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 upgrade for blue box Athearn GP-9s

782 views
9 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    September, 2008
  • 167 posts
DCC upgrade for blue box Athearn GP-9s
Posted by NILE on Monday, July 09, 2018 9:46 AM

Well I guess it is a little bit like Christmas.  I was rummaging through my model train room and found three blue box GP-9s without decoders in them.  I upgraded all my bluebox Athearns years ago.  As I recall Digitrax had a harness kit that made this relatively simple.  However some Athearns required the chasis to be insulated, was that the GP-9?  If so what needs to be done?

  • Member since
    February, 2002
  • From: Mpls/St.Paul
  • 10,732 posts
Posted by wjstix on Monday, July 09, 2018 10:44 AM

If you do a google search on something like "athearn blue box dcc installation" you'll come up with quite a few hits (including videos) of how to do it. All bluebox Athearns are pretty much the same inside. DCC conversion isn't super hard, but you do need to remove the motor and put down tape or something similar so the motor no longer contacts the engine frame. Once you do one, the next one is a lot easier.

Stix
  • Member since
    December, 2004
  • From: Bedford, MA, USA
  • 18,028 posts
Posted by MisterBeasley on Monday, July 09, 2018 12:08 PM

How well do they run on DC?  If they're not smooth, a decoder may be a waste of money.  I was going to replace the motor, drive train and trucks, but I found a brand new Proto model for less.  I removed the motor and turned it into a sound dummy.

At the very least you will need to install plastic draft gear to insulate the couplers from the frame.

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

  • Member since
    October, 2001
  • From: OH
  • 16,456 posts
Posted by BRAKIE on Monday, July 09, 2018 1:03 PM

Mister Beasley
How well do they run on DC?

Apparently good enough for the OP.

There are ways to enhance BB operation by setting various CVs.

I use start volt,speed step and momentum.

Larry

SSRy

Conductor

“Shut one’s eyes tight or open one’s arms wide, either way, one’s a fool.” Flemeth-the witch of the Wilds.
  • Member since
    June, 2007
  • From: Northern Virginia
  • 6,037 posts
Posted by riogrande5761 on Monday, July 09, 2018 1:12 PM

NILE
I upgraded all my bluebox Athearns years ago.  As I recall Digitrax had a harness kit that made this relatively simple.  However some Athearns required the chasis to be insulated, was that the GP-9?  If so what needs to be done?

I don't have exhaustive knowledge but it has been my understanding that all Athearn blue box motors were grounded to the frame so I'd assume yes, you will need to insulate the motor from the frame just like you did with all those other Athearn blue box engines you said you upgraded last year.

Rio Grande.  The Action Road

Never tangle with a troll.  They will only bring you down to their level and beat you with experience.

  • Member since
    June, 2007
  • From: Northern Virginia
  • 6,037 posts
Posted by riogrande5761 on Monday, July 09, 2018 1:18 PM

MisterBeasley

How well do they run on DC?  If they're not smooth, a decoder may be a waste of money.  I was going to replace the motor, drive train and trucks, but I found a brand new Proto model for less.  I removed the motor and turned it into a sound dummy.

There should be some techniques that will turn a noisy rough runner into a much smoother quieter one.  Those probably can be found on the internet or some know them here.

I tend to agree that it's a judgement call whether or not some blue box Athearns are worth upgrading to DCC.  There are often better models out there inexpensive.  The Athearn bb GP7's are wide body but some are ok with them.

 

Rio Grande.  The Action Road

Never tangle with a troll.  They will only bring you down to their level and beat you with experience.

  • Member since
    February, 2002
  • From: Reading, PA
  • 24,994 posts
Posted by rrinker on Monday, July 09, 2018 1:44 PM

 Yes, all BB locos need the motor isolated - the Digitrax kit was just a repalcement set of motor clips that had wires soldered to them and a plug to go intot he decoder. Their lower clip had the tab removed that linked the motor to the chassis, plus it was recommended to put a layer or two of tabpe in the space under the motor to be doubly sure it couldn't touch the frame - decoder will fry instaltly if this happens. Nothing else needs to be done,t here are typically no screws between the frame and the motor in an Athearn loco, just the plastic/nylon brackets that clip to the motor and plug in to the holes in the bottom to hold the motor in place.

