Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

DCC, Dummy locos for sound

4346 views
12 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    December 2007
  • From: Gateway City
  • 1,593 posts
Posted by yankee flyer on Tuesday, March 17, 2009 9:21 AM

wjstix

You'll probably always have a little bit of a pick-up problem with the dummies. In the long run it might be easier to install a sound-only decoder (several companies make them by the way, you don't have to spend extra money to get a sound and motion decoder that you're only going to use the sound part of) and run two wires back from a lead engine. You can use mini-connectors if you want to be able to split them up and use the sound dummy with other units.

Hello
This is a learning project.  I wanted to try repainting a loco and needed something cheap to practice on. The dummy sound unit seemed like a good idea. I found one at the swap meet for $15 which didn't seem  toooo  bad Dunce  but then I bought one for $6, that's why I have two practice units. This has to be on the cheap. Looks like I'll do the jumper wire to the powered unit and yes there are low cost sound decoders that appeal to me.

Thanks to all that offered help.  Bow
Lee

  • Member since
    February 2002
  • From: Mpls/St.Paul
  • 13,892 posts
Posted by wjstix on Tuesday, March 17, 2009 8:25 AM

You'll probably always have a little bit of a pick-up problem with the dummies. In the long run it might be easier to install a sound-only decoder (several companies make them by the way, you don't have to spend extra money to get a sound and motion decoder that you're only going to use the sound part of) and run two wires back from a lead engine. You can use mini-connectors if you want to be able to split them up and use the sound dummy with other units.

Stix
  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,483 posts
Posted by MisterBeasley on Tuesday, March 17, 2009 6:41 AM

Texas Zepher

MisterBeasley
For a sound-only engine, having a metal frame which is part of the circuit is not a problem, since there is no motor to isolate.

I beg to seriously differ with that comment.  Any time one is running wires inside a locomotive, especially really sensitive ones like speaker circuits, a hot frame should make one take extra extra precautions.   With a neutral frame two wires have to come loose and accidentally touch it simultaneously for there to be a problem.  With a hot frame all it takes is one loose wire accidentally touching it any time and one can expect smoke.

Well, we'll have to agree to disagree on that one.  I've got a dummy F7B with a hot frame and sound, and it works just fine.  I agree with everything you've said, but as long as the decoder is wired, soldered and insulated properly, the "loose wire" scenario should be a very low probability.  With shrink-tubing protecting the soldered wire ends, there should be vitually no chance of any decoder wires coming in contact with the frame.

This F7B is an old Athearn.  For engines of this vintage, Athearn used the frame to provide the electrical path from one rail to the motor frame.  So, the wheels-to-truck-to-frame path is essential.

Yes, extra care is needed when wiring an engine with a hot frame.  But, no one should think the project can't be done that way.  If you've got a plastic frame with all-wheel electrical pickup, so much the better.

It takes an iron man to play with a toy iron horse. 

  • Member since
    February 2004
  • From: Elyria, OH
  • 2,586 posts
Posted by BRVRR on Monday, March 16, 2009 10:19 PM

I have several dummy locos with sound decoders in them. They are all Athearn BB PAs or F7s. In every case all I had to do was change the wheels to the metal wheels used in powered locos. Most of my 'sets' are wired together with a Miniatronics two conductor plug sett. In the F7s that gives me 16-wheel pick-up and in the PAs 24-wheel pick-up which all but eliminates the 'stutter' so often encountered with 'light' dummy locos.

I'm not familiar with the Athearn GP35 or GP40 dummies but I assume the trucks have metal plates on them. If so the replacement wheels should drop right in. The bearings will carry the power to the metal plates. Simply solder a wire to each plate and you have 'pickup' without all of the fooling around necessary with wipers.

As an alternative, simply power the sound decoder in the dummy with a two-conductor Miniatronics wire set from the powered loco. Or just install a sound decoder and speaker in the powered loco and run two wires to a speaker mounted in the dummy. I have done this last with a P2K E8A/E7B set. Works fine.

 Simple is better. Check out the trucks in your dummies. If they have metal plates on both sides of each truck, just install "powered loco" wheels. Incidentally, P2K wheels and Athearn wheels are pretty much interchangeable. So if you have some old P2K GP wheels with cracked gears you can use them in your dummies.

Good luck whatever you decide to do. Let us know how you make out.

Remember its your railroad

Allan

  Track to the BRVRR Website:  http://www.brvrr.com/

  • Member since
    July 2006
  • From: Austin, Texas
  • 875 posts
Posted by jasperofzeal on Monday, March 16, 2009 7:32 PM

yankee flyer
C:  Can the parts be ordered somewhere at a reasonable price?

You can buy replacement trucks with metal wheels and gears to replace your dummy trucks.  The problem I see with this (other than being kind of pricey for two locos) is that you'll also need to buy the correct sideframes for the GP35 since the power trucks come with blomberg-M sideframes.

An alternative, as someone else suggested, is to buy the metal wheels to replace the plastic ones.  This is a better deal since you can do 3 locos with the 12 sets that come in the package.  All you would have to do then is find a way to isolate the trucks from the frame and run wires from the trucks to wire in the decoder.

