Large Scale Central

Switch Machine Project

Track and Trestles
#61

Since mechanical turnout indication was brought up on the sister thread at MLS, here’s where I’m heading. I’ll go into it more, once my first-article switch drive is working. But as an overview, this is an indicating (not controlling) switch stand, mounted to the opposite side of the drive. It could be various versions of harp or rotary, with easily swappable targets for different rr’s. I model the V&T, so the harp approximates their target.

It has electrical contacts for aux functions, such as (again) indication or relay powering. I’m testing different magnets for the reed switches, but seem to be settling on two 1/8" dia x 1/16" thick ones.

Here’s a section showing the basic magnet / reed / throwbar interaction. I’m using 2 reed switches, which can be SPST or SPDT. I’ll probably pot them in with silicone, and just have terminated leads hanging out.

A variant I’d like to try has a magnetic coupling in the throwbar, so that the stand can be used as an actual switch. For example, sending a command to the drive to flip. Once that move happens, the magnet re-registers, and the stand serves once more as an indication device.

This design isn’t complete, obviously, but feel free to comment.

Thanks for viewing,

===>Cliffy

#62

Back to the servo saver. All 4 manufacturers replied to my inquiry, but only one in the affirmative:

Hi Cliff:
Yes the #131 servo saver should fit right on the Standard size servo saver HS-311 24 spline. Also the rest of our servo saver sizes med and large.
Jay Kimbrough

This can be purchased for as little as $3 +shipping,
http://www.amazon.com/dp/B0006MZN7W

So I ordered one for testing. Hopefully it’ll fit.

#63

Neat looking Cliff! A word of caution to file away for later, design any such device to clear the largest 1:20.3 locos, should they visit your layout!

Regards, Greg

#64

Greg Elmassian said:

Neat looking Cliff! A word of caution to file away for later, design any such device to clear the largest 1:20.3 locos, should they visit your layout!

Regards, Greg

Yeah, I learned that lesson the hard way. I got my Shay stuck, hard, in a friends tunnel.

#65

Thanks Greg, I was hoping you’d like it!

Right, I have some BM geared loco’s, I should measure their sweep on my small-radius test loop. I just measured the current clearance from centerline to harp target edge (swung toward the track), and it’s 3". My tightest switches are R4 (Train Li parlance), meaning 4’. Most are R5’ though. So yeah, I should probably increase that to 3 1/2" or 4" clearance.

Your thoughts, Greg and Steve?

#66

I’ve picked 4", there’s a few cars that get to 3.5", the RDC comes to mind, as well as the USAT car carriers.

Greg

#67

Four inches of clearance should be enough. If you have tunnels, provide at least eleven inches vertical clearance from the railhead.

#68

Thanks guys, 4" it is.

#69

Back to the drive. I’m supposed to get the servo saver in today, which would allow me to finish up the model.The connection to the saver is still hopefully with the Dubro EZ, but we’ll see. After the Dubro comes a piece of brass rod and a wire clamp (cut out of a nylon terminal block). It bites down nicely onto the wire rope. It would be cleaner to just drill a side hole in the wire clamp, and fasten directly to the saver’s tab…

Also supposed to get the box today. It has a clear lid to be able to see the LED status lights, and otherwise monitor things. Not sure if I mentioned it, but the LED’s are bi-color. From the Tam Valley web site:

Bi-Color LEDs - Gives you full control of the indication color for each track. Each LED can be set to one of 4 colors - red, green, yellow (red and green on simultaneously) and dark(off) for each position. For example you can indicate the open track with green and the closed track with red, or you could use green/yellow, or you can have the open track be green and the closed track be dark.

The board also works with a remote button, which I’ve shown at the end of the box. You press it once to alternate the throw.

===>Cliffy

#70

How are you going to get a screw driver inside to use that Dubro EZ?

#71

Cliff Jennings said:

A variant I’d like to try has a magnetic coupling in the throwbar, so that the stand can be used as an actual switch. For example, sending a command to the drive to flip. Once that move happens, the magnet re-registers, and the stand serves once more as an indication device.

(http://forums.mylargescale.com/attachment.php?attachmentid=17098&stc=1&d=1425330083)

This design isn’t complete, obviously, but feel free to comment.

Thanks for viewing,

===>Cliffy

Cliff,

I would, but I can’t see the pictures?! BTW what are the overall dimensions of that box again? (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)

#72

Thanks again Hans! I’d uploaded the pics to my freight shed, but forgot the replacement step, sorry about that!

