narrow siding switches

You have a couple of issues you need to consider.

- What are you going to park there?  It looks like a small station, so maybe a passenger car?  You can place straight sections of FastTrack almost next to the wall, but the curve coming off the switch will require more room to allow for overhang of the edge of the car or engine. If you use 40' freight cars, shorty passenger cars, or small diesels, you can probably get away with 1 3/4" center rail to the wall depending on the curve (O-31 may need 2").  Longer equipment will need more room.

- FastTrack switches are set up for 6" from center rail to center rail (C-C) between straight tracks, so they will not work for you unless someone knows how to cut them down.  You would need to use something like Atlas or Ross #4 switches, and those can get your parallel tracks down to 3 1/2" C-C.

I expect others will have a better answer, but as a minimum I think you would need maybe 5 1/2" from the center rail of your mainline to the wall, and it looks like you have about 6".   You just need to figure out how to make the FastTrack to Ross/Atlas transition somehow to use a #4 switch.

Thanks for your reply.. I was going to use it as just a deadend siding to park a few cars....  I guess I will just have to try and play with it.  I have a 036 switch but lots of 031 quarter turns, so I will see if I can do something with that.   Doug

Dougie,

Let us know if you can make it work.  I did some quick addition, and with the O-36 switch and O-31 sections, from the center rail to the wall would need to be about 7.5".  I don't use FasTrack, but if you can cut the curved leg back a bit, you probably can make it work.

I would say there's a zero percent chance of using fastrack and making that work. Agree with Ron, you need a numbered switch. A radius divergent ("O-XX") switch curves away and is usually a curve replacement, so the curvature is 22.5 degrees to replace a curve section. and would take another full curve to turn it back. It wouldnt matter what radius you used (unless it was miniscule), you wouldnt be able to bend it back before you hit the wall.

A numbered switch diverges at an angle from the straight leg, but continues in a straight path, which is why you can get them into more compact spaces.  A number 4 would do the job like Ron said. Use a Ross #4 and a TR35 transition track and you'd have 3.5" center to center.   Personally, I'd use a ross regular, rather than a #4. The angle is 11.25 rather than 13, but the length is about the same. Less angle, less "S" in the siding entrance, and the effective radius of a Regular is over 50" so anything would go through it.

Installing it in fastrack would take either  3 of the O to fastrack conversion pieces and 9 O to gargraves transition pins, or you can cut and drill out fastrack and solder the O to Gargraves conversion pins into the tops of the fastrack rails.

A possibility is a Gargraves 100" switch, and then cut short the branch section with a mototool and replace it with an opposite curve.

I agree with the previous suggestions to use either a numbered or long switch for smoother transitions from one track to the next.

However, if you're intent on sticking with FasTrack, the narrowest you can make the two parallel tracks would be to use an O31 switch and 3x O31 Quarter curve pieces.  The total width of this arrangement would be 8 3/4" wide from the outside edges of the roadbeds like so:

If you were to try to use an O36 Switch with O31 Quarters, the narrowest you could get would be about 9 1/8" OD.

Also look at the clearances between the main and the siding with the numbered switches. Since the branch is coming off at a straight angle from the main, you will need the first car to be parked further back from the switch in order to clear the main.

This is a significant limitation of Fastrack, I have yard tracks spaced at 3.5"   A #4 switch will get this job done with a bit of trimming.

I didn't pull the switch out to actually hook them together, but using an O36 half curve with an O72 switch measured less than 7.5". The half curve roadbed would have to be trimmed. It would work according to the picture.

Looks like 4.25", not bad , but not nearly as close as the OP is looking for.

I know of no way to switch Fastrack spaced like this!  You're looking for about 3" center-to-center spacing, that ain't gonna happen with any available Fastrack components.  AAMOF, I don't know how you'd do that with off the shelf switches with any O-scale track system.

I meant if you move the left track against the wall. With an inch between the roadbed, you get the 4.5". Without the 1 3/8" fitter on the switch, it comes pretty close.

@gunrunnerjohn posted:

  AAMOF, I don't know how you'd do that with off the shelf switches with any O-scale track system.

