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Started by mallonee, February 09, 2013, 11:05:26 AM

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jward

if you eliminate the crossing, and just use the switches it should fit. especially if you use the #6 crossovers. if you use the 18r switches for your crossover, you need to push the table width out a couple inches. i don't advise going smaller than 18r under any circumstances except for trolleys.
Jeffery S Ward Sr
Pittsburgh, PA

Doneldon

Quote from: jbrock27 on February 12, 2013, 07:51:53 PM
Ok, can anyone tell, me if mal (OP) was to pull this off on a 4 x 8 space, would mal have to use a curve with a radius of less than 18" for his inside loop?

Thanks much,

-jb

jb-

No. It's possible to have nested loops on a 4x8 without going less than 18" radius curves.
The layout I built for my grandson has two nested loops and a third track which serves as
a yard lead and there are no curves tighter than 18" radius.

                                                                                               -- D

jbrock27

Thank you Jeff and Doc.

Jeff, I take it when you say 18R switches, you are referring to "snap switches" as opposed to #4s or up, correct?  Luckily no trolleys on the layout but I would like to stick with no less than 18R bc I do have a couple of old time SD45s that run fine on my 18R track and 18R switches.

I have nested loops now, using just snap switches to accomplish that on my layout section that is 4 x 8-I was wondering about using Mal's idea and if it would work, making the crossover using the same space. 
On the back of a package for an Atlas #4 turnout, instructions are given how to make one, using 4 #4s but they also instruct using a 25 degree crossover, not a 30.  I wondered how much this mattered.  Ideas???

Thanks again.

-jb
Keep Calm and Carry On

Balrog21

if you want I can try and do one up in anyrail and see how it goes for you all? Just let me know!
B

jward

#19
Quote from: jbrock27 on February 13, 2013, 07:20:59 AM
Thank you Jeff and Doc.

Jeff, I take it when you say 18R switches, you are referring to "snap switches" as opposed to #4s or up, correct?  Luckily no trolleys on the layout but I would like to stick with no less than 18R bc I do have a couple of old time SD45s that run fine on my 18R track and 18R switches.

I have nested loops now, using just snap switches to accomplish that on my layout section that is 4 x 8-I was wondering about using Mal's idea and if it would work, making the crossover using the same space.  
On the back of a package for an Atlas #4 turnout, instructions are given how to make one, using 4 #4s but they also instruct using a 25 degree crossover, not a 30.  I wondered how much this mattered.  Ideas???

Thanks again.

-jb

you are correct that the 18r switches are the "snap switches" from atlas, and their equivalents from others. these would also be the ones included in the layout expander packs. their geometry is very close no matter what brand you use.

the numbered switches, however, are completely different between manufacturers. so the angle of the crossing matters a great deal. for example, the atlas 4 is actually a #4.5 with a frog angle of about 12.8 degrees. thus they have  12.5 and 25 degree crossings designed to be used with their 4s. the bachmann 4 is about 14.5 degrees, give or take. so it needs about a 29 degree crossing.  a 30 is close enough to work.

another difference between the two brands is that atlas has designed their switches to make crossovers and yard tracks on 2" centers. they did this by eliminating most of the track beyond the frog.   with the crossings, they have trimmed the length so that only the track around the diamond remains. thus a 25 degree crossing measures about 4.5 inches in length as opposed to bachmann's 30 degree which is 9" bachmann switches are also singnficantly longer, with much more track beyond the frog.

the net effect of this is that a crossover using atlas 4s takes up 16" on 2" centers, and a scissors type double crossover takes up 20.5" on 3" centers. this is actually similar to a regular crossover using bachmann 4s which is 19.5" long on 3.25 " centers.

for the scisssors crossover using bachmann 4s and a 30 degree crossing, the length is 31" and the track centers are 7" apart.
believe it or not this is less than the same type of crossover using atlas 6s, which works out to 26" long on 3" centers.

that extra space is why i had suggested earlier trimming some track off each leg on the crossing, and possibly the switches themselves, to get the track centers down to a more reasonable distance.
Jeffery S Ward Sr
Pittsburgh, PA

jbrock27

Bal, if you wouldn't mind doing that, that would be awesome!  Thank you.

