How To: Two Powered PF Boogies, one IR receiver...

[edsmith0075]

This may have been posted already but I have come across other people searching for a remedy to adding an extra PF boogie to there existing setup. Having one PF motor will work for short length lightweight trains but most people like to run lots of rolling stock and the designs are becoming heavier with the more details being added to the design. So we need more power! You can simply add another PF Boogie, Right?! Yes and No. The additional boogie in most cases will face the opposite direction of the already installed one. This means the boogies pull in opposite directions! the simple solution to this is a switch to change polarity of the current on the new boogie. I picked up the part at Toys-R-Us. It was the Power Functions starter kit, came with a switch lights and small motor. I did this project on my latest locomotive and was pleased with the results. Fortunatly there was plenty of space in the frame to hide the switch and having the additional powered boogie allows me to hook up additional cars with little to no signs of strain or wheel slippage. Below are pics and you can refer to my Flickr page for additional pics.

Feel free to add feedback or ideas to this tip. Previously I was splicing wires and soldering connections to fix this problem. This is much easier and cosmetically appealing.

[Locomotive Annie]

I didn't know there was a polarity switch available so thanks for this information.

With my own project I tried having both bogies pointing in the same direction and found that there always seemed to be problems with the cable on one of the bogies limiting movement. Not being terribly keen on having to undertake solder and splice surgery on the built in wiring cables means that this switch could be the ideal solution provided I can get it to fit.

[NoEinstein]

Thanks for this info, it helped me a lot.

I also applied it to my horizon express after I read in the LEGO reviews of the horizon express that putting the second PF boogie under the other locomotive had a high chance of derailing everything.

I did position the polarity switch a bit different, while I could not fit it like in the picture maybe due to me having the PF lights installed?

Due to the 2x2 brick on the lights I had to stack the switch on top of that. This made the power connector on the switch fit tight against the back of the drivers seat. The braided hair of the train driver gave issues so I sent her to the hairdresser for a french bop cut and a black hair dye. Weirdly one of the passengers now has brown long hair in a braid ;)

It is a tight fit but nothing is strained as far as I could tell, even after a few days no bricks popped loose.

Result:

horizon_express_pf_switch by NoEinsteinNL, on Flickr

Now I have to save for some train tracks other than the 4 straights that came with 7937 the train station so I can really enjoy this awesome train.

Edited August 1, 2013 by NoEinstein

[Hrw-Amen]

Yes I have done the same with my Horizon Express. It was a very, very tight fit to get that polarity switch in and like you I have butted it up against the rear of the drivers seat. Like you say, nothing has popped out yet so hopefully after three months it will not!

[edsmith0075]

Looks good! I want to add lights to mine so that will be the next mod. Oh and with the extra motor this train will move and at full throttle is capable of derailing on a tight turn!

[1974]

Much easier to just reverse the wires in the motor. I'm sure I've seen pics here .. That's what I do

[Rustie86]

I've used this method for double-motoring my Lego locos since I picked up 7939. Fitting the switch and the extra wire was no problem in 7939 (won't be in my red 7939 either) or my custom steam loco 2625, but in the custom center-cab shifter I built and 3677 it was a real pain.

[pluto7443]

Coming from mainly Technic building, this seems like a no-brainer. But whatever.