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Radii of Peco curved turnouts

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Radii of Peco curved turnouts
Posted by John-NYBW on Sunday, March 27, 2022 11:54 AM

I have an Atlas #8 curved turnout which has been nothing but a problem from the day I installed it. You might as well call it a #8 derailer. I want to replace it and since I don't trust the Walthers name enough to try their new line of turnouts, that leaves Peco. I have several of their turnouts and know they are top drawer. I now wish they were all Peco but that would get very expensive to replace them all so I'm just changing the problem turnouts.

I have code 83 track. I have to decide between a Peco #7 or #8. Does anybody know what the true radii of these curved turnouts is. The outside curve of the turnout is on a 36" radius curve and the inside would be about 34". I can fudge the rails on either side of it so it doesn't need to be an exact match for the Atlas turnout. I can get either on ebay for just under $40 including shipping. If it can solve this problem, it will be well worth the money.

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Posted by maxman on Sunday, March 27, 2022 7:45 PM

I believe that you can go to the PECO website and print out full size template.

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Posted by hon30critter on Sunday, March 27, 2022 9:53 PM

Hi John-NYBW,

Here is a link to the Peco HO scale curved turnouts. The product pages list the radii. Click on the turnout that you are interested in, and then click on the link under  'Downloads'. That will get you to the full sized template.

Note: Your printer may not be printing at exactly 1:1. You may have to resize the drawing a bit. There is a scale ruler on the template to test for proper size.

https://peco-uk.com/pages/search-results-page?q=curved+turnout&page=1&rb_snize_facet3=OO+HO+%3D+16.5mm

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by DigitalGriffin on Monday, March 28, 2022 8:58 AM

The NEW walthers curved turnouts are true to their word on radius.  I own a few and they are nicely wired up including a solder point for the frog.

That said, if you download and install anyrail, you can print 1:1 scale.  This includes the NEW walthers track, and PECO.  I have overlaid the real thing overtop the printout and it's a perfect fit.

The programmer of anyrail went to great lengths to accurately put in those turnout geometries.

(If you want I can take a picture of my turnout sitting over the 1:1 printout to show you how accurate it is.)

I can also show you cheaters way of using a tramel to find centerpoint and radius of a turn (provided the curvature is constant)

 

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

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Posted by CharlieM on Monday, March 28, 2022 9:22 AM

A note of caution on Peco full sized templates. I ordered the new SL-U8362  Unifrog HO #6 right turnout. The downloaded template showed overall length at 8.8" but when it arrived the actual part was 9-3/16". This is closer to the old pre Unifrog item. Not sure where the difference comes from. Maybe an error in the Unifrog documentation or a new guy in the drafting dept.

That said the new part works beautifully and I'm becoming a convert to Peco vs Atlas.

Charlie, Northern Colorado

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Posted by Doughless on Monday, March 28, 2022 9:36 AM

I think PECO only makes what they call a #7 curved turnout.  Working with the two that I have, the radius of the outer curve is approximately the same as the embedded radius of the diverging route in a straight#8 turnout.  Its very broad, probably in excess of 50 inch radius.  The inner curved radius might be about 34 inches, to OPs point. 

There is a greater disparity in the outer and inner radii of the PECO than all other brands, allowing enough spearation in the two routes to keep the length of the turnout compact.

I'd have no hesitation in buying a new Walthers turnout, since its outer/inner radii are closer to what OP is looking for, making for a pretty long piece of track however.

- Douglas

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Posted by riogrande5761 on Monday, March 28, 2022 1:28 PM

I've purchased and laid Peco Streamline code 100 curved and Peco #7 code 83 curved.  From modeltrainstuff:

Peco HO Streamline code 100 curved turnout:

Length: 10-1/16"
Nominal radii: 
Outside: 60"
Inside: 30"

 

Peco HO code 83 #7 HO curved turnout:

Length: 11-1/10"
Nominal radii:
Outside 60"
Inside 36"

 

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by John-NYBW on Monday, March 28, 2022 5:30 PM

riogrande5761

I've purchased and laid Peco Streamline code 100 curved and Peco #7 code 83 curved.  From modeltrainstuff:

Peco HO Streamline code 100 curved turnout:

Length: 10-1/16"
Nominal radii: 
Outside: 60"
Inside: 30"

 

Peco HO code 83 #7 HO curved turnout:

Length: 11-1/10"
Nominal radii:
Outside 60"
Inside 36"

 

 

If the 36" radius is accurate, that should be ideal for what I have. Currently, I have an easement leading into the curved turnout and I should be able to position the outer curve somewhere along that easement. It's going to mean pulling up some track and relaying the roadbed but well worth the effort if it will eliminate this problem turnout. Right now it seriously limits which equipment I can run through the inner curve and even the outer curve gives me an occasional derailment. 

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Posted by John-NYBW on Monday, March 28, 2022 5:34 PM

Doughless

I think PECO only makes what they call a #7 curved turnout.  Working with the two that I have, the radius of the outer curve is approximately the same as the embedded radius of the diverging route in a straight#8 turnout.  Its very broad, probably in excess of 50 inch radius.  The inner curved radius might be about 34 inches, to OPs point. 

There is a greater disparity in the outer and inner radii of the PECO than all other brands, allowing enough spearation in the two routes to keep the length of the turnout compact.

I'd have no hesitation in buying a new Walthers turnout, since its outer/inner radii are closer to what OP is looking for, making for a pretty long piece of track however.

 

What you say about the Walthers turnouts might very well be true but I've been disappointed too many times by the quality of products with the Walthers name on them to take a chance when I know I will get a quality product from Peco. I've installed three of them now, one which replaced a problem Atlas turnout and they have performed flawlessly. 

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Posted by bagal on Sunday, April 10, 2022 12:33 AM

CharlieM

A note of caution on Peco full sized templates. I ordered the new SL-U8362  Unifrog HO #6 right turnout. The downloaded template showed overall length at 8.8" but when it arrived the actual part was 9-3/16". This is closer to the old pre Unifrog item. Not sure where the difference comes from. Maybe an error in the Unifrog documentation or a new guy in the drafting dept.

That said the new part works beautifully and I'm becoming a convert to Peco vs Atlas.

Charlie, Northern Colorado

 

I pointed out that error to Peco but they didnt respond. I dont have one in front of me but i think the actual length is 233mm but they have put the length at 223mm and sized the template to that. 

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Posted by hon30critter on Sunday, April 10, 2022 1:18 AM

bagal
I pointed out that error to Peco but they didnt respond. I dont have one in front of me but i think the actual length is 233mm but they have put the length at 223mm and sized the template to that. 

I'm not surprised. Peco has an excellent product, but their product documentation and nomenclature has been sadly lacking. On too many occassions they have changed the design of their turnouts without noting the changes in their literature or on their packaging. For example, there are at least two different versions of the HO scale Code 100 Electrofrog Streamlined turnouts, all with the same part #. Some of the more recent ones have feeders attached to the frog whereas the earlier versions have a tab on the side of the frog to which a feeder can be attached.

Ultimately they all work fine, but it is a crap shoot when you are ordering them.

Cheers!!

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

  • Member since
    July 2006
  • 289 posts
Posted by bagal on Sunday, April 10, 2022 2:48 AM

Yes, I believe the #6 unifrog has changed recently. I have just received a batch so curious to know if I have the  newer version or the initial version. 

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