Not that it's practical but an Atlas #7.5 switch and an O36 1/4 curve yields less than 2.5" center rail to center rail spacing or a #5 switch and O54 half-curve yields ~ 2.75" center rail to center rail spacing or an O54 switch and an O27 half-curve will give you a 3" center rail to center rail spacing.

-Greg

@John H posted:

I didn't pull the switch out to actually hook them together, but using an O36 half curve with an O72 switch measured less than 7.5". The half curve roadbed would have to be trimmed. It would work according to the picture.

This will work..I think..  I went and measured. From the wall to the table edge I have 8 and one quarter inches.  I'll order the 072 left hand switch tonight.   Thanks you so much.   I will post a picture to you when I get it in.. Doug

@John H posted:

I didn't pull the switch out to actually hook them together, but using an O36 half curve with an O72 switch measured less than 7.5". The half curve roadbed would have to be trimmed. It would work according to the picture.

Good call @John H on the O72 switch.

Alternatively, if 2x O31 Quarter curves (one with roadbed trimmed to fit the the O72 switch) were used without the 1-3/8" fitter, that would get the outside dimension down to about 7 3/8".

Well I have a few of those to... I will play with them when I get the switch in, suppose to be Friday. I'll post some pic's.. Thanks Doug

4 inches is a good distance, center to center or whichever point you measure on both tracks.   That looks close to the one post above.   

I think you use the largest number/radius switch you can to avoid potential for derailments.    the Atlas 7.5 is good, I have used a lot of Roco #6, and the Atlas #5 might be fine too.    I don't really have a feel for how sharp an 072 switch is.    Basically to go into the siding you have to shove the cars through an "S" curve.   An S curve this sharp with 031 inch track often leads to derailments.

The numbered switches will impart less of an S-curve on the entry, so they're preferred for the task.  I did all my track cross-overs with numbered switches.

you could try using an 072 wye, with a short curve on each track bringing the two tracks into parallel. this will put a bend in the main line, however it is how I get my yard tracks as close together as possible.

This configuration is used on the first two leads in the upper left of this picture.

@SteveH posted:

Good call @John H on the O72 switch.

Alternatively, if 2x O31 Quarter curves (one with roadbed trimmed to fit the the O72 switch) were used without the 1-3/8" fitter, that would get the outside dimension down to about 7 3/8".

Well here is the pictures.....I cut the 072 switch so that the 036 half would fit.   I also put a 1.38 dead piece in so I have the siding power by a different transformer.  As always...need more space..

@Boilermaker1 posted:

I would say there's a zero percent chance of using fastrack and making that work. Agree with Ron, you need a numbered switch. A radius divergent ("O-XX") switch curves away and is usually a curve replacement, so the curvature is 22.5 degrees to replace a curve section. and would take another full curve to turn it back. It wouldnt matter what radius you used (unless it was miniscule), you wouldnt be able to bend it back before you hit the wall.

A numbered switch diverges at an angle from the straight leg, but continues in a straight path, which is why you can get them into more compact spaces.  A number 4 would do the job like Ron said. Use a Ross #4 and a TR35 transition track and you'd have 3.5" center to center.   Personally, I'd use a ross regular, rather than a #4. The angle is 11.25 rather than 13, but the length is about the same. Less angle, less "S" in the siding entrance, and the effective radius of a Regular is over 50" so anything would go through it.

Installing it in fastrack would take either  3 of the O to fastrack conversion pieces and 9 O to gargraves transition pins, or you can cut and drill out fastrack and solder the O to Gargraves conversion pins into the tops of the fastrack rails.

Well.. I made it work..072 switch with a bit of trimming..  The siding is 5 feet long and dead ends way under the top lay out.

@CAPPilot posted:

Dougie,

Let us know if you can make it work.  I did some quick addition, and with the O-36 switch and O-31 sections, from the center rail to the wall would need to be about 7.5".  I don't use FasTrack, but if you can cut the curved leg back a bit, you probably can make it work.

Made it work....072 switch with 036 half piece.  I did put a 1.38 dead piece so I can power the siding with another transformer.  The side is 5 feet long and winds under the top layout.