Large Scale Central

Air Wire Drop-In MU

Electronics Power and Sound
#21

Steve, the easiest way is going to be to build some splitters to take the motor outputs from the Airwire board back to the motors on the 2nd unit. What I’d do is split one output to control the motors on the lead unit, then run an extension off of the back motor output to run to the 2nd unit. Split that output inside the 2nd unit to control the two motors on that loco. That gives you two motors running off of each motor output of the Airwire, and only two wires running between units. You can get the 2-pin connectors that USA (and Aristo, etc.) from www.allelectronics.com if you don’t have spares lying around already.

Later,

K

#22

Kevin

your saying about the same thing i did but changing to two wires and i like that. he could use the 4 wire clip that came on the motor block for power pick up use that in side the b unit and also use it to hook the two motors in the a unit together.

#23

The only issue, now that I think about it, is the lights in the second unit. You’d have to tie them to them to the motor voltage. They’d operate no differently than they would under analog track power. In that case, I’d keep the motors tied to the factory control board in the 2nd unit, and disconnect the track pick-ups coming from the trucks to the control board. Use the motor feed from the 1st unit to feed the control board instead of the power from the track, then it will feed the motors and the lights.

Later,

K

#24

Kevin, take a look here. Paul Norton has done a good job setting up the slave B unit. On the A unit, with the battery and the Airwire board, I suppose splitting one of the leads to the motors would work, but I was thinking about farther upstream, on the board, itself, before Airwire splits the power to the motors. To me, that makes more sense.

#25

It looks like Paul is describing the same thing I am, with the benefit of photos.Thanks! I’ll remember that for future reference.

In terms of splitting the power off of the motor outputs on the Airwire board, it doesn’t really matter where it happens. You can split a second connector off of the wires coming from the Airwire board just as simply as wiring together a “Y” harness, and you save extra connectors in the process. I’d split the forward one on the Airwire board to power the two motors in the 1st unit, then just run an extension off of the rear motor connector that will become the MU connector to the 2nd unit. Minor surgery only to one motor output, and you’re up and running.

Later,

K

#26

We just have to keep an eye on polarity, as the trucks on the GP 9 are reversed from each other. Good idea, thanks.

It would probably be easier just to bite the bullet and front the coin to buy a second battery and board for the other GP 9. I wonder if "GoFundMe would take this on?

#27

Kevin, Paul has most of the USAT, 2 Bachmann, and 2 LGB listed here. for adding a “MU” hookup. The more recent Aristo don’t need it, and the techniques will transfer readily to the older Aristo. Its a great resoulrse.

#28

If the GP-9 trucks are like the NW-2 trucks, if you get the polarity wrong, just reverse the wires where they connect to the pins on the motor blocks. (Not that I’ve ever gotten them backwards, mind you. But–in theory–if one were to do such a silly thing, it’s an easy fix.(http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-embarassed.gif))

Later,

K

#29

Kevin Strong said:

If the GP-9 trucks are like the NW-2 trucks, if you get the polarity wrong, just reverse the wires where they connect to the pins on the motor blocks. (Not that I’ve ever gotten them backwards, mind you. But–in theory–if one were to do such a silly thing, it’s an easy fix.(http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-embarassed.gif))

Later,

K

Hypothetically, mind you, just assuming that everything was done according to the directions, color for color, and the loco ran backwards from the lights… yeah, easy fix, just reverse the wires. Not that it ever happened to me, I heard about it from a guy. (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-innocent.gif)