Improved wiring for the 3-truck Shay

[Tom Lapointe]

 I've LOVED the pulling power of my Bachmann 3-Truck Shay!

-but HATED  that miserably-fragile that miserably-fragile loco-tender wiring harness from almost "Day 1"!

-Within a week of when I got it, one of the wires going from the loco to the tender connector broke loose from it's header pin.  I had (VERY carefully!) removed the tiny female pin from the header, pulled a little extra "slack" out from the Bachmann printed-circuit board in the loco , & resoldered it.

-For several months, all was OK, until I went to use the 3-trucker for snow-plowing this past winter; bringing it out from the house, I found that SAME wire broken again, & 2 others ready to let go as well!

-At that point, I decided I'd had it with the original header, & decided to see if I could come up with something more reliable, since I have to disconnect the loco & tender to carry them out to garden railroad or back into the house.

-I did have a few "specs" I wanted the new connector to meet:
-easy to insert & remove...
-gold-plated contacts for reliable connections...
-solid "clamping" of the cable jacket (to prevent MORE broken wires!)...
-readily available & inexpensive

Here's what I came up with - conventional modular telephone plugs & jacks!







The new wires were soldered directly to the Bachmann PCB in the fuel bunker section of the loco...



And since the white jacket on the wires didn't look too realistic, I got busy with a black "Marks-A-Lot" marker...









I ran it outdoors last weekend; no problems, & now it's EASY to separate the loco & tender!  We'll see how well it holds up long term (has to be better than that original header)!   (Hint, hint, Bach-man!)

                                                                                                         Tom

[jimtyp]

Tom, excellent upgrade! 

I think manufacturers should take note.  I may do this for the K-27 as the plug is a bit clunky and very difficult to remove.  I work with the connectors you used every day and never thought about using them.  Sweet!

[Tom Lapointe]

Actually, Jim, I'm surprised the idea didn't occur to me earlier either.  Over the years, if I needed multi-pin connectors for a project, I usually "defaulted" to Molex connectors; inexpensive, available in a wide variety of configurations, & polarized, and readily available at the nearest Radio Shack.  (I've had at least a couple of RC planes flying for years using the Molex plugs & sockets as multiple-servo connectors on wings, where I'm typically dealing with 2 ~ 4 servos; they've been VERY reliable!). 

Unfortunately, they're isn't that much room to play with in the Shay, and most of the Molex plugs are way too big to be easily used here. Also, Radio Shack is becoming next to useless as a parts source (they're not even carrying small parts any longer in mall stores! ) - they're pretty much just catering to the MP3-player & cell-phone (perhaps "SELL-phone" would be a more appropriate description! ) market these days....

I had also looked at a lot of electronic parts vendors online; most of what I was finding on connectors was of questionable usefulness, & / or didn't meet one or more of my "specs".

Having been a ham radio operator & electronic tinkerer for decades , I've got a substancial electronic parts stash, & started raiding that for ideas.  I had gone as far as salvaging an 8-pin header & short wiring harness out of a scrapped disk drive, but the header WASN'T polarized, & the wires seemed a bit stiff for this application.  The phone wires & sockets I used were actually the cut-off ends of 2 phone extension wire sets - I think I may have paid something like $1 EACH for them at an electronics flea market years ago!

I should warn anyone thinking of trying this that soldering to that Bachmann printed circuit board is NOT for the inexperienced!   - I used to do this sort of thing all day at work, but my current job has me handing off anything I troubleshoot to a separate department (for the actual soldering - a lot of the current techniques are becoming VERY specialized!), so even I'm a bit rusty.   (Mid-50's eyesight isn't helping either  - I used to have close-up vision sharp as a laser, now I use a pair of cheap reading glasses to help whenever I work on something like this!).  Took me the better part of a day to document the original wiring fully, make up a chart corresponding the color codes of the phone wires to the original Bachmann harness, then do the actual rewire.  I also Dremeled a larger rectangular opening in the tender floor to accomodate  the new jacks; they're hot-glued to the inside of the tender floor.

                                                                                                            Tom