Tuesday, May 22, 2012

Servos and Servo mount

In the same way I decided not to use any more digital modules from Uhlenbrock (I found better and cheaper do-it-yourself ones), I also decided to find a cheap and better solutions for servos.

I bought a bounch of 6 servo to Chine via ebay: 6 Tower Pro 9G for 16$ including shipping. But I needed also servo holders to fix servos under the desk in a firmly way and without glue to change them easily if necessary. After some time sufing ebay and the web in general, I bought the following 10 servo mounts in Hobby King for a total ammount of 25$:




These servo mount are stronger than the two L shaped tiny squares delivered with Uhlenbrock servos:


It comes with two allen screws, and holes of the servo mount are also screwed so servo is attached really well. Uhlenbrock screws must be screwed to the servo because square holes are not screwed and that kind of fixing to the plastic is weak.


That's my cheaper and best solution found, hope you like it!!!
Posted by Picasa

Thursday, February 2, 2012

Definitive modules for DCC

I've been testing until now Uhlenbrock modules, last ones where servo modules with contact relays for turnout frogs, and I felt a bit disappointed with them for the following reasons:


  • They are not connected to Loconet bus, directly connected to DCC instead
  • Programming must be done accessing the module to press a button or connecting the module to the programming track
  • They have the option to change polarity in the middle of the movement (necessary for Peco code 55 turnouts), but it's difficult to adjust and anyway it generates short cuts in some turnouts.
  • Price: all modules are expensive, but like any other good brand (Digitrax or ESU also)
I've been searching DIY solutions because there is no solution in the market able to accomplish my own requirements:
  •  All accessory modules (outputs, retro, servo, lighting, ...) must be communicated through LocoNet (Digitrax and Uhlenbrock compatible). I don't want to waste the DCC "band width" for anything else than locos and rolling stock.
  • Power to modules must be delivered through loconet connector (using Loconet professional with power wires, not as Uhlenbrock), and all modules must be feed with the same voltage in order to simplify wiring.
  • Servo modules must be able to drive the switch frogs through an optional relay board, as an option or expansion of the servo module. When feeding frogs, it must disconnect the frog power, do the movement and after feed again the frog with the correct polarity. In this way you avoid all problems and short circuits when changing polarity at the beginning, end, or in the middle of the movement (very difficult to adjust).
  • Loop management module working by current consume detection, not by short circuit detection. I don't want short circuits in my layout, doesn't matter how well protected and short in time they be.
  • These loop management modules must be able to work stand-alone or connected to Loconet for feedback.
  • Lighting modules with many light effects
  • Modules optoisolated from Loconet and other communication interfaces
  • Programming should be done without the need to access fiscally to the module (no changing switches, disconnect other modules or similar) 
  • All wire connections through standard connectors or screw terminals, never soldered
  • Modules for everything!!!!! Even to connect Loconet to internet or publish all services in a wireless. I want to drive everything with my tablet or PC with no wires, wireless.
  • CHEAP! CHEAP! CHEAP! Possibility to do-it-myself and solder boards.
  • Modular boards: one Loconet interface board common to all modules and expansion boards for each type of accessory.
And I found through the Rocrail project (a freeware railroad model layout control software) the modules from Mr. Peter Giling. These modules have all the previous requirements implemented and you can buy only the boards (for 3€ or less) or the completed kit with programmed pics and components to solder yourself. You can even build your own station or control panel. That's a ruff schema, and think that all Loconet modules from any other brand are compatible: 


More information can be found in http://www.phgiling.net/

Until now I've tested GCA50 (the main interface board between Loconet and all the other boards), GCA93 (8 current detector interface with fused connections) and GCA136 + GCA137 (servo modules with relay board). All this modules work perfectly with my Intellibox Basic and the programming is really easy from Rocrail.

In a future I plan to build the 3Amp power supply when the number of GCA50 increases, because Intellibox hasn't enough power (just 0,5Amp). This 3Amp power supply also gives you an optoisolated ethernet connecton to deliver the control of all your layout to the net...... really interesting.....

I'll post my experiences with each of the modules soon.

Monday, January 9, 2012

Adding screw terminals to Uhlenbrock 67810

The only bad things about this servo decoder are:

1) Not Loconet communication, directly connected to DCC Loop
2) It has no terminals to connect wires coming from switch frogs. You have to attach them using a kind of plastic caps to keep the wire in touch with the decoder terminals. But this caps don't hold it properly and produce false contacts between the wires and the decoder, it's really a botch.

There is nothing to do with the first issue, but you can solder very easily screw terminals instead of using those plastic caps. For each servo decoder you will need 2 double terminals and 4 triple terminals. These terminals must be of 3,5 mm gauge.  I bought them in RS-ONLINE, and references are:

* Double screw terminals: 648-8484
* Triple screw terminals: 648-8513

That's the result with the screw terminals soldered: