Calipers and Clueless

[FJ and G]

Last Friday I received a shipment of 300 feet of what supposedly is Code 148 rail to use for my outdoor toy train layout.

When I put the rail up to the Atlas code 148, it came up short by a smidgeon, which places greater hazards that flanges could hit spikes during frost heaves.

Perhaps the rail (Right O Way) is correct and the Atlas is incorrect or the other way around; or possibly I received a batch of ROW code 145.

The only way to know is by calibration using calipers.

I just went to Radio Shack and they only have depth gauges.

A Crystal City hardware store carries 4 types of calipers. One does only metrics, 2 are too gross in measure, another costs $39 and has a fancy gauge that I don't know how to use.

1. Can anyone recommend a set for what I need

2. How would one go about measuring 148/1000

I'm math and tool challenged.

Thanks

[Anonymous]

http://www.allendesignsllc.com/shan_calipers1.htm

one on the left, 6" $28,95

[wrmcclellan]

Dave,

Home Depot and Lowe's usually have economical sets, but these are usually digital. What you need is a simpler dial caliper.

http://www.wihatools.com/411serie_calipers.htm

It will be diificult to find a cheaper set that have the accuracy (+/- .0005 or +/- .001 inch) to make the measurement you wish.

Why don't you ask around at work. Likely someone has a dial caliper that you could borrow.

I just measured some Altas O rail from an Atlas O 3-Rail switch that I disassembled and the rail measures .215 which would make it Code 215.

I can tell you from experience that some hi-rail flanges hit the molded spike heads on the Atlas O track. Makes an obnoxious ticking/zipper sound when the train goes down the track.

Regards,
Roy

[lionelsoni]

Dial caliper: Close the jaws, using the little thumbwheel. Turn the dial until it reads zero. (There may be a screw locking the dial. Loosen it while turning the dial.) Open the jaws. Put the rail between the jaws. Close the jaws. Read the size from the dial. Add however may full revolutions the dial made to the reading. For example, if the dial makes a revolution every .1 inch, you will need to add .1 to the reading of .048 (for .148" rail).

A metric caliper is not much trouble. Just get the reading in millimeters and divide by 25.4 to convert to inches.

Unsquare jaws can give a bad zero reading. If you are unsure of the squareness of your caliper jaws (as I am with my old, cheap plastic caliper), stack up two rails and measure them together, then measure one alone (at the same place in the jaws) and subtract the readings.

[FJ and G]

thanks guys; running to catch VRE train for early trip home.

Happy thanksgiving

[EIS2]

Costco has a nice set for about $39 as I recall. I believe there were three different types in the set.

[lionelsoni]

Here's a kind of tedious low-tech way to measure your rail, which I assume comes in 3-foot lengths:

Stack 28 of the rails on a flat table in a triangular arrangement. Lay the first rail flat on the table. Lap the second rail over the first. Lap the third rail over both the first and second to make a triangle. Then put the forth rail above the first. Keep going around the triangle until one corner has 19 rails stacked up. Measure the height of the corner. If it is 2 13/16", the rails are each .148" tall. For each sixteenth of an inch that the stack differs from 2 13/16", the rails are about .003" off.

[dougdagrump]

Dave, Instead of calipers you could also use a micrometer.

[FJ and G]

Bob,

I couldn't stack that high w/out collapse so stacked 5 and equaled 3/4", then stacked 4 and equaled 9/16.

So, 3/4" X 3 + 9/16 = 2 13/16.

Which means that it is code 148 and the old Atlas 2 rail track was actually higher, which means that I'll have to spike the rails down very tightly to prevent flange interference.

Also, thanks to others for good suggestions. Eventually I'll need to get a good pair of calipers or micrometer.

Have a great weekend.

[lionelsoni]

Where there's a will, there's a way!

Maybe there won't be a problem. If this is scale rail, the rail flange is about 6 inches wide and the rail head about 3 inches, which means that the rail flange is only 1 1/2 inches closer to the center of the track than the rail head, or 1/32 inch. On the other hand, the tip of a Lionel-style wheel flange is about 1/16 inch closer to the center of the track than the edge of the wheel tread. So, if you can keep your spike heads within 1/32-inch from the rail flange, the wheel flanges cannot (should not!) hit them.

It may be too much to do, but you could also cant the rails (like the prototype), which would move the rail flanges a little farther out and out of trouble.

[FJ and G]

Bob,

Your advice has been fantastic (I'd certainly remain clueless w/out this forum).

BTW, my next door neighbor just came over with his calipers and I was surprised to find that code 148 rails actually vary thru out the length of the rail by 1/1000 of an inch. THus, the rails in some place is 148 and in others 147.1 or 147.3 or 148.1 but the variation is usually on the below 148 side.

I really learned a lot today.

He also showed me how to do a continuity rail check using an audio signal. Previously I was just using ohm meter reading so now I can check my jumper wires between rails a lot quicker.

Goin to see movie Walk the Line or Jarhead now.

Later!