Author Topic: Question for track hand layers  (Read 1453 times)

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narrowminded

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Question for track hand layers
« on: January 13, 2020, 02:22:22 PM »
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Anybody with point tools of various sizes, I have this question.  I know the frog is specific to a number BUT, is the point angle that's built in to the tools the same over various turnout sizes, even over all sizes?  I strongly suspect it is because of 1:1 switch rail length specs but need confirmation of that.  I'm making fixtures for machining the rail components for my new turnouts, don't have all of the sizes drawn yet, but want to proceed with the all of the various size fixtures while the machine is set-up.  Looking at a set of Fast Tracks tools, say a #5 and then maybe a #10 might have the answer.  I suspect they are all about 1.9 to 2 degrees.  :|
Mark G.

RBrodzinsky

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Re: Question for track hand layers
« Reply #1 on: January 13, 2020, 02:43:07 PM »
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The frog is specific to number.  If you look at the photos here (https://www.handlaidtrack.com/fh-me55-m), you can see a difference on the divergence angles.  As the number increases, the differences in the angles decrease.
Rick Brodzinsky
Chief Engineer - JACALAR Railroad
Silicon Valley FreeMo-N

jdcolombo

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Re: Question for track hand layers
« Reply #2 on: January 13, 2020, 04:32:23 PM »
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Anybody with point tools of various sizes, I have this question.  I know the frog is specific to a number BUT, is the point angle that's built in to the tools the same over various turnout sizes, even over all sizes?  I strongly suspect it is because of 1:1 switch rail length specs but need confirmation of that.  I'm making fixtures for machining the rail components for my new turnouts, don't have all of the sizes drawn yet, but want to proceed with the all of the various size fixtures while the machine is set-up.  Looking at a set of Fast Tracks tools, say a #5 and then maybe a #10 might have the answer.  I suspect they are all about 1.9 to 2 degrees.  :|

If you are talking about the angle at which the two rails that make the frog join, I believe it changes depending on frog number: shallower for high number frogs, more acute as frog number decreases.

John C.

Santa Fe Guy

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Re: Question for track hand layers
« Reply #3 on: January 13, 2020, 04:39:11 PM »
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Maybe you could check this out on the Fast Tracks web site where they have all the turnout templates by scale if not done so already.
Rod.
Santafesd40.blogspot.com

narrowminded

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Re: Question for track hand layers
« Reply #4 on: January 13, 2020, 05:44:15 PM »
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Thanks for the replies BUT... it's the point rail angle built in to those fixtures that I'm talking about, not the frog angle.  The frog fixtures are already designed and ready to machine, #4 thru #12, every whole # (halfs exist but enough is enough).  ;)  The second set of grooves, the point side of the tool, not the frog, in tools like Fast Tracks makes for the frogs and point rails is what I'm suspicious are the same.  I'm making individual fixtures for machining these, not filing.  If I was filing I'd probably just buy their tools but... if I was filing all of these I also wouldn't be thinking about this as a venture. :D

I'd be checking it on the individual turnout drawings but they aren't done yet and I really want to batch all of these fixtures together to put through the machine as the overlaps in tools and setup are so very much alike that it saves LOTS of machine time to take advantage of those similarities. 

If somebody owned two of those tool sizes, say a #5 and a #10, it would be as simple as looking at the point side of the tool, not the frog, and see if they are the same.  The end entry and the side exit will match if they are. 8)  Thanks.
Mark G.

Jim Costello

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Re: Question for track hand layers
« Reply #5 on: January 13, 2020, 06:05:24 PM »
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If I read into your message correctly, they are different..you have to be careful that the flanges on both the point blade and the stock rail clear each other. A # 4 will be much shorter in length on both the point blade and the stock rail than say a #10 etc.
I have a #8 set and just move the rail in the jig to get the clearance required.

