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bachmann f7 motor question?

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  • Member since
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bachmann f7 motor question?
Posted by raptorengineer on Tuesday, August 07, 2018 11:35 PM

 so 4 or 5 years ago i pick up bachmann royal gorge and empire builder passenger train set, and i'm getting around to upgrade the f7 a&b to dcc. so i finally open one up (B-unit) and looking around how i would add dcc harness i saw on the side of the motor these resisters. i wondering for anyone who upgraded bachmann trainset locomtive to dcc would i leave the resisters in or take them out? here pictures

  • Member since
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  • From: perogie flats
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Posted by wvg_ca on Wednesday, August 08, 2018 12:40 AM

they are -probably- not resistors ....

they -may- be chokes / inductors, what does the parts diagram say ...??

unfortunately no pictures to view as of yet..

IF they are chokes, they are for noise reduction [emi] and should be removed

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Posted by rrinker on Wednesday, August 08, 2018 7:11 AM

 There are capacitors across the motor leads, thoose can be snipped out and should for best DCC operation. There are ALSO inductors in series with the motor leads. You can;t just snip these out, it will break the electrical path to the motor. With the capacitors removed, they inductors have little effect on anything and can be left alone. If you do remove them, you need to solder short jumper wires in place of them to maintain the motor circuit. Most leave the inductors alone and just remove the capacitors.

                                             --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by richg1998 on Wednesday, August 08, 2018 9:12 AM

Those are 4.7 microhenry inductors. They are on my Bachmann locos.  Without the caps they are a moot point. They should be zero resistance. Some think they are resistors. They never check the stripes. If on a PC board they have an L prefix.

Rich

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Posted by raptorengineer on Wednesday, August 08, 2018 10:41 AM

ah ok. now for the f7 A unit it has led light now i will be using digitraxx SDXH166D decoder i guess you need resister for led light unless decoder has resister built in to the decoder.  

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Posted by raptorengineer on Wednesday, August 08, 2018 4:34 PM

so i have wired up decoder on b unit and it runs well and it was simple. now i going to added sdxh166d decoder to f7 a unit and i i thiking of adding class light by using led light and clear fishing line. btw long time ago i bought rapido cp caboose and the marker lights where showing up very well so i replace the fiber optic tube with fishing line and it worked really really well. anyway what colour is good. i thinking green or white.  

 

update: so i having trouble finding the right resister for led bulb that came with f7. i put a resister on orange wire and when the led lights up it get very very hot. it start to smoke. i have tube full of differnt resisters.   

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Posted by garya on Friday, August 10, 2018 12:42 PM

raptorengineer

 

update: so i having trouble finding the right resister for led bulb that came with f7. i put a resister on orange wire and when the led lights up it get very very hot. it start to smoke. i have tube full of differnt resisters. 

What gets hot, the resistor or the LED?  When you say orange wire, is that from the decoder or is that a wire in the loco?  Orange from the decoder is for the motor, not for lighting.  White is for the headlight.

I usually use a 1K ohm, 1/4 watt resistor for LED lights in my locos. 

Gary
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Posted by BigDaddy on Friday, August 10, 2018 2:30 PM

Henry

COB Potomac & Northern

By the Chesapeake Bay

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Posted by raptorengineer on Friday, August 10, 2018 3:46 PM

so i figer it all out. what was getting hot was bachmann led light when you turn it on with out the resister. so with no success what type of resister to use for bachmann led i got fed up and when out and bought soundtraxx led light and pack of resisters to. once i got home i look up what reisters soundtraxx use 1k ohm and so once i found one and wires it right to led and wire it to decoder. white wire to to white amd blue wire to blue. then i place it on track and it worked. new led didn't heat up, it was bright and the engine ran good. i had some extra color wire around the house so i added white and blue to led then solder the wires to right colors of decoder harness. 

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Posted by BNSF UP and others modeler on Friday, August 10, 2018 7:10 PM

Nice decoder wiring job! Also suprised and curious that Bachmann made GN f7s...

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Posted by raptorengineer on Friday, August 10, 2018 7:28 PM

thanks the a unit is mess at moment. 

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Posted by raptorengineer on Friday, August 10, 2018 9:57 PM

well i did it. it finish both great northern f7 -A&B have dcc in them. the a unit has dcc and sound with sdxh166d. and i added class light to unit. boy that was little tricky with the a f7 with class light. now it not as bright but it will do. now i got to change cv cause with sdxh166d decoder the bell turn on when you hit class light. 

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Posted by raptorengineer on Monday, August 13, 2018 2:30 AM

well that shocker. so i got everything hooked up right. f7 A unit has sdxh166d sound decoder in it, and f7 B unit got sdh163d decoder. i made test track layout and program my engines in to the dcc dynamis system. now one engine eather A or B unit runs fine but once i added the second engine and make consist it seem one engine will run and the other won't run. so looking online it seem the bachmann motors have low current limit. meaning you can only run one engine at time with out going over stall current limit or maybe it the digitraxx decoder current limit. i have to look in to it more. 

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Posted by joe323 on Monday, August 13, 2018 6:41 AM

raptorengineer

 so 4 or 5 years ago i pick up bachmann royal gorge and empire builder passenger train set, and i'm getting around to upgrade the f7 a&b to dcc. so i finally open one up (B-unit) and looking around how i would add dcc harness i saw on the side of the motor these resisters. i wondering for anyone who upgraded bachmann trainset locomtive to dcc would i leave the resisters in or take them out? here pictures

 

so what would be snipped is the yellow capacator in the center? 

Joe Staten Island West 

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Posted by richg1998 on Monday, August 13, 2018 10:07 AM

joe323

 

 
raptorengineer

 so 4 or 5 years ago i pick up bachmann royal gorge and empire builder passenger train set, and i'm getting around to upgrade the f7 a&b to dcc. so i finally open one up (B-unit) and looking around how i would add dcc harness i saw on the side of the motor these resisters. i wondering for anyone who upgraded bachmann trainset locomtive to dcc would i leave the resisters in or take them out? here pictures

 

 

 

so what would be snipped is the yellow capacator in the center? 

 

Again, those are not resistors, they are chokes. Just cut the capacitor out.

Below is a a link for the history on this issue. Some chokes are wire wound. Some of my Bachmann locos had wire wound and ferrite type.

Some locos could have one to three caps. Yellow blobs or SMT types.

https://sites.google.com/site/markgurries/home/technical-discussions/decoder-motor-drive/motor-capacitors/bachmann-engines

Rich

N

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Posted by raptorengineer on Monday, August 13, 2018 2:36 PM

well i remove the yellow cap things and it worked. both engines run together now. thanks. so all 4 bachmann f7 units have dcc in them :)

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