Santa Fe in China Basin

[GaryHinshaw]

Fantastic!

When faced with a project of this complexity, the only way to approach it is "one step at a time."  Hope you got the gaps in all the right places.   

Best wishes getting the compound points to work well.  Are you planning to power the frogs? 

[railnerd]

Fantastic!

When faced with a project of this complexity, the only way to approach it is "one step at a time."  Hope you got the gaps in all the right places.   

Best wishes getting the compound points to work well.  Are you planning to power the frogs?

Just got back into town after being off grid for a week. (Dang, 7 pages of TRW backlog to get through!)  Hoping to get back to this project in a few days with a clear head.

Yep, the compound points are the biggest issue here‚ I have a backup plan to use proto87stores' milled points as a second attempt if I cannot make this work.  Frogs and triple track will be powered, which will be "fun."

I did some drawings for the electrical bits at one point, but plan on re-checking my work.  Plan is to use two throwbars to actuate the points, which may require adjusting the cross ties to make room for a smooth mechanism.

Had an idea to use a multi-pole rotary switch for the control mechanism, but may use an Arduino to sequence things electronically instead.

-Dave

[railnerd]

Did pick up another new book, with plenty of great shots of the SF Bay Area railroads in action. Lots of SP and WP coverage, but no pics of China Basin. A few shots of ATSF street running in SF, some shots of the NWP car ferry operation in Tiberon, and a nice view of the WP 25th street ferry dock.

http://morningsunbooks.com/collections/frontpage/products/trackside-in-california-1964-99-with-george-drury



-Dave

[railnerd]

Worked on the 3-way turnout again today.  Took a few iterations to tune the points as the constraints are a bit fiddly:




The points are "interesting" as they overlap and must be thrown in sequence to set the route:







Next up will be a mechanism to throw those points.

[craigolio1]

I just saw your post on the weekend update which caused me to read your entire thread. Amazing. Keep it up!

Craig

[Jesse6669]

If it's possible to make a video of this in operation or just testing.. that would be amazing...!   

[railnerd]

I'm thinking of sequencing the whole shebang with an Arduino, since the power routing is going to be "fun."  My guess is that I'll end up doing a blog post and a vide to demo.  I'm trying to document the entire project so I can do a clinic someday.

-Dave

[Chris333]

That turnout is nuts! 

[M.C. Fujiwara]

Did you coat the side edges of the PC board ties with something, or place a lubed barrier between them (like slim styrene)?
Those PC board ties seem to have some flaky metal bits that cause shorts sometimes.

Otherwise: looks great, Dave!
Major accomplishment to get the points lining up while lapped.
(though I still think you're a wussy for not trying manual slide switches  )

Can't wait to see it in action.
Gonna be a great car float scene.
(almost wrote "cloa fart" scene, which means 1. my dyslexia is getting worse, by dog, and 2. it's time for deb  )

[railnerd]

Did you coat the side edges of the PC board ties with something, or place a lubed barrier between them (like slim styrene)?
Those PC board ties seem to have some flaky metal bits that cause shorts sometimes.

There is actually a fair amount of gap, but I did file the edges to remove the dangly metal bits; planned on "painting" with NeoLube…  bet that won't help.

(though I still think you're a wussy for not trying manual slide switches  )

I may still do that— I have some bluepoints in a box at home; big issue is "operator error" in that there are only 3 valid combinations, but 4 configurations— and that fourth option puts the silver solder on those points under too much stress.

[Mark W]

I may still do that— I have some bluepoints in a box at home; big issue is "operator error" in that there are only 3 valid combinations, but 4 configurations— and that fourth option puts the silver solder on those points under too much stress.

If I'm visualizing the way the turnout operates correctly, I bet there's a way you could fit a 'floating' drawbar stopper between the slide switches preventing both from being thrown "in" at the same time.  I'm thinking a thin metal sheet that slides under the turnout ties, has a notch for each slide on the ends and is the exact length between one slide in the 'in' position and the other 'out'.  So when the other slide is thrown 'in' the drawbar pushes on the other slide, throwing it 'out' properly.  This would put the pressure on the slide switch, not the rail.  The drawbar would not be physically connected to either slide, allowing both to be 'out' at the same time.
You'd have to align the slides directly opposite each other, then bend the connection from the slide to the throwbar as necessary.

[jagged ben]

I'm thinking that with a simple diode matrix you can easily prevent operator error if using switch motors.

If using slide switches, a simple 'interlock' type sliding bracket can be used on the switch controls.   You'd put it between the switches, perpendicular to the direction of the switch motion, such that it has to be slid towards one switch for the other to be pushed to the middle.  That way both can't be pushed to the middle at the same time.

I'm not sure if I'm saying exactly the same as Mark, but I don't think so.  Similar concept maybe.

BTW I think I almost posted two different versions of complete nonsense before I stared at the pictures for a third time and figured out how this turnout actually works.  At least I hope I finally figured it out correctly and didn't miss anything.      In any case it's definitely satisfying to have something constructive to say in this thread.

[wcfn100]

I think a 3-way toggle switch and 2 tortoise machines should be all that's needed. 



In theory, the correct set of points will always start throwing first at B when going from A-C or C-A so there shouldn't be any pushing.


Jason

[railnerd]

I think a 3-way toggle switch and 2 tortoise machines should be all that's needed. 

Yep.  That's the easy part— did that same drawing myself a few months back.

Also have to route the power appropriately for the 3-frogs.

-Dave

[davefoxx]

Yep.  That's the easy part— did that same drawing myself a few months back.

Also have to route the power appropriately for the 3-frogs.

-Dave

I'd use a Hex Frog Juicer to control those three frogs automatically.  BTW, I like the plan to use the three-way toggle switch.  Could a rotary switch be used?

DFF