Jeff, I knew that about the "snap switches" but did not know that about the numbered turnouts.  Thank you for the information :)  Is there a difference in the geometry of the Bachmann turnouts you are speaking of, between the ones they make now with roadbed and the older ones they used to make w/o the roadbed?  Another question, I have only seen numbered turnouts in the "old style" made by Atlas and a few other manufacturers but don't recall seeing them made by Bachmann-did they make them in the non roadbed version?
As always, thank you for your assistance.
Keep Calm and Carry On

jward

i don't believe bachmann ever made numbered switches before ez track. like most of the low end train set companies (ahm, tyco, lifelike) they used switches designed to replace a standard curve.

ahm and i believe model power made numbered switches. ahm even had some specialty items like a double slip switch, and a curved one with 22r and 18r.

bcahmann's ez track line is far more extensive than anything they ever produced before.
Jeffery S Ward Sr
Pittsburgh, PA

jbrock27

Thank you Jeff.  Yes, I have seen numbered turnouts in AHM track as you mentioned.
Keep Calm and Carry On

Johnson Bar Jeff

Quote from: Doneldon on February 13, 2013, 01:00:30 AM
No. It's possible to have nested loops on a 4x8 without going less than 18" radius curves.
The layout I built for my grandson has two nested loops and a third track which serves as
a yard lead and there are no curves tighter than 18" radius.

Sounds like the layout my grandpa built for me when I was a little shaver.  :)

Wish I had thought to make an exact track plan before it was disposed of years ago.  :(

Balrog21

here ya go..two plans done real quick in Anyrail. Both use the #6 Crossovers the outside loop is 22", the second is 20" -using 22's & 18's alternating,and the inside loop is 18". So with both of these plans you could have 3 trains running, two circling and one doing yard work. =) You could put a third isolated loop in with 18's, I guess if you wanted that to be a trolly or something,but you couldn't get to the outer two tracks with it and it would have to have it's own power supply. Anywho, there ya go! Both of these layouts are on a 4x8 board. Question answered!
B.


Balrog21

I made a bigger yard with this 4x8 plan and some optional industries as well. The options are pretty wide open!
B


jbrock27

Keep Calm and Carry On

Balrog21

Anytime! I LOVE me some Anyrail!

Joe Satnik

B21,

I like AnyRail, too.  Looks like you're having fun.   

I've yet to post a layout picture, so you're 3 steps ahead of me on the learning curve.

Good job.

I do see a few problems, though. 

First, narrow track centers.  See http://nmra.org/standards/sandrp/s-8.html

The charts there show that for the shortest rolling stock (class 2)

you need at least 2-3/16" spacing from 18"R to the next radius to avoid sideswiping. 

Similar for the next gap up...

Next problem,  "S" or "Ess" curves.  Elegant looking, but....

Body mounted couplers derail, and you cannot back up truck mounted couplers through S curves.

Rule of thumb to eliminate S curves, according to John Armstrong: 

"Put a straight between opposing curves that is at least as long as your longest rolling stock."

Hope this helps.

Sincerely,

Joe Satnik





If your loco is too heavy to lift, you'd better be able to ride in, on or behind it.

Balrog21

thanks for the heads up Joe, and you are correct, this was just an exercise to see the tightest curves that would fit with #6 crossovers for jb. Here is my layout I'm working on right now below. =)

turnouts are 4's and 5's all curves are 22 or higher and the 2 crossovers are the #6's. All EZ track except for the pieces of flex track that you can tell on the pic! The tables are 5x8's (4 of them)

However I do appreciate the caution. It's always nice to know that we trainiacs have others looking over our shoulders and helping to guide us!
B