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@ Photo (1) - Just for shirts and giggles, here's a chart to compare prototype turnout lengths and proportions: Cheerio!Bob Gilmore
thanks bob. I will move into using the paper templates but for now, id like consistency in my turnouts and I believe the FT jigs will help with that until I pick up the new skill. ill have a couple curved turnouts at summit ill be building so this is why im starting with the jig to get going. Drasko
@ Hey Bob, I have that same template sheet and was thinking about where it came from. If I remember right, it came in a NMRA Bulletin back in the '80 or '90's. I've used it a lot over the years building turnouts.
I got ya Bob. The fitment isn't what i was after. Im actually using it to run my steam locomotives through to test reliability before i decide on that size. Cajon pass had what looked like real #10s all over it and my minds eye sets that as a #8 in our terms. I want to see how my steam handles this turnout before i order the jig. Drasko
Drasko @draskouasshat , Since the effective diverging radius of an N-scale #8 turnout built to prototype standards is 38.02", I doubt very much that your long-wheelbase steam engines are going to have a problem negotiating them.Interestingly, just going with #9's instead, will increase the effective diverging radius to 51.29", which would a noticeably larger radius.Just for the sake of comparison, a #10 has an effective diverging radius of 64.40".Cheerio!Bob Gilmore
FWIW . . . I have built #6 turnouts using a FastTracks jig, and #4's using a paper template. All my steam locos, which include Walthers/LL Berkshires; Bachmann Berkshires; a Kato UP FEF; a Kato GS4; two Bachman EM-1's; a Walthers N&W 2-8-8-2; and an Athearn Challenger and Big Boy negotiate the #6's as smooth as silk. They will even negotiate the #4's without problem (I don't use my big steam power for switching duties which will encounter the #4's, but just as a test, I ran the Berks and the Big Boy over them just to see). By the way, these engines routinely have issues with Atlas Code 55 #5's, which just aren't built very well, IMHO.All modern plastic steam locos are advertised as being capable of negotiating 12"-radius curves, though I have found that my Berks are more comfortable with 13" radius minimums. Some rigid-wheelbase brass, like a C&O T1 (2-10-4) might require a higher minimum - my Key brass Berkshire requires 16" if I have the tender mounted at its closest (and most prototypically correct) position. But as Bob has pointed out, the diverging radius of a #8 turnout is WAY more than this. There is no N-scale steam loco I'm aware of, including rigid-wheelbase brass, that would have any problem whatsoever on a #8 turnout built to NMRA standards.Of course, there is a difference between operating well and LOOKING like the prototype. Mainline turnouts on prototype railroads - for passing sidings, for example - are typically VERY high numbers, with #16's (allowing 40 mph speed through the turnout) or #20's (good for 50 mph) common. So if you are after the prototype look as opposed to simply excellent operation, a #8 won't do it. A #12 would be more appropriate for getting the mainline passing-siding look.But as Bob noted, what you WILL have to do regardless of the turnout number you use is take an NMRA wheel gauge to EVERYTHING and make sure the wheels are EXACTLY in gauge. I've found that the drivers tend to be pretty much spot on with modern N scale steam (e.g., anything built after 1995). But trailing truck wheels, pilot truck wheels, and especially tender wheels are often severely out of gauge. Ditto for diesels - I have never bought a diesel loco from a mainstream manufacturer (Atlas, IM, FVM and BLI) that had the wheels correctly gauged; they are almost always a tad narrow. Why this is so hard to get right at the factory I do not know. But apparently it is.John C.
john,modern mainline turnouts are more like #24s although there are some older 20s and even 152 still out there. all new installations on the BNSF for crossovers and sidings is usually a 24. Also, a #16 is most definetly not good for 40. ill have to look at some timetables for an exact speed restriction but 40 is waaaay too high. thats whats on a 24 as of now. Drasko
Fast Tracks state that the diverging radius of their #8 turnout is 36”. It’s near the top of the paper template.
