Digital Direct Couplers Review
By Bill Flude.
Adapted with permission from MERG.

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I was browsing the Tony’s Train Xchange website back in December and found a news item about DCC controlled Kadee couplers. I read the article and took part in an online survey designed to find what I wanted from DCC couplers. About a month ago an email popped up telling me that this product was now available to convert a Lifelike SW switcher and as thanks for taking part in the survey I could have a kit for $60 instead of $100. I posted the order straight away. The kit arrived and I now have control of both Kadees on my Boston and Maine SW9.

The kit comprises and interface board, two micromotors, a pair of mounts for the motors, some bell cranks, a pack of Kadee #58s and sundry other bits and pieces. In addition there is a 13 page instruction leaflet. I also received (but hadn’t ordered) a new frame casting with strategic lumps removed.

Fig.1 Shows complete installation, left coupler down=uncouple, right coupler up=normal.

I read the instructions a couple of times and then stripped the loco down to component parts. The instructions take you through the process stage by stage. The kit that I received had some of the steps in the instructions already completed; this caused a little confusion but did save some time. At strategic points you are advised to test the work that you have done. In about 3 hours I had a completed chassis with working couplers.

The Kadees are in their normal pocket (but the trip pin is removed) and they slide up and down a brass pin, the micromotor raises the pocket using a bell crank and a preformed piece of steel rod. The interface runs the motor for about half a second, the mechanism is designed to lock the coupler in the up or down position. The interface board connects to standard function outputs, it doesn’t seem to draw any significant current from
the decoder. My loco uses F1 for the front and F3 for the rear coupler as F2 on my DT400s does not latch.

Fig.2 Shows the two end views, note the micro-motors with the operating cranks and ‘coupling rods’.

I did have some minor problems initially with clearance inside the shell but everything is now working very well. The up and down action isn’t very prototypical but I can live with that!

Could the kit be fitted to other locos? Yes - but you would have to work out how to get all of the bits in. The installation in the SW9 is quite a tight fit. Kits for more locos are promised soon, check out Tony’s website
www.TonysTrains.com. My main worry is that like sound in DCC locos (I have 7 locos with sound fitted so far) this could get addictive!

Digital Direct Couplers
Editor, Larry Maier

I was interested to find reference to a dc motor operated form of locomotive based DCC controlled uncoupler on one of the email lists. I approached Bill Flude who had reported a successful installation, and Larry Maier who has designed the solution that is available through TonysTrains.

The product is shown at: http://tonystrains.com/tonystips/2003/020403.htm which gives the accompanying diagram, showing the quite engineering based installation and approach. I thought this would make an interesting comparison with the article by Gordon Hopkins last time, so here goes: (I had asked for some clarification on exactly how it worked)

From: Larry Maier <grnmtnflyr@gmavt.net>

David:

Thanks for the positive feedback on the DDC product. The motors used are not geared, but are actually the motors used in pagers and cell phones to provide the vibration annuciation mode. They are 1.5 volt 0.17 (stall current) motors with no gear train. We nail them VERY hard (about 1 amp) for a very short time (about 50 ms) so that the total energy is well below the destruct level. Our test unit was run with over 100,000 coupler operations. It still worked perfectly when I stopped the test, but I had worn out monitoring it. All of the motor control is done in the add-on controller board, which is customized to provide the proper signals for coupler operation. Switches or stall operation would either be unreliable (switches) or run the risk of motor damage (stall).

It is fine to publish the web address. We appreciate the publicity. One note: we have made arrangements with Tony’s Trains to provide some of the more esoteric operations, such as machining of the frame. We probably will not offer DYI diagrams since each coupler installation is unique to the engine and requires a significant amount of engineering time to get the pieces to fit. Your members are certainly free to attempt a copy of the system for their own personal use (perhaps adapting existing parts and controllers, etc.), but the general approach is patented and requires a license for any commercial application.

I do not at this time have any more documentation, etc., but the installation instructions that we have posted on Tony’s site give a pretty good overview of the approach. Hope this helps you out.

Larry Maier

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