Tuesday, April 26, 2011

Adopting a "little steps" policy ...

I’ve take a decision: force me to dedicate half an hour of my time everyday ( well, “more or less” everyday) to advance on my layout. That’s the only way to see something moving, given a sad event to my mother-in-law that make like impossible for me to have a whole afternoon during weekends. 
This “little steps” approach demonstrates “very” effective ( you remember the Esopo story about the fox and the grapes? )
Anyway: I’ve finish to wire the DCC track power bus on the two intermediate peninsulas and done with one of the command panels at Burlingame!
To finish the panel I draw it in 3rdPlanit as show, and will print on a transparent adhesive sheet ( pay attention to select a "proper" sheet... if you've a Laser printer and don't want throw away it).

The electronic driver board is one of the “old” Octopus from Tam Valley with fixed angle servo driver ( I’ve another two and want to check if I can use for turnouts or I’ve to relegate to drive in the future a semaphore blade or other animations). The main reason I doubt was my Fast Tracks point: it's very hard to hold in position.
Experimenting some different solutions for the music wire lever, I turned out with a solution as described in this past post: http://valleybeforesilicon.blogspot.com/2011/01/modified-actuator-for-servo.html

Note a short piece of code 55 rail on top of the throw bar that hold the moving wire. I weld it and then made a slot with a Dremel abrasive saw.
This way I use the elastic wire play, to hold firmly the point rail against the side rail leaving the servos to reach his programmed angle. I’ve add to the octopus 8 relay to switch the frog polarity.
See this short movie of the result. To hide the actuator wire I plan to cover it with a replica of the pneumatic actuator that was used on the peninsula Coast line at the time ( and till now too! See this picture taken at 3rd ...OPS... 4th&Townsend in the City):


On the command panel, made by a Forex sheet, I’ve used DPDT  switches (double pole) connecting one pole to the Octopus input and using the second to light a pair of Led indicating the valid route on the front fascia.
I use rectangular LEDs ( mainly ‘cause I’ve already have a bunch of it) but at the end the visual effect … was better than the “classic” ? To fit the leds just drill a couple of holes with your Dremel tool, then file with a little file (Oh, my poor English!) to obtain the squared corners.
Ok, here a short movie of the "thing":



Tuesday, January 11, 2011

Modified actuator for servo



Sorry, friends, but I’ve not found any time 'till now to add a proper description to the movie:
Now It’s time!
I always dislike the arched movement given by the “usual” mounting of music wire on Tortoise and Blue Point actuators, mainly ‘cause on the center point of the movement the wire is out for some part and at both end-points is level with the throw-bar.
Additionally I want to be able to mount everything from the track side, as in some point I don’t have comfortable space from under.
So, ( I know I’ve re-discover the fresh water!) here is my solution:
-          take a 1,5 mm diameter brass pipe and cut 1mm + your roadbed deep +  your plywood deep + 2cm (for me means 5 cm )
-          Take the music wire ( flexible 1 mm) and bend it at 90° at one extremity, leaving 1cm to connect to the throw bar.
-          Make a hole in the plywood at 1 cm from the throw-bar and
-          Insert the pipe in the hole and insert the wire in the pipe.
-          Bend again at 90° on bottom side using the end of the pipe
-          Cut the wire at 4-5 cm from the pipe.
-          Solder a little “U” part ( I’ve used a pin used to hold resistors I’ve spare, but … well check your “maybe can be useful in the future”  box for something that can fit your wire and act as support
-          Fit the upper end of the wire into the “U” on the throw-bar.
-          Take your servo – fit a piece of strong double side tape on the larger side, to firmly stick the servo on plywood.
-          Insert the wire in the servo arm and position the servo aligning the motor perpendicular to the pipe ( in parallel with the turnout throw bar. It don’t need to much precision as the movement is ensure by the flexible wire arm.
That’s all, folks! And … it’s working well too. The strength needed to force the points to side rails is ensured by the ample swing of the servo arm ( program it at 150° or more)