The box is a Hammond RP1085C, 4.13"L x 2.95"W x 1.58"H.

http://www.digikey.com/product-search/en?KeyWords=RP1085C&WT.z_header=search_go

John, that’s what the 2-screw wire clamp is for, to get a vertical hex key in to release the cable. And thanks again for initially pointing out that problem. BTW, I’d like to get rid of the Dubro EZ altogether, with some simple right-angle thingy. Could just insert a wire hook, but I’d rather have defined bearing surfaces in the joint; so I’m leaving the EZ in, until something better surfaces…

Thanks guys!

#73

Can’t waite to see the finished product!(http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-cool.gif)

#74

Ok Bright Guy (you r one); a bent wire hook that is secured with a snap over keeper.

Recently saw it when replacing speakers in the truck door, the unlatching rod is a push pull, like yours and uses that simple device.

I’m not thinking of the washer type keeper, too hard to install. Just a keeper riveted to the fixture that rotates to ‘keep’.

Your Welcome, my ‘eye’ is mechanical.

John

#75

Cliff Jennings said:

Since mechanical turnout indication was brought up on the sister thread at MLS, here’s where I’m heading. I’ll go into it more, once my first-article switch drive is working. But as an overview, this is an indicating (not controlling) switch stand, mounted to the opposite side of the drive. It could be various versions of harp or rotary, with easily swappable targets for different rr’s. I model the V&T, so the harp approximates their target.

It has electrical contacts for aux functions, such as (again) indication or relay powering. I’m testing different magnets for the reed switches, but seem to be settling on two 1/8" dia x 1/16" thick ones.

Here’s a section showing the basic magnet / reed / throwbar interaction. I’m using 2 reed switches, which can be SPST or SPDT. I’ll probably pot them in with silicone, and just have terminated leads hanging out.

A variant I’d like to try has a magnetic coupling in the throwbar, so that the stand can be used as an actual switch. For example, sending a command to the drive to flip. Once that move happens, the magnet re-registers, and the stand serves once more as an indication device.

This design isn’t complete, obviously, but feel free to comment.

Thanks for viewing,

===>Cliffy

Thanks Cliff,

Missing this would have been a bummer. I have some very simple manual throws i.e. a SPDT toggle switch that connects to the throwbar.

…

…

Your versions are definitely interesting, especially if they have auxiliary contacts (frog power). (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-cool.gif)

#76

I saw those while surfing the other day Hans, and didn’t know they were yours, that’s great! Simple, yet effective, which means elegant!

I tested the board just now, and guess what? Everything worked perfectly, and I didn’t smoke anything! Thanks again to Greg E. for pointing me to Tam Valley, this system is pretty amazing. Here’s the test setup:

Starting at top and working clockwise:

  1. Power in (in my case, DCC; but it can be DC or AC, though I’ve not gone into that at this point).
  2. Relay, in this case DPDT 2A (they have an SPDT 10A available, and I need to make sure that fits in the box…).
  3. Servo. This is the heavier duty Hitec HS-311 that TV recommends for this board.
  4. Local button. Press once, the servo goes to the opposite side. I used a JST female battery-type plug to connect.

The DCC address was simple to program. And seeing the indicator lights do their thing is very cool. It was also great to verify that the servo operated via 3 command opportunities: the pair of on-board buttons, the single local button, and the DCC handheld.

The auto-align feature is massively neat. When in that mode, the servo slowly hunts in one direction until it meets hard resistance, then backs off a hair, and the board remembers that position. Then it does the opposite. In this simple test setup, and by using my fingers as the “hard stop,” it worked like a champ.

===>Cliffy

#77

One more thing, about that Dubro EZ connector. I added the 2-screw wire clamp to allow release the cable easily, via a vertical screw or hex driver, because the Dubro screw isn’t accessible (thanks to John C. from LSC for pointing out that issue). But now that the clamp is there, I’ve been wanting to can the Dubro.

So, I drilled a hole in the clamp at right angle to its axis. It was easy, because the clamp turnout to be plated brass. I clipped and inserted a brass nail, and voila:

Need a cleaner nail and a couple washers, but it looks workable. And, it will accommodate the thicker tab of the servo saver.

===>Cliffy

#78

Sean McGillicuddy said:

Can’t waite to see the finished product!(http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-cool.gif)

Thanks Sean!

#79

John Caughey said:

Ok Bright Guy (you r one); a bent wire hook that is secured with a snap over keeper.

Recently saw it when replacing speakers in the truck door, the unlatching rod is a push pull, like yours and uses that simple device.

I’m not thinking of the washer type keeper, too hard to install. Just a keeper riveted to the fixture that rotates to ‘keep’.

Your Welcome, my ‘eye’ is mechanical.

John

I just noticed your post John, thanks for that, and how bout my last post?

#80

Getting there … carry on!

(http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-laughing.gif)