Bachmann Message Board

Discussion Boards => Large => Topic started by: wsommariva on December 08, 2008, 03:59:24 PM



Title: Power loss on 4 year old set
Post by: wsommariva on December 08, 2008, 03:59:24 PM
This is the fourth Holiday season for my North Star Express.  I keep the track clean, it's connected properly and I grease and lube the engine and cars when I set it up every year.  This year the train is running considerably slower than normal.  Only one difference.  This year I am using the entire length or track, about 32 feet.  The power pack provides 16 volts ac.  I time one lap at 15 seconds.  Track measures 17.5 volts dc.  Any ideas? 

Thanks to all in advance


Title: Re: Power loss on 4 year old set
Post by: Loco Bill Canelos on December 08, 2008, 04:44:05 PM
While I am sure you have the first thing to check is your track. one bad connection near rhe power pack can cause trouble.  If you have one of those chea[ voltage testers, turn the power pack on full no train on the track and check the voltage all the way around if it is equal and the train is still slow the problem may be the power supply.  Check you local hobby shop and get a powerpack with more output.  Also try running with the smoke unit off and any lights in the cars turned off(if any).  The original equipment power supply is barely able to run the full load. 

Make sure you locomotives front pilot truck is facing in the direction of the arrow on it.  Check your locomotive to be sure the gears are no slipping as well.

As you can see there are lots of possibilities, so try them until it works again.  Let us know how you make out either way, and we can take it from there.

Good Luck and Merry Railroading,


Title: Re: Power loss on 4 year old set
Post by: wsommariva on December 08, 2008, 05:13:57 PM
I'll check the track again and test the volts as you suggested.  The front pilot truck is positioned properly.  How do I know if the gears are slipping?  My heavy lube bottle leaks and therefore the gears got lots of heavy lube.

 


Title: Re: Power loss on 4 year old set
Post by: Loco Bill Canelos on December 09, 2008, 12:56:26 AM
To determine if the gears are slipping turn the locomotive over and try to turn the wheels by hand with fairly heavy pressure.  If it is slipping the wheels will turn.  They should not turn.   If they do not turn the problem is either the motor or one of the other previously mentioned problems.  If the track is well conneceted you should not need extra feeder wires, but extra feeders are definitely a plus.  In the order parts section on the left Bachmann even sells the track clip. 

Keep trying.


Title: Re: Power loss on 4 year old set
Post by: wsommariva on December 09, 2008, 12:03:14 PM
Ok, no slipping gears.  Volts are 17.5 dc all around.  I'm going to clean the wheels.  I don't think I have an extra lube problem at the motor since I can never figure out how to oil it.  It's too deep into the body.

I'm ok with the speed that I compute at 1.36 mph.   If it slows down more I'll get a more powerfiul powerpack.

Thank you for your help.  Now, how do I get the kids to stop knocking it off the track?


Title: Re: Power loss on 4 year old set
Post by: Joe Satnik on December 10, 2008, 12:56:24 PM
Dear W,

Does your train run faster near the power pack connection?

While your train is running, please measure the track voltage near the power pack, then far away from the power pack.

More tests to follow.

Sincerely,

Joe Satnik   


Title: Re: Power loss on 4 year old set
Post by: wsommariva on December 10, 2008, 02:02:30 PM
No, train runs at consistent speed all around.  I'll check the voltage during a run and advise results.


Title: Re: Power loss on 4 year old set
Post by: wsommariva on December 10, 2008, 09:03:22 PM
Ok, when train is running I get 16.5 volts dc at the power pack and 16.2 at the furthest distance from the power pack.


Title: Re: Power loss on 4 year old set
Post by: Joe Satnik on December 11, 2008, 09:12:32 AM
Dear W,

Well, with 16+ volts at the track you should be setting land speed records.

Whatever is wrong is most likely in your engine, as you state that the wheels and the tops of the rails are clean. 

Possiblities:

Electrical:  Bad electrical pickups, broken wires (especially from the front truck), unplugged pickup wires from bottom plate, fouled motor brushes/fouled commutator, open motor winding(s) , bad solder joints, bottom plate pickup arms not resting on brass bushings.

Some of the newer Large Scale models had a second switch behind the smokebox door for track polarity.  (First switch smoke on/off, second LS/NMRA)  If you have a polarity switch, (not likely in a Big Hauler) that could be also be a source of electrical trouble.

George Schreyer's excellent web page:

http://www.girr.org/girr/tips/tips1/big_hauler_tips.html 

Note: Multiple chassis versions are covered - some things are not applicable to all versions. 

Since you have a Volt-meter, the most useful reading would be motor voltage as your engine is running.   To read this, you would need to connect a wire from each of the two motor terminals to the outside of the engine.  Small alligator clip leads would do, or temporarily solder wires to the motor terminals.  Put your meter on a trailing car, such as a flatcar or gondola. 

Hope this helps.

