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Bachmann Motors

Started by plint, August 31, 2020, 12:26:35 PM

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plint

Are the same motors in  the F7s as is in the GP9s and GP40s?
I ask because the GP9s seem to pull more easily up my 2% grade than the RS3s and definitely the S4s.  I'm looking at an F7 or GP40 and want to know if the motor is the same as the GP9.  I need to pull 6 Athearn passenger cars up the grade.  The GP9s do so I'm hoping the F7 or GP40  motor  is the same and will, too.
Thanks
By the grace of God go I in Amherst NH.

jonathan

Plint,

The Bachmann F and GP units all come with motor #8812A. Also, if you look at the on line diagrams, the trucks are identical.  I suspect their weight is very close to the same, too. 

I don't have their GP units, but I have 5 of the F units and they all pull quite well.  I tend to double-head my trains so pulling a long train (20+cars) up a 2% grade is no problem.

Regards,

Jonathan

Len

The RS-3, GP-9 and the F-7 all use the same 8812A motor, although there are some differences in the flywheels and power lead attachments. I suspect the difference in pulling power has more to do with the weight and gearing of the locomotives than which motor it has.

Len
If at first you don't succeed, throw it in the spare parts box.

plint

Thank you Jonathan and Len.
Good to know
By the grace of God go I in Amherst NH.

plint

Where do you find these weights?
By the grace of God go I in Amherst NH.

plint

Those engine weights from a scale?
How do you know what the proper weight would be?
By the grace of God go I in Amherst NH.

plint

Ok so my GP9s weigh 14.7 oz
RS3s weigh 10.6 oz
S4 weighs 8.6 oz
Atlas H16-44 weighs 15 oz
So adding weight should increase the pulling power, right?
Is there room for this?
By the grace of God go I in Amherst NH.

jonathan

Adding weight does help with pulling power.  That being said...

It's difficult (read nearly impossible) to add weight to diesel models.  Usually, the only dead space is in the cab, which means taking out the crew to make room for lead or whatever heavy material.

The F units have some dead space where a speaker would be installed. As long as you don't want sound...

I tried to add weight to my S-2s.  I managed to to add such a thin slice, that the slice wasn't worth it... no significant improvement.

Steamers always seem to have dead space, little nooks and crannies, begging for more lead.

Regards,

Jonathan

plint

By the grace of God go I in Amherst NH.

jward

The Bachmann GP series models are heavier than the Alcos simply because there is more room for weight inside the body. As you noticed, the different drastically affects pulling power.

You mentioned you wanted to pull six passenger cars up a 2% grade. Have you tried decreasing the rolling resistance of these cars? Using a truck tuner to ream out the journals will help them roll better. Also, if these cars are lighted and use axle wipers to conduct electricity from the track you may want to eliminate these. I'm pretty sure you can power the lights with a 9 volt battery and eliminate the need for any electrical pickup.
Jeffery S Ward Sr
Pittsburgh, PA

plint

The F7 I got weighed in at 15.1 ounces while the GP9 s were about 14.7 so no problem pulling up the 2% grade.  However, the S4 was about 9 ounces :D
By the grace of God go I in Amherst NH.