 You can easily replicate this, with a major improvement. Unless you are good at soldering, I wouldn;t try soldering the wire to the motor clip with it all assembled, but it can be done with no damage to the motor. Just keep in mind, it is those clips that wholed the motor together, so removing both requires a lot of careful handling to keep the motor from coming apart. Also, those tables hold the brushes and brush springs in place - don't lose either of those.

 SInce you ahev more than one - you can 'leapfrog' the clips - take the top clip loco #1, take one off loco #2 and put it in place of the one removed from loco 1. Solder a wire to removed clip . Remove the bottom clip from Loco #1. Place the one with the wire soldered to it in its place. Solder a wire to the removed clip. Swap the top clips on Loco #1. Now you have wires soldered to both clips on the motor for loco #1 - with the top clip, which does not have the extra tab for chassis contact, now on the top. Put a stip or two of Kapton tape in the motor well.

 The Digitrax harness had a rie connected to a clip that repalced the hadlight bracket clip - this is not a great idea, the tab on the chassis side is just loosely riveted to the chassis and it's not a great connection point. Here's where DIY is an improvement - inside enough to clear the shell, drill and tap a hole for a small brass screw. Drive a screw in the hole and then solder the wire to this screw. Far better than the Digitrax harness. The other track pickup in the Digitrax harness had a piece of wire conecting two clips that went over the truck towers. You can find crimp connectors that fir the towers, or just solder wires right to them - just leave enough slack between the two so that the trucks can freely swivel.

It sounds a lot harder than it is - these are fairly easy to convert to DCC. Just not pure plug n play - very few actually are.

                                        --Randy


Modeling the Reading Railroad in the 1950's

 

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

  • Member since
    October, 2001
  • From: OH
  • 16,456 posts
Posted by BRAKIE on Monday, July 09, 2018 2:39 PM

riogrande5761
There should be some techniques that will turn a noisy rough runner into a much smoother quieter one.

Jim,CVs are your friend and I experimented with start volt,speed step and momentum until my BB engines moved at 2 scale mph and worked their way up to 18 scale mph..Perfect for my ISL switching speeds.

BTW One must turn the throttle off two and a half car lengths from the switch for a smooth slow stop 1-2" beyond the switch points..

Larry

SSRy

Conductor

“Shut one’s eyes tight or open one’s arms wide, either way, one’s a fool.” Flemeth-the witch of the Wilds.
  • Member since
    April, 2012
  • From: Huron, SD
  • 696 posts
Posted by Bayfield Transfer Railway on Monday, July 09, 2018 5:11 PM

The later BBs run pretty fair with clean track and wheels.

The other good news is that there is a TON of room inside them, so it's not a tricky install.

 

Disclaimer:  This post may contain humor, sarcasm, and/or flatulence.

Michael Mornard

Bringing the North Woods to South Dakota!

  • Member since
    January, 2001
  • From: US
  • 238 posts
Posted by tankertoad70 on Monday, July 09, 2018 6:19 PM

I modified a pair of my older Blue Box Athearn GP7s (I ignore the wide shell due to the bullet proof details and handrails) and the motor must be isolated from the frame as others have indicated.  Athearn's traditional lokeys are usually quite noisy, but I have found that running them continuously for around 24 hours breaks the mechanism in nicely and after doing so, I tear 'em down, clean and lube gears and motor bearings.  When reassembled they are remarkably quieter and draw less amperage.  There is plenty of room under the "hood" for a decoder and "keep alive" unit which I added to this puppy and she runs better than fellow club members Proto 2000s and is much more reliable to boot.Cowboy

Don in 'Orygun' City

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!

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!