There Ain't Nuthin' To This Railroad Buildin!

[jacon12]

I've got it figgered out. You just draw a line and saw to it, bore a hole and peep through it. WahLAAAA, you're done.
No.... seriously now.. I've taken up a huge portion of my track. I've practiced now all I'm going to, its time to get serious about this thing. I'm laying the track using flex track as much as I can, even around curves. I'm drawing the centerline and pinning the track down as I go so things will quit shifting on me. Now I'm to a big curve, a BIG'UN. Where the benchwork does a 90 degree turn. And I want to draw the curve on the benchwork. I have the tangent track where I want it to be. I got a tripod and I measured out 22 inches from both benches, now I need a wooden ruler to place on the tripod and scribe the line, the most graceful, loveliest 22 inch radius arc, on the table. The question is, when I get the ruler, do I drill the hole dead on the 22 inch mark or leave the mark. Yaknowwhutimean? Maybe I should lay the curve first and run the tangent lines (mainline) off it?
No, I can do that because of other factors.
How do the pros do it?
Jarrell
P.s. Now I wish I'd paid attention in geometry class instead of paying attention to sweet Michelle so much.

[Big_Boy_4005]

Jarrell, if you have a lot of curves to do, you might want to invest in a special tool. I use a piece of predrilled metal strapping. The holes are at regular intervals, just put a nail or screw where the center is going to be, and swing an arc. This is great for parallel curves.

The metal strapping can also be used as a straight edge, as well as a spline for doing transitions.

At the top of this photo is my compass. It happens to be mounted with an eyebolt to a piece of electrical conduit which is acting as my center for helix construction.

[jacon12]

QUOTE: Originally posted by Big_Boy_4005

Jarrell, if you have a lot of curves to do, you might want to invest in a special tool. I use a piece of predrilled metal strapping. The holes are at regular intervals, just put a nail or screw where the center is going to be, and swing an arc. This is great for parallel curves.

The metal strapping can also be used as a straight edge, as well as a spline for doing transitions.

At the top of this photo is my compass. It happens to be mounted with an eyebolt to a piece of electrical conduit which is acting as my center for helix construction.

Thats a good idea, thanks. I also found I could do it fairly well using 4 sections of curved sectional track. I just keep adjusting them until the ends hit on the centerline of the straight tangent rails, but I do have a parallel curves since I have a double mainline.
Thank you for the tip!
Oh, I'd never attempt a helix. My hats off to anyone who can do them.
Jarrell

[pcarrell]

I just took a piece of heavy guage wire (OK, it was a coat hanger all straightened out), put a loop in one end to slip over a nail and marked off the inches from the back edge of the hole right onto the wire with a sharpie. Then I just tape the sharpie at the inch mark I want, slip the loop over the screw I put into the curve center, and swing that puppie around!

Wanna change radius? Tape the pen to the wire at the mark for the new radius and swing away.

I was desperate for a trammel late at night once and this was what I had on hand. It worked good so I've used it ever since.

It's kind of low tech I know, but so am I. [:D]

[tommyr]

I used a camera tripod & a yardstick. Drill a hole the same size as the screw that holds the camera at the 1" mark & another hole at the 23" mark , put in a pencil or marker & viola!![^][^]
Tom

[rrinker]

If you are using pretty much only 22 and 18 inch radius, a couple of packs of sectional track a worthwhile investment.
A simple yardstick with a couple of holes drille din it makes a handy trammel. Use a photo tripod if the enter ens up being off the benchwork.
Track dimensions are generally give to the centerline of the track, so any line you draw is for the middle of the track.
If you used a drawign program to do your track plan, you cna often print it out across multiple sheets of paper, in 3rd PlanIt at least you can put registration marks on these sheets to aid in taping them together. I did this for my first section, and will NEVER do it again - from now on my trak plan is only to get a good idea of where I'm going, not a device to locate tracks to the nearest tenth (one ten thousandth of an inch - I used to work in a precision machine shop [:D] ).

--Randy

[jacon12]

Since I'm so new at everything it is probably best I stick to standard curves, like 22s and 18s. I have some sectional track so I'll use it for now but I'm going to make a trammel (my wife calls it a compass) and practice with it on a piece of plywood. I AM getting rid of the little pieces that I used for filler and cutting one long piece to take their place where needed so maybe I'll improve things that way also.
I've got to figure out how I'll do the mainline double track curve though, I haven't gotten to there yet.
Randy, you sound like PCarrell. If I remember right thats about the way he likes to do it.
Jarrell

[oleirish]

QUOTE: Originally posted by jacon12

Since I'm so new at everything it is probably best I stick to standard curves, like 22s and 18s. I have some sectional track so I'll use it for now but I'm going to make a trammel (my wife calls it a compass) and practice with it on a piece of plywood. I AM getting rid of the little pieces that I used for filler and cutting one long piece to take their place where needed so maybe I'll improve things that way also.
I've got to figure out how I'll do the mainline double track curve though, I haven't gotten to there yet.
Randy, you sound like PCarrell. If I remember right thats about the way he likes to do it.
Jarrell

I use 22degree curved sections,as for a double track curve you can use 18's inside the 22's on the out side lay the 22's then from center of the 22smesure out 2.5 to three inches then use flex track.
JIM

[howmus]

Arcs can be draw quite easily with a simple length of heavy string measured to the radius of the arc you want to draw. On one end tie a pencil and tie the other end to a tripod/push pin/anything that you put at the center of the circle. It can be easily adjusted and stores in a small place. For easements at the beginning and ends of the curves, I just draw it in by hand.

[jwar]

Hi Jacon 12

There are many ways to skin a cat and here are a few of mine. whoooops the animal rights peopel here, were about to flame me, but skinning a cat is a term for pulling logs with a dozer[:D]

Using strings and other fictures to lay out curves are a bit time consuming if not awkward in certain areas.

For a straight line I use the factory edge of a 1/8 plywood, I think its called lauon, (at a blank on how to spell it) Its 2 1/2 wide, on one side I use a sabre saw cut to accept a carpenters pencil at any radius I choose to make 18 20 22 22 1/2 ect. the pivot end has a small hole to accept a ice pick so it can be adjusted to elevation.

Then make curve templates out of the ply, for different radius, lets say I want a 22 and a 24 1/2 double track turn. scrib a heavy black line for both radius, cut to the outside with a sabre say and sand back to 1/2 the line, I use a orbital sander and is very quick. In one setting you have both track marked and a templat for both single track radius in other areas.

It also helps to have a couple or radius templates and the straight one to see how a future Idea may work. or in setting up s turns.

Im still chuckling over your tunnel picture you posted[:D]
Take care...John