The online store that I linked the items to is a good place to buy from.  I've purchased many times from them and have always received great service with no problems.

TONY

"If we never take the time, how can we ever have the time." - Merovingian (Matrix Reloaded)

  • Member since
    December 2007
  • From: Gateway City
  • 1,593 posts
Posted by yankee flyer on Monday, March 16, 2009 6:29 PM

Hamltnblue
You could install a sound decoder and just not hook up the motor.

 

Hammblue  Smile
Yes that is what I wanted to do. I bought the dummies, GP35 and GP40 at a swap meet wanting to just put in sound only decoders to augment my SD7 DCC with with no sound. The only thing is the dummies don't have electrical pick ups and they have plastic wheels. Soooo I'm trying to find the cheapest way to accomplish that.
thanks for the interest.


Lee

  • Member since
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Monday, March 16, 2009 3:29 PM
You could install a sound decoder and just not hook up the motor.

Springfield PA

  • Member since
    January 2003
  • From: Ridgeville,South Carolina
  • 1,294 posts
Posted by willy6 on Monday, March 16, 2009 12:26 AM

Metal wheels for Athearn dummies is part # 40019 and cost about $20.00 and they do have a wiper set used for the passenger cars as a lighting kit, part #90201 which should work for a locomotive.

Being old is when you didn't loose it, it's that you just can't remember where you put it.
  • Member since
    October 2004
  • From: Colorful Colorado
  • 8,639 posts
Posted by Texas Zepher on Sunday, March 15, 2009 8:35 PM

MisterBeasley
For a sound-only engine, having a metal frame which is part of the circuit is not a problem, since there is no motor to isolate.

I beg to seriously differ with that comment.  Any time one is running wires inside a locomotive, especially really sensitive ones like speaker circuits, a hot frame should make one take extra extra precautions.   With a neutral frame two wires have to come loose and accidentally touch it simultaneously for there to be a problem.  With a hot frame all it takes is one loose wire accidentally touching it any time and one can expect smoke.

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,483 posts
Posted by MisterBeasley on Sunday, March 15, 2009 6:40 PM

Maybe you can find another pair of engines at a swap meet with metal wheels and trucks.  Seriously, if you find them, they will probably serve you better than putting axle wipers on replacement wheels and axles.  For one thing, having all the wheels picking up power, as you will get from metal trucks with pickup through the frames to both sides, is better than only half the wheels, as you get from axle wipers.

For a sound-only engine, having a metal frame which is part of the circuit is not a problem, since there is no motor to isolate.  However, you should take care to isolate the couplers.  Either use plastic couplers, or use plastic draft gear boxes with metal couplers (better.)

It takes an iron man to play with a toy iron horse. 

  • Member since
    December 2007
  • From: Gateway City
  • 1,593 posts
Posted by yankee flyer on Sunday, March 15, 2009 6:39 PM

Texas Zepher
Tap the powered locomotives and make a power bus coming back to the dummy unit. 

 

Actually that seems to be the most economical way but I had not thought of it (duh).  I'm not thrilled that the wheels of the dummies are made of plastic.....  I do have an Email in to Athearn maybe they will have a suitable solution.

I also want to paint the shells, but  I have yet to figure out how to get the windows out of the cabs. There seems no way to relieve the pressure that holds the windows in.

Thanks to whom ever can help. Bow
Lee

  • Member since
    October 2004
  • From: Colorful Colorado
  • 8,639 posts
Posted by Texas Zepher on Sunday, March 15, 2009 5:23 PM

yankee flyer
A:   Do I have to replace the entire truck

No, but it is easier to get the power from them if you do.  Hence your next question.

B:   Is there a way to replace the wheels and put wipers in these trucks?

Yes.  There are many ways to do this.  One of the simplest is to put a brass piano wire attached to the truck body wiping either the back of the wheel or the axle.   The trick with this is that how well it works is directly proportional to ones modeling skills in this area.

There are also companies that make pick-up wipers that are mounted on the bottom of the truck and rub along the top of the rail. (Tomar maybe).  

Tap the powered locomotives and make a power bus coming back to the dummy unit. 

Combination of any or all of the above.

C:  Can the parts be ordered somewhere at a reasonable price?

Don't know.  Try Caboose Hobbies in Denver.  They always seem to have a good selection of parts.

A final comment is that another issue with Athearn units is that they utilize a hot frame for one of the wires.  So simply replacing a dummy truck with powered one will make the frames hot and this must be dealt with.  Doing it yourself with some form of axle or wheel wiper will not create this situation. 

  • Member since
    December 2007
  • From: Gateway City
  • 1,593 posts
DCC, Dummy locos for sound
Posted by yankee flyer on Sunday, March 15, 2009 12:23 PM

Hello    Smile
I have an Athearn GP35 and GP40 dummy locos and would like to make them into DCC sound cars. Can anyone point me in the right direction. They have plastic wheels and no pickups. I bought them at a swap meet so age is a question.

A:   Do I have to replace the entire truck?
B:   Is there a way to replace the wheels and put wipers in these trucks?
C:  Can the parts be ordered somewhere at a reasonable price?
As always any help is appreciated.  Bow

Lee

 

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!