Jim

narrowminded

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Re: Question for track hand layers
« Reply #6 on: January 13, 2020, 07:31:33 PM »
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If I read into your message correctly, they are different..you have to be careful that the flanges on both the point blade and the stock rail clear each other. A # 4 will be much shorter in length on both the point blade and the stock rail than say a #10 etc.
I have a #8 set and just move the rail in the jig to get the clearance required.

Jim

Thanks @Jim Costello.  Would it be too much trouble to get caliper measurements of the point grooves on the #8 tool that you have?  Off the point rail end of the tool, a measurement of the span between the grooves (the inside edges) and then the distance up the side where the groove exits the tool would be helpful.  I have a #4 and could compare those numbers.  That would help to confirm my suspicions, one way or another. 8)
Mark G.

Jim Costello

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Re: Question for track hand layers
« Reply #7 on: January 13, 2020, 08:05:09 PM »
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Sorry I cannot help for the moment,I have lent out my jig for a month or two and he is a few hundred miles away.  However, when I have used the jig I have had
to provide extra clearance at different times...whether I didn't file enough off originally I don't remember now. I don't think it makes that much of a difference anyway.
Have you had a look at the Fast track templates, I think they show what you are looking for.( I don't have the templates here either.

Jim

CNscale

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Re: Question for track hand layers
« Reply #8 on: January 13, 2020, 09:26:43 PM »
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I have a #5 and a #8 tool.
The distance between the grooves on the end is the same on both: 19.5mm.
The distance to the groove exit on the side is 47mm on the #8 and 52mm on the #5.
« Last Edit: January 13, 2020, 09:38:53 PM by CNscale »

wcfn100

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Re: Question for track hand layers
« Reply #9 on: January 13, 2020, 10:01:40 PM »
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This would seen like a straight forward math problem.

What's the length of the point rail?

What's the flange clearance at the heal of the point rail?

What's the width of the rail head?

With those three things, you'll get your angle.  Assuming you only want to make a single fixture, you would want to assume the longest point rail, narrowest flange clearance, and narrowest rail head to get your maximum angle.

Jason

« Last Edit: January 13, 2020, 10:33:45 PM by wcfn100 »

narrowminded

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Re: Question for track hand layers
« Reply #10 on: January 13, 2020, 10:24:12 PM »
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I have a #5 and a #8 tool.
The distance between the grooves on the end is the same on both: 19.5mm.
The distance to the groove exit on the side is 47mm on the #8 and 52mm on the #5.

That's exactly what I wanted!  Thanks. 8) 

Now, could you eyeball the caliper to the witness mark where the groove exits the side of the body?  Nominally 75 to 77 mm?  I ask this because the part gets so thin at the sharp wall exit that just the deburring changes that dimension pretty substantially.  My #4 measures 49mm on one side and 51mm on the opposite at that point.  And while at it, body width on my #4 is 25.07mm wide and the end face groove dimension is 19.8mm, well within acceptable tolerance.

If your side dimension to the witness mark is around 77mm and the body width is
Mark G.

Maletrain

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Re: Question for track hand layers
« Reply #11 on: January 13, 2020, 10:26:26 PM »
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Mark,

I think I understand the question you are asking, and maybe why. 

If you look at pages 83,and 85 of the B&O drawings I sent to you, you will see that the distance from the point rail tip to the place where the flangeway is specified (between the point rail and the stock rail) differs with the number of the switch.  [Don't be confused by the drawings for "Wharton Switches" on page 84, which shows the distance to be the same (18' for #s 7, 8 and 10), because those are "stub" switches that move blunt ends of the rails to align with 2 different routes across a gap.]  The flangeway for regular "split" switches is specified as 5-1/2" for #s 4, 5 and 6, and then 6-1/2" for #s 7, 8, 10, 16 and 20. The lengths for those point rails is 11', 11', 13', 15', 16'-6", 16'-6', 24' and 30' for #s 4, 5, 6, 7, 8, 10, 16 and 20, respectively.  So, #s 4 and 5 end-up being the same angle, 10 and 16 end up being the same angle.  Why those two pairs don't differ, I don't know.  I calculate the angle of a #4 to be = 2.3880 degrees (2 degrees, 23 minutes, 17 seconds).  But, the table on page 82 gives it as 2 degrees, 15 minutes, 51 seconds.  Similarly, for the #20, I calculate 1.0346 degrees (1 degree, 2 minutes, 4 seconds) but that table gives 0 degrees, 59 minutes, 23 seconds.  So, my calcs are "off" by 7 and 3 minutes of angle and I don't know why.  But, in N scale I don't think anybody would notice.  In fact, it might not really matter for looks or operational reliability in N scale whether all of the turnouts had their point angles set the same, instead of varying with the frog number. 