Since I downloaded my FT turnout templates in 2014, the version I had was 1.02, and the effective diverging track radius is not included on the PDF's. This caused me to go to the FT site and take a peek at what is there now as far as track templates are concerned, and the version on nearly all of the new drawings is version 2.00...with lots of interesting and useful information included, including the effective diverging track radius on most turnouts.I thought it was interesting, because the information I used to get the diverging track radius was contained in the box in the chart that I uploaded to my initial comment here...from the "Engineering and Maintenance of Way Cyclopedia", which lists the diverging centerline radius of the diverging tracks for #8's as "509.39' ", for #9's as "683.95' " and for #10's as "845.68' "...which when converted to 1/160th scale equals an N-scale diverging track radius of 38.024" (#8), 51.29" (#9), and 64.40" (#10).Did this mean that since Fast Tracks says their turnouts are built to NMRA standards, that the NMRA's diverging track radius is different than a scaled-down prototype turnout??I decided to take a closer look at the NMRA's "Recommended Practices" page.When I looked at the information contained in the NMRA bulletins RP-12 Turnouts - General - (2/2015), and RP-12x (zip file contains 12.1 to 12.54) (2/2015) I found some interesting and disturbing information which changed my assumptions about NMRA turnout standards.Hmmmm...the NMRA lists two turnout standards for N-scale turnouts (1) "Fine:N Scale" and (2) "N Scale"...and most of the turnout measurements for these two standards are different.Even the diverging track radius is different between the two NMRA standards, with the diverging radius of a "Fine:N Scale" #8 turnout being 33.374" as opposed to the NMRA "N Scale" equivalent at 31.94", both dimensions being significantly smaller than what Fast Tracks gives you at 36". Prototype equivalent diverging track radius is 38.024"Even worse for the NMRA is the diverging track radius of an NMRA "Fine:N Scale" and "N Scale" #9 turnout, listed respectively as 42.183" and 40.333", as opposed to the Fast Tracks product which is at 50". Prototype equivalent diverging track radius is 51.29",Finally, for a #10 turnout, NMRA "Fine:N Scale" and "N Scale" turnouts are listed respectively as 53.837" and 51.524", as opposed to the Fast Track #10 product which is 64". Prototype equivalent diverging track radius is 64.400"It's late, and I didn't check the other dimensional and clearance differences between the NMRA's two standards, Fast Tracks and prototype equivalent, but it is pretty clear that the NMRA's two standards aren't even close to equivalent prototype dimensions at least for the diverging track radii. The opposite side of the coin is that turnouts made from Fast Tracks fixtures are MUCH closer to the equivalent prototype dimensions for diverging track radii than turnouts built to NMRA Standards...either NMRA "Fine:N Scale" or plain ol' NMRA "N Scale" standards.This is a discovery for me, and I've always claimed that I built my turnouts to a "tight" NMRA standard, which evidently isn't true. HOWEVER, the NMRA sells only one (1) N Scale RP-2 track "gage"...the Mark IV, for checking such essential clearances at flangeway width and depth, point toe width, and check gauge...all of which are different each other in both "Fine:N Scale" and "N Scale".I use the N-scale Mark IV RP-2 "Gage" when checking clearances on each and every turnout I make, and make all of my clearances "tight" so that the gage's feelers and nubs have an interference fit. Truthfully, I've never felt the need to actually measure the nubs and notches on NMRA's gage, so I don't know exactly what the measurements are on my turnouts. All I know is that my turnouts function excellently using the "interference fit" protocol when building them, and proportioning them very close to how prototype turnouts are built.Fast Tracks states in their literature that their turnouts are built to NMRA standards, but this doesn't appear to be correct, and in this case, is a good thing. I'm guessing that Fast Tracks, like me and others who use reduced-to-N-scale paper templates of prototype drawings, have made our turnouts proportioned very closely to what the real deal looks like, but used the NMRA clearance "gage" to establish our product as NMRA compliant so that our rolling stock and motive power equipped with NMRA compliant wheels, will run reliably on our tracks. An added benefit from doing it this way instead of adhering to all of the NMRA's turnout dimensions, are turnouts that will run prototype-proportioned equipment more reliably because the relationship between the equipment and the track remains the same no matter what volume it occupies. In other words, reliable operation for prototype turnouts is much the same for N scale turnouts, and fiddling with the basic proportions is just asking for reliability problems.These discoveries makes me feel even better about Fast Tracks, and in the future, I am going to more fully endorse their fixtures and construction methods (with a few exceptions) to anyone wanting to get into hand-laying their own track.Cheerio!Bob Gilmore
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Topic: Who has a fasttracks #8 jig for code 55? (Read 9139 times)