Sincerely,

Joe Satnik   



Title: Re: Power loss on 4 year old set
Post by: wsommariva on December 11, 2008, 11:06:21 AM
Thank you Joe,

I do have that track polarity switch.  I'll check that.

Front truck - is that the trunk that has four non-powered wheels?  Why is it wired?  I'll check them. 

The motor is so deep in the body that I may not be able to do a motor voltage test, but I will try.  I'll also check for bad connections as best I can. 

The train still runs at the same speed, so it's not getting slower.  I can live with it.  But I like working on the engine.


Title: Re: Power loss on 4 year old set
Post by: Joe Satnik on December 11, 2008, 12:32:54 PM
Some simpler tests...

Try working the polarity switch back and forth, which may get some dirt out of the switch contacts.

Try running it in the opposite polarity. 

Lay the engine on its side on a soft surface so as not to damage it.  Make sure that moving driver linkages won't snag something on the soft surface. 

There are 4 axels that have electrical pickup (8 wheels total).  The middle driver axel, which has no wheel flanges (aka "blind driver") does not.

Apply track power, one wire to any left wheel, the other wire to any right wheel, until you find a combination that spins the motor and wheels.   

Leaving one wire on a good pickup wheel, (say, the left one) move the right side wire to a different right wheel.  If the motor doesn't spin, you've found a bad right wheel pickup. 

When you've found and noted all the bad right wheel pickups, change the right wire to the good right pickup wheel, and move the left wire until you have found and noted all the bad left wheel pickups.

Note that you can read motor voltage (previous post) on the center terminals on the rear of the polarity switch.  The front of the boiler just pulls out to gain access.  Careful not to yank on the smoke or polarity wires as the front pops off.   

Hope this helps. 

Sincerely,

Joe Satnik       

Edit: added the words in italics


Title: Re: Power loss on 4 year old set
Post by: wsommariva on December 11, 2008, 01:18:33 PM
Ok, I'll do this over the weekend and let you know.  Last time I oiled the insides I did break one connection and another popped off.  I soldered the broken one.  My continuity test showed that my solder job was good.  Maybe the other two electrical pickups are broken.


Title: Re: Power loss on 4 year old set
Post by: Joe Satnik on December 11, 2008, 01:42:45 PM
Dear W.,

Since you know how to check continuity, (Ohm-meter?) just check that all 4 pickup wheels on each side have less than 1 Ohm resistance between them.  (Off track.)

Yes, all 4 front truck wheels (are supposed to) pick up power.

Hope this helps.

Sincerely,

Joe Satnik

Edit: spelling


Title: Re: Power loss on 4 year old set
Post by: wsommariva on December 11, 2008, 01:56:39 PM
Ok, will check wheel continuity on all wheels.

I did notice that the front trunk wheels don't really meet the track.  I'll figure out how to lower them.

 


Title: Re: Power loss on 4 year old set
Post by: wsommariva on December 13, 2008, 02:42:03 PM
Well I think I check most things.  I changed the polarity switch.  I tested each wheel's pick up.  All 8 are picking up current.

I tested the motor voltage at the center terminals of the polarity switch and it reads 16.5 v DC when running.

So, maybe my speed of 15 seconds for 30 feet is the way it was designed.  This is the first year that I am using all the track supplied with the set.









Title: Re: Power loss on 4 year old set
Post by: Loco Bill Canelos on December 13, 2008, 03:56:44 PM
I have looked at all you have done so far, and to me the biggest clue is the fact that your voltage is about 16 all the way around and the speed remains constant.   There is nothing wrong with your locomotive!!

I do not know the rated output voltage of the Bacxhmann Power pack you have.  If it is the one that plugs directly into wall with wires going to the speed controller the rated output voltage is printed somewhere on the power supply.  If the rated output is more than16 volts this could be a sign that the power supply is going bad.  So I would keep an eye on that rather than the loco. 

My non-Bachmann power supplies put out about 22volts.  The loco really flies at 22 volts and I don't feel comfortable at that speed. Looking at my voltmeter I find that a more realistic top speed for me is at about 14 volts. 

If you must have more speed it it time to get a better power pack,  if not enjoy what you have!!

Cheers


Title: Re: Power loss on 4 year old set
Post by: Barry BBT on December 14, 2008, 04:42:25 PM
Loco Bill and Joe Satnik;

Nice work, both of you.  I am admiring you patience and your instructions.  Plus you have a good user. 

Well done.

Barry - BBT


Title: Re: Power loss on 4 year old set
Post by: wsommariva on December 14, 2008, 06:09:43 PM
Yes I agree.  I received very good instruction and I am very grateful.  I just checked the controller and it says 16v ac input.  As this is a holiday item, I am ok with the speed.  Maybe down the road if we decide to expand, I'll get a more powerful power supply. 

Once again I thank everyone who has responded; I learned alot about my train, learned some diagnostic tools and met some nice people.

Bill