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Life-Like F7 DCC Conversion

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  • Member since
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  • From: Dearborn Station
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Posted by richhotrain on Tuesday, June 17, 2014 4:44 AM

gmcrail

I want to add one little fact in here that often gets overlooked in discussing DCC conversions of older engines: 

You do NOT necessarily have to isolate the motor from the chassis.  You DO have to isolate the BRUSHES from the motor and thus the chassis.  The brushes need to be hard-wired directly to the decoder. 

  

Yep, that is a very good point.  

When I first went DCC about 10 years ago, it was very common for someone to say, "isolate the motor from the chassis".  But that isn't necessarily true.  As you say, you do have to isolate the brushes from the motor and chassis.

I found that out the hard way when I installed a decoder in a "DCC Ready" Proto 2000 S3.  A brush wire was connected to the metal frame.  A derailment and resulting short where the wheels touched the ooposite rails would immediately fry the decoder.  But the motor was isolated from the frame.

The only electrical path to the motor brushes should be through the decoder.

Rich

Alton Junction

  • Member since
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  • From: Bradford, Ontario
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Posted by hon30critter on Tuesday, June 17, 2014 12:24 AM

Gary:

Very good point!

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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  • From: Kansas City Area
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Posted by gmcrail on Monday, June 16, 2014 11:45 PM

ALEX WARSHAL

Thanks for the info guys, I ended up putting it in a newer Athearn loco.

Good choice.

I want to add one little fact in here that often gets overlooked in discussing DCC conversions of older engines: 

You do NOT necessarily have to isolate the motor from the chassis.  You DO have to isolate the BRUSHES from the motor and thus the chassis.  The brushes need to be hard-wired directly to the decoder. 

 

---

Gary M. Collins gmcrailgNOSPAM@gmail.com

===================================

"Common Sense, Ain't!" -- G. M. Collins

===================================

http://fhn.site90.net

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Posted by ALEX WARSHAL on Sunday, June 15, 2014 2:23 PM

Thanks for the info guys, I ended up putting it in a newer Athearn loco.

My Layout Photos- http://s1293.photobucket.com/user/ajwarshal/library/

  • Member since
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  • From: Bradford, Ontario
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Posted by hon30critter on Saturday, June 14, 2014 11:49 PM

Alex:

One more suggestion - leave the decoder leads as long as possible so that you will have something to work with if (and whenSmile, Wink & GrinLaugh) you decide to put the decoder into another engine.

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

  • Member since
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  • From: A Comfy Cave, New Zealand
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Posted by "JaBear" on Saturday, June 14, 2014 11:30 PM
Gidday Alex, as much as I am a big fan of trying to make a silk purse from a pigs ear, in this case I think you’ll still end up with a pigs ear.
That said as long as you carry out Daves tip regarding testing for amperage draw, give it a go. At the very least it will be good practice, and if it is a disappointment, the decoder can be used on a better loco.
BTW if we were closer you could borrow my Umbrella

Cheers, the Bear.Smile

"One difference between pessimists and optimists is that while pessimists are more often right, optimists have far more fun."

  • Member since
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  • From: East Haddam, CT
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Posted by CTValleyRR on Saturday, June 14, 2014 10:39 PM

And to continue raining....

Tom at Toms Trains, who is normally great about installing decoders that you buy there, refuses to add decoders to crappy locos that don't run well.  He steadfastly refused to add a decoder to an old Tyco loco, even though it had been my fathers and was of great sentimental value to me.  So it is now a "shop queen" in the roundhouse.

Connecticut Valley Railroad A Branch of the New York, New Haven, and Hartford

"If you think you can do a thing or think you can't do a thing, you're right." -- Henry Ford

  • Member since
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  • From: Bradford, Ontario
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Posted by hon30critter on Saturday, June 14, 2014 10:05 PM

Alex:

Make sure you test the amperage draw on the motor. If the motor draws more current than the decoder's maximum you will "let the smoke out of the decoder!"

If you don't have an ammeter they are quite inexpensive. Make sure you read the instructions on how to measure amps. To test the draw, put the locomotive on a DC powered track at full power and push down until the wheels stall, then quickly note the draw. Don't hold the motor down for more than a couple of seconds, if that.

Unfortunately I have to agree with the posters who question the value of putting a decoder into such a primitive engine. The performance will not necessarily improve because of the four wheel pickup. It will stumble and stall regularly at low speeds. The only value I see here is that you will get some more experience installing decoders.

Sorry if we have rained on your parade!

If you check out eBay you will find decent quality engines from Atlas/Kato or Athearn for good prices. Here is just one example:

http://www.ebay.com/itm/F7A-ATHEARN-SANTA-FE-/181437317276?pt=Model_RR_Trains&hash=item2a3e81c09c

(This is a Canadian view of the listing so ignore the shipping prices.)

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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  • From: Shalimar. Florida
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Posted by Packer on Saturday, June 14, 2014 7:20 PM

It can be done, but in the end it's not really worth it.

I've put a Lenz in a Bachmann E60C, the old one with the traction tires and pancake motor... IMO, the decoder was wasted on the engine...

Vincent

Wants: 1. high-quality, sound equipped, SD40-2s, C636s, C30-7s, and F-units in BN. As for ones that don't cost an arm and a leg, that's out of the question....

2. An end to the limited-production and other crap that makes models harder to get and more expensive.

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  • From: Sierra Vista, Arizona
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Posted by cacole on Saturday, June 14, 2014 5:55 PM

Does this locomotive really run well enough to justify the cost of a decoder?  The ones I have seen have a pancake motor mounted on one truck with plastic wheels, and the other truck is the only source of power pickup.  Too cheaply made to be worth converting, IMHO.

  • Member since
    November 2013
  • 379 posts
Life-Like F7 DCC Conversion
Posted by ALEX WARSHAL on Saturday, June 14, 2014 5:47 PM

I have a HO Scale Life-Like F7 (from a cheap train set), and I would like to convert it to DCC. I have an extra Digitrax DH123AT to do the job. Any articles or former threads would be helpful.

-Alex

My Layout Photos- http://s1293.photobucket.com/user/ajwarshal/library/

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