Calculating curves for flex track...

[TheMacDiesel]

Hi, Newbie question again...

I'm planning to use a railbender on code 332 flex to create some large diameter turns with gentle easements.  My question is this -- do I bend both rails to more, or less, the same diameter, and then count on the plastic ties to keep them in gauge?  Or, do I bend one to say 12' diameter + 22.5 milimeters, and one to 12' diameter - 22.5 milimeters?

I appreciate all of the help and commentary on all my posts thus far, what a great forum!

 --Sean--

[kstrong]

Bend 'em to the same radius and let the ties hold things in check. You'll drive yourself absolutely mad trying to calibrate a railbender to give you exactly 45mm differences in radii, and even on tight curves, it's not worth the hassle.

Alternatively, you can buy a 2-rail railbender, such as that made by Train-Li. These things are--in my opinion--the slickest things to hit garden railroading. With these, you assemble the track prior to bending it (or buy the pre-assembled flex track), and the railbender bends both rails at the same time, with the ties in place. They're about 3 times the cost of a single-rail railbender, but well worth the expense.

If you do stick with the single-rail bender, mount it so that when the rail bends, it runs through the rail bender so that the rail hangs down in the direction of the bend as it's being run through (Think of a frown). This keeps the rail from twisting as it's being fed. Once the rail is twisted, it's difficult if not impossible to remove the twist.

Later,

K

[ttrigg]

Bend 'em to the same radius and let the ties hold things in check. You'll drive yourself absolutely mad trying to calibrate a railbender to give you exactly 45mm differences in radii, and even on tight curves, it's not worth the hassle.

Alternatively, you can buy a 2-rail railbender, such as that made by Train-Li. These things are--in my opinion--the slickest things to hit garden railroading. With these, you assemble the track prior to bending it (or buy the pre-assembled flex track), and the railbender bends both rails at the same time, with the ties in place. They're about 3 times the cost of a single-rail railbender, but well worth the expense.

If you do stick with the single-rail bender, mount it so that when the rail bends, it runs through the rail bender so that the rail hangs down in the direction of the bend as it's being run through (Think of a frown). This keeps the rail from twisting as it's being fed. Once the rail is twisted, it's difficult if not impossible to remove the twist.

Later,

K

 

I absolutely 100% agree!!!!!!!!!!  No need to bonkers attempting to get exact diameters.  My rail bender is a single rail, I bend them both to the same curvature and let the ties hold them apart.  After bending I have even tightened up the curve a little, ( I use LGB brass and it has a little flex even when bent.)  As far as I'm concerned Kevin has hit it exactly on the mark.  Do what he said and you'll not go wrong.

[Rex in Pinetop]

The two rail bender from Train-Li is fantastic.  I used it the first time last weekend for a long sweeping curve.  I started at one end, clamped the next section of track down, and continued bending.  The only thing I had to do was make sure the inside rail was not fastened to the ties.  That way I could cut off the excess rail with a dremel tool before clamping on the next section.  The tool also has some level bubbles so you can get your side-to-side leveling down while you're putting down your primary balast.  Works great!

Rex

[Anonymous]

OK, now I am going to have to save for 1! You twisted my arm

[TheMacDiesel]

All,

 

Thanks for the feedback!  Yes, going +/- 45mm would drive *me* nuts...  

 

I just got my Aristo ties yesterday (the rail is a few days behind them) and have another Q for you.  The ties are pretty INflexible out of the box.  What is your "pattern" for cutting the plastic spans between ties?  Do you cut every other span, alternating sides?  Do you cut them into isolated pairs?  I'm planning fairly wide curves (in my mind) in the 14-22' diameter range, if that helps your answer. 

 

Thanks!

 

--Sean-- 

[Rex in Pinetop]

I cut the inside only and did not put those tie screws back on the inside rail.  That way when I used the rail bender the inside rail would slide and I could cut off the excess.  I used my trusty cutoff wheel on my dremel to slice through the plastic leaving a gap which turned out to be just enough for the radius I was making.  If the radius were tighter you may have to take off more.  I did cut all of the inside spacers.

Hope this helps.

Rex