The NMRA spec for the separation of the point rails and stock rails scales out to about 6-1/2 prototype inches, so it seems like a reasonably good looking model switch can be designed to meet NMRA specs with the proper point rail scale length to the hinge and near-scale spacing from the stock rail.

I assume that Fast Tracks has already gone through the development efforts to make a nice looking switch with NMRA flangeways that operates well. So that is probably the best guide (unless you don't like the way they look).  Maybe a single angle can be found for all N scale point rail angles for the switch numbers that you want to build.  If so, I bet Fast Tracks has already figured that out.  But, as you probably already know, their filing jig tools come with jigs for both the frogs and points for each frog #.  And, as you probably already know, their website does not specify what those point angles are, nor whether the point angles are the same for all of those jigs.  You could ask them, directly, if others here don't have jigs available to measure.  But, can we really measure the angles of their jigs to something like a half-degree accuracy, anyway?  I really doubt that a half-degree matters visually or operationally.

So, the angles you spoke of (1.9 to 2 degrees) don't seem out of the ball park, at all.  But, I think it is better for the angle to be a little too small rather than a little too large, so that the tip of the point is sure to be held tight against the stock rail.  The other way seems like it could promote point-picking by flanges and thus derailments.
 

narrowminded

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Re: Question for track hand layers
« Reply #12 on: January 13, 2020, 10:38:28 PM »
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BETTER YET!  I'm being thick skulled over here. :facepalm: :D  You have two tools.  I'm really trying to measure the angles to see if they are the same.  If you could just unbolt the two fixtures and place about a .8mm to 1mm wire in the groove and set the second tool against it, see if the sides remain parallel.  That would say they're the same, a #5 and a #8... or they're not the same. :| ;)  I'm guessing they are the same. :|
Mark G.

wcfn100

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Re: Question for track hand layers
« Reply #13 on: January 13, 2020, 10:43:14 PM »
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Using the NMRA Gage for point clearance (.043) at the point heal, an 18' point rail (PRR #8 turnout) and a .018" rail head width (c43 rail), anything under 2.5 degrees would work.


Jason

narrowminded

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Re: Question for track hand layers
« Reply #14 on: January 13, 2020, 11:24:42 PM »
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This would seen like a straight forward math problem.

What's the length of the point rail?

What's the flange clearance at the heal of the point rail?

What's the width of the rail head?

With those three things, you'll get your angle.  Assuming you only want to make a single fixture, you would want to assume the longest point rail, narrowest flange clearance, and narrowest rail head to get your maximum angle.

Jason

That calculation is easy.  It's getting good measurements that's not so easy especially when there are uneven arcs involved, a relatively sharp shallow angle at the throw bar area, then a short straight before the radius starts, and in relation to a second rail that is piggybacked to a first rail.  There's a lot going on there and I won't have the honest numbers until I start drawing all of them to scale.  I'm trying to get that fixture in the batch of frog fixtures which I DO have designed (#4 thru 10 +#12) that I'm lining up to run this coming week while I can get the CNC machine time.  They may not make it and it's a crapshoot when I'll get the time again.  It could be months. 

These fixtures will allow for the part cuts to be made VERY accurately and efficiently in a good manual machine for the relatively short quantities involved (twenties to hundreds).
Mark G.