User avatar
asatxj
Master Pine Head
Master Pine Head
Posts: 121
Joined: Thu Sep 11, 2003 5:08 am
Location: Grant MI

Re: Rail Riding - "How To Guide"

Post by asatxj » Mon Feb 22, 2010 2:52 pm

Our rules state "Axles may not be angled in the car body slots/holes

Based on that, you could bend the axle slightly. That's part of the alignment process for many cars. it will allow the wheel to migrate out and still run almost flat. If you check it with a light and set it on a flat surface while it rolls it may come off of "flat" a little but not likely. If your rules let you work your wheels a bit you could put a 1.5* taper on your wheel itself.
I wouldn't scrap rail riding, it's very effective! The top 10 cars at our Awana race were all using RR.


Awana Commander
Jeep Fleet Maintenance Director
Dad
Bowhunter
I can't break the rules, I write them
!

User avatar
FatSebastian
Pine Head Legend
Pine Head Legend
Posts: 2646
Joined: Wed Jun 17, 2009 2:49 pm
Location: Boogerton, PA

Re: Rail Riding - "How To Guide"

Post by FatSebastian » Mon Feb 22, 2010 6:37 pm

:welcome: brentsherman!
brentsherman wrote:Our rules state "Axles may not be angled in the car body slots/holes so as to prevent the wheel from running flat on the track surface."
asatxj wrote:Based on that, you could bend the axle slightly.
It seems that the intent of Brent's rule is to require that the wheels flatly contact the track. I believe that either bending or canting would be allowed so long as the tread contacts flatly. The usual alignment procedures would seem to still apply.
brentsherman wrote:Question is, are we better off keeping a front dominant wheel not knowing what the rear wheel will do or should we scrap rail riding?
IMO you should not scrap rail riding.



User avatar
Stan Pope
Pine Head Legend
Pine Head Legend
Posts: 6888
Joined: Sat Jul 05, 2003 7:01 pm
Location: Morton, Illinois
Contact:

Re: Rail Riding - "How To Guide"

Post by Stan Pope » Mon Feb 22, 2010 6:39 pm

brentsherman wrote:Question is, are we better off keeping a front dominant wheel not knowing what the rear wheel will do or should we scrap rail riding? Is there another method to get the rear wheel to move towards the axle head?
Thanks,
Brent
Since you have indented the DFW 1/16" and tightened its hub clearance to about 1/32", your rear wheels should clear the rail easily, even if they stay in. You can check what is happeing by using a yard stick on your alignment board to act as the track rail. Run the car down that short gentle slope and watch the wheels.

I think that it is better to stay inside the intent of the rules, even though the intent is not as clear as they probably intended it to be. (Just to "twist the knife a little", I'd be asking them if they really meant to leave that loophole. :)
Last edited by Stan Pope on Mon Feb 22, 2010 7:11 pm, edited 1 time in total.
Reason: "stay", not "say"


Stan
"If it's not for the boys, it's for the birds!"

User avatar
FatSebastian
Pine Head Legend
Pine Head Legend
Posts: 2646
Joined: Wed Jun 17, 2009 2:49 pm
Location: Boogerton, PA

Re: Rail Riding - "How To Guide"

Post by FatSebastian » Mon Feb 22, 2010 6:59 pm

Stan Pope wrote:I think that it is better to say inside the intent of the rules, even though the intent is not as clear as they probably intended it to be.
:? Here I thought Brent's rule writer did an excellent job of injecting the rule's true intent: the wheel tread must run flat on the track. So how might the intent of Brent's rule be made clearer? What is the hooplole?



User avatar
Stan Pope
Pine Head Legend
Pine Head Legend
Posts: 6888
Joined: Sat Jul 05, 2003 7:01 pm
Location: Morton, Illinois
Contact:

Re: Rail Riding - "How To Guide"

Post by Stan Pope » Mon Feb 22, 2010 7:03 pm

FatSebastian wrote:
Stan Pope wrote:I think that it is better to say inside the intent of the rules, even though the intent is not as clear as they probably intended it to be.
:? Here I thought Brent's rule writer did an excellent job of injecting the rule's true intent: the wheel tread must run flat on the track. So how might the intent of Brent's rule be made clearer? What is the hooplole?
The rule did not say that the wheel must run flat on the track. It only said that it could not fail to run flat on the track due to an angled hole or slot. Any other means is, therefore, fair game!

I'm sure that the intent was to require the wheel to run flat. But I must read their words, not their minds.


Stan
"If it's not for the boys, it's for the birds!"

Post Reply