Bachmann HO GE 70 Ton

[2-8-1]

I recently acquired said locomotive, in generic red, and thought that I would give it a test run. It runs well enough, however it seems very loud. I'm not sure if this was intentional to replicate the engine sounds of the prototype engine, or if it is just a problem with my individual locomotive. The sounds is similar to a card in bicycle spokes, it rises and falls with the speed of the locomotive. Any ideas?

Thanks!

-Aaron

 

[wheeler1963]

I recently acquired said locomotive, in generic red, and thought that I would give it a test run. It runs well enough, however it seems very loud. I'm not sure if this was intentional to replicate the engine sounds of the prototype engine, or if it is just a problem with my individual locomotive. The sounds is similar to a card in bicycle spokes, it rises and falls with the speed of the locomotive. Any ideas?

Thanks!

-Aaron

Aaron, check the axle gears, sounds like they are broke. Happens a lot on those 70 tonners.

 

[2-8-1]

How would I do that? Disassemble the locomotive? I bought this new, but on discount, is it common enough that something like this would happen in transit?

 

[tomustang]

How would I do that? Disassemble the locomotive? I bought this new, but on discount, is it common enough that something like this would happen in transit?

More of a build quality issue, there's a recient thread here about another switcher http://www.modelrailroadforums.com/forum/showthread.php?t=17887 (44ton)

There's been a slue of these problems when all the little spectrum switchers, also have heard about them running hot as well.

If you bought it new at a hobby store see if you can return it for another, but test run it first

 

[2-8-1]

Well, I pulled everything apart, no noise from the gearsets in the trucks when I free turn them. As soon as I plug the "flywheels" back into the electric motor, and put power to it, I get the noise. I'm thinking it is in the actual motor itself. I also bought it from a hobby shop, but it was one of the last, as they are moving. So, return is pretty much out of the question.

 

[wheeler1963]

Then another option would be to repower it with a can motor.

 

[Charles Smiley]

What are you powering it with?

I have a new Athearn RS3 that reacts to two different MRC packs with terrible noises - plus a buzzing sound. It's the truncated unfiltered sine pulses they use that rattle the drivetrain in some locos. See photo inset.

The RS3 is quiet running on pure DC.

photo taken this morning on the test-track workbench. 0-volts is the dashed horizontal line in the center of the screen.

Chas.

 

[2-8-1]

It's running on a pure DC powerpack that came with an old Bachmann (circa 2003/4) train set with a Grey UP 0-6-0 Switcher, two cars and a caboose. It's not the best pack in the world, to say the least, but currently, all that I have.

Oscilloscope for the win!

I personally never thought about checking with a scope. I have a homemade line conditioning power supply, what v/a does this need to run at?

 

[Charles Smiley]

"It's running on a pure DC powerpack "

Pure would come from filtered DC using some very large electrolytic capacitors -a very unlikely possibility. To get rid of all the "ripple", a rule-of-thumb is about 2000-ufd per load-ampere.

On low-cost packs, they usually just have a transformer and a pair of diodes (center tapped xmr) or a bridge (4-diodes). The result is a 120 half-sine "humps" per second controlled by a reheostat or a transistor. The unfiltered DC can also cause buzzing.

Check it with a scope if possible.


When you ask how many VA, do you mean to run a scope?

 

[2-8-1]

"It's running on a pure DC powerpack "

I meant it isn't DCC or anything like that.

VA I meant what volts and amps are spec'ed to run on a HO layout.