"How do I determine what the

      You pretty much answered your own question. Draw the intersection of the two  routes full size then build the turnout to fit. You don't need the layout benchwork to draw the turnout full size ,you only need to know what the alignment of the two routes will be then make a mock up with a tape measure on some cardboard or scrap plywood. It might simplify the process a bit if you bend some flextrack and tack it over the proposed routes then if it looks fair draw around it as a guide. I build these kind of turnouts on the workbench by cutting out a thin plywood switch base and gluing the ties to it, no need to spend money on twistties  if you have some regular switch tie material.....DaveB

I don't want to..

...scratchbuild a turnout with an unknown frog angle.  I have Fast Track tools to make #8 and  #10 turnouts.  At the moment, I have no way of knowing what the outside radius for this turnout will be, or the angle of the "normal" route for the turnout.  This is why I am asking what i'm asking.  Using either a #8 or a #10 frog, what would the resulting outside radius of the turnout be?

Thanks

Ken L.

Old school

 Take a piece of flex track.  Temporarily tack it in place along one route.  Lay a big piece of paper over the area.  Trace the rails (and ties) onto the paper by rubbing a pencil over it.

Untack the portion from the points through the frog.   Tack it back down on the other route.  Put the paper back over the area.  Trace the rails (and ties) onto the paper by rubbing a pencil over it.

Remove the paper, build the switch.

That would require making a custom frog angle!

Which is something I do not want to do.  It would require me to file the frog and points to a frog angle which I do not have the skills to do. It is why I avoided handlaying turnouts all of this time.  Now that there are tools to help in the process, that  allow me to file the rails to the appropriate angles for the turnouts, it allows me to make my own turnouts.  In this case I need a custom turnout with a set inside radius, but I still need a method that will result in an established frog number. In this case a #8 or #10.

Ken L.

Use #10

You don't have the skills to file a frog?  Hmmm.  Lay rail on side.  Put flat side of file on rail and slide back and forth until the rail is pointy.  

If you still don't want to do that do the same thing I described and drop in a number 10 frog. Build the rest of the switch round the frog.  

Good illustration of the benefits of learning how to build a switch without all those jigs.  Old school, you would be rolling a car over the switch two hours from now.  With the jigs you'll be fiddling around with plans for another day or two.

Go to RMweb Forum

Go to RMweb Forum http ://www.rmweb.co.uk/community/ , look for Martin Wynne(the designer) ,or Templot (the product) and explain what you are trying to do.  It will produce turnout plans to any scale or radius you desire, and Martin is very accessable.

Templot

Templot has an own website: http://www.templot.com/martweb/templot.htm

On the other hand you could look at the Fast Tracks templates for curves layouts. They show a #8 curved turnout with an inner radius of 35'' having an out one of 50 inch: http://www.handlaidtrack.com/HO-Scale-Printable-Track-Templates-for-8-Curved-Turnouts-s/108.htm

With 36'' inner radius the outer radius should be around 52''.

The same can be looked up for #10 turnouts: http://www.handlaidtrack.com/HO-Scale-Printable-Track-Templates-for-10-Curved-Turnouts-s/109.htm

The radii should be ri/ra = 36''/ approx. 43'' to 44''

Regards, Volker

Frog filing is not that critical

You can always use a long angle tool to build a shorter  frog. The two pieces will just have a slight gap at the inside of the joint which will easily fill with solder. The real advantage of the tool is it makes the mating surfaces vertical.

pqe

 "I have Fast Track tools to

The outside radius will be whatever radius it takes to get the route where you need it to go. If you don't know where it's aimed yet then wait till you do. If you know where it's aimed then mock it up and then see what  frog angle fits the best. The point filing jig number doesn't matter, as long as the point touches the rest can be filled with solder so either your #8 or #10 will work depending on what the mock up shows.Once you have it drawn full size the different possibilities will become clear, you'll see how the #8 and #10 frogs fit and how much straight needs to be incorporated to accommodate them.....DaveB 

I would suggest downloading

I would suggest downloading and printing the #8 and #10 turnout templates from fast track that have 36" listed as the inner radius.  They will also tell you the outer radius.

-Doug M

I considered

using the fast track templates.  Trouble is they don't have one with a big enough frog with a 36" inside radius.  Though I I suppose it would be "close enough" to determine if such a turnout would fit.  I 'm just afraid the ouside radius would be something extremely different than the templeate.  Such as 6+" different.

Ken L.

Tracing

Take a look at this thread:  https://forum.mrhmag.com/post/hand-laying-a-turnout-without-jigs-12192628 That's a set of instructions by Ken Rickman on how to build a turnout starting with a tracing of the rail path.

To get a tracing, fit a piece of flex to the outer curve. Tack a big piece of paper over the area of the turnout. Only put tacks on the point end. Rub a pencil along the rails to trace the outer curve. After you are done, flip the paper aside, but don't let the tacked end move.  Now loosen the flex starting at the points and bend it for the inner curve. Rub again with the pencil-- you should have a tracing of exactly where you want the tracks to go. Then follow Ken's instructions, but use one of your tools to file the frog.

It's easier than you think it is, and all you have to loose is a dollar's worth of rail.

pqe

As describe in

As described in http://model-railroad-hobbyist.com/node/22307#comment-193462 they have a template for a #8 with ri/ra = 35''/ 50''

ri = inner radius, ra = outer radius

Regards, Volker

You can flex turnouts in 3rd

You can flex turnouts in 3rd planIt and with a little trial and error I found a 63" outer radius gives you a 36 1/16 inner with a #8 frog. 

Thanks,

Ken, you seem to to be finding more reasons to...............

..............not build this turnout than all the advise you've been given.  I think you are over thinking this a bit too much  I build all my own in O scale and Pelsa is right, the angle is not critical as any gap will be filled with solder.  Here's a picture of a wye turnout built using both sides of a #4.5 turnout jig and then putting it together. 

As the Nike folks say, "Just do it'!!  Good luck!

Peter

Well if your using the tie

Well if your using the tie strips with the location of the rails marked on them then you just need to Mack the center line of the 36" inside route. The bend the tie stip to mach that curve.  The outside radius will take care of itself.

Filing and fitting

I have the Pointform tool for a #7 and used that as the starting point for my custom curved turnout.

(Skip to about the 4:00 minute mark)

I laid out a line on my subroadbed, laid a piece of paper over it and did a rubbing of the track and drew the line in on my sheet of paper.  Took that whole mess into my printer/scanner and scanned the page.  Then brought the scan into my CAD program (Draftsight - it's free!) and used the arc tool to draw out the geometry.

  The #7 was not quite the right angle, but it was close enough to get me started and I filed and fitted until I had something "close enough".

Why the frog angle being certain is important for me...

Though I will look at the video and consider the options, having the frog angle set (either #8 or #10) means I can file the points EXACTLY using the Fast Track point form tool.  I then can go to the Frog Helper tool (I think that is what it is called) which is a jig JUST for the frog section of the turnout (versus using the turnout jig fixture) and I can solder it together and I know that the frog will be in it's proper alignment.  Of course I will still need to use the NMRA track gauge and other point tools, however guessing what the angle is and having to file less or more to get and imprecise angle for the frog is not something I have the skill for.  I barely have the skills to use the jigs.  The jigs keep everything in place for me. 

For those that can do it "free style" I am envious of you.  I know that it can be done, just not by me. 

What I plan to use is the Fast Track Twist Ties for the turnout.  What I have asked, and I THINK I saw the answer I needed above, is a fairly precise (though perhaps not totally accurate) determination if a curved turnout in this one location will work.  I would like to maintain my minimum radius of 36" (which is why I didn't want to use the 35" IR Turnout template from Fast Tracks) but someone was able to figure out how to use 3rd PlanIt (i didn't know it could flex a turnout!) to curve the turnout and gave me an outside radius, now I can print it out full size to see if it will work!

Thanks all!

Ken L